Vintage Pioneer Audio

[dennyd]

Have a vintage Pioneer SA-9800 amp that has a defective transistor 2SC2526 in the Output stage, naturally. can't find a replacement. There are two pnp 2SC2526 in parallel and only one is bad. can a 2SC3264 can been used as a suitable replacement, and must I replace both...

[Chuck[_11_]]

On Thu, 2 Jun 2011 16:04:52 +0000, dennyd
> wrote:

>
>Have a vintage Pioneer SA-9800 amp that has a defective transistor
>2SC2526 in the Output stage, naturally. can't find a replacement. There
>are two pnp 2SC2526 in parallel and only one is bad. can a 2SC3264 can
>been used as a suitable replacement, and must I replace both...


I would use a NTE 92 (the 2sc2526 is a npn transistor) and I would
set the bias to factory spec. after installing it. Chuck

[Trevor]

"Chuck" > wrote in message
...
> On Thu, 2 Jun 2011 16:04:52 +0000, dennyd
> > wrote:
>
>>
>>Have a vintage Pioneer SA-9800 amp that has a defective transistor
>>2SC2526 in the Output stage, naturally. can't find a replacement. There
>>are two pnp 2SC2526 in parallel and only one is bad. can a 2SC3264 can
>>been used as a suitable replacement, and must I replace both...
>
>
> I would use a NTE 92 (the 2sc2526 is a npn transistor) and I would
> set the bias to factory spec. after installing it. Chuck


Without looking up the number myself, I'd add that if the two are in
parallel then absolutely I'd replace both.

Trevor.

[Arny Krueger]

"Trevor" > wrote in message
...
>
> "Chuck" > wrote in message
> ...
>> On Thu, 2 Jun 2011 16:04:52 +0000, dennyd
>> > wrote:
>>
>>>
>>>Have a vintage Pioneer SA-9800 amp that has a defective transistor
>>>2SC2526 in the Output stage, naturally. can't find a replacement. There
>>>are two pnp 2SC2526 in parallel and only one is bad. can a 2SC3264 can
>>>been used as a suitable replacement, and must I replace both...
>>
>>
>> I would use a NTE 92 (the 2sc2526 is a npn transistor) and I would
>> set the bias to factory spec. after installing it. Chuck

> Without looking up the number myself, I'd add that if the two are in
> parallel then absolutely I'd replace both.

Agreed.

When I find a blown output transistor, replacing the devices that are in
parallel with it is a knee-jerk and replacing every active part that is in
series with it or drives it or is driven by it can make sense.

Overstressed silicon can lose beta, but appear to still be working.

[Mark Zacharias[_3_]]

"Arny Krueger" > wrote in message
...
>
> "Trevor" > wrote in message
> ...
>>
>> "Chuck" > wrote in message
>> ...
>>> On Thu, 2 Jun 2011 16:04:52 +0000, dennyd
>>> > wrote:
>>>
>>>>
>>>>Have a vintage Pioneer SA-9800 amp that has a defective transistor
>>>>2SC2526 in the Output stage, naturally. can't find a replacement. There
>>>>are two pnp 2SC2526 in parallel and only one is bad. can a 2SC3264 can
>>>>been used as a suitable replacement, and must I replace both...
>>>
>>>
>>> I would use a NTE 92 (the 2sc2526 is a npn transistor) and I would
>>> set the bias to factory spec. after installing it. Chuck
>
>> Without looking up the number myself, I'd add that if the two are in
>> parallel then absolutely I'd replace both.
>
> Agreed.
>
> When I find a blown output transistor, replacing the devices that are in
> parallel with it is a knee-jerk and replacing every active part that is in
> series with it or drives it or is driven by it can make sense.
>
> Overstressed silicon can lose beta, but appear to still be working.
>

I' d replace all four output transistors, the NPN and PNP. There are modern
replacements, in a TB34 package, the 2SA1494 and 2SC3858. Watch out for
counterfeits, though. In the US I get them from B&D Enterprises, a Sanken
distributor. They are about 5.00 each. B&D can supply them with the needed
larger mica insulators, just ask.

1-800-458-6053

If one output was bad there may be other bad parts - a bad resistor or
driver transistor for example.

30 plus years experience talking here...

Mark Z.