SV04F / SV04-F Bias Diode For Sony

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sansuilove

Active Member

• Jun 28, 2014

• #1

Hello to you all , A friend has an old Sony STR 2800L that is not working and
asked me to look inside.. As a good friend I did and I saw that the diode D701 (SV04F) that is located on one of the transistors that mounts to the heat sink is disconnected (the wire is cut from the body close to the body) .
Unfortunately , no wire left even no 1mm to solder back the wire.
I am trying to find a replacement.
Can 3 1N4148 in series do the job ? how to locate them eventually on the transistor / heat sink ? Thank you sincerely .
Jean .

 

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Hyperion

Roobarb & Custard

Subscriber

• Jun 28, 2014

• #2

This thread might help http://www.audiokarma.org/forums/showthread.php?t=279530

Or just do an AK Advanced Search using the keyword "SV04" (no quotes) yields some results for you to research.

 

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Baron K Rool

Well-Known Member

• Jun 28, 2014

• #3

Try filing down the plastic or cutting some off with a knife, to get something to solder to. Then glue the wire to the plastic so that it cannot get pulled off. This part is a major pain since you cannot get it anymore. It's worth some effort to fix it.

 

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sansuilove

Active Member

• Jun 28, 2014

• #4

Thanks John , Baron .
John , I can't seem to find an ABSOLUTE answer about SV04F. I found out the EchoWars
suggested using 3X 1N3595 for SV04. Not F. Does it matter?

 

Hyperion

Roobarb & Custard

Subscriber

• Jun 28, 2014

• #5

"Does it Matter"? No I don't think so, to be honest I don't know what the 'F' stands for.

The spec' of the SV04 is Vf=3.0V @ If=70mA, Ir=10µA Max @100V Max, If=100mA Max.

Which looks like any small signal silicon diode - except for the forward voltage drop.

Providing you can satisfy the fwd voltage drop requirement and the max current & max voltage ratings are ok, you are good to go. The only other issue is 'mounting' - these 3 diodes should all be in close thermal contact and able to be mounted in the same style as the originals.

 

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sansuilove

Active Member

• Jun 28, 2014

• #6

John again thanks , I will try to be creative and mount them
Using JB weld and for sake of future readers .

 

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sansuilove

Active Member

• Jul 10, 2014

• #7

Maybe my english is not so much good , but I can't understand what they mean with :

"For replacement use semiconductors except it ( ) "

What do they components in ( ) represent and for example for Q706,Q756 - why there are 2 part numbers : 2sa684 (2sa777)

:scratch2:

 

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Binkman

Lunatic Member

• Jul 10, 2014

• #8

(not often you see a lug like that in an amp.)