Tonepad CE-2 strange problem

Started by DarkKnight_so, May 28, 2013, 10:30:14 AM

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DarkKnight_so

Greetings I've been building the CE-2 from tonepad and Its not working properly. When i turn it on I can hear the guitar but not with chorus so no modulation just the clean signal. By my understanding it means that the signal is passing through but not being modulated. I've used everything as on the parts list except the RD11EB, I'm using the 1n4001.
Now the strange problem begins here. When i put my finger underneth Q4 and D1 around there I can start hearing the modulated signal and the chorus effect. Now that means to me that the IC's are okay (correct me if im wrong). As soon as i lift my finger up it goes back to clean. I tried replacing the trimmer, tuning it its the same the sound changes a little but still clean.
I just need a little help debugging it and i would aprichiete it if you people could help me :)

Thank you very much for your help in advance :)

The schematic and layout:
http://www.tonepad.com/getFile.asp?id=101

P.s. I can take pictures of my board or mesure the nessesery values i have a multimeter but dont have an audio probe sadly :(

duck_arse

check your values/parts/soldering around R36 and R37, and C22 as a start ....
You hold the small basket while I strain the gnat.

DarkKnight_so

The values of the resistors are both correct and the capacitor too. I've resoldered that whole bit but no change. I messured some voltages now and this is how it looks.

Q4:
C: 9.52V
B: 4.54V
E: 4.85V

GGBB

Use a jumper wire to make each of the connections between components around that area.  Maybe you have a hairline break in a trace.
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DarkKnight_so

Quote from: GGBB on May 28, 2013, 02:05:25 PM
Use a jumper wire to make each of the connections between components around that area.  Maybe you have a hairline break in a trace.
Will try that right now :) I pinpointed the place where my finger makes it work its on the spot where D1 D2 and R38 meet.
To me its very strange that it only works when i touch that spot?!

bukas


Mark Hammer

Forum member, and co-worker, alparent finished up a Tonepad CE-2 board I had stuffed most of and lost interest in.  After completing it, it didn't work.  At first I felt bad about possibly gifting him with a mostly stuffed board that was going to be an endless source of troubleshooting.  But it turned out the MN3007s he had bought on ebay were no good.  I brought in my Zombie chorus so he could try the MN3007 he had bought in a known functioning circuit, and try out my MN3007 in the CE-2 board.  My 3007 worked in both boards, his in neither.

The moral?  Possible you may have an error of some kind on your build, but also possible you may have bought a bad 3007 from somewhere.  Was your source a reputable one?

DarkKnight_so

#7
Quote from: Mark Hammer on May 28, 2013, 02:46:27 PM
Forum member, and co-worker, alparent finished up a Tonepad CE-2 board I had stuffed most of and lost interest in.  After completing it, it didn't work.  At first I felt bad about possibly gifting him with a mostly stuffed board that was going to be an endless source of troubleshooting.  But it turned out the MN3007s he had bought on ebay were no good.  I brought in my Zombie chorus so he could try the MN3007 he had bought in a known functioning circuit, and try out my MN3007 in the CE-2 board.  My 3007 worked in both boards, his in neither.

The moral?  Possible you may have an error of some kind on your build, but also possible you may have bought a bad 3007 from somewhere.  Was your source a reputable one?
It was from ebay first time buying. True it could be but remember mine WORKS only when i touch the bottom of the board with my finger on a certain place. I get a chorus effect straight away. If the ICs where bad wouldnt it work at all?
I think this bit is the problem where D1 D2 R38 meet when i touch there the chorus starts right away. I took one of the resistors leftover pins and just soldered between D2 and R38 nothing changes but when i touch it it comes right on. I dont understand that?

EDIT: i bought them on ebay from a 99.9% user china ofc. I was messuring the voltages compared to someones and they seem to be okay almost identical.
EDIT2: Big update discovered just now that i have 3V on D2 is that normal is looks to me a bit much?

guitar413

#8
Quote from: DarkKnight_so on May 28, 2013, 10:30:14 AM
Greetings I've been building the CE-2 from tonepad and Its not working properly. When i turn it on I can hear the guitar but not with chorus so no modulation just the clean signal. By my understanding it means that the signal is passing through but not being modulated. I've used everything as on the parts list except the RD11EB, I'm using the 1n4001.
Now the strange problem begins here. When i put my finger underneth Q4 and D1 around there I can start hearing the modulated signal and the chorus effect. Now that means to me that the IC's are okay (correct me if im wrong). As soon as i lift my finger up it goes back to clean. I tried replacing the trimmer, tuning it its the same the sound changes a little but still clean.
I just need a little help debugging it and i would aprichiete it if you people could help me :)

Thank you very much for your help in advance :)

The schematic and layout:
http://www.tonepad.com/getFile.asp?id=1

P.s. I can take pictures of my board or mesure the nessesery values i have a multimeter but dont have an audio probe sadly :(


I have the same problem. didn't try the finger touch thing, but the exact same thing...no effect. I ordered a new mn3007 and took the old one out, I'm waiting for the new one....did you ever solve this?