Reviewer: Srajan Ebaen
Financial interests: click here
Sources: Retina 5K 27" iMac (4GHz quad-core with Turbo boost, 32GB RAM, 3TB FusionDrive, OSX Yosemite. iTunes 12.2), PureMusic 3.02, Qobuz Hifi, Tidal Hifi, Fore Audio DAISY1, COS Engineering D1, Aqua Hifi La Scala MkII, Metrum Hex, AURALiC Vega,
Preamplifier: Nagra Jazz, Esoteric C-03, Vinnie Rossi LIO (AVC module)
Power & integrated amplifiers: Pass Labs XA30.8; FirstWatt SIT1, F5, F6; Crayon Audio CFA-1.2; Goldmund Job 225; Gato Audio DIA-250; Aura Note Premier; Wyred4Sound mINT; AURALiC Merak [on loan]
Loudspeakers: Albedo Audio Aptica; Sounddeco Sigma 2; EnigmAcoustics Mythology M1; soundkaos Wave 40; Boenicke Audio W5; Zu Audio Submission; German Physiks HRS-120; Eversound Essence
Cables: Complete loom of Zu Event; KingRex uArt, Zu and LightHarmonic LightSpeed double-header USB cables; Tombo Trøn S/PDIF; van den Hul AES/EBU; AudioQuest Diamond glass-fibre Toslink; Black Cat Cable redlevel Lupo; Arkana Research XLR/RCA and speaker cables [on loan]
Power delivery: Vibex Granada/Alhambra on all components
Equipment rack: Artesania Audio Exoteryc double-wide 3-tier with optional glass shelves, Rajasthani hardwood rack for amps
Sundry accessories: Acoustic System resonators, Verictum Silver X block on preamp and amplifier
Room: Irregularly shaped 9.5 x 10m open floor plan with additional 2nd-floor loft; wood-paneled sloping ceiling; parquet flooring; lots of non-parallel surfaces (pictorial tour here)
Review component retail in the US: $3'000


Originally published by National Geographic
Something smelt very big fishy. The amps looked like FirstWatt M2, from PCB to chassis to heat sinks to rear panel. But they came from Thailand and were advertised for $850 on eBay. They went by M2-X, with verbiage lifted near verbatim from the Pass site. A quick check with the man affirmed it. These were FakeWatt. "It’s a guy who was banned from diyaudio.com. Years ago he apparently had some clone chassis made and tried to flog them since.

"I'm under the impression that he hasn't been very successful at it. Previously he had been shut down on eBay for trademark infringement. I note that his PCBs read 'uncopyrighted' which is not the case. It’s always somebody. Note that I am in the process of shipping the very last of the M2, making way for newer stuff. Meanwhile, work continues. I just sent off the PCB artwork for the 2SK77B SIT amps of which I will be making 20. The 2SK77B is a 300-watt VFET and makes for a very nice SE Class A no-feedback amplifier along the lines of the SIT-1 but with 50 watts and about twice the damping factor. Oh, and my daughter is getting married here at Sea Ranch this Saturday so hoist one for me." That note came down the pike December 1rst, 2014. A stiff drink duly followed, saluting Nelson and his kin! As far as IP predators go, they get two thumbs down, six feet down. Shark sushi anyone?


The next email arrived July 22nd. "Gentlemen, my apologies. Per our last emails, I was sending you an F7 for review. You may know that I tend to be more timely than this. But, in an idle moment, I tried a variation of the circuit using a new concept and the result was striking, both in terms of measurement and sound.  It’s a really different animal. It has put me on a new path for this product and I’m still working out some of the details. I think it will transcend the 'another nice amplifier' category. I hope that it will be worth more than the delay. I will be sending out a copy very soon. Best regards." - Nelson Pass

