I thought I'd finally add an update regarding my Absolute Audio Labs SIT-A15...... Performance is just breathtaking. Instruments and voices just sound utterly real with great solidity to the sound. Sound staging is not just wide but also has great depth. Spectacular natural sounding detail. Basically as a direct result I ended up selling off all other secondary sound systems I had around the home. Just no point listening to them as they can't compare.
I've now a preamp being made by Watchara to go with it as it really would benefit from a bit more gain vs my passive icOn 4PRO. Nonetheless performance is the best I've ever heard.
ha ha, but it is not about measurements to see if it is built right as I think your amp looks to be built more than right. I did go a bit through the forum and I am tempted to build the same amp...I sure have plenty of tokin devices to do it...
I did find some harmonics profiles of the amp posted by ZM and I do appreciate the 2nd harmonic dominance over the rest of the range. Very similar to that of the FW3, which leads me to believe that it sounds very very good at low volumes...maybe up to ~5w, then the THD starts to play a factor..once it tips the 1%+ scale. But that is to be expected since there is no NFB. I was hoping to win the auction on the Sony builds, but I guess I will just have to find a suitable alternative to build...so I did consider the sissysit3 ;)
BTW, listening to a "refreshed" Yamaha B-3 now ...read: BIG SMILE ON MY FACE.
I'd be lying if I said I wasn't tempted by the C-1, but my Pioneer Exclusive C3 is just so gorgeous that it would be hard to let go. Plus, all the work I've put into recapping and cleaning... :0
I've not posted any measurements, no. I'd love to get mine measured, tho. Just to verify I built the thing 100% correctly (aside from test point measurements).
You're right about the B-2, I'm not sure what condition the amp was in. I need to get her properly restored and redo the test. As for the TA-N7, the C-1 and the B-3s, I was told they were fully restored by my tech bloke, so I believe they really were restored. I can't be sure, of course, but I have no reason not to believe him.
I will soon acquire an Sony ta-N7b power amp (my dream), it was completely restored about a year ago in Paris Seine et Marne. (excepted big filter capacitors)
I'm also on a second hand speakers opportunity, it's a pair of Pioneer/Tad S-2ex.
Yes, thought it might be of interest as it’s a current production (albeit very low numbers) amp which can be purchased right now. I believe only about 5 made per year.
FW_SIT3 2nd harmonic is significantly dominant over the rest of the higher order harmonics. I do not believe that any more dominance of the 2nd would add any benefit. I have studied this quite a bit...on the bench with a proper audio analyzer and most importantly side by side comparison with other vfet amps.
I can't wait for your impressions of the new amp. Based on the few photos I see on the net it looks like a nice project and of good quality too.
Well I’ve an Absolute Audio Labs SIT-A15 SE power amp being built for me presently. Supposedly greater treble and bass extension than First Watt SIT3 and predominantly negative 2nd order harmonics which should give a more expansive sound stage than the SIT3 also, due to use of Tokin SIT’s. I’ll pair with a icOn 4PRO Unbalanced passive pre and Accurate Ultimate D1000 DAC. The pre has 3db gain and DAC very high output so it should be a favourable pairing. I believe this will be a significant upgrade over my Existing Pass Mini Aleph and 15W rather than 10W is nice also. ;)
hi @fiesta75the B-2X is a really nice amplifier indeed. I have compared in the sense that I do have a couple of B-2Xs amps and I am well aware of their sonic qualities but my units are not fully restored yet and it would be immature to state an opinion, one way or another, between my B-2Xs and the vfet units.
@kitrI have no doubt your units are in OK working condition. Full restoration with the specific key components addressed is a bit more than just a refresher and a recap.
As and example, the B-2 you compared to the 2XB3s and others, based on your video, that B-2 looked like it was no where near the state of back to prime (e.g original ill fated drivers and pre-drivers, original signal path routed via the original selector robbing you of details, etc). Comparing that B2 with anything else would only yield an opinion on the effective age of two different units and not how they would work in prime condition. This is particularly important is when you compare vintage units with modern gear.... it is important they have relatively close effective age so that the actual age can be ignored, rendered a non-factor.
As far as properly restoring a TA-N7 or the B-3s, our definitions of proper restorations might vary. All I can tell you is that it is not as simple as replacing a bunch of parts and hoping it will sound OK. It is not about the bench tests either. It takes a good amount of time and research to make an already good sounding amp sound excellent.
I have listen to all of those amps and very much any vfet amp ever made, and have done it numerous times, with different units in different conditions, with various degrees of restoration, etc.
Based on what I know today, I do not think I could come up with a similar pecking order, as that pecking order would have changed at least half dozen times over the years as I learned more about these units...their strengths and weaknesses, areas of improvement / that must be addressed, etc.
