MRX phase 45 distorting

[Dirk_Hendrik]

help needed ....

I have a phase45 on my bench for repair with the complaint of doing nothing. Tracing the signal showed signal was absent from the output of the first opamp stage. After replacement of the opamp phase signal was present at all phaser stages output again as well as on the output. The problem I ran into when testing the thing with a guitar is that the output signal, especially with lower frequency notes tends to distort pretty much. Checked battery but that's fresh. Scoping shows the distorted signal comes when the signal on the phase stages is at low level. Clean level remains undistorted. Anyone with a straight "check this" idea?

Other than that, the modulation wave is currently like a 2 level sawtooth. Fast up, logaritmically going down to 0, fast down and logarithmically going up to 0 level. Is that the waveform as it's supposed to be?

[toneless]

I think you have to match the transistors for this circuit to work properly.
Another guess is that somewhere after the opamp you have a short. Does this phaser has a feedback resistor?

[petemoore]

 Could be the first opamp isn't biased or something else

[Dirk_Hendrik]

Solved,

with quite a few experiments te only conclusion left was that the replacement opamp (a new one) was defective which turned out to be tha case. Thanks for the suggestions nevertheless.