Hi guys, I bought an english sustain overdrive pedal from the buy/sell on here and populated everything....i don't get bypass and in effects mode get low volume output...i subbed a 2n3904 for the bc549c it calls for, would this be my volume problem? And does anyone know why i'm not getting bypass? Also, the led isn't working.
Quote from: danwelsh on April 08, 2013, 11:14:04 PMi subbed a 2n3904 for the bc549c it calls for, would this be my volume problem?
It depends. Post a schematic and I'll take a look. It is possible that in certain designs you'd have misbiased it without sufficient gain, but those would be rare.
here's the schematic
(http://memberfiles.freewebs.com/81/25/104952581/photos/undefined/ENGLISHSUSTAIN-(1)-3-1.gif)
It's a Cornish P2 clone. I think the transistor is basically just a buffer, so the gain shouldn't make a huge difference.
Aren't the BC549 and 2n3904 different pinouts? Try flipping it around.
Okay, ill try that.
So you got no bypass? How is it wired?
It's buffered bypass like all of the Pete Cornish stuff. The buffer tranny might be reversed - would explain the lack of sound in bypass mode and weak signal when engaged.
okay, i reversed the tranny, and it's louder now but i still have no bypass, or led.
I have it wired up like this except i'm using a DPDT switch:
(http://memberfiles.freewebs.com/81/25/104952581/photos/undefined/ENGLISHSUSTAIN%20(1)-2%20copy.jpg)
Since its louder, do the controls do anything? How loud compared to the unity/original signal? How do you know it is bypassed vs. engaged if the LED isn't working?
Might be time to post pics/voltages and break out the audio probe.
I know it's in effect mode because the volume and tone pots work, and my amp is on clean setting....i'll do the audio probe and post voltages tomorrow(bed time, gotta get up at 5 for work), thanks so much guys for helping me with this, i just know with your people's help i'll get bypass goin :)