& 产品参数对比
三星GALAXY S5 Active和三星GALAXY S6有什么区别
参数仅为参考，产品以当地实际销售实物为准。
Samsung（三星）
三星GALAXY S6（G9200/全网通）
Samsung（三星）
三星GALAXY S5 Active（G870）
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请选择型号
请选择品牌
请选择型号
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[32GB行货][北京]
，，，，，，，，，
触摸屏类型
电容屏，多点触控电容屏，多点触控
5.1英寸5.1英寸
Super AMOLED HD
主屏分辨率
屏幕像素密度
576ppi432ppi
双面第四代康宁大猩猩玻璃
3.5mm4.5mm
70.93%69.65%
移动TD-LTE，联通TD-LTE，联通FDD-LTE，电信TD-LTE，电信FDD-LTE
移动3G（TD-SCDMA），电信3G（CDMA2000），联通3G（WCDMA），，联通3G（WCDMA），
2G：GSM B2/3/5/8
2G：CDMA 800
3G：CDMA EVDO 800
3G：WCDMA B1/2/5/8
3G：TD-SCDMA B34/39
4G：TD-LTE B38/39/40/41
4G：FDD-LTE B1/3/4/7/8/282G：GSM 850/900/
3G：WCDMA 850/900/
双频WIFI，IEEE 802.11 a/b/g/n/acWIFI，IEEE 802.11 a/n/b/g/ac，MIMO
，，，，，
连接与共享
，，，，蓝牙4.1，，，，，
Android 5.0Android OS 4.4
高通 骁龙801
2.1GHz（大四核），1.5GHz（小四核）
Mali-T760高通 Adreno330
2550mAh2800mAh
理论待机时间
约251小时（2G+4G）
其他硬件参数
支持快速充电
摄像头类型
后置摄像头
前置摄像头
f/1.9f/2.2
4K（，30帧/秒）视频录制
1080p（，30帧/秒）视频录制
720p（，30帧/秒）视频录制4K（，30帧/秒）视频录制
延时自拍，连拍，自动对焦，OIS光学防抖，HDR，定时拍照，滤镜，全景拍照，慢动作，快动作，虚拟拍摄延时自拍，连拍，自动对焦
传感器类型
星钻黑色，雪晶白色，冰玉蓝色，铂光金色黑色，白色，蓝色，金色
143.4x70.5x6.8mm142x72.5x8.1mm
感应器类型
重力感应器，光线传感器，距离传感器，，加速传感器，心率传感器重力感应器，加速传感器，光线传感器，距离传感器，，心率传感器
指纹识别设计
，Micro USB v2.0数据接口，Micro USB v3.0数据接口
其他外观参数
可扩展多项功能的后壳
支持I67级防水，I67级防尘
服务与支持
支持MP3/WAV/eAAC+/AC3/FLAC等格式支持MP3/WAV/eAAC+/AC3/FLAC等格式
支持MP4/DivX/XviD/WMV/H.264/H.263等格式支持MP4/DivX/XviD/WMV/H.264/H.263等格式
支持JPEG/PNG/GIF/BMP等格式支持JPEG/PNG/GIF/BMP等格式
计算器，备忘录，日程表，电子书，闹钟，日历，录音机，情景模式，主题模式，地图软件计算器，备忘录，日程表，收音机，电子书，闹钟，日历，录音机，情景模式，主题模式，地图软件
飞行模式，数据备份，数据加密飞行模式，数据备份，数据加密
说明书&x1主机&x1
全国联保，享受三包服务全国联保，享受三包服务
主机1年，充电器1年，有线耳机3个月主机1年，电池6个月，充电器1年，有线耳机3个月
400-810-5858400-810-5858
周一至周五：8:00-20:00；周六至周日：8:00-17:00（在线服务）周一至周五：8:00-20:00；周六至周日：8:00-17:00（在线服务）
自购机日起（以购机发票为准），如因质量问题或故障，凭厂商维修中心或特约维修点的质量检测证明，享受7日内退货，15日内换货，15日以上在质保期内享受免费保修等三包服务！注：单独购买手机配件产品的用户，请完好保存配件外包装以及发票原件，如无法提供上述凭证的，将无法进行正常的配件保修或更换。自购机日起（以购机发票为准），如因质量问题或故障，凭厂商维修中心或特约维修点的质量检测证明，享受7日内退货，15日内换货，15日以上在质保期内享受免费保修等三包服务！注：单独购买手机配件产品的用户，请完好保存配件外包装以及发票原件，如无法提供上述凭证的，将无法进行正常的配件保修或更换。& 产品参数对比
三星GALAXY S6和三星Galaxy S6 Active有什么区别
参数仅为参考，产品以当地实际销售实物为准。
Samsung（三星）
三星Galaxy S6 Active（移动4G）
Samsung（三星）
三星GALAXY S6（G9200/全网通）
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请选择型号
请选择品牌
请选择型号
删除 →← 删除 →← 删除 →← 删除
[32GB行货]
，，，，，，，，
触摸屏类型
2.5D屏幕电容屏，多点触控
5.1英寸5.1英寸
主屏分辨率
屏幕像素密度
576ppi576ppi
3.54mm3.5mm
70.78%70.93%
双面第四代康宁大猩猩玻璃
双频WIFI，IEEE 802.11 a/n/b/g/ac双频WIFI，IEEE 802.11 a/b/g/n/ac
，，，，，
连接与共享
，，，蓝牙4.1，，，，蓝牙4.1，
移动TD-LTE，联通TD-LTE，联通FDD-LTE，电信TD-LTE，电信FDD-LTE
移动3G（TD-SCDMA），电信3G（CDMA2000），联通3G（WCDMA），
2G：GSM B2/3/5/8
2G：CDMA 800
3G：CDMA EVDO 800
3G：WCDMA B1/2/5/8
3G：TD-SCDMA B34/39
4G：TD-LTE B38/39/40/41
4G：FDD-LTE B1/3/4/7/8/28
Android OS 5.0Android 5.0
三星 Exynos 7420/高通骁龙810
Mali-T760Mali-T760
处理器位数
32GB/64GB/128GB
3500mAh2550mAh
2.1GHz（大四核），1.5GHz（小四核）
理论待机时间
约251小时（2G+4G）
其他硬件参数
支持快速充电
摄像头类型
后置摄像头
前置摄像头
f/1.8f/1.9
4K（，30帧/秒）视频录制4K（，30帧/秒）视频录制
1080p（，30帧/秒）视频录制
720p（，30帧/秒）视频录制
延时自拍，连拍，自动对焦延时自拍，连拍，自动对焦，OIS光学防抖，HDR，定时拍照，滤镜，全景拍照，慢动作，快动作，虚拟拍摄
迷彩白，迷彩蓝，金属灰星钻黑色，雪晶白色，冰玉蓝色，铂光金色
143.51x70.6x8.86mm143.4x70.5x6.8mm
玻璃机身玻璃机身
支持防水，防尘，防震
感应器类型
重力感应器，加速传感器，光线传感器，距离传感器，心率传感器重力感应器，光线传感器，距离传感器，，加速传感器，心率传感器
，Micro USB v3.0数据接口，Micro USB v2.0数据接口
指纹识别设计
其他外观参数
可扩展多项功能的后壳
服务与支持
支持MP3/WAV/eAAC+/AC3/FLAC等格式支持MP3/WAV/eAAC+/AC3/FLAC等格式
支持MP4/DivX/XviD/WMV/H.264/H.263等格式支持MP4/DivX/XviD/WMV/H.264/H.263等格式
支持JPEG/PNG/GIF/BMP等格式支持JPEG/PNG/GIF/BMP等格式
计算器，备忘录，日程表，电子书，闹钟，日历，录音机，情景模式，主题模式，地图软件计算器，备忘录，日程表，电子书，闹钟，日历，录音机，情景模式，主题模式，地图软件
飞行模式，数据备份，数据加密飞行模式，数据备份，数据加密
说明书&x1主机&x1
全国联保，享受三包服务
主机1年，充电器1年，有线耳机3个月
400-810-5858
周一至周五：8:00-20:00；周六至周日：8:00-17:00（在线服务）
自购机日起（以购机发票为准），如因质量问题或故障，凭厂商维修中心或特约维修点的质量检测证明，享受7日内退货，15日内换货，15日以上在质保期内享受免费保修等三包服务！注：单独购买手机配件产品的用户，请完好保存配件外包装以及发票原件，如无法提供上述凭证的，将无法进行正常的配件保修或更换。查看: 13313|回复: 27
高手请进，询问关于FIRST WATT F系列无反馈后级驱动AG K1000的效果
主题帖子积分
高级会员, 积分 54, 距离下一级还需 46 积分
高级会员, 积分 54, 距离下一级还需 46 积分
感谢关注耳机俱乐部网站，注册后有更多权限。
才可以下载或查看，没有帐号？
记得HEAD-FI那边有推荐FIRST WATT的后级，比如F1之类的推KK的，评级不错。国内也有烧友把玩。但不知道驱动效果如何。
有无高手测试过？
The F1 is a 10 watt per channel stereo amplifier operating in balanced&&single-ended Class A without feedback.& & Each channel has only one gain stage and draws a constant 100 watts.&&It is a power trans-conductance amplifier (or power current source,if you like), replicating an input voltage into an output current.& &A regular amplifier sends output voltage to the loudspeaker. This is not that kind of amplifier. & && && && && && && && &
&&This amplifier ignores the elements in series with the load circuit,&&including back-emf, wire resistance, inductance and such, and creates voice coil acceleration in direct proportion to the input signal.