Then the rest of the other relevant factors would compound the problem even further..., such as the rest of the system components which could work with one amp but not the others (B2 and sissy preamps is an example that comes to mind...B-2 can sound awful with certain preamps..ask me how I know), the type of music, etc.
Last but not list, the audio memory comes in play. We as human have a surprisingly short audio memory..so comparing something I heard a few months back with something I would be listening at today, it is no way a relevant comparison.
Now, those are things I learned based on my personal experience, based on my curiosity and depth of involvement with these vfet amps over the years which is extensive, yet it is not general by any means BUT, if I learned one thing for certain is that coming up with a specific pecking order would have to be done with the all the amps at the same listening session and with all other things being equal and even that might prove to be difficult.
For similar reasons I will never state who I think is the most beautiful woman in the world or which vfet amp sounds best ;)
Well, both B-3s and the TA-N7 are fully restored, so I reckon they're in their prime. If I was to rate all V-FETs I've tested so far, it would be like this:
Sony and Yamaha Vfet's are still my favorite amplifiers after all of these years. Trying to keep my B-2 running for the next generations! Just wondering if anyone has compared any other V-fet amps to the B-2x?
If you have not fully restored these units, you are really hearing the impact of aging on these units and comparing that is really subjective. Simply getting the ~45 years old amplifiers stable enough to power on and play music might not equate to an accurate representation.
Speaking of the TA-N7 alone, N7 is a superb amplifier, but there are noticeable differences even between N7 units with different degrees of restoration, leave alone comparing them to other units. Speakers you pair them with is also a critical factor as N7s will not do as well on hungrier loads.
The N-7 fully and properly restored with bulk caps replaced and a critical set of ill fated semiconductors will fare well against most amps, including its vfet rivals from Yamaha and others. To the same token, a properly restored Yamaha such as a B-2, will give the N-7 a full run for the money.
After many hours of listening and tweaking these machines, both on the bench and the listening room, I find the N7 is very precise with a tight bass and airy highs. On the same token, the B-2 goes deep in the lows and has a clear advantage here, especially when pushing anything lower than 8ohms, yet keeping comparable on the highs and separation / depth, but with a wider soundstage. I can't say that I would trade one over the other so for this reason I will keep both..as a matter of fact I will be keeping two of each. If you liked the dual B3s in BTL, you need to hear 2xB2s or 2xN7s bi-amped. My hypothesis is that 2XB3 bi-amped do better than 2xB3s BTL, which is something I am yet to find time for setting up.
It's been a while since I've posted something here. I've got my TA-N7 restored and the results are quite interesting.
I'm going to compare the Sony with my two B-3s in BTL. Of course, it may be just my lying ears but it's something like this:
1. Sony resolves more detail
2. Sony's got a bit more air
Otherwise they are rather similar in every way.
When I pitted the B-3s against the Accuphase A-75, the B-3s were clearly better and I reckoned that the B-3 is a pinnacle of sound design. However, the TA-N7 just proved that it can always get better.
If you like to improve stuff then you might check out my page on mods to the First Watt amps. The things listed can be done by you or a friend or me.....simple stuff really. Much better sound whether its Sit-3 or J2 or F5 or whatever.
I've got completely restored C-1 about a fortnight ago and I've been playing around with her since.
I always reckoned that the best preamp is no preamp, but the C-1 convinced me I was wrong. Before the C-1 I was using Sony TA-E88. I was using it mainly because of the MC head amp and an input for my reel to reel deck. TA-E88 is a good preamp, she does what she's supposed do, adds volume control and some additional inputs and doesn't cock up the sound in any way but she didn't add anything either. However, when I replaced the Sony with the C-1, I've noticed two major differences. Better instrument separation and better detail reproduction. I had my mate come over to assess the sound, if it's not just my imagination or wishful thinking. He heard exactly the same thing as I did, and he also fancied a deeper bass (which I didn't notice). Nevertheless, the difference wasn't that big to justify steep prices of hi-end pre-amps.
re: "It's really odd that the contemporary top of the line amplifier sounds worse than 45 year old piece."
Not add at all and your expereince is not unique. I withnesed various astute audiophiles having similar reaction and favoring Vfet amps over some TOTL equipment of the likes of Accuphase, AR, Merrill, etc. The vfet amps of the 70s were build with parts that were some of the most linear amplification defices ever conceived. Unfortunately, they prooved too expensive to produce and were ultimately detroned in favor of Mosfets, BJTs, etc, due to cost of production advantaged.
Nelson is the last amp designer that offically worked with new vfets in his FirstWatt series, which are also great sounding amplifiers, but due to limited supply of vfets, the production of theose units stopped as well.
I still haven't found any B-1 for a reasonable price and the N7B is being refurbished. So, I hope I'll find out soon, if I'll keep using the B-3s or switch them for the Sony.
It's really odd that the contemporary top of the line amplifier sounds worse than 45 year old piece.