Another stiff one followed. Inspiration is a fickle mistress. Her real name is She Who Must Be Obeyed. Do not and she may stop visiting. Idleness is not the devil's workshop. Doing nothing, spring cometh and the grass grows by itself. Tricky balance though. Inspiration requires preparedness. Which is far from the same thing as doing nothing to be a lazy slobber. Lest you think that I had finally achieved the blue-blooded royal 'we' to be addressed as a proper pluralist chap, not. For this assignment, we'd organized a divide-and-conquer approach. Dawid Grzyb, a newer contributor from Poland without any prior experience with Pass Labs or FirstWatt gear, was to handle the meat and potatoes of the assignment. Afterwards, I was to add some sauce and second opinion. "Mr. Pass, thank you for your update. As for me, no problem. Take your time. When the right moment comes, I’ll be here to do my part." Dawid clearly wasn't bothered by any delays. Neither was I. About that non-standard intro? Being the truly generous chap np is—he commonly publishes his circuits for non-commercial DIY projects—invariably means that some ahole somewhere decides to commercialize his IP for a quick profit. Fortunately for DIYers everywhere, Nelson is a passifist. He continues giving rather than go on the offensive and stop. Blame the ion of Pass: pure passion. And that's all I had for months, on the upcoming F7 whose genetics were seemingly struck by lightning to detour into what I knew not. Not that I had any prior notions, on what the F7 was gonna be before its course correction from on high. We'd chase after something different. Not that any of the preceding FirstWatt amps weren't. But if np called this one out, those in the know knew to strap up. Here is a blog entry by The Abso!ute Sound's Robert Harley, on visiting Nelson in his coastal Northern Cali digs, his fortress of solitude as he calls it.


By October 25th, the master dropped another crumb. "I know you’ve been waiting patiently. So I've gone to some effort to ensure that it’s worth it. The new F7 boards are in house. I hope to send both you and Dawid copies at the beginning of the month. In the meantime, here's the link to my fabulous talk at BAF 2015. As they would say in Bonzo Dog Band, another turner for the books." To which I replied: "Already listened to the talk. Fascinating. What I took away was that, with a clever application of Schade feedback—through a transformer no less—a conventional pentode-style transistor can be strapped to triode, a Mosfet or BJT made to exhibit Vfet/SIT curves virtually indistinguishable on the test bench. Did I get that about right? Can’t wait to see what you’ve got cooked up in the F7. I’m thinking it’ll be a variation on that theme." It was admittedly a wretched excuse for invisible prodding. But would he fall for it, divulge more and put his DIY forum crowd out of our collective misery? There a developing thread on the F7 had this: "The F7 at the Burning Amp Festival [right] was an early prototype, not the end product though a perfectly nice amplifier. It's just that I had a nice insight into something when playing with the original and decided that it was too good not to use. I plan to get one off to 6moons and another to Dick Olsher so they can get a jump on the release. Just so greedy boyz know, this is not going to be a DIY like the F6." Here's a PDF of Nelson's complete talk of CAS 2015. On November 9th, the hammer fell. "Good news, Srajan. Revised F7 passed listening tests. I'll start finishing yours tomorrow."


Other DIYaudio posters kept doing their own shameless bit of fishing disguised as speculating. "I am still guessing at a new circuit using Schade feedback. It was a new idea at BAF and a way to get SIT sound without a SIT." Another suggested that Nelson might revisit his stash of custom VFets as successfully exploited in the SIT1 and SIT2. On November 13th, this crumb dropped: "The F7 is very different, more similar to an F5 but with some refinements and new ideas." Push/pull then? Another prediction favoured "fully symmetrical". Nelson was doing the slow-mo striptease. It worked his captive audience into a thick sweat. Tickling for another sock to come off, someone proposed a "folded cascode front end or symmetrical double-differential pair?" If Nelson was to have real fun, he'd simply wait for my obligatory inside photos. They'd launch his most experienced posters into a decryption frenzy. He'd egg them on here and there with corrective hints. It'd be another major teaching lesson and the master only had to confirm what his followers got right, not reveal secrets they overlooked. Giving it all up when this was to be a commercial product would only encourage the copycatters again.