It is well suited to sensitive full-range drivers such as Lowther or Fostex, and allows easy use of parallel loading networks to tailor the driver response.
&&It has both balanced and single-ended inputs. The input impedance is nominally 80 Kohm, and the output impedance is 80 ohms. The output noise is around 100 picowatts (100 trillionths of a watt).
The simplified schematic of the F1 looks like this:
& && && && && && && && &
& && && && && && && && &
At&&this time, F1's are only available used, but there are a very few&&copies of new F1's which are updated using the new power Jfets as found in the J2 amplifier. See the F1J product page.
&&Download&& and the
Reviewer: Srajan Ebaen
& && && && && && && && && && && && && && && && && && &&&Source components: Accustic Arts Drive 1; Zanden Audio Model 5000 MkIV
& && && && && && && && && && && && && && && && && && &&&Preamp: Bel Canto Design PRe2; Wyetech Labs P Eastern Electric MiniMax
& && && && && && && && && && && && && && && && && && &&&Amplifier: FirstWatt F-1 [on review]; AUDIOPAX Model 88; Eastern Electric MiniM Butler Audio 2250 [on review]
& && && && && && && && && && && && && && && && && && &&&Speakers: Cain & Cain Abby [on review]; Omega Loudspeaker Systems TS33 [on review]; Nelson Pass prototype Lowther DX-55 sealed box; [on review]; Avantgarde Acoustic Duo
& && && && && && && && && && && && && && && && && && &&&Headphones: AKG K-1000 with Stefan AudioArt replacement cable
& && && && && && && && && && && && && && && && && && &&&Cables: Crystal Cable Reference speaker ca Stealth Audio Cables Indra analogue interconnects and Varidig digital interconnect
& && && && && && && && && && && && && && && && && && &&&Power Delivery: BPT BP 3.5 Signature P Walker Audio V 2 x ZCable Cyclone Ref1
& && && && && && && && && && && && && && && && && && &&&Resonance Isolation: Grand Prix Audio Monaco (2); GPA APEX foote I WorldPower cryo'd H Mapleshade butcher block platform underneath BPT Walker Audio Super SST
& && && && && && && && && && && && && && && && && && &&&CD Treatments: Furutech RD-2 Walker Audio V Audiotop AUT 05.0
& && && && && && && && && && && && && && && && && && &&&Room size: 30' w x 18 d x 10' sloped ceiling, concrete slab, 2 long-wall setup
& && && && && && && && && && && && && && && && && && &&&Review Component Retail:: $2,500
Single-ended. Class A. Zero feedback. Fully balanced operation with both RCA and XLR outputs. Noise of 1/10,000,000th of a watt. Input impedance of 80kohm. Output impedance of 80 ohms. Constant draw of 100 wall watts. Output? 10 music watts. The only aspect of Nelson's FirstWatt's F-1 stereo amp that might suggest thorns with certain lovers of high-efficiency loudspeakers? The same aspect that will have others sit on needles to find out about today's results? This amp ain't gotz toobs. It's solid-state thru and thru. Nothing glows in the dark except for those two cobalt-turqoise power indicators on the front panel. But it has something no tube amp ever had - transconductance or current drive.
Read our two prior articles [1 & 2] in this triptych of F-1 writeups to learn about this rare amplifier topology and what loudspeaker loads are recommended with it and which ones aren't. One above spec will raise eyebrows with those unduly burdened by common wisdom. The output impedance exceeds by a factor of 10 the 'worst' of tube amps struggling for niggling respect with John Atkinson's test bench. Again, refer to our prior installments why Nelson Pass -- who's certainly fully capable of giving us amps with essentially zero output impedance -- has here opted for this counter-intuitive recipe. It deliberately lowers the operative damping factor. In a nutshell, single-driver loudspeakers of high sensitivities use ultra light-weight cones with massive gauss factors behind their motors. That equates to excellent self-damping properties. Add to this self damping action redundant damping from amplifiers and you become guilty of over-damping. And that, friends of single-driver speakers, will kill low-frequency weight and extension. It rolls of das bass prematurely and often to the sorry tune of more than 15dB. Premature - er, roll off? By fifteen inches? Considering how bass extension and displacement are well-acknowledged soft spots for such loudspeaker designs, that's naturally the last thing manly men want to be known for. What the good sound doctor orders instead is a stiffening of the nether regions. Let them no longer telegraph 'compromise, compromise' while the famous immediacy and rhythmic fidelity of zero timing distortion coo 'perfection, perfection' in unison farther up in the frequency range. Redress the balance. Get down - as low as you can.
While designers Terry Cain and Louis Chochos kindly made available speakers for today's test, I will not be focusing on their creations per se. Instead, I'll report on how their speakers' performance with the F-1 differed from that of my other in-house amplifier options specifically in the areas of frequency extension, LF definition, impact and overall tonal balance. I will additionally report on what changes the outboard passive networks made in this regard.
For a first get-to-know-you session of the Abbys, I cued up &Bandari& from Strunz & Farah's Rio de Colores [Selva 1010]. It expands the famous guitar duo to include the virtuoso Greek bouzouki player Danny Papakalos. Fixing center fill by moving the speakers closer together, I was bothered initially by the quality of the bass. It sounded a bit hollow, soft and 'ringy' compared to the rest of the spectrum. Imagine the difference between a string fitted to a thick board versus one fitted to a large resonator. The Abbys' bass suggested generation by a resonator while the remainder of the audible band was board-mounted for firmer attacks and faster stops. And guess what - resonance is exactly how the whizzer-fitted Fostex loading into the 1/4-wave Voight pipe goes about producing its mid bass below the driver's native reach (the 20-40Hz octave is completely missing and roll-off probably sets in somewhere around 60Hz).
