Small Clone chorus debug

Started by reverend, June 21, 2009, 01:38:02 PM

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reverend

I need help debugging with Small Clone chorus. I made this with Tonepad's schem and pcb. http://www.tonepad.com/project.asp?id=8
I haven't changed any components. I used true bypass with 3PDT. When the effect is off the sound comes thru but when it is turned on it is dead silent.

Q1 2N5087:
E = 4.9
B = 4.3
C = 0

Q2 2N5088:
E = 4.8
B = 5.3
C = 8.8

Q3 2N5088:
E = 8.2
B = 8.8
C = 8.8

4558:
1 = 4.4
2 = 4.4
3 = 4.35
4 = 0
5 = 4.35
6 = 4.3
7 = 4.4
8 = 8.6

LM358:
1 = 1.4-2.1 (changes between)
2 = 3.95
3 = 3.9
4 = 0
5 = 1.7-2.6 (changes between)
6 = 2.1
7 = 1.6-6.1 (changes between)
8 = 8.6

MN3007:
1 = 8.0
2 = 3.9
3 = 5.5
4 = 0
5 = 0
6 = 3.9
7 = 5.4
8 = 5.4

CD4047:
1 = 7.8
2 = 0.1
3 = 7.0
4 = 8.0
5 = 8.0
6 = 8.0
7 = 0
8 = 0
9 = 0
10 = 3.9
11 = 3.9
12 = 0
13 = 7.8
14 = 8.0

D1
A = 5.5
K = 4.9

D2
A = 0.1
K = 7.2

reverend

Ok, I'm asking the help again.
Really don't know where the problem is. All the caps seems to be right and also diods and transistors. I still get no sound, just the bypass works.

gena_p1

it seems you have problems with wiring, mbe u mess up input and output jacks,or power polarity (it seems OK).

if all ok, on effect mode it working as on bypass (and begin chorusing after trim pot adjusting).
Double check 3dpt, or remove it. Else you can check by replacing input-output opamp (4558).




this is my tonepad small clone at debugging stage
(recently i replaced all cheap caps with film ones, because ceramics have no high freq. at all!).

doitle

Is the small clone the same as this pedal?

http://www.buildyourownclone.com/chorus.html

If so I've got one that I can't get working either. Checked placement of all parts, checked all wiring. Spot on. Reflowed all joints. No dice. My uncle gave it to me to fix after his brother in law built it for him and it didn't work. I haven't had a chance to get it in the labs on the scopes and I don't have an audio probe built yet. That hardly seems like a good excuse but if that is the same pedal maybe I can show my voltages too and get some more data in here.

gena_p1

doitle - it seems small clone, but on theirs own pcb.
small clone is simple enough (especially if you have oscilloscope  ;) ), it bypass clean tone through 4558, all you need - carefully adjust trim pot with little screw driver to add chorus .

http://www.axecentral.com/small-clone-repair-notes-9312610.html - here more info about small clone, than you need


P.S. imho  John Hollis's Zombie Chorus sounds better, than Small Clone, but after some declick solutions and minor changes.