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I'm not at all going on a limb by strongly impressing upon you that the Yamamoto A-08S is the most beautifully crafted amplifier I've ever come across. To boot, I think it's beautiful, period - far more than photographs can convey. Needless to say, beauty lies in the eye of the beholder. However, there can be no argument about this amplifier being built to exceptionally high standards. "Handcrafted" as a tag rarely ever signifies this level of bespoke luxury in $3,000 amplifiers.

Marvel over how turret-style point-to-point wiring has been implemented with the precision of a surgeon.

I have seen more than one $8,000 amplifier not as nicely put together as this.

With the A-08S, we're plainly in the presence of something touched by pure mastery, from the ebony-encased custom capacitors to the flawlessly sculpted, gorgeously finished resin Cherry.

Even the included Yamamoto analog interconnect proudly sports custom Yamamoto connectors.

What's more, kneeling in front of this beauty by way of camera penance, I put my ear in as close proximity to the amp and transformer cover as possible. Nothing -- and I mean nothing -- of even the faintest transformer hum or other mechanical activities gave away that the amp was, in fact, on. The only lie put to that notion was the glow of the power button and the tubes - Cunningham 45s, those mushroom 717As and the 80 rectifier.


This mechanically silent perfection was all the more astounding given the size of the transformers which, for the rated 2-watt output, seem very generously proportioned indeed.

If there were laurels for highest percentage of custom parts in an amplifier, the Yamamoto would win hands-down and essentially by default. Even the binding posts are made in-house, with an ultra-fine pitch that allows proper tightening by hand. "The government today announced that it is changing its emblem from an eagle to a condom because it more accurately reflects the government's political stance. A condom allows for inflation, halts production, destroys the next generation, protects a bunch of pricks and gives you a sense of security while you're actually being screwed." The Yamamoto instead is a royal eagle all the way.

Once installed in my main rig, the eagle proved just as quiet in flight as sitting pretty on its perch. 2-watt amplifiers mandate 100dB speaker sensitivities. That makes noise an ever-present concern. The basic premise of micro-power amps mandates mating them to high-efficiency speakers. This would suggest that the noise issue is always handled on principle. Unfortunately, that's often not the case. Perhaps entirely unsurprising considering how much fastidious care has obviously gone into this amp, the very yummy Yammy -- dispatched straight from the just concluded Tokyo Tube Fair -- attends this requirement in high style and with absolutely zero complaints.

2nd opinion side bar
Reader Chopper87 posted an owner's impression of the Yammy S on Audio Asylum, confessing to his prior concern that the switch to DC heaters from the previous version could have hurt the sound. Why did he believe that? As an owner of Wavelength Gemini 45s, he knew that Gordon Rankin is rather outspoken about the need for AC heaters to get the best from 45s. Since I wouldn't be able to compare between the two Yamamotos (old AC and new DC heated versions), I will let Lance A. aka Chopper87 fill us in on his experience vis-à-vis the AC-coupled Wavelength Audio Geminis: "... It has been stated on more than several occasions (on the Asylum and other locations) that the 45 tube was designed for AC filament heating and that DC filament heating this tube type results in an inferior -- specifically, dry-sounding -- amplifier when compared with a good AC-heated design. I am fortunate to own and enjoy a pair of Wavelength Audio PF Gemini amplifiers that AC heat the filaments of their 45 output tubes..."


"...The mids and highs are very rich and a long way from dry. Vocals and cymbals sound more in the room than ever before. From every aspect that I can think of (from the midbass on up) this Yamamoto is the best sounding amp I have lived with to date. However, I do not feel that its bass performance is better than that of the Geminis or other good amps on hand. That isn't a bad thing at all though. It's just that the damn thing is such an overachiever in almost all other areas. Can the new DC-filament heated Yamamoto A-08S compare sonically with a very good AC filament heated 45 SET amplifier? In my opinion, absolutely!


I really had two objectives when purchasing the new Yamamoto A-08S unheard. The first was the investigation above. The second? I wanted to know whether one of the newer breed of sub $3,000 45-based single-ended amplifiers could compete sonically with a $6,000 pair of Wavelength PF Gemini amplifiers.


For about two years, I have been very pleased with my Wavelength PF Geminis driving a pair of Lowther DX-4/Medallion III back horns. The Medallion III cabinets were redesigned to properly work with the much smaller magnet structure of the DX series of Lowthers. The compression chamber is shallower and the cabinet as a whole is a bit less deep. I also use a corner-loaded subwoofer because the Medallion cabinets, as big as they are, offer little low bass at all. The subwoofer comes in at 50Hz, which does the job quite nicely.


My source is a Sony XA777ES SACD/CD player plugged into a Bent Audio TVC passive wired for 0 gain. I originally purchased the Bent because I wanted to stay with passive preamplification but hoped that the +6dB passive option would offer me the gain needed with my Geminis. Unfortunately, I found the added gain caused noticeable sound quality degradation that I just could not live with. So I changed the feedback resistor values on the audio output board of my Sony player and gained 6dB of gain right at the source. Had I only known that my new Yamamoto would have a substantially higher input sensitivity. It has no problem reaching full volume with either of my passive preamplifiers.


When I got to serious comparisons, I pulled out Carmen McRae's Sarah - Dedicated to You, a well-recorded CD that displays some great vocal and instrumental Jazz. With the new Yamamoto, I could tell that I was listening to a better sounding amplifier within seconds. It just added things that I was not used to hearing. Carmen McRae had a 3-dimensional air attached to her beautiful and sultry vocals. There was a marked increase in presence to vocals and instruments. There was more dynamic slam to instruments such as a hard-struck piano note. This is the very first time I have felt the true presence of a piano in my listening room.
The Yamamoto presents music with more tone than any amplifier I have owned before. It presents rich and deep tonal colors that I find quite intoxicating. I can't decide whether the A-08S really has better bas or high frequencies than my Geminis. I do know that I listened to Sarah all the way through for the first time since the day I brought it home - fourteen years ago.


The Yamamoto S is anything but dry sounding and presents instruments and vocals with presence, tonal colors and image specificity unlike any amplifier I have owned. The Yamamoto makes me have to work far less at imagining real music at the far end of my listening room. Keep in mind that I have a brand new pair of TJ mesh 45s, new EML solid-plate 45s, Radiotron Globes and Cunningham ST type 45s. I have tried all tubes in both amplifiers and am stunned at how much better the Yamamoto sounds regardless of which 45 is introduced. Also, every output tube is plug'n'play with absolutely no noise of any kind when plugged into the Yamamoto amplifier. The Yamomoto's sound is far more musical, with absolutely dead silence in-between that make a far bigger impact on their sense of realism than I had anticipated. I also love the fact that Mr. Yamamoto builds so much of his amplifiers in house, including the huge output transformers."

Not intended to be a categorical statement regarding AC or DC heating of 45 triodes at all, this actual owner's feedback simply provides a valuable bit of information on a related subject I wouldn't have been able to comment upon. Once the Yamamoto has settled in, expect a three-way comparison with the 4-watt Fi 421A and 8-watt Canary Audio CA-308 monos to report on three different tubes and flavors in the micro/low-power realm of single-ended triodes.