Polyfill to the rescue. Nelson Pass had thoughtfully dispatched a 12oz. bag and recommended stuffing each speaker enclosure with half of it. Our local Walmart sells the same brand for a few bucks in the fabric department. Places that cater to doll or pillow makers carry it as well. Bingo - once the mouth of the line was stuffed, the 'organ pipe resonance' quality of the bass noticeably firmed up to no longer suggest a discontinuity of texture and mien between the vocal range and the upper bass/lower mid transition. While the lowest notes of an upright bass were still attenuated, most of that range had now locked in to be considered well integrated. Despite neccessarily lacking raw displacement, mounting the speakers to their 'Russian onion'- optimizing toe-in (very moderate); fixing speaker-to-speaker distance for the right amount of upper bass/lower mid warmth (less distance than I commonly use in my room); I was now able to follow Rene Camacho's bass without feeling cheated or as though listening to two different systems.
Inserting the custom outboard networks was next. Those were crafted with clip leads to allow experimentation with different resistor values. An owner would settle on the preferred value to likely mount the finalized passive filter inside the speaker. Remember, these were compensation networks deliberately designed to flesh out the speaker's bottom: Nelson's Jenny Craig diet in reverse. On this particular rear-loaded speaker, this scheme did not do much to recover certain lower MIA notes previously masked. If it shifted downward the 'fading zone' below which things clearly rolled off, it was subtle. However, proper speaker positioning in the room in conjunction with the Polyfill and F-1 driver extended to around 45Hz and respectable reach into the high 30s, with a listener distance of ca. 12' while the speakers were still out in the open by 54 inches. Moving them back by another foot to play on some boundary reinforcement with the wall behind them really locked things into place.
Obviously, my measurements both in inches and electrical network values were a function of room and personal taste. Yours would vary. The benefits including the polyfill damping were three-fold thus far: The stuffing altered the quality of bass. The networks subtly improved the quantity of the bass. Combined, both improved top-to-bottom coherence and tonal balance. The latter shifted downwards to remedy the relative lite-on-the-feet sensation of the very first encounter. Bass freaks will still insist on Terry's own Bailey subwoofer for oomphosity. But devotees of acoustic music in the Strunz & Farah vein -- and set up in not too large a space -- would not need to sub out bass duties to get the LF goods on their CDs.
Next up on my to-do list? Replace the 10wpc F-1 with the 250-watt Butler Audio monster to stand in as an example of a low-output-impedance amplifier endowed with oodles of power and solid-state-type current from a voltage-drive design. If the claims for the transconductance amp were factual, this amp despite it superiority on paper should take away certain LF gains into Terry's sort of specialty speaker load. Naturally, one would also expect changes in harmonic distortion content (the Butler amp is a novel hybrid with one 6SN7 per channel). But at this point, I'd be focused not on a comparison between hybrid valves and solid-state but one between current and voltage drive.
And indeed, compared to the F-1 with the networks, the Butler's bass reach and subjective weight took a step backwards into the shadows. What prevented a subjective tipping up of the tonal balance was the enhanced timbral density in the vocal range. Harmonically richer, the Butler amp added weight in another domain. Concentrating specifically on the audibility and relative prominence of the lowest notes, however, the F-1 took the prize. By comparison, the Butler incurred the hollowness of octave-doubling whereby certain fundamentals were now completely masked by the first harmonic.
By now, I had progressed to Luciano Pavarotti's first-ever crossover album Ti Adoro [Decca B]. I had orchestral complexity, stellar vocals and tympani and massed basses to contend with. The F-1 was faster, something particularly noteworthy on vocal climaxes. It was also leaner and more lit-up, translating subjectively as greater transparency. However, the sheer headroom of the Butler even into a load that apparently didn't require it made for more across-the-board fullness. Returning to the guitar music with its intricate rhythms and percussive string attacks, the Butler's tonal juiciness -- very impressive on Luciano -- degraded to sound clearly sluggish, distinctly - er, indistinct around the edges and in dire need of a blood infusion to regain life and energy.
Clearly, the excitement, blister, accuracy and sheer verve of rhythmic propulsion had followed Elvis and his butler to leave the building. On this type of music, there was no contest - the F-1 was a Formula 1 racer while the Butler was a passenger car with softly-sprung suspension. However, in a perfect world, I would dig some of the Butler's harmonic saturation especially on power music. Eastern Electric's MiniMax preamp to the rescue. Trading a bit of dynamic speed
-- one of the Wyetech Pearl's aces -- the MiniMax added a becoming degree of tonal development. The critical amplifier/ speaker interface remained untouched so as to not sacrifice control or 'cone velocity'. Those aspects, I was quite convinced by now, the FirstWatt amp owned in its back pocket like a street thug owns his back alley. To be sure, I inserted the MiniMax amp into the rig. I substituted its namesake preamplifier for the Wyetech to not overdo the tonal aspects of going MiniMax-squared. Ayee! Likely because it lacked the Butler's headroom and drive, I had suddenly relocated to the fog-ridden highlands of my Scottish ancestors. Now that I'd heard what the FirstWatt could do, the soft-focus romanticized rendition of the MiniMax despite its push-pull cancellation of heavy THD clearly played in a lower league of accuracy, incisiveness and involvement. Too much honey, not enough vinegar, pep and spunk.
Having thus sorted through some of the available 'spice mixtures' my on-hand components afforded, I returned to the MiniMax/F-1 combo as the one that gave me the perfect mix of tone and speed, warmth and excitement, beauty and accuracy. Despite being less than 20% of the Wyetech Pearl's asking price, this match-up made the unassuming MiniMax preferable because it can be made to sound more tubey than the more neutral Canadian champ. And that's what you need to squeeze from them tubes and butter the F-1's bread with: Some inside-the-notes body without smearing their articulated beginnings and ends. Without some fat, the F-1 operates on the lean and precise side of the fence. It doesn't inject color but is solely concerned with translating input voltages into output current that grips the voice coils without booking any what-ifs. I'm not just being cavalier with the language here, either. Consider the infamous AKG K-1000s.
With their ring magnets and off-the-ear 'free space' environment, they're inefficient as hell (74dB/1w/1m). Common sense suggests to drive them with a sufficiently powerful amplifier. But sometimes, common sense is just that - common and not very special. Special sense + AKG K-1000s = FirstWatt F-1. What these 'phones crave is current, not unreasonable headroom reserves. Remember Witches of Eastwick the movie ? Horny lech Jack Nickolson entertains his harem-of-three on the tennis court. As the game gets into high gear, he and one of his ladies are facing off inches removed from the net. The ball ricochets back and forth rapidissimo between their rackets which don't move at all. Jack hammer time of staccato volleys, superior reflexes, lightning-fast exchanges and child's play control, so virtuoso yet apparently easy. That visual perfectly captures the sensation of listening to the K-1000s when driven by the F-1. You suddenly discover a whole nudder level of precision and resolution. It's well beyond what you already knew these cans could do. And just like with the Abbys, the ideal scenario is to precede the signal chain with the Eastern Electric preamp or something like it.