Let's start from the beginning. We tested both amps with Infinity Kappa 9.2 loudspekers.
First, we listened to some tracks on the B-3s, then we connected the Accuphase, but since it was couple of minutes later, we didn't remember perfectly how the B-3s sounded, and it seemed pretty much the same, except for the bass, where the B-3s had more kick. It's that sort of bass you feel inside and that's what the A-47 lacks.
Then we had decided we want to do an A/B listening test. Since I've got only one pair of loudspeakers, we put the source into a mono mode, connected one B-3 in a BTL mode to the left channel, the A-47 in a bridge mode to the right channel and corrected the volume for both channels, so the both channels were ballanced. Then we played some tracks. We were turning off and on channels in random to listen just to one amp at a time.
Well, to my ears hights were pretty much the same, however, mids on the B-3 were clearly superior, the A-47 sounded a bit "veiled" to me and again bass was superior on the B-3. It's got more punch.
But my room is not perfect and the speakers are not perfectly centered, one is closer to a sidewall and the other one is a bit farther. So, we reversed the channels and did the test again. This time, the highs and mids sounded pretty much the same to me, but the bass was still much better on the B-3.
So, the conclusion is, if I average the last two tests, the B-3 has the same hights, a tad better mids and a lot better bass. I am quite happy with these results, I don't need to buy new amp to upgrage the sound. But what is quite funny or maybe sad, is that new amp, that is supposed to be the top of the line, can't compare to a 45 year old crap.
but do not be surprised if your friend ends up selling his Accuphase after that session.....my friend ended up selling his A-65 after a similar experience with a vfet amp.
Hi @kitri I am glad to hear you have the Hitachi sorted out 👍
I also want to point out that it is possible to make the amp sound worse than they actually did when new, if critical components ate not replaced with proper replacements. That said, your assessment of the Hitachi vs the Yamahas, is just about right. About the C-1 and the Sony, I hope you find someone qualified for the job. Remember, if something wrong with any of the Sony vfets, there is still a possibility you might get it to work again. That changes drastically when it comes to the C-1. Yamaha has service bulletins out for the C-1 that must be implemented, depending on the serial number of the unit, otherwise you might end up with a beautiful door stopper. I wish you good luck in bringing those two statement pieces back to prime.
@thebiglebowski, sonetduo is right, it's not a vfet preamp, at least according to the official specs
I just got the Hitachi working. Well, she's not a bad amp, but she's not even close to the B-2 or the B-3. Sure, she's an integrated amp and wasn't even hi-end at the time of the release, but I soft of expected more. Every possible aspect of the sound is worse, except maybe for the bass response, which is quite good.
C1 is still under repair, as well as N7B. I hope it's going to be done soon.
The AN M7 looks like a state of the art preamp, which I would not mind owning, but it sure is not a vfet based preamp.
ECC803S x2, 6072 x2 (Phono) 6072 x4 (Line) EZ81 x1 (Rectification)
perhaps you are thinking of a different preamp? The C-1 :)
@mikem, that is great to know, thanks for sharing. Since the NP designs are single output transistor designs, means that replacements should be drop-ins...which is great! ....hope I never need them for my FW
@kitr Pass labs keeps spare SIT output devices for warranty repairs.. being that these SITs are built to military spec and can handle extreme conditions, according to pass labs support… I doubt there will be too many issues.
@kitr, you are starting to build a vfet geat collection that is quite impressive. Congrats on your recent purchases! Any of the gear you called out can be repaired if the vfets are still OK, with C-1 being the most difficult to repair out of the rest. Restoring them to proper order, is quite a different thing than just getting them to work again.
I am glad you got the B-2 to work again and thanks for sharing your listening impressions. Depending on how the B-2 was restored / repaired, will determine if it would sound noticeable different than the B-3 or B-3 x 2/ BTL mode. Key aspects of the B-2 restoration are the choice of bulk caps replacements and how the selector assembly is addressed. B-3 is simpler and does not have the selector assembly issue B-2 has. In BTL mode the B-3s might sound different to you but will have difficulty driving any difficult loads (below 6 ohms). That is not the case with a B-2. The warmer sound and soundstage of B3 in BTL mode might be a matter of speaker marching as the vfets of the B2 and B3 are technically the same and the circuit design is also mostly similar. I found that I actually prefer the B-2 over the 2 x B-3s in my system, and I did extensive real time A/B listening with no variables other than the amplifiers, so I guess is a matter of system synergy??
additional observations: If the C-1 you bought was listed as non-functional, if it is one of the units sold at the auction site in JP recently, CAUTION on who you take it to for repair! Do not take it to the corner tech / shop for repair or you will be sorry. You must make sure that you specifically ask the tech if he has experience with this unit...not with other Vfet units, but specifically with the C-1. Otherwise you will be sorry. The AK forum is full of such stories where a "tech with 30+ years of experience" takes on the job, just so that he returns the unit to the owner with fried unobtanium small vfets. C-1 has multiple types of small vfets, some only used in this unit and nearly impossible to source if gonne bad. You will find one person in the US that still works on these, one in Canada and a couple in Europe. Amp8 in Japan would also take on these units.
