Yamaha B-2 restoration journey

Firstly, allow me to go back to your first phrase: 1700 km driving to pick these up....
Where did you go for that from Haarlem ? Southern Germany, Swiss or France?
Congrats anyway :)

I am currently deeply into a 100% restoration of a B-2, full disassemble.
Feel free to come over to The Hague for a coffee and full details on any given replacement part.
Southern Germany, near the borders of Czech Republic and Austria :rockon:

And all in one day :crazy:

Thanks for the invite, I will certainly do that :thumbsup:
 
Over the years I've restored 4 B-2's and none have needed the VD1212's replaced. I think people confuse these with the similar looking infamous VD1221's that Sony used in their V-FET amps.
 
Over the years I've restored 4 B-2's and none have needed the VD1212's replaced. I think people confuse these with the similar looking infamous VD1221's that Sony used in their V-FET amps.
1221vs1212...You can't blame us.... I am a master of dyslexia. Thanks for pointing out the diagnosis :rolleyes:.

@clinic, thanks for the nudies.
 
OK it was a long trip yesterday, but it was more than worth it. I'm still flabbergasted by the condition of the B-2 (and C-2 and T-2), it looks like it just left the manufacturing plant. Everything from first owner and it came with all original (and mint) prospects and owners manuals. There is even an A1 format original unused schematic of the B-2 :bigok: So I have to do some HQ scanning for me to share this wit other owners.

The guy had it playing when I was there yesterday, so when I got home, I checked bias, DC offset and the -85 and +85. They're all in spec, except for the left bias, that was 30 mV. Adjusted them both to 50 mV to begin with. Very tempting to hook the B-2 to my C-4 and NS-1000M's and that is exactly what I'm going to do tonight :banana:

On the inside everything looks great, except for some old repairs. There were some invoices with it which stated there were some repairs and I wasn't to happy to see how a professional repair shop did what they did. Take a look of the pictures of the left driver board. They replaced some transistors and used 2 caps to get to the right value of the one BP electrolytic. I also wonder whether they used the right trannies. And then we have also some fooling around at the power button.

The rest looks original and unrestored.

Some pics:

IMG_0591.JPG IMG_0592.JPG IMG_0593.JPG IMG_0594.JPG IMG_0595.JPG IMG_0596.JPG IMG_0600.JPG IMG_0601.JPG IMG_0602.JPG IMG_0603.JPG
 
Very very nice, I like the overhead shot number 7 in post #29, showing a nice balanced internal design, with heat sinks that look like they really mean it. :D
 
Absolutely beautiful. I have a B-2 and a T-2 and they are works of art. That was definitely worth your trip. I drove a few hundred miles to get my B2 last year!

You have the original schematic with color signal path on it and all the original manuals and pamphlets. :thumbsup:
 
Looks great! It's rare to see gear from that era in such perfect cosmetic condition.

I would have the B-2 refurbished, including replacing the main filter caps.
 
On the inside everything looks great, except for some old repairs. There were some invoices with it which stated there were some repairs and I wasn't to happy to see how a professional repair shop did what they did. Take a look of the pictures of the left driver board. They replaced some transistors and used 2 caps to get to the right value of the one BP electrolytic. I also wonder whether they used the right trannies. And then we have also some fooling around at the power button.

I would say that you have an absolutely beautiful B-2 there! Are you able to see what the transistor part numbers are? They look like either Panasonic or Sanyo's from where I'm sitting¿
 
I would say that you have an absolutely beautiful B-2 there! Are you able to see what the transistor part numbers are? They look like either Panasonic or Sanyo's from where I'm sitting¿
I'll have a look into that!

It was so tempting to listen to the B-2 and so I did (still listening). But man, what can I say :music:

Listening to Neil Young - Southern Man at the moment :bowdown:

I did never audition a B-2 before in my system, but sound's absolutely great. Blows the M-2 away sound wise in my opinion. I also heard people complaining about the (lack of) bass, but I do not agree. This thing has plenty of bass.

It would be very difficult to disconnect it in a few days in order to do the needed mods and repairs..

And btw, does it needs a warm-up or something? It looks like it began to really shine after an hour or so :rolleyes:

Not sure the C-4 is the right partner, but it doesn't look bad for now.

IMG_0611.JPG

IMG_0612.JPG
 
Blows the M-2 away sound wise in my opinion.

I traded a B-2's for a very nice M-2; it's also a very fine piece but IMHO not the equal of the B-2. Luckily I still had another B-2 in reserve. :thumbsup:

And btw, does it needs a warm-up or something? It looks like it began to really shine after an hour or so

It should be all warmed up after about 15 ~ 20 minutes ...
 
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What I have gathered around from AK so far for replacement parts:

Power board


C205 & 206 Nichicon UPW2C101MHD
C209, 210 Nichicon UPW1H100MDD's
C213, 214 Nichicon UPW2A100MED's
C215 & 216 Nichicon UHE2A151MHD's
C219 Nichicon UPW1E471MPD
C220 ?
C223 Nichicon UPW1C101MED
C221 Nichicon UVZ1C100MDD
C227 & C228 Nichicon ES
C225 & C226 Nichicon ES

TR203, 204, 215 en 219: 2SC458C -> KSC1845

D205, 206: Zener Diode EQB01-30 -> BZX85C30

D210: Zener Diode WZ-130 -> ?

Filter Caps: 4x Nichicon KG 22.000 uF or CDE Snap-in (not sure yet).

Speaker relais: Omron LY2-0-DC12 - Z978-ND

Driver board:

C114 & C115 Nichicon ES Bipolar 100 uF / 6,3V

All fuses

DC Balance + Bias pots

Bourns 3299P-202 - VR101 (x2)
Bourns 3299P-104 - VR102 (x2)
Bourns 3299Y-502 - VR201, 202

So, not sure about C220 and D210. Any ideas?

And then we still the VD1212 / HV-36R / MV12 discussion: one says don't touch, the other says replace with 2 1N4148's in series. I know that there's no substitute available, but they aren't broken either (yet).
 
I did never audition a B-2 before in my system, but sound's absolutely great. Blows the M-2 away sound wise in my opinion.

Could you elaborate on how / what each amp does better than the other?
I think these sorts of comparisons are very useful to people who aren't able to audition gear they potentially want to buy.

It really helps if there are detailed comments on sound signature / soundstage and other subjective measures, partly because what's "better" for one person might not be for another, but the description makes it easier to decide.

The C-4 looks very nice, I can't get enough of those square buttons.
 
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