Most owners agree that the Austrian earspeakers need tubes. I wholeheartedly concur. Alas, based on my FirstWatt experience (and I've often confessed how I was still looking for that perfect K driver), I will now recommend to not drive 'em with valves but merely to inject the thermionic aroma via the preamp or CDP or both. When it comes to broad-shouldered moxy, let transistor current do the dirty control work. What Nelson's amp does for the K-1000s is a rare thing of beauty. It transcends any prior best-case scenario I've encountered thus far. It's become my new favored setup for these specialty cans and I use the MiniMax voiced on the warm side of neutral to get my tube rush. I'm not sure whether admiral Nelson considered this particular employ for his transconductance amplifier. Still, I'm hear to tell you that this is one ride you won't want to miss if you're a fan of the AKGs like I am. The MiniMax/F-1 combo gets you the luv with archetypal recording monitor precision. And that is arguably the best of both worlds - very high fidelity and musical persuasiveness. To get that level of sonic perfection from a speaker-based system costs an enormous amount of money easily outside x 10 as much and involves endless fights against room-induced issues. But this isn't a headphone review so back to the subject of speaker drive.
What did the Fostex Fe166e sound like in the Abbys once I had optimized their positioning and mated the F-1 to the MiniMax preamplifier? First off, most whizzer-fitted full-range drivers I've heard thus far do suffer varying degrees of peakiness. Depending on the cleverness of the designer fashioning an enclosure for them, this either gets tamed down to merely suggest a certain liveliness and energy or remains troublesome especially on charged female vocals. Terry Cain's neat speaker cabinet turns the 4kHz/4dB peak of his affordable Fostex driver into something that measures far worse than it sounds. Listening to Øystein Sevåg's and Lakki Patey's Visual [Windham Hill -2] with its tasteful synth pedals, solo guitar and piano and certain high-frequency effects was a very impressive demonstration of balance. While the Abbys couldn't energize the room with certain bass drones I know from my Avantgardes, the whizzer cone of the Fostex unit did an amazing job of capturing the whizzing effects of &Old Man& with the synth-generated shards of broken glass twinkling in the sunlight or certain upper piano attacks reflecting off venue boundaries. I'd dare any first-time listener of this record to not be impressed with the F-1-driven Abbys. One would really be at a complete loss as to what else to expect if asked to point out any shortcomings. Naturally, transitioning to my $18,000 Avantgardes with active bass modules would reveal more of the subterranean trickery and certain of its wave-like surges cresting and breaking in the low 30s; and you'd occasionally hear more upper- and certain drones would simply be sustained with more prominence and growling - but going back to the Abbys, you wouldn't at all feel like a bandaged cripple.
In fact, even challenging female vocals like Dulce Ponte's Lagrimas [BMG
2] -- which can quickly expose a full-range driver's Achilles heel in the lower-to-mid-treble band -- only elicited very few and transitory glimpses of isolated prominence but even then never objectionably so. Truly, as far as full-range drivers go, this Fostex unit is one smooth and extended operator. Any whizzer jokes are not on the driver but the jokster who'll be exposed as a wheezing old-timer who hasn't kept up with them new and present times. To be honest, I'm not sure whether to feel more impressed by the Abbys' treble or bass performance. At the end of the day, I'll cop out and opt for 'overall balance'. That's really the most compelling reason for why to consider ownership of the Abbys.
Nobody in their right mind expects to buy a $1,500/pr speaker that does it all. What you get with the Abby if you build the system as described -- minus my front end which is criminal overkill in this scenario -- is a surprisingly warm-sounding speaker. At non-excessive listening levels, it's not zippy or tipped-up at all but rather, meaty and gutsy. Naturally, it's dynamic -- you expect that from a zero crossover design -- but it isn't hyper-dynamic like the Third Rethm which really is a speed freak of sorts. The Abby tracks dynamic swings very well and scales instantly but doesn't exaggerate this aspect to seem unnatural. Going to the most challenging of materials --classical symphonic -- you'd be surprised by how well this single driver sorts through the thicket of massive complexity. You'd really appreciate dynamic responsiveness when the first crescendos carry the climaxes farther than expected.
Going all transistor -- something I ascertained with the Bel Canto Design PRe2 -- is not recommended, however. The F-1 is so clean, fast and accurate that the lack of the bottom octave in the Abbys requires a small infusion of fat elsewhere. That elsewhere is the tonal domain and now becomes the responsibility of the preamp. And there I have a hard time believing that you could do better than the hotrodded MiniMax for $900. If you wanted to go Bailey at a later point and add Terry Cain's aesthetically integrated subwoofer, the Eastern Electric piece gives you twin preouts so you're all set. Seeing that our resident chef John Potis is signed up to spill the cyber ink on Terry's new Super Abby (it merely adds a rear-firing horn-loaded ambient tweeter with user-adjustable attenuator over what I had), I shall leave the detailed reporting to him. I'll conclude today's Abby commentary with the following. Ed Schilling of the Horn Shoppe, Terry Cain of Cain & Cain and yours truly are unapologetic tube hounds and far more liable to experiment with some obscure valve amps nobody's ever heard of than give solid-state contenders from properly established makes much of a fair hearing.
That said, Ed is so stoked by the F-1 that his Model 1 [left] currently at Nelson's has already been earmarked for a review by yours truly and with Nelson's amp. And despite Terry's predilection for rare 2A3 and 45 triodes -- preferably in one of Josh Stippich's outrageous creations -- he too is smitten as hell with the F-1 and, like me, fancies a valve preamp ahead of it. Nelson Pass is definitely on a hot track with his transconductance amplifier. Not for nothing do valve aficionados toss about terms like immediacy, tacitness and musical intimacy. When the F-1 mates with a speaker load for which it was designed, the same thing happens except that these effects don't come about as a function of THD or overload behavior but -- and now I'm stretching since this is new territory -- as a function of more precise coupling between signal and driver which eliminates fuzziness and indecision without killing off the spark or preventing notes from gushing forth or ringing out. There's nothing edgy, hyped or unnatural about the F-1 and into a truly full-range load like my AKG headphones, a solid-state preamp works splendidly. That surprisingly does not emphasize the peculiar zippiness these cans can dish out if mated to the wrong electronics
The F-1 really makes an ultra-convincing argument for itself when you compare speaker outcomes within its respective circle vis-à-vis more conventional amplifiers. The mighty Butler amp cracks like a whip on my Gallos and the Hyperions and is growing our own Chip Stern a massive smile on his Josephs - yet it sounded strangely sluggish on the Abbys when compared to the FirstWatt. The 8wpc MiniMax amp in the nearfield works far better than expected on the Gallos yet was clearly out of its depth on the Cain & Cains once I heard 'em with the F-1. An 80-ohm output impedance on a standard speakers is a likely recipe for disaster. When mated to current drive and the intended loads, the results are disastrous only to your loyalties of common wisdom.
So don't mistake my tube-pre comments as suggestive of a lack in the F-1 that requires valves to become complete. My preference for the Eastern Electric over the Wyetech or Bel Canto units with the Abbys simply resulted from the speakers' relative lack of low bass foundation which becomes far less of an issue when tubes deliberately expand the harmonic envelope. Single-driver speakers require a bit more work than conventional multi-way designs to minimize their weaknesses via copasetic electronics and optimized room interaction. The reason you put up with their limitations in the first place are their strengths. Those attuned to them would have a mighty hard time duplicating them elsewhere. By necessity, they'd have to be minimum first-order designs to mimic the coherence and speed of single-driver designs and approach their dynamics. The Gallo Reference 3, Star Sound Technologies Caravelle and Green Mountain Audio Callisto and Continuum 3 come to mind - more expensive and full-range overall but with a clear family resemblance of core traits nonetheless. However, if you're truly sensitive to time domain issues and insist on the top-to-bottom coherence you otherwise only get from headphones, single-driver loudspeakers are your door to sonic bliss. Terry Cain's standard Abby gets a very strong recommendation for sonics and an abbysmal no-brainer one for low price and fine furniture appearance. Stay tuned to learn how it gets along with its Bailey subwoofer stablemate.