The TA-N88 uses a pulse lock PSU that has the tendency to self destruct....which takes out a vfet or two. Hoping that is not the case and that yours can be repaired.
For the Hitachi, there is no service manual or schematic available. Someone on a JP forum back-engineered the schematic but use that at your own risk as I do not believe it is fully accurate or complete...I couldn’t find the link at the moment.
Good luck with all your units. I hope you get them properly serviced and restored so that they provide you with sweet vfet musical bliss for the next 40 years!
The B-2 is fixed and working like a charm. Sound-wise, it's very similar to the B-3. I fancy the B-2 more than one B-3, but two B-3s are definitely better than the B-2. Two B-3s have a tad better soundstage and are a tad warmer.
@kitr thanks for sharing and I am not surprised. The B-3s along with its vfet family produce very engaging listening experiences when in working order. Get those B-3s fully restored, bump the bias up to 50-60mv. if you like them so much now, you will love them even more after.
Well, I just want to share my latest experience with the V-FET.
My mate just bought two Starkrimson monoblocks from Orchard, which are supposed to be one of the best amps out there, at any price level. So, we pitted them against the B-3s.
Weeeeeeeeeeell..... I have to say, it was really interesting. Before he came, I was wondering if I'll get rid of the B-3s and buy a new amps.
1. The Starkrimsons were certainly a bit cleaner. Nothing I'd kill for, but they were. 2. There were more details. Again, nothing to kill for, but I heard some details I couldn't with the B-3s. Which was pretty good. 3. Instrument separation was on par. 4. The imaging was miles better on the B-3s. 5. The B-3s have a bit deeper and nicer bass. 6. And the most important thing... The Starkrimsons sound so boring, it was almost painful. With the B-3s, the sound is so nice, you don't want to turn the music off, you just want to keep listening whatever you're listening.
So, the conclusion is, I am not getting rid of the B-3s anytime soon. If these two were combined, the clarity and details from the Starkrimsons and the imaging and the warmth that's coming out of the B-3, I'd get that for sure.
The first is that its possible using them to design an amplifier that will make the lower ordered harmonics (2nd or 3rd) as the primary distortion component, in enough amplitude to mask the higher orders. This results in a smooth sound and might be an order of magnitude lower than a tube amp of the same power (and lower output impedance too).
The 2nd advantage is that of soft clipping, but this is somewhat ameliorated by the fact that nearly all the designs *manufactured* employ feedback, and when you do that soft clipping isn't a thing so much.
You can build other kinds of amps that can get the same distortion signature. One key element is to insure that whatever the distortion signature is, its consistent at 100Hz, 1KHz and 10KHz. Some of the VFET designs seem to do this (so do zero feedback designs regardless of tube, traditional solid state or class D, so long as the bandwidth is wide enough).
It is nice when you get get an amp to perform that way as the improvement is easily heard and the system sound is all about the music- you can forget about the system making it.
There's no 'maybe', there is an enthusiasm in that statement :)
However, an enthusiasm or not these amps are amazing. I wouldn't call them exactly cheap, but you can hardly find anything better in their price range, or any price range really.
The only problem is, if the transistors go, you won't find a replacement, only another working amp (maybe).
@atmasphere maybe there is some enthusiasm in @kitr statement but it is not inaccurate. Most vfet amps will ride right along the top 1%-5% of the amps build new or old, in terms of sound finesse and detail. True, none will win any races for driving difficult loads (much below 4 ohms), but for average to efficient speakers, they are extremely difficult to match by other SS amps and some of the vfet amps do just fine against vacuumed glass.
If you have the opportunity, you should try to pickup something like a B-3 or a B-2. For the B-2, I would send you something that would take care of the "stuff" in the signal path, so that there is nothing between the rear input and the driver board. B-2, B-3 are DC amps. Most of the ancillary circuitry is about protection, which actually works quite well, hence the high survival rate of these amps after 40+ years.
Don't worry too much about too many stages or other "old school" amp design. If you have the opportunity, try getting one and if it is still kickin' even in original condition the sound is extremely engaging. With some proper TLC, they are world-class amps.
Well, I've played about with the Victor for couple of days now and I need to share my findings. Since it's a V-FET, it sounds very similar to Yamaha's B-3. Very detailed, perfect imaging, deep bass, but it's not exactly on par with the B-3. Something was a little bit off. I don't know how to describe it, but the Victor sounds a bit dry and not so "musical". Still better than almost anything on the market today, though.
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