Vfet / SIT Amplifiers

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.

@sonetduo
Today, my mate is bringing the Accuphase A-47, which should be one the best amps today. I wonder if it sounds better, than 40 year old B-3s.

Don't worry, the C-1 is going to turn out just fine. I am not sure about the Sony though. 

@kitr  let us know.

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.

Soooo, the test results.....

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.

@sonetduo 

BTW, I still haven't heard what are the B-1 and N7B capable of. Maybe I will just toss the B-3s aside and keep using either the B-1 or the N7B.