The same Strunz & Farah + bouzouki track managed to set off the port resonance of the $849/pr Omega loudspeakers and I opted to stuff the port with the earlier Polyfill, then move the speakers to the floor and angle them up at the listening position via Walker Audio Valid Points and resonance control discs to make up for the loss of bass extension. This worked like a charm but still cut out well before the optimally set-up Abby. Nelson had warned me that his outboard passive filters really rely on sealed alignments to create predictive results. The back-loaded quasi-horn of the Abby does benefit to a modest degree but the front-ported vented alignment of Louis' TS33 model didn't respond to any extent I could hear. No surprise really based on Nelson's warning but still a pleasing confirmation to obtain the same results.
Swapping the F-1 for the Butler Audio 2250 as before, the Pass amp once again had the clear edge in speed and incisiveness and -- perhaps even more than on the Abby -- presented a more intelligible picture of what relatively little there was to be had down low. This followed the strange upside-down logic of the transconductance world where zero damping factor behaves as though it held plenty of zeros in reserve. So far, following Nelson's experimental detour into the wild corner of single-driver speakers had netted exactly what the man claimed himself in his lengthy white paper. So I was particularly curious about the DX-55 Lowther he had stuck into a sealed box to give me an opportunity to replicate some of his own testing when conditions for his compensation networks were optimum and supposed to give the most obvious results. (Incidentally, this plywood box isn't earmarked for commercial production. It's simply a manifestation of Nelson's experimental spirit and a one-upper.)
The Lowther and the Butler were a marriage made in hell. It made the speaker sound so unforgivably bright and strident that had this been your first and only Lowther encounter, you'd have written the brand off in all of 10 seconds of perfectly efficient character assassination. &The subject has been retired, sir. What's my next assignment?&
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Fortunately for Lowther, inserting the F-1 into the chain became a poster child for what the term day-and-night difference should imply. Holy crap. Had I not heard this for myself, I'd have called it impossible based on the first impression. The Lowther now exhibited all the speed, openness and crush-on-vocals it's known for, quite exceeding the Omega Fostex implementation in the clarity and communicativeness sweepstakes. But more importantly, rather than being shrill and relentless with no bottom end whatsoever, it now had bass the equal of the TSS3 - still not sufficient to really go the distance without a sub but no longer imbalanced, just a little light in the loafers and now with a truly glorious midband. Removing the network decomplished two things: the bass rolled off far earlier and the top end became hotter, the latter either just a function of upshifting the tonal center or also because the treble output had in fact increased. I couldn't determine from listening which of the two it was but the net result was the same - far less bass to make the presentation distinctly top-heavy. Having heard Jacob George's Second and Third Rethm, I know how much bass this driver can produce when loaded into an enclosure optimized for that goal. That it would produce less bass in Nelson's small box was no surprise. That there would be a considerable difference in bass quantity in my listening seat 12 feet away depending on whether or not the network was inserted was a big surprise. Some enterprising Lowther builder should team up with Nelson Pass. Build a floorstanding sealed DX-55 tower with this network hardwired to the driver and add this amp as part of the whole package. It could rewrite Lowther history as we know it.
So what did we learn?
Simply put, read Nelson's white paper, then take it to the bank. The man knows his stuff and presents his findings in a scientifically accurate fashion that was readily repeatable on my end. His implementation of current drive does for single-driver speakers what balanced/bridged operation does for the Bel Canto Design eVo amplifiers. When the latter are bridged, it's not just that power triples. Far more importantly, the anti-phase boards of the bridged channels go into fully balanced operation which lowers the noise floor and ups the resolution without any sonic penalties. Feeding single-driver speakers with high-power amplifiers whose first watt sucks in such applications is clearly not the answer. Feeding such speakers with sufficient power from the usual tube suspects can be very copasetic indeed but based especially on my experience with Cain & Cain's Abby, the solid-state F-1 goes places where even they cannot go. If you fancy what tubes do in the tonal domain, simply precede the F-1 with a valve preamp of your choosing and you'll have the best of two worlds - control, precision and expanded bandwidth from the F-1, timbral girth from the preamp. Simply change your perspective. The control amp no longer is the usual preamp (controlling volume and input selection) but the power amp which truly controls the speakers and leaves sonic flavoring to the preamp.
We are also reminded again how a one-size-fits-all recipe in audio doesn't exist. Every unique circumstance requires a unique solution and that's exactly what the FirstWatt F-1 amplifier is: a unique address on how to get single-driver speakers to behave more full-range and linear than they want to if left to other devices. If Pass Lab's history is any indication, this amplifier should essentially be bullet-proof and smartly outlive its first owners. And because it's true Class A and thus operates at 10% efficiency, it takes 100 watts from the wall to give 10 watts to the speakers. This translates as heat. It's not quite sufficient to fry eggs with but definitely sufficient to make picking it up -- and dropping it quickly after an hour's operation -- more elegant if you wore gloves or used your shirt sleeves to protect your hands. This is one hot operator both literally and sonically. It's also limited to 100 owners which, considering how many single-driver devotees are essentially DIY types, seems about the right number to service those in this sector who'd rather own a turn-key solution. Who knows what specific scenario Nelson's forthcoming F-2 will address? One thing's for sure: this is one creative designer who is as comfortable in the mainstream as he is in a very small niche category. And that makes the F-1 into definite 6moons (and AKG K-1000) material.
[ 本帖最后由 davidxtb 于
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这个代理专门代理FRIST WATT和PASS的~~
还有MARTEN~卡玛等~~~~
他那里有一对样品MILES 3特价~~~雄大去的话可以去听听~~~~
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Reviewer: Srajan Ebaen
Financial Interests: click here
Source: APL HiFi NWO 3.0-GO; Ancient Audio Lektor P Raysonic Audio CD-168
Preamp/Integrated: Supratek Cabernet D ModWright LS-36.5 with PS 36.5; Melody I2A3; Woo Audio Model 5; Trafomatic Experience One [on loan]
Amp: 2 x Audiosector Patek SE; 2 x First Watt F4; Yamamoto A-08s; Fi 2A3 Yamamoto A-09s
Speakers: Zu Audio Definition P DeVore Fidelity N WLM Grand Viola Monitor with Duo 12; Rethm S Zu Presence [on loan]; Mark & Daniel Maximus & Ruby Monitors w. OmniHarmonizer
Cables: Ocellia Silver S Crystal Cable U Zanden Audio proprietary I²S Crystal Cable R double cryo'd Acrolink with Furutech UK plug between
Stealth Audio Indra and Meta Carbon
Stands: 2 x Grand Prix Audio Monaco Modular 4-tier
Powerline conditioning: 2 x Walker Audio Velocitor S fed from custom AudioSector 1.5KV Plitron step-down transformer with balanced Furutech RTP-6 on 240V line feed
Sundry accessories: GPA Formula Carbon/Kevlar GPA Apex footers underneath stand, DAC Walker Audio Vivid CD Walker Audio Reference HDLs; Furutech RD-2 CD Nanotech Nespa P Acoustic System Resonators and front wall sugar cube matrix
Room size: 16' w x 21' d x 9' h in short-wall setup with openly adjoining 15' x 35' concrete floor and ceiling, concrete/brick walls
Review Component Retail: $3,000
elson's infamous Kleinhorns used to evaluate a large range of wideband drivers. These horns have since been gifted to an artists' collection. One of Nelson's current speaker experiments centers around a Feastrex D9nf in an open baffle.
