Treble loss with a Boss Ph-1 Phaser

[Rand]

Thanks Rob - after a few days of reading up on your links and testing I'm satisfied q5 and q6 are working ok. So perhaps there are no other solutions? Maybe the thing just is a tone sucking machine, in bypass or with effect on?

Am I right that there probably aren't any other things left?

Thanks for all your help

[Rob Strand]

One very worthwhile test  is,  *with the two JFETs out of circuit*,  to check the level at the following four points:
- pin 7 IC2  (output going to R20)
- pin 3 IC2  (other side of R20 and input to last opamp)
- pin 1 IC2  (output of last opamp)
- Final output on PCB "PCB terminal 15" where V9 and R23.

If everything is working I can't see how this pedal can tone suck.  Each one of those four point should be at the same level.
If you all look good except the last point then you can check at "in between" point between R22 and C9.

it shouldn't make any difference but you can check all those points in both effect and bypass mode.  Normally it shouldn't make a difference but it's worth checking just the same.

So *if* all those points check out that means the circuit is basically *not* inherently tone sucking.