I am restoring a Japanese Teisco mixing amplifier from the 1970s. It's a solid state 5-channel mixer with 16ohm speaker outs and a line out.
Amongst other problems, I have discovered a couple of the bridge rectifier diodes have shorted out.
Here is a photo of the diode bridge:
Now i am trying to find a suitable replacement for these diodes as they have no markings.
I cannot find any circuit diagrams or info on the unit at all.
The diodes and the PCB both have no markings.
If we can't identify this component ~ Is there a common equivalent used for typical solid state amps from this time? Surely.
The filter capacitor is 2200uf 63V.
Would a 1N4007 do the job?
Thank you in advance, Looking forward to a reply.
Best Answer
1A is a bit wimpy for an audio amplifier; 1A into 8 ohms is only 8W. I would concur with Mattman that these were probably 3A (1N5403 rings a bell, or 5405 for higher voltage) in that case shape.
A Google image search for "3A diode" shows several in this case shape (merely illustrating my confirmation bias; "1A diode" shows some too, but fewer I think)
After eliminating avalanche diodes and other fluff, these show several possible 3A rectifier diodes :
BYW 95A Rectifier diode, SOD64, 200 V, 3 A
BY228 Fast Diode 3A 1000V
SF5408 SOD64 3W1000V 75NS Ultra-high Speed Fast Recovery Diode
(image from BYW95A link above)
Fast recovery is not needed here but now we have the package style SOD64 allowing us to search a supplier for SOD64, in this case giving 27 results; mostly 3A rectifiers.
So you can even keep the original look if you are so inclined.