Nelson Pass. FirstWatt. Kitchen table venture. Surely all this has been active long enough to no longer catch our readers in the dark. For a light switch reminder, reviews of the F1 thru F4 plus Aleph J have all the relevant information covered solid in our archives. Here's what bears repeating though. By design, all FirstWatt products are tailored to certain very specific uses. As the name gives away, those are focused on the higher-sensitivity speakers that come on song within the very first watt to consume little power.
&Jack of all trades but master of none.& &Being everything to all people.& Not! So exclude, eliminate, focus, optimize, perfect. Arrive. That would be limited editions of 100, with each amp model -- and five line-level products are in the chute next -- custom-tailored for very narrow applications. Single-ended and push/pull transconductance amps. A low-power amp with JFETs for output devices. A pure power buffer with zero voltage gain. And, as the odd one out by being a perfectly normal amp in this group of eccentricities, a new installment of the classic Aleph circuit with JFETs at the input, hence Aleph J. That's been Nelson's output under FirstWatt thus far.
Common to it all h class A twin 18V hand assembly by and a very generous transfer of the circuit schematics into the public domain once the limited editions had sold out. To recap, with FirstWatt, Nelson Pass is beholden to no one but his own creative genius. His livelihood and economic viability are secured by Pass Labs. FirstWatt is thus the quintessential mad scientist's lab at the edge of the mainstream abutting another universe. You just never know what to expect next. Except that five follows four. In this universe.
In his own, would the man pull another stunt as he did with the Aleph J? Not that way, this time. The latest in the F series (which might stand for fun or fabulous or far out) is the F5 which follows numerically on the heels of the F4 buffer/follower amp. The F6 thru 8 have already been conceptualized as higher-power mono versions of the 3, 4 and 5 respectively. FirstWatt is about narrow paths less traveled, not milking repetition in overgrazed fat meadows. &I think it will be a little while before FW starts repeating itself& quipped Nelson laconically. So watts up with the 5? What particular niche and needs does it fill? (For a great read on Nelson's earlier career by the way, jump over to Thomas J. Norton's 1991 interview with the man in the Stereophile archives.)
It introduces a few firsts for FirstWatt: feedback*; and a full 50 stereo watts. The simplified circuit shows a DC-coupled 2-stage current source amp with 15.15dB into 8-ohm voltage gain, specifically a complementary MOSFET common source output stage (as previously seen in Nelson's Zen Variation 5 DIY circuit, here biased at 1.3A and class A up to 2.6A) driven from a complementary JFET common source with +/-24V rails. On the subject of bandwidth, check out the square wave performance into 200kHz - scarily close to perfection. Might the lack of signal path capacitors have anything to do with that?
When I first saw that graph, I had to know - was this ultra-low distortion and speed due to newfangled parts or circuitry? The latter. Nelson describes himself as a circuit mechanic. Parts are important but to him, circuit architecture is senior. Where modifiers will throw money at designer parts, a true master of the craft goes to the source. He manipulates how the electrons flow, resets the levies and dikes and flow valves in the three-dimensional construct of an electronic circuit. This enforces very specific electron behavior to establish ideal relationships between voltage, current, distortion, bandwidth, amplification factor, ground plane, noise, impedances. It writes the 'molecular code' for how a circuit behaves. That would seem rather more creative than dressing up parts.
* Nelson Pass: &As I have previously pointed out elsewhere and in the F5 write-up, the term current feedback probably came from the marketing departments at the chip companies when they began selling high-speed op amps using this approach.&
The distortion performance at 1 watt is below 0.002% and rises to a negligible 0.05% at 20 watts which would turn low-power SETs green with envy. Poster Klaus on the
forum suggested &would the master be offended if I called the F5 a modern FET-based Hiraga? I see some similarities, current output (open loop), current feedback, straight two-stage design (if one wants to count a diamond buffer and a CFP as one stage, resp).& to which Nelson replied: &Not at all. It's a topological classic - the devil is entirely in the details.& Other posters called the circuit &an amp so simple, even a cave man could build it&. &Of the Zen and FirstWatt series and for damping factor, the F5 would be the best since it has a DF of 80 and will drive 2 ohms without burping. I don't believe, however that I would point it at a speaker with both a low impedance and a low sensitivity. Reactance is not an issue. The performance is slightly more robust into a fully reactive load vs a resistive load of the same impedance. The F5 has the lowest distortion yet achieved by either a Zen or First Watt amplifier, descending to 0.001% below 1W. Suffice it to say that the F5 has more power, more damping, more current, more bandwidth, lower distortion and higher input impedance than the other Fs. Many will think it sounds better.&
Those looking for ground-breaking circuit innovation will come up short. The F5 takes wing at the zenith of a master's career where, regardless of craft, less becomes more. A simple sketch conveys more meaning than a technically advanced photo-realist painting. A short haiku nails more essence than a florid novel. It's about trimming the fat. It's about distilling a circuit down to its barest essence while seeing and manipulating the interrelatedness inside that simplicity with new clarity.
Nelson has penned a how-to F5 article in AudioXpress. &One of the aims of these articles is to get people to build amplifiers&. With 50 stereo watts, low output impedance and feedback, the F5 appears to move away from the FirstWatt center focus and toward the periphery.
But the distortion figures suggest clearly that the core of the credo -- the ability to track the most minuscule signal fluctuations inside that very first watt -- isn't merely retained. It's arguably been heightened with a high-speed wide-bandwidth circuit of uncommon linearity. The culprit or boogie man in this instance is feedback. It's also a contentious and misunderstood topic on which Nelson is penning an upcoming paper for our readers.
&This circuit employs feedback in a dual pair of low impedance voltage dividers -- low impedance feedback has been (incorrectly) referred to as 'current feedback' -- and one of the charms of this arrangement is that unlike the classic two transistor differential pair, the drive current available exceeds the bias of the input stage. Each JFET has its own feedback so there are two separate and independent feedback loops to this amplifier. The input impedance is 101 Kohm and the output impedance 0.1 ohms for a damping factor of 80. The noise is about 30uV. Because the output stage employs only two output devices per side which are capable of very high current, deliberate limiting is set by 3-watt power resistors to the source pins of the MOSFETS to increase thermal stability and serve as convenient current-sensing elements. The amplifier with 24V supply rails is good for a 50-watt peak into 8 ohms or about 2.5 amps. For a 4-ohm load we would want 5 amps and for a 2-ohm load, 10 amps. Since we only have two output devices, we probably are best off stopping there to ensure against damage into dead shorts. Current limiting gets a bad rap in general, but I think it's a matter of where and how the limits are set. In toto, a nice little amplifier without too many parts that sounds great.&
In the end, that's the part which matters most to you and me. Nelson's haiku instructions to thinking DIYers are for the hands-on crowd. Amazingly here, detailed instructions on how to roll your own are out prior to first commercial units. For the F5, Nelson's very sporting generosity has put DIYers on equal footing with FirstWatt. To hell with commercial considerations. Off to fun 'n' games. That's been the prevailing attitude of this kitchen table effort all along: &The B1, a buffered &passive& using my new Jfet buffer is in production, that is to say I have stuffed one up and it works. I have the boards for another 10, so it will be waltzing shortly. The specs are fabulous and it will be really interesting to see if the buffer solves the age-old passive problem that people have. I think it will, insofar as the concept worked very well for our INT150 integrated, which is really just an X150.5 with a selector and buffered volume control.& If it takes two to tango, Pass Labs and First Watt are partnering up very nicely.
