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Mesjoggah
Gold Member
Netherlands
595 Posts |
 Posted - 12/23/2008 : 07:10:15
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| I need an ODB-3 schematic, looked up the well known places but cannot find one, any change one of you guys can help me out? |
Edited by - Mesjoggah on 01/02/2009 20:34:20 |
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Dr. Bob
Moderator
Australia
6593 Posts |
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Mesjoggah
Gold Member
Netherlands
595 Posts |
Posted - 12/23/2008 : 13:22:54
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Thanks Dr.Bob!
I'm currently awaiting a defective odb-3, according to the former owner the led lits up and the sound passes through but the knobs don't seem to work, i do not know if the sound passes through clean or distorted, hopefully tomorrow or later this week when i have it i can tell more. |
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Mesjoggah
Gold Member
Netherlands
595 Posts |
Posted - 01/01/2009 : 15:02:56
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pedal arrived today, the led goes on but there's no distortion, knobs do not make any difference to the clean sound except for the level that does seem to affect the sound a bit.
Clipping diodes do not light up, but all components look fine at a visual inspection. |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 01/01/2009 : 15:58:46
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quote:
Originally posted by Mesjoggah
pedal arrived today, the led goes on but there's no distortion, knobs do not make any difference to the clean sound except for the level that does seem to affect the sound a bit.
Clipping diodes do not light up, but all components look fine at a visual inspection.
Hi Mesjoggah
Do you think it has been modded?
Does it work with a GOOD battery?
Does it work with a power supply?
Maybe it got a belt of rev, polarity?
If the protection diode/zener went open, then the rev. volts probably took out an opamp.
Op-amps absolutely hate rev. volts. period!
Can you inject a signal into it, & attempt to trace it out?
Regards Dr. Bob 
PS some pics might help us help you... [:)
Did you try emailing the guys on the Italian forum, I am sure they would help.
This is all I have:
ODB-3.jpg
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Mesjoggah
Gold Member
Netherlands
595 Posts |
Posted - 01/01/2009 : 18:29:32
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It doesn't work with either a adapter or battery, i don't know if it got a belt of reversed polarity.
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Edited by - Mesjoggah on 01/01/2009 19:44:04 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 01/02/2009 : 02:51:04
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quote:
Originally posted by Mesjoggah
It doesn't work with either a adapter or battery, i don't know if it got a belt of reversed polarity.
Hi Mesjoggah
How did you go with the schematic I posted?
Keep us updated on your efforts.
Regards Dr. Bob |
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Mesjoggah
Gold Member
Netherlands
595 Posts |
Posted - 01/02/2009 : 10:56:30
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Well Bob, i am not experienced in troubleshooting and i think i don't have the necessary tools (scope) and i don't think the schematic is complete as i cannot find all components on it. I guess i just have to replace some components with others i have lying around and see what comes out of it.
i'm going to switch the op-amp now.
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Edited by - Mesjoggah on 01/02/2009 10:57:22 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 01/02/2009 : 11:21:49
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quote:
Originally posted by Mesjoggah
Well Bob, i am not experienced in troubleshooting and i think i don't have the necessary tools (scope) and i don't think the schematic is complete as i cannot find all components on it. I guess i just have to replace some components with others i have lying around and see what comes out of it.
i'm going to switch the op-amp now.
Hi Mesjoggah
I guess by the time you read this, you will already replaced the op-amp,
But if you can, solder in a socket, before you replace it, it will make things easier in the long term.
Good luck 
Regards Dr. Bob |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 01/02/2009 : 11:22:47
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quote:
Originally posted by Dr. Bob
quote:
Originally posted by Mesjoggah
Well Bob, i am not experienced in troubleshooting and i think i don't have the necessary tools (scope)
and i don't think the schematic is complete as i cannot find all components on it.
I guess i just have to replace some components with others i have lying around and see what comes out of it.
i'm going to switch the op-amp now.
Hi Mesjoggah
I guess by the time you read this, you will already have replaced the op-amp,
But if you can, solder in a socket, before you replace it, it will make things easier in the long term.
Good luck
Regards Dr. Bob |
Edited by - Dr. Bob on 01/02/2009 11:25:22 |
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Dirk
Platinum Member
Netherlands
1309 Posts |
Posted - 01/02/2009 : 11:49:06
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| In this schematic, exactly how does it bypass? Or is that part just not drawn? |
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Mesjoggah
Gold Member
Netherlands
595 Posts |
Posted - 01/02/2009 : 11:52:33
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quote:
Originally posted by Dirk
In this schematic, exactly how does it bypass? Or is that part just not drawn?
I think that part isn't drawn.
I replaced the op-amp for a known good one, but it stays the same. what should i do next?
Is it possible that the clipping diodes or just one of them is broken or placed in the wrong direction? |
Edited by - Mesjoggah on 01/02/2009 12:01:46 |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 01/02/2009 : 20:37:32
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quote:
Originally posted by Mesjoggah
Is it possible that the clipping diodes or just one of them is broken or placed in the wrong direction?
To confirm one of the symptoms with you - the clipping LEDs don't light up - at all - with the effect "on" and strong signal going through the pedal?
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Mesjoggah
Gold Member
Netherlands
595 Posts |
Posted - 01/02/2009 : 23:17:27
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quote:
Originally posted by Laurie
quote:
Originally posted by Mesjoggah
Is it possible that the clipping diodes or just one of them is broken or placed in the wrong direction?
To confirm one of the symptoms with you - the clipping LEDs don't light up - at all - with the effect "on" and strong signal going through the pedal?
That's right Laurie, nothing happens with the clipping LEDs. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 01/02/2009 : 23:30:52
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OK. And the opamp is changed for a known good one I saw above. So it's not the opamp, therefore the signal is disappearing somewhere before the opamp - if there was signal at the opamp input, the LEDS would be lighting.
Just to be completely sure we are talking the same language - if you plug in a guitar, turn the levels on the guitar and the pedal to max and really lay into a chord, there is no(zero) light coming out of the LEDS?
Do you have any sort of signal probe? The input to an amplifier through a 0.1uF capacitor will work... (amp volume turned way down!)
We need to probe around a little to find out whereabouts in the circuit the signal is disappearing.
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Mesjoggah
Gold Member
Netherlands
595 Posts |
Posted - 01/03/2009 : 09:00:40
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quote:
Originally posted by Laurie
OK. And the opamp is changed for a known good one I saw above. So it's not the opamp, therefore the signal is disappearing somewhere before the opamp - if there was signal at the opamp input, the LEDS would be lighting.
Just to be completely sure we are talking the same language - if you plug in a guitar, turn the levels on the guitar and the pedal to max and really lay into a chord, there is no(zero) light coming out of the LEDS?
Do you have any sort of signal probe? The input to an amplifier through a 0.1uF capacitor will work... (amp volume turned way down!)
We need to probe around a little to find out whereabouts in the circuit the signal is disappearing.
Laurie, i have zero light coming of the LEDs the signal seems to get bypassed somewhere and comes out as a clean signal, just like the pedal isn't switched on.
about the probe, if i understand this right i have to cut a cable and put a 0.1uf cap in it?
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Topic |
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ODB-3 troubles
