Help with a ts 808

[whomeno]

 I built a ts808 from tonepad. pcb from tonepad , parts from small bear. no mods all stock. bypass works good. when I turn pedal on volume drops alot( like going from 10 to 5). do have some clipping which sounds good. but no volume would have to turn volume up every time I turn on pedal.

Readings are
Q1
E-2.49
B -2.79
C -9.27
Q2
E -3.22
B -2.79
C -9.23

IC
p1  4.54
p2  4.7
p3  4.4
p4  0 Gr
p5 4.5
p6 4.5
p7  4.5
p8  9.1

Diode 1
k  4.7
A  4.5

diode 2
K  4.5
A 4.7

Diode 3
jumpered

I checked the pots for the right place
checked for bridging
checked for cold solder joints.

If I can get more volume I would be happy
Thanks

[Kipper4]

Welcome to the forum mate.

I think Q2 could be an issue. (this is not certain since you may have the wrong readings on B and E)
I'd expect the transistor emitter to be a diode drop (0v7) less in volts to the base.
more like your Q1 is.

Have a look around there for a bad solder joint maybe.

PS i think you misread the IC pinout too.
pin 8 should be +9 volts
not pin 5

[Kipper4]

IC pinout for dual op amps

https://arduino-info.wikispaces.com/file/view/lm293-n-pinout.jpg/328510794/lm293-n-pinout.jpg

[whomeno]

OK I went back over solder joints and these are my readings now. using 9 volt batterry

q1
e    2.98
b    2.66
c    8.82

q2
e  3.04
b  2.67
c  8.80

io
1  4.38
2  4.56
3  4.30
4  0
5  4.37
6  4.38
7  4.37
8  8.79

d1

k  4.37
a  4.55
d2
k  4.55
a  4.37
d3 jumper

[bloxstompboxes]

Pictures sometimes reveal all.

[antonis]

q1
e    2.98
b    2.66

q2
e  3.04
b  2.67

If your readings are correct you've back-biased transistors.. 

In case of mismatching E & B, Q2 seems to be OK but Q1 doesn't..
(unless Q1 is of Ge type..  )

Considering +4.5V OK, check for 510k base bias resistor correct value..

[duck_arse]

what sort of transistors are they? howw are they connected? izz there a circuit dia?

and +1 photos, please.

[Kipper4]

schematic pdf

https://www.hobbielektronika.hu/forum/getfile.php?id=247049

[Laguna]

i THINK the schematic has a "bug".
If you check the real schematic, it has a 2M2 res to ground from input.

Check my blue arrow:


I'm building this same project this weekend, so i'll tell you how it goes

[bloxstompboxes]

i THINK the schematic has a "bug".
If you check the real schematic, it has a 2M2 res to ground from input.

Check my blue arrow:


I'm building this same project this weekend, so i'll tell you how it goes

Not a bug, it's a pulldown resistor to avoid pops when using true bypass switching. The schematic and layout are good. It was my first pedal build, actually.

[Laguna]

Well, i built it and there's a farting noise and nothing else...
I spent a couple of hours trying to debug it and nothing.

I don't have a PCB, i wired everything by hand. I double checked and triple checked but probably still made a mistake. Would you recommend buying a printed PCB? any one in particular?

Thanks guys