Distortion

[Latteman]

I have quite a few used Nva amp boards I’ve collected over time for spares repair and general experience/ experimentation.
I’ve successfully restored a pair with no blue smoke when connected to the psu- when connecting music I have a distortion in one channel only- there is music but with distortion.
The amp tests well on all points via a multi meter except one of the resistors that measures 0.8 instead of 0.6ohmn.
What I’m asking is -what could be the cause of distortion- faulty resistors/ transistors tp142/147 or…….?
Cheers for any advice
Just to confirm these were faulty boards to begin with

[Geoff.R.G]

I have quite a few used Nva amp boards I’ve collected over time for spares repair and general experience/ experimentation.
I’ve successfully restored a pair with no blue smoke when connected to the psu- when connecting music I have a distortion in one channel only- there is music but with distortion.
The amp tests well on all points via a multi meter except one of the resistors that measures 0.8 instead of 0.6ohmn.
What I’m asking is -what could be the cause of distortion- faulty resistors/ transistors tp142/147 or…….?
Cheers for any advice
Just to confirm these were faulty boards to begin with

Difficult to say without a circuit diagram but, if the incorrect resistance is causing a transistor to run on a non-linear part of the curve then, yes it could be the cause.

[Latteman]

Bit of progress made- changed the 7w cement resistors and renewed a lot of the general solder joins.
Had sweet music for a few mins then the distortion returned
I am waiting on a delivery of a pair of Tip - after that I wil have exhausted my basic repair knowledge