pedal w/ a volume drop issue

[space6oy]

i recently bought an old ibanez flanger and signal does pass through it but at like a 90% volume drop. isn't an issue w/ the cables or power, nothing else chained, does it when active or bypassed, have a bunch of others from the same series that don't do this. at all. anyone have any suggestions on something i might try? maybe a pot inside to adjust? idk.

[jrfox92]

Which one is it?
Assuming it has in/out buffers, something could be wrong with them.

[space6oy]

[jrfox92]

Looks like it has three trims: clock, bias, and regen.
I'm pretty sure VR2 is the bias control.
It's possible adjusting that could fix it, but, like I said, it's more likely an issue around the op amps (which would require some testing to figure out that, I assume, you're not set up for).

[comesect2.0]

goddamn thats so hot, I dont want to do it, but I just may have to if no one else will....wait, fuck it...im gonna do it.

[Chankgeez]

Yeah, I don't think messin' with the trimmers'd help either.

Problem could possibly be something with the switch or a bad component and/or connection somewhere in the signal path.

[crochambeau]

Apologies on my tech/DIY style response..

Since it does it when both active and bypassed I would focus on sniffing out circuitry between the input and output jack. I'm not looking at an SF10 schematic, but this may include opamps in the signal path (adjusting gain on one may resolve the issue if so). As it switches between effect and bypass I would ignore the FET switching for start, but come back to it if the always on stuff doesn't offer a solution..

If you have access to a scope it could be ripped out pretty quick.

[space6oy]

i don't.
the weird part (to me) is how signal still does pass through, it's just damn near inaudible.
you can hear it, but it's soooo quiet...

[jrfox92]

i don't.
the weird part (to me) is how signal still does pass through, it's just damn near inaudible.
you can hear it, but it's soooo quiet...

Yeah, that could be because the circuitry around the opamps shorted, or the opamps failed but didn't totally short or open.
It's too bad I'm over 3 hours away from you, because it's something that should probably only take an hour to diagnose with the right equipment.

[crochambeau]

If it's anything like the PH10 schematic I found, IC1 does both input and output buffering. Since there is a resistive path through the negative feedback gain setting resistors, that part failing will not impede operation (0 ohm at input, feeding phase circuitry and output, and 12K gain recovery at output - explaining why the effect is still there, but also at diminished volume). I'd swap that IC out and see what happens if you want to go caveman on it.