| Author |
 Topic  |
|
|
Boss_8
Copper Member
USA
44 Posts |
 Posted - 02/14/2010 : 03:10:22
|
Hello,
I have a stomp box that someone gave me that doesn't work, I don't know if it ever did work. Can anyone give a novice some trouble shooting help. I started a thread earlier and someone was kind enough to give some advise but I might need a little more detail. C22 has some flying leads that were meant for an alternate cap value on a switch. The solder joint with the black circle around it was there when I got it. I also noticed that the one op amp is not the specified one. Attached are some pics. I would appreciate any help.
Regards,
Doug
|
Edited by - Boss_8 on 02/14/2010 03:15:12 |
|
|
ranjam
Bronze Member
Canada
82 Posts |
Posted - 02/14/2010 : 04:47:35
|
Ooooh, I thought you had a CS-3, not a CE-2! This may be easier. The basics are check for signal at the base of Q1, the emitter of Q1, pin #6 of IC1, pin #7 of IC1, pin #2 of IC1, and pin #1 of IC1. In that order. That's the straight signal. The delay line should be something like the base of Q2, the emitter of Q2, pin #3 of IC3, pin # 7 and #8 of IC3, the base of Q3, the emitter of Q3, the source of Q9, the drain of Q9, pin #2 of IC1, and pin #1 of IC1. In that order. Something like that. Use a CE-2 schematic, and follow it as best as you can with your signal tracer. It'll come to you. Check voltages, check that the right transistors are put in with the proper orientation. It'll be something silly. |
 |
|
|
Boss_8
Copper Member
USA
44 Posts |
Posted - 02/14/2010 : 05:48:30
|
quote:
Originally posted by ranjam
Ooooh, I thought you had a CS-3, not a CE-2! This may be easier. The basics are check for signal at the base of Q1, the emitter of Q1, pin #6 of IC1, pin #7 of IC1, pin #2 of IC1, and pin #1 of IC1. In that order. That's the straight signal. The delay line should be something like the base of Q2, the emitter of Q2, pin #3 of IC3, pin # 7 and #8 of IC3, the base of Q3, the emitter of Q3, the source of Q9, the drain of Q9, pin #2 of IC1, and pin #1 of IC1. In that order. Something like that. Use a CE-2 schematic, and follow it as best as you can with your signal tracer. It'll come to you. Check voltages, check that the right transistors are put in with the proper orientation. It'll be something silly.
Is it ok to use a signal probe like one I saw posted on this forum? Did you see the one made out of a ball point pen case, a pop rivet, and a small capacitor? I think they put a 1/4" jack on one end and plugged it into the amp. You also said to check for voltages, where should I do that and what voltages should they be. BTW, what about the bias pot? What should that be adjusted to? Forgive me for asking silly questions but I'm not a electronic tech just yet. Thanks for your willingness to help!!! |
Edited by - Boss_8 on 02/14/2010 05:50:43 |
|
|
|
Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 02/14/2010 : 07:09:13
|
Hi Boss_8
You can find all the PDF's, schematics & instructions for that CE-2 clone ,
over on the TonePad site:
http://www.tonepad.com/project.asp?id=53
I'm not too sure about the NTE1641 chip that seems to be in the socket
in place of the MN3007.
Is it a direct replacement?
If it's not a direct replacement - you will be fighting an uphill battle to get it going.
Did this circuit ever actually work at any time?
Regards Dr. Bob 
|
Edited by - Dr. Bob on 02/14/2010 07:14:12 |
|
|
|
Dr. Bob
Moderator
Australia
6593 Posts |
|
|
Boss_8
Copper Member
USA
44 Posts |
Posted - 02/14/2010 : 14:04:23
|
quote:
Originally posted by Dr. Bob
Hi Boss_8
You can find all the PDF's, schematics & instructions for that CE-2 clone ,
over on the TonePad site:
http://www.tonepad.com/project.asp?id=53
I'm not too sure about the NTE1641 chip that seems to be in the socket
in place of the MN3007.
Is it a direct replacement?
If it's not a direct replacement - you will be fighting an uphill battle to get it going.
Did this circuit ever actually work at any time?
Regards Dr. Bob
Hey Dr. Bob,
I noticed that oddball NTE1641 chip also, I will try to find out if it will cross-reference. As far as the proper operation of the pedal, I don't know if it ever did work, it came from a friend who got it in a Craigslist purchace with a pile of other stuff. I've been wanting to learn more about electronics and I thought this would be a perfect oportunity, it doesn't work already so what have I got to loose? It looks like I'll be saying Thank you a lot on this forum! Thanks again |
|
|
|
Boss_8
Copper Member
USA
44 Posts |
Posted - 02/14/2010 : 14:09:13
|
quote:
Originally posted by Dr. Bob
Hi Boss_8 & Guys
quote:
Is it ok to use a signal probe like one I saw posted on this forum?
Did you see the one made out of a ball point pen case, a pop rivet,and a small capacitor?
I think they put a 1/4" jack on one end and plugged it into the amp.
Dr. Bob's Simple Audio Probe can be found here:
http://www.bossarea.com/forum/topic.asp?TOPIC_ID=5599
Laurie & Mesjoggah were also kind enough to post their Audio probe.
http://www.bossarea.com/forum/topic.asp?TOPIC_ID=6284
Like the one zerksies just built.
http://www.bossarea.com/forum/topic.asp?TOPIC_ID=9005
I think there was another link to Laurie's Audio probe?
I hope Laurie remember it?.
Regards Dr. Bob
Dr. Bob,
Between the above links and ranjam's instructions I'll be busy for a while. BTW, are you a real Dr. or do you just play one on TV? |
|
|
|
ranjam
Bronze Member
Canada
82 Posts |
Posted - 02/15/2010 : 01:10:51
|
| Sometimes I have bad luck with NTE replacements, and sometimes they work just perfectly. It really is a crapshoot. While technically the 1641 is a direct replacement for the MN3007, you may have to adjust the clock input, or just try another chip. It really is something I don't grasp at all. Sometimes the driver (MN3101 or IC4) just doesn't 'drive' the BBD properly. Although looking at the CE-2 schematic, what's between IC3 and IC4? One capacitor. I just don't know. Maybe change that one capacitor? |
|
|
|
Boss_8
Copper Member
USA
44 Posts |
Posted - 02/15/2010 : 03:21:53
|
quote:
Originally posted by ranjam
Sometimes I have bad luck with NTE replacements, and sometimes they work just perfectly. It really is a crapshoot. While technically the 1641 is a direct replacement for the MN3007, you may have to adjust the clock input, or just try another chip. It really is something I don't grasp at all. Sometimes the driver (MN3101 or IC4) just doesn't 'drive' the BBD properly. Although looking at the CE-2 schematic, what's between IC3 and IC4? One capacitor. I just don't know. Maybe change that one capacitor?
Ranjan,
You won't believe it I just started looking at the components on the board to match with the schematic. I started on the caps:
C9- NP should be polar
C17- same
C18- polarity is reversed
C30- should be 220 MF, it's 330 MF
You think that might be an issue? I'm going to have to check every value of every component on this whole board. Do you think that with the above stated cap issues it could've fried the op amps? |
|
|
| |
Topic |
|
|
|
Tonepad CE-2 troubleshooting help
