Why bother?
Edit: Scratch that,
The B-2 is worth repairing. My "why bother" comment was for the modified B-3.
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YAMAHA B-3 on the way...to me!
- Thread starter Cosmin2000
- Start date
Edit: Scratch that,
The B-2 is worth repairing. My "why bother" comment was for the modified B-3.
Cosmin2000
Active Member
I am very saddened to inform you guys that my beloved B-3 entered yesterday in protection mode twice. 
I also observed a rather unusual rising temperature on hand inspection. After the first protection mode click, it took like 5 seconds and came back to normal operation, then again to protection and afterwards I just stopped the operation of the unit.
After I came back to Romania, I have listened once the B-3 with no issues, like a two hour session. Now, how can I deal with this?
I also observed a rather unusual rising temperature on hand inspection. After the first protection mode click, it took like 5 seconds and came back to normal operation, then again to protection and afterwards I just stopped the operation of the unit.
After I came back to Romania, I have listened once the B-3 with no issues, like a two hour session. Now, how can I deal with this?
Depends which engine..LOL
This is a unit that is over 30 years old now. There re components such as electrolytic capacitors the are well beyond their useful life in that unit.I am very saddened to inform you guys that my beloved B-3 entered yesterday in protection mode twice.
I also observed a rather unusual rising temperature on hand inspection. After the first protection mode click, it took like 5 seconds and came back to normal operation, then again to protection and afterwards I just stopped the operation of the unit.
After I came back to Romania, I have listened once the B-3 with no issues, like a two hour session. Now, how can I deal with this?
I cannot tell you what to do, but I can predict what it will happen if you do nothing..You will end up with a nice paper weight or door stopper.
If this was my unit, I would have performed minimum maintenance even before I would have plugged it in the first time.
If you turn that amp on in its current state, you are playing Russian roulette. You are on borrowed time my friend...
Take it to someone that understands V-Fets for the maintenance.
I am sure you will find someone in Romania. Otherwise there are a couple of AKers on your side of the pond that might be able to help ya
PM me if you would like contacts.
True that!
using that amp as is, without having it serviced is gambling in my book.
are you planing a B-3 big rebuild anytime soon?
Cosmin2000
Active Member
The fact is yes, I have used the laptop as my preamp and source, but my setting on the back if the amp was on AC coupling. I shouldn't have done that, I know...
Although I have a proper preamplifier, Trio L-07CII, and CD Players, I have them stored until I will build my own house.
The protection engaged after two hours or so.
Nevertheless, I will not use the B-3 anymore until I'll find a proper technician which knows to work with V-FETs.
Although I have a proper preamplifier, Trio L-07CII, and CD Players, I have them stored until I will build my own house.
The protection engaged after two hours or so.
Nevertheless, I will not use the B-3 anymore until I'll find a proper technician which knows to work with V-FETs.
there is your answer Cosmin. You could not find a better solution to your problem. It sucks to have to wait for a year, but it would suck worse otherwise.
Yes, an ill faited semi is most likely acting up and giving you a nice warning.
I might be getting in line myself if I end up with one ...or two B-3's by then
you should start a waiting list
lol, is already kinda' late for the self imposed prohibition...given my increasing flock of B-1s.Looks like you have negotiated yourself a new shutdown level at headquarters, considering the earlier purchase stop you imposed on yourself
Just want to pay respect to the master. I should be able to restore those B-3s if I should ever have them in my possession, but I just think that you would be the person to do a better job than even what I would be able to do for myself
wait, does test equipment count against the self imposed prohibition..hmm, I have to think about thatLooks like you have negotiated yourself a new shutdown level at headquarters, considering the earlier purchase stop you imposed on yourself
Cosmin2000
Active Member
According to the schematics of the B-3, which are the semiconductors prone to failure in time?
I discussed with someone with expertise on reviving vintage audio in Romania and he suggested to change all the small signal transistors. Prior to that, he adviced for a complete recap, except the big 27000 microF/63V capacitors from the power supply which will be tested to leakage, ESR and capacity.
Are all the transistors bad in a unit like B-3, known to be in good working order until now? Or shoud I focus on certain transistors from key circuits which are known that will cause problems?
Thanks for your considerations and advice.
I discussed with someone with expertise on reviving vintage audio in Romania and he suggested to change all the small signal transistors. Prior to that, he adviced for a complete recap, except the big 27000 microF/63V capacitors from the power supply which will be tested to leakage, ESR and capacity.
Are all the transistors bad in a unit like B-3, known to be in good working order until now? Or shoud I focus on certain transistors from key circuits which are known that will cause problems?
Thanks for your considerations and advice.
I wouldn't blindly change all small-signal transistors unless they are known to go bad/noisy, many modern subs can be lacking in certain areas compared to original parts. Oilmaster would be the resident expert on "what is mandatory to change", I'm not sure if he'd share that info here - although I think it would be very handy for future B-3 owners without access to his services.
If you intend to keep the piece forever, it's probably worth tracking down an expert on V-FET pieces - as much as that's probably not what you want to hear. Some careful packaging and insured shipping to/from a reputable tech is probably a safer bet than letting a non-expert tackle the job.
There's some interesting pictures here showing replacement of various parts during maintenance:
http://www.hifido.co.jp/KWYamaha+B-3/G1/E/0-10/C12-68890-54800-00/
Not sure if the jump to 39,000uF is excessive - perhaps @Oilmaster could comment?
If you intend to keep the piece forever, it's probably worth tracking down an expert on V-FET pieces - as much as that's probably not what you want to hear. Some careful packaging and insured shipping to/from a reputable tech is probably a safer bet than letting a non-expert tackle the job.
There's some interesting pictures here showing replacement of various parts during maintenance:
http://www.hifido.co.jp/KWYamaha+B-3/G1/E/0-10/C12-68890-54800-00/
Not sure if the jump to 39,000uF is excessive - perhaps @Oilmaster could comment?
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PM Sent.
How handy are you?
Can you manage removeing the driver boards from the unit without damaging anything? then reconnect them after they were rebuilt?
B-3 looks super easy to work on and it is very modular.
I am saying this because if you are sufficiently handy, I suggest that you take the driver boards out and mail them to @Oilmaster (if he wants to take them). You will not find a better tech for your B-3.
Cosmin2000
Active Member
rottalpha, thanks for the PM. Unfortunately, I have no time available to disassemble the B-3, hence probably I will drive to Bucharest to hand in the B-3 to the specialist.
You are right, the B-3 construction is user friendly, the unit has like 14 electrolytic capacitors on the two boards, aside from the two big 27000 microF/63V from the power supply. Therefore, a recap is not very laborious, but the rest of the job (transistors, diodes etc.) is not my field of expertise. I will not hurry with this unit, I want to have it functional for another 40 years if possible. Thanks once more for the assistance!
You are right, the B-3 construction is user friendly, the unit has like 14 electrolytic capacitors on the two boards, aside from the two big 27000 microF/63V from the power supply. Therefore, a recap is not very laborious, but the rest of the job (transistors, diodes etc.) is not my field of expertise. I will not hurry with this unit, I want to have it functional for another 40 years if possible. Thanks once more for the assistance!
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Aw man, read this whole thread and no happy ending? Cosmin, what happened to your B-3? Rottalpha did you buy a B-3 or 2?