Act 2. Having now reviewed every FirstWatt amplifier made save the Aleph J, something's plain. They all dance in a very small circle of freedom around a tether pole staked through neutrality: variati how to reach Rome from yet another direction. I'm reminded of the Indian saint Ramakrishna. He attained ecstasy following one line of esoteric teachings. Then he pursued an entirely different discipline only to encounter the same ecstasy. Again. All roads lead here became his personal verification. The ecstatic could thus assure devotees of various religions that their different beliefs didn't matter. In the end, they'd all get consumed in and erased by the Luminous.
But the material form remains a filter even with a highly sublimated personality. Flavors continue. Nirvana in the body isn't stark white. It's not neutral boring nothing. So the F3 is sweeter. A mini triode dose. As exceptionally transparent as it is to the preceding preamp literally doing the driving, the F4 is more limpid. It doesn't 'grip' but floats and flows. The F5 articulates. That very first impression held. I was spinning Instrumental 1, a custom compilation by the good doctor in Berkeley who had co-financed Alon Wolf's Magico Ultimate hornspeaker project as one of three original commissioners. The doc has the best musical tastes of anyone I've ever met - simply by perfectly overlapping with my own. Instrumental 1 is minimalist gossamer in-the-zone stuff expertly sequenced. Artists include Eleni Karaindou, Markus Stockhausen, Herbert Joss, Anouar Brahem, Arild Anderson, Paolo Fresu, Terje Rypdal, Ketil Bjørnstad and others.
Having come directly off intense inspections of Yamamoto's reference amp with various 300Bs when Nelson's second silver-faced model landed, I was shocked by how ridiculously low its playback level could be without causing any serious participatory losses. I got deeply involved at whisper levels without crank-reflex intrusions. Regardless of which 300B I rolled, the A-09S -- whose 27dB gain is far higher than the F5's -- needed higher playback levels to come on song. This demonstrated how the... um, purity of nano-level distortion in the transistor amp (which a valve lover would call a wholesale stripping away of benign and desirable THD) actually served the music better. It was more intelligible.
Allow me a brief detour to stress the point. Certain erotic movies celebrate their protagonists as pursuing ever more outlandish means to sexual gratification. It's as though their continued use of toys, fetishes, strangulation and pain severely desensitized them to require ever more bizarre measures of stimulation. The less one feels, the more effort must be made to elicit the desired response. The same occurs with junk foods' high saturation of salt, sugar and fats. Once a palate has been dulled by such assaults, eggs or veggies not tarted up with salt and sauces become tasteless and boring - for simply tasting like themselves. The F5 invites such ruminations and applies them to the habits of us valve addicts. Compared to a Halcro's nonexistent distortion, tube THD seems completely j in fact, outright necessary. Why then is it that faced with the F5's impossibly low distortion (impossible certainly for any tube amp), thermionic liberties suddenly seem far less justified or necessary? Are valvers addicted to unnatural stimulation?
I don't have the answer. It's an open question to point at something real but elusive. The technical purity of the F5 isn't flat. Its feedba its proud specmanship has real relevance to the experience. But it certainly doesn't sound like my glowing amps. As you prime their pump, they come into their own with great tone density. Viewed from the F5's seat, there's less resolution within that density. There' less residual grunge around a faint muted trumpet, less swishiness on swirling cymbal brushes, less ephemeral glitter on bell trees. Something congeals. Greater loudness distracts from it but truly subdued midnight levels with the SETs obscure. One can no longer enter into the music. A door closes. One stands outside and removed. The glowing bottles clearly suffer when my wife is already dreaming and I'm still chasing the tunes and the most immaterial of fades.
Viewing things from the strengths of the glowing bottles when their amplitude is sufficient to skip over that get-real hurdle, the F5 is leaner. Less padding of tonal girth. But it doesn't sound lean per se. It's completely beyond threadbare (and granted, I ran the 12dB-gain tubed ModWright LS/PS 36.preamp at 3:00 o'clock + on the above Zu Presence). There's more treble tintinabulation to re-use Nelson's crafty term. That action doesn't saturate timbres like 2nd-order octave doubling does with tubes. It instead increases finesse of insight and subtle energy. After all, upper harmonics are high in frequency and subdued in output. To track them requires extension and ultra-low noise floor. Then the live factor survives when you dim the volume lights. Loudness is often a substitute to create the illusion of seeing more. Then we forget what we really don't see. It's compensation. It proves out insufficient illumination at quieter levels. In plain speak, that's inferior and ultimately insufficient resolution. The need for SPLs nearly always signifies it.
This segues back to the all-roads-to-Rome statement. To your tubular scribe, all FirstWatt amps are examples for how superior resolution can truly serve -- and not distract from -- the music. Tubes can serve in their own way. That makes for a different experience. It shifts the focus to tone colors, textures and a certain kind of inner voluptuousness. The F Series of Nelson Pass amps focuses instead on the 'outer' voluptuousness of contributing complexity riches. How many tiny spinning wheels and belts and gears make up the musical construct, make it all happen? Calling one inner and one outer is bound to mislead of course. It's all part of the same music.
Since I brought up Ramakrishna earlier, perhaps it's appropriate to speak in terms of perceptional doors from which the listener enters the experience. If the (good) tube experience is ultimately a melting in the heart for expanded feeling (anahat, the heart chakra), the superior transistor experience is an expansion of the mind where seeing occurs (ajna, the third eye). They're different experiences but not superior or inferior one to the other. This could be a meditator's attempt of describing the same phenomena which sound doctor Nelson Pass talks about as 2nd and 3rd-order type amplifiers. Needless to say, this is all quite subtle, dancing in a small circle of freedom around the center point of neutrality. Suchness as the Buddhists would say. Without filters. The remaining F amp filters are very transparent.
In the world of FirstWatt, the F1 had the strongest 3rd-order flavor. Super articulation. Separation. Crispness. And drive. The F1 sounded driven. Propulsive, a clear personality. The F4 and F5 are rather more relaxed entries in that domain, with the F5 slightly more gathered up and sorted than the F4. The buffer/follower amp is the most kif of the bunch as the stamboulis would look for in an opium den - supremely relaxed, in a go-with-the-flow state. The F2 and F3 are sweeter and 'rounder', with the F3 deepest into that particular terrain, the F2 just slightly. In general, numbers 3 to 5 strike me as closer to the center than the first two.
Take anything massed -- a chorus, symphonic strings à la Samuel Barber -- and as predicted by Mr. Pass, the degree of sight the listener enjoys into that layered action from the 5 is brilliant. Take anything speedy and sharp -- rapidly plucked strings, blatty brass, drum kit workouts -- and the F5 is clear and incisive but never brutal and hard. Except for the F1, none of the FirstWatt amps struck me as bass monsters. As a transconductance amp, the F1 could only be properly used on crossoverless widebander speakers. Those are never really endowed in that sense, making what the F1 got from them just shy of freakish but still quite relative in the bigger scheme of what's ultimately possible from 15& woofers.
