This little Xtant is in line to get its vaccination.
Received this amp with blown IRFZ44 power fets x4. There is no pre-driver circuit in this amp after the SG3525 so I replaced the 44s with new, and lowered the original gate resistors which were smoked looking 47ohms down to 22 ohms.
Amp powers up now and plays fine on the LEFT channel, but the RIGHT channel I get no audio. Rail +- looks good as does regulated voltage to all of the opamps. I pulled some kinda crossover module out and just used standard jumpers in its place which is a thing with Xtant. Looked like a high-pass module?
Anyway, I traced an audio signal from right RCAs through the opamps and across the jumpers, but I'm a bit lost after that. Theres a full monty of TO92s on this amp, and SMD stuff to boot.
A schematic would be helpful if anyone has one. Anybody happen to have one or anything come to mind?
Received this amp with blown IRFZ44 power fets x4. There is no pre-driver circuit in this amp after the SG3525 so I replaced the 44s with new, and lowered the original gate resistors which were smoked looking 47ohms down to 22 ohms.
Amp powers up now and plays fine on the LEFT channel, but the RIGHT channel I get no audio. Rail +- looks good as does regulated voltage to all of the opamps. I pulled some kinda crossover module out and just used standard jumpers in its place which is a thing with Xtant. Looked like a high-pass module?
Anyway, I traced an audio signal from right RCAs through the opamps and across the jumpers, but I'm a bit lost after that. Theres a full monty of TO92s on this amp, and SMD stuff to boot.
A schematic would be helpful if anyone has one. Anybody happen to have one or anything come to mind?
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1 J108 per channel. Only left channel leg1 has audio.
Left: Q35 has audio on leg 1
1: 14.70
2: 0
3: 0
Right: Q36 NO audio on leg 1
1: 14.70
2: 0
3: 0
Left: Q35 has audio on leg 1
1: 14.70
2: 0
3: 0
Right: Q36 NO audio on leg 1
1: 14.70
2: 0
3: 0
My bad. Made a mistake in writing that one out since I was looking at it upside down.
Left: Q35 has audio on leg 1
1: 0
2: 0
3: -14.70
Right: Q36 NO audio on leg 1
1: 0
2: 0
3: -14.70
Left: Q35 has audio on leg 1
1: 0
2: 0
3: -14.70
Right: Q36 NO audio on leg 1
1: 0
2: 0
3: -14.70
I looked through the pre-amp section again of this amp, and what I'm finding is there is little to no right channel audio on anything much past the U4 OpAmp. While the left channel has audio on the caps near the gain, the right channel does not. Also there is no right audio on the horizontal nor vertical module slots.
I had a hunch that U4 opamp may have had an issue and so I swapped it with a spare TL072. That helped nothingl.
I had a hunch that U4 opamp may have had an issue and so I swapped it with a spare TL072. That helped nothingl.
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Did you try removing then reinstalling the jumpers to see if that changed anything?
Are the gain pots set the same?
With no audio on pin 1 of the J108 transistor, the FET could be defective, but remember, it doesn't read like a standard transistor. Compare readings for each of the two J108s.
Are the gain pots set the same?
With no audio on pin 1 of the J108 transistor, the FET could be defective, but remember, it doesn't read like a standard transistor. Compare readings for each of the two J108s.