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Summer Project I- Recapping 2215B, need help!!

Space, money and time.....

Film caps will be larger and more expensive than the typical same spec Electrolytic.

These are the two best reads on audio caps that I have found...

http://web.archive.org/web/20030807122631/http://capacitors.com/picking_capacitors/pickcap.htm

http://members.aol.com/sbench102/caps.html

read up.... and lets chat....otherwise its a recommendation without meaning. But the Tantalums than cheapy electrolytics are the lowest on the food chain....but sometime you have no choice and sometimes it does not matter..... You can greatly improve some caps by putting a .1 film cap in parallel. That is usually easy to fit in the same space.

Film cap are almost always going to last longer.....and sound better.

jk
 
edit- oh shi......... http://www.audiokarma.org/forums/showthread.php?t=144415

UPDATE!

Some good and bad news folks! First up is the excellent news: recap is complete! Phono, tone, power supply, and power boards completely recapped. I ran into a few snags along the way- there was one instance where the (pad, I take it) was ruined by the old solder or gunk or whatever was there, it just dissolved when taking the solder off with the wick. Fortunately, the trace was easy to connect to and all things good, still was pretty scary at first. Another funny bit was that I found a ground wire on the tone board had somehow disconnected itself- the exposed wire at the end, where it was soldered to the chassis, was gone and it was just floating there. I am not sure if I yanked it while flipping the tone board over those few times, but in any case a little bit of solder fixed that right up. Last real issue were the big filter caps with the bent pins- damn are they annoying, took a lot of effort and force to get those off.

Ok, now the bad... I was just setting the bias after everything was finished and my gator wires for the multimeter touched the heatsink on the power amp board which caused a big spark and blew the fuse.

So I have to wait for the morning to get a replacement and finish the adjustment.

Fortunately, until that point, everything sounded great and worked great as I did periodic tests after each board was completed.

Anyway, I'll return tomorrow with hopefully good news about the completion of the recap process. Goodnight!
 
mantis,
I feel your pain,

I think the OEM's were matched , If they are 2sd313/2sb507's and you can't match up two pair's and don't mind NTE .............
>>>>>>>>> NTE 153MCP <<<<<<<<<
Do you have a dim bulb tester or a variac ?

Check the emiter resistor's also ( I replace them with new transistors)

Good luck


Barney
 
I like On-Semi for output transistors. I don't have the service manual on this one, what are the original part numbers?

Tom
 
service manual says H711/H712 are 2SD313D or E
and H713/H714 are 2SB507D or E

I will try to take out the old ones. The only testing equip I have are a couple of multimeters, one is pretty good as I recall.
 
MCM shows them both in stock ones $.58 and the other $.82 .

(2SD313 and 2SB507)


Barney
 
What type of test equipment do you have ?

You would have to buy more then needed for the repair first then match the transistor gain of the pairs .

But I have just put in fresh ones before with out matching them and was OK. Just to get the best performance out of the repair matching them up is the way to go. (IMHO)


MCM will have a min. order of $25.00 so get some DeoxiT too or what ever .....


Barney
 
Oerets said:
What type of test equipment do you have ?

You would have to buy more then needed for the repair first then match the transistor gain of the pairs .

But I have just put in fresh ones before with out matching them and was OK. Just to get the best performance out of the repair matching them up is the way to go. (IMHO)


MCM will have a min. order of $25.00 so get some DeoxiT too or what ever .....
Barney
Click to expand...

Some DMMs have a transistor test function that will measure beta for matching. I don't have much faith in MCM's semiconductors anymore since I got some counterfeit 2SD424's there, and some suspicious looking 2SD235's.
I do buy some other stuff there, like DeoxIT.

As far as Japanese semiconductors, I've had good service at Consolidated.

http://www.ceitron.com/

Tom
 
Good to know about MCM ,although I've never had a problem yet from them.
I use my Sencore to match transistors , my DMM and VOM are to Vintage (old) ,unable to check beta with them .



Barney
 
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