Take soundstaging -- depth, width, localization, stability -- and the F5 is a champ. No drift, no wander, no blur. No etch or grippiness neither. The F4 appears even 'floatier' but those are very subtle matters appreciable only in a direct comparison. Which of course is what the man already said in his own words. Nelson is definitely equipped to not just design amplifiers but review them objectively. Take microdynamics -- those heart palpitations caused by a singer's or instrumentalist's unexpectedly emphatic inflections -- and I'd have to call the F5 superior to my most cherished valve amps. If that's directly related to circuit speed, the F5 certainly lives up to that obnoxiously ideal square wave graph we admired earlier. This returns us, again, to that ability for remaining involving at very subdued levels. There's enough wiggly, jumpy, kicking live factor left to be interesting and gratifying. It's all there, not lost in any THD fog.
At elevated levels, over the Zus and on vocal peaks, I did detect the occasional glimmer of spiciness, of likely response peaks in their widebanders which my usual valve amps don't bring out. On my Lowther DX-55-based Rethm Saadhanas, this happened as well but not objectionably so, just a presence-region tweak for some enhanced if ultimately not entirely honest fun but clearly intrinsic to the speakers, not amp. Nelson has done extensive measurements of such drivers and could tell you precisely what operational aspects of the F5 contribute. I'll merely confirm that yes, if your widebanders are spicier than you wish, the F3 would remind you less if at all.
The monster SuperPAC tweeters on my 98dB WLM Grand Viola monitors -- paralleled horn-loaded paper units high-passed at 800Hz -- told their own tales of F5 treble elucidation. This amp suffers neither high-frequency phase shifts nor premature coagulation. If infrasonics help recreate the full scale of audible recorded space per se, high frequencies light up the space around individual performers. The deliberately wide-dispersion WLM 'tweeters' (their low crossover point makes them rather more than traditional treble units) do this holographic lock to a much higher degree than the Zus. The power response of the upper end is higher too as is the perceived energy of the ambient field. In plain speak again, they soundstage like demons. The F5 builds out this asset with panache. Soundstage freaks with the right speakers to heighten this stereophonic illusion will be over the six moons and on the seventh. Way wide and deep far-out stuff.
It's no surprise that the F5 is no overdamped control freak. Unlike the S.A.C. il Piccolos from Germany with their 80dB of feedback and claimed full-bandwidth damping factor of 20,000 which fairaudio.de described as &dry as dust and super slamming in the bass&, the F5's so-called damping factor, though higher than all other F amps, is still modest in the scheme of things. It's innocent then of cyborg bass, my term for entirely unnatural low frequencies that sound hard as nails or concrete. Truthfully (I've waited to tell you this so you'd keep with this review), you could take my F4 add 15dB of voltage gain and 2- season with just a touch more articulating action, separation and concomitant 'visibility'; add a smattering of treble energy and presto - brothers from the same mother.
Ditto for operational noise. All F amps are quiet like the proverbial graves. That's perfect for noise-critical applications with high-sensitivity speakers. Mum's the word as well on the 240V mains transformer inside the F5. With my wall power often about 10% above its rated value, some iron protesteth and goes into hum. Not this one. Even the piercingly blue eyes of earlier F models have gotten turned down by popular request so the power LEDs no longer sear your retinae. Super-clean bill of health all around for the F5.
Act Three. This is where the main actor bursts into song while being stabbed in the back. Opera and all. We call it the conclusion. So, Nelson also is right about the 1-hour improvement. I didn't clock it but after between one to two spun CDs, the amp arrives and settles down. Could I tell the F5 runs on inferior feedback-fossil fuel compared to the other Fs? No. I have tested tube amps with selectable feedback where even small amounts of 2dB were clearly audible. Usually but not always, those did sound best with zero feedback on the speakers I used. Feedback then did dry out things, curtailed elasticity and swing if you will. However, I hear none of those drawbacks here.
Just as ultra-low measured harmonic distortion can sound sterile but doesn't here, feedback can but needn't. Hell though if I have a clue as to why, when and how come not then. It's interesting coming from tubes when first encountering the F5 in a well-dialed system that won't get embarrassed by greater honesty. While I've always known that tubes introduce 'pleasing distortions' (the main challenge finding machines that do this subtly enough to flavor, not become headline intruders), Nelson's FirstWatters from the F3 on have caused some head scratching and second-guessing.
Particularly for midnight listening, ears keen as Spock's, lover dearest sleeping next door, the F5 stomps my SETs. At regular levels, triode tricks catch up to make their own case. For me at least, then it's a question of what flavor experience I crave. If it's a highly visual one, if a melted heart, the tubes. I admit this commentary isn't the stuff of scales and tape measures. The level of game Nelson Pass engages these days when commercial considerations are out the window means that this brazenly subjective approach as an experiencer becomes mandatory. After all, the graphs already show us ruler-flat response with distortion so low, we'd assume it below our ear/brain threshold.
Addressed solely at us nutters in the Tube Corps, ultra-low distortion isn't intrinsically boring and uninvolving, clean as a whistle but bereft of juiciness. It's about more though than chasing textbook perfection no matter the means. This is no Halcro. Yet transistor goodness needn't mimic valve amps to somehow clone their behavior before a transistor amp can make its very own kind of magic. Depending on how your personal journey through audiolandia has proceeded, this could all be self-explanatory. In fact, you might wonder how a reviewer could take six busy years before coming to that conclusion. Um - we're not all the Silver Surfer. But Oliver Stone's &Greed is good& speech for Gordon Gecko comes to mind. How it stood normal values on its head. So the F5 could stand the aural beliefs of valve
not for sounding the same but because it achieves equal validity -- arguably superior in aspects as explained, merely different in others -- via such contrarious means. 20dB of feedback. Pah. Or perhaps the very reason for the F5's sterling showing? If feedback is bad, tell that to Mr. Pass and my zero-feedback ears. Glorious confusion. Or as Gurdjieff is rumored to have muttered under his last breath: &You're all royally screwed now&.
Curtain time. The F5 brings the Nelson Pass sonics explored in the present FirstWatt range to 25wpc needers with enough gumption for 2 ohms. Be aware though that 15dB of amplifier gain isn't very much. To serve up 90dB speakers in style, you'll want 20 - 25dB in your preamp . Not that those are FirstWatt's focus. But the F5 could be a back-door opportunity for those not subscribed to the hi-eff religion. You'll simply no longer be running the amp inside that first watt where its distortion drops off the map. Nelson predicted that some listeners would like the F5 best of the bunch. I certainly see why. As much as an audiophile floozie can at any given day, I might just share that opinion in fact. It's unmistakably the most universal FirstWatt yet, with the high-power 'muscle' versions of F3 thru F5 already announced to welcome those with even harder-of-hearing speakers into the fold. Consider this SET freak deep inside the fold already. The old Zen master is cooking and with his latest amp, even cavemen and Geico customers are reportedly capable of rolling their own. What a gift to the DIY community - and those of us reluctant to inhale solder fumes. Thank you, Mister Pass! ... who, it is only proper, shall have the last word on this matter:
&How do these effects come about? I really don't know. My experience so far is that good ideas, technique and philosophy all help but you have to build things and play with them at length, and if you can't hear or you don't put in the time, then you're out of luck. Edison was right - invention is 10% inspiration, 90% perspiration.&
[ 本帖最后由 davidxtb 于
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我记得推KK好像推荐的是F1和M2这些无反馈的，J2好像不是吧？
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原帖由 冰冰鱼 于
12:02 发表
我记得推KK好像推荐的是F1和M2这些无反馈的，J2好像不是吧？
记错了，确实是F1
[ 本帖最后由 davidxtb 于
13:09 编辑 ]
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