Does anyone know the gate resistor value for the power supply fets ?
Got this amp in and they are missing along with the fets I know PPI uses z44n’s as the fets
Got this amp in and they are missing along with the fets I know PPI uses z44n’s as the fets
They used 47 ohm resistors in most of that series amps. Most had either a Z44 or 50N06 FET so they may have used resistors slightly lower than you might normally use.
Later amps used 22 ohm gate resistors, even with the 50N06.
Later amps used 22 ohm gate resistors, even with the 50N06.
Do you happen to have a pic of the power supply area ?
It’s missing 2 caps C135 and C4
C4 sits behind the power led and C135 Sits behind the bass control
It’s missing 2 caps C135 and C4
C4 sits behind the power led and C135 Sits behind the bass control
They appear to be performing the same function. Confirm by comparing the RC network for the two capacitors. I can't read 135 but C4 is marked 2A103j. 100v, 0.01uf, 5% tolerance.
1 last question 1 of the outputs failed MJL21193 I’m
Gonna replace them both on 1 side of the amp the other complimentary parts test good MJL21194.
Should these also be replaced I’ve hear different things some say yes replace them since they are in the same channel that failed and other say they should be fine .
Wondering what are your thoughts on this ?
Also the source resistors for this are 0.68 ohm correct ?
Gonna replace them both on 1 side of the amp the other complimentary parts test good MJL21194.
Should these also be replaced I’ve hear different things some say yes replace them since they are in the same channel that failed and other say they should be fine .
Wondering what are your thoughts on this ?
Also the source resistors for this are 0.68 ohm correct ?
Last edited:
I feel that it's better to replace all of the outputs in the blown channel since they were all presented with the same stress that killed the ones that failed. Even if there was a random failure, the other polarity that survived were stressed by the shorted ones.
Right on the emitter (not source, these are bipolar transistors) resistor values.
Right on the emitter (not source, these are bipolar transistors) resistor values.