Yamaha B-1 restoration/repair

[cabbi]

Hi Claudio and welcome to Audiokarma! Always nice to meet another B-1 owner even if it's not working.

Sadly, due to the recent rediscovery of V-FET's by Nelson Pass and others the 2SK180's are quickly becoming as scarce as 2SK77's ...

Thank's Vint Age, I can understand that. I can source genuine Tokin 2SK180 from Asia @ +/- $ 31/ea + shipping. However, there is no way to find matched pairs. Some idea how much devices would be needed to get 4 matched units ?? if there is some statistics about this question I can consider making the move.

Thanks a lot.
Claudio.

 

[rottalpha]

Thank's Vint Age, I can understand that. I can source genuine Tokin 2SK180 from Asia @ +/- $ 31/ea + shipping. However, there is no way to find matched pairs. Some idea how much devices would be needed to get 4 matched units ?? if there is some statistics about this question I can consider making the move.

Thanks a lot.
Claudio.

Buying a larger number of sk180s, then have them matched, is unfortunately the only real way to get matched pairs, unless someone offers to sale you a matched pair.

 

[Kannan_s]

Hi Every one
this is my first post here. I had used AK extensively to understand Sony TA-5650 repair and successfully restored with power supply repair. Then I had acquired 2 B-2 and working on restoring. Just last week I acquired one Yamaha B-1 as non working but cosmetically in decent condition. It was supposed to power up with with Overload indicator on. I did not power up but started stripping for checking each of the boards and replacing mainly all Capacitors first. I found the V-Fets are fine and the 200V Power supply / protection board had blown rectifier diode already.

Now I need the Power Supply adapter PCB if i can get from any AK member ( if spare is available?)
please let me know if you have or other ways to make one. I will try to document in a separate thread later once i get time as these threads are valuable in restoring some of these unique /rare amplifiers.
kannan
Austin -TX

 

[Vint Age]

Now I need the Power Supply adapter PCB if i can get from any AK member ( if spare is available?)

Hi kannan and welcome to AK!

Hey congrats on the B-1 and good luck with the restoration. As far as I know extender boards for the B-1 are rarer than B-1's. I've often thought about having some built because they'd certainly be handy to have but so far I haven't. If you find some let me know.

 

[Kannan_s]

Thanks Vint Age for your support- but I am first looking for the Power supply Capacitor adapter to replace PSU cap ( Dual Caps) as mentioned in this thread.
kannan