Tube screamer build not making any sound...

Started by adam_f, September 08, 2007, 04:23:27 PM

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adam_f

Hi guys, could you help me debug my tubescreamer? I've build one already, but this time it's not working... I've been testing plugged into a power supply, and the IC is a JRC4558 from small bear. I've been looking for solder bridges and mistakes etc for ages, but I can't see anything.

1. Bypass is fine, but when engaged there's no output

2. TS 9 from Torchy's layout

3. http://www.indyguitarist.com/torchy/Distortion_Overdrive/Tubescreamer/

4. No modifications

5. Substituted the 51pF cap for a 47pf one.

IC1
1: 4.46
2: 4.55
3: 4.43
4: 0
5: 4.45
6: 4.42
7: 4.51
8: 9.02

Q1
C: 9.02
B: 1.83
E: 1.25

Q2
C: 9.02
B: 1.83
E: 1.25

D1
A: 0
K: 9.02

D2
A: 4.64
K: 4.44

D3
A: 4.58
K: 4.63

D4
A: 4.44
K: 4.58

Thanks a lot in advance,

Adam


adam_f

anyone got any ideas? I've noticed that the volume, gain and tone controls do have a slight affect on the background noise when it's engaged (ie it get's slightly noiser/louder etc). Also, I've compared transistor, diode and IC voltages with my working ts808 and it is almost exactly the same, so something's gotta be working right?

yeeshkul

That's the same problem i had - mind the pinout of your transistors. If you have Japanese trannies the pinout is ECB (facing the flat side, pins downwards). I had the completely same voltages - it must be the pinout.

ulysses

got your in wire and out wire round the right way?

cheers
ulysses