XO Stereo Clone Theory issues
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- Posts: 3
- Joined: 25 Nov 2015, 00:37
Hello,
I have one of the newer stereo Clone Theory pedals from Electro Harmonix. This was my favorite pedal until I messed with the internal trim pot, thinking that it would lower the volume boost Now it doesn't chorus, or it does for a few seconds and then sound like a bomb dropped and explodes and then... no more effect.
I don't have a schematic, but I was wondering if anyone has worked on one of these before? I was just wondering what I should be measuring to make sure that I adjust the trim pot correctly.
Any help is much appreciated.
Thank you!!
I have one of the newer stereo Clone Theory pedals from Electro Harmonix. This was my favorite pedal until I messed with the internal trim pot, thinking that it would lower the volume boost Now it doesn't chorus, or it does for a few seconds and then sound like a bomb dropped and explodes and then... no more effect.
I don't have a schematic, but I was wondering if anyone has worked on one of these before? I was just wondering what I should be measuring to make sure that I adjust the trim pot correctly.
Any help is much appreciated.
Thank you!!
- Fender3D
- Cap Cooler
I don't know how much different is the new CT respect the older...
but if it has a BBD chip, then the trimmer is the bias setting.
It should be set for a symmetrical clipping:
apply a sine waveform then set trimmer for a symmetrical clipping.
Otherwise post some pics so we can guess about schematic...
but if it has a BBD chip, then the trimmer is the bias setting.
It should be set for a symmetrical clipping:
apply a sine waveform then set trimmer for a symmetrical clipping.
Otherwise post some pics so we can guess about schematic...
Information
- Posts: 3
- Joined: 25 Nov 2015, 00:37
Information
- Posts: 3
- Joined: 25 Nov 2015, 00:37
Awesome, I think we have an o-scope at work, so I will try and do this.
Thanks!
Thanks!
Hi, sorry for reviving an old thread. Where should I measure for the symmetrical clipping? Thanks.Fender3D wrote: ↑25 Nov 2015, 17:05 I don't know how much different is the new CT respect the older...
but if it has a BBD chip, then the trimmer is the bias setting.
It should be set for a symmetrical clipping:
apply a sine waveform then set trimmer for a symmetrical clipping.
Otherwise post some pics so we can guess about schematic...
- Fender3D
- Cap Cooler
If you can locate the first LPF output after BBD you' ll get the best signal to "see" on scope...
Otherwise you should check at BBD's output pins (7-8 for MNxxxx)
Apply ~200Hz signal at input, raise it until you get clipping and set trimmer for a simmetrical clipping, raising and lowering signal applied will help
Otherwise you should check at BBD's output pins (7-8 for MNxxxx)
Apply ~200Hz signal at input, raise it until you get clipping and set trimmer for a simmetrical clipping, raising and lowering signal applied will help
Thanks for the tips. I pumped in 200Hz to input jack, measured pin 7 & 8 of MN3007. I couldn't see a sine wave on my scope, it looks like noise. I suspect the culprit is CD4047.
Question: How do I measure the clock signal output from the CD4047?
Question: How do I measure the clock signal output from the CD4047?
Hello have you solved your problem?
I have a one with issues too... but I think it's different issue than yours (I'll post a video later).
First of all, how did you take it apart? It seems impossible to me without desoldering pots and switch (maybe I'm missing something though )
Hi kiltro. My pedal is still not repaired. I was not able to drill down to the exact root cause.kiltro wrote: ↑19 Sep 2022, 10:25Hello have you solved your problem?
I have a one with issues too... but I think it's different issue than yours (I'll post a video later).
First of all, how did you take it apart? It seems impossible to me without desoldering pots and switch (maybe I'm missing something though )
I'll post here and eventually create another topic if you think is better.
This is a brief video of the issue I'm having with my pedal.
Obviously there is some pot cleaning to do, but what about the other weird sounds (the one at the start and the one at the end of the video)?
I guess is due to auto-oscillation? How should I go about solving it?
Thanks
This is a brief video of the issue I'm having with my pedal.
Obviously there is some pot cleaning to do, but what about the other weird sounds (the one at the start and the one at the end of the video)?
I guess is due to auto-oscillation? How should I go about solving it?
Thanks
- Fender3D
- Cap Cooler
It looks related with power supply noise to me... the oscillation looks like a power supply loss in clock generatorwhat about the other weird sounds (the one at the start and the one at the end of the video)
it's really strange rate pot can make those heavy scratches.
Sure there's no cold solder or cracked track?
I've cleaned the pots and the scratches are gone.Fender3D wrote: ↑06 Oct 2022, 16:48It looks related with power supply noise to me... the oscillation looks like a power supply loss in clock generatorwhat about the other weird sounds (the one at the start and the one at the end of the video)
it's really strange rate pot can make those heavy scratches.
Sure there's no cold solder or cracked track?
Oscillation still happening though.
Power supply? Can it simply be the battery?
I dont see any cracked tracks but I'm not sure about cold solders
- Fender3D
- Cap Cooler
You can hear that noise when there's loss of power supply in chorus or flanger usually, that's why I thought about issues in tracks or cold solders.
If you have DMM with max/min function, you can check supply at VCO, the clock chip.
BTW, it occurs in particular circumstances? Is it repeatable?
If you have DMM with max/min function, you can check supply at VCO, the clock chip.
BTW, it occurs in particular circumstances? Is it repeatable?
My DMM has a peak button, but unfortunately it detects only max voltage, not min.
I've an oscope but I dont think there is something like that
Well as far as I'm noticing...
this one happens only with "chorus 1" and "chorus 2" selected
and only with rate knob in the range of min to 11 o'clock
This one happens with range at max when not playing. Almost at random, or at least I'm not able to repeat it every time I try.
Also after the final "pop" the pedal exit chorus, after that if I play I get the bass sound without effect. I have to move the range pot to re-engage the effect
I'm also noticing that I get a subtle hum when the effect is on and if I touch the body of the jack that goes to the amp the hum is somehow reduced
Hi Fender3D. I presume the clock output from MN3007 at pin 7 & 8 is a sine wave? This is the 1st time I deal with chorus pedal. How about the clock driver IC (CD4047), what should I expect to see on pin 10 and 11?
Thanks in advance for your time
- Fender3D
- Cap Cooler
@ MN's out pins you got the same signal injected at pin 3 altough delayed and "chopped".
@ 4047's pins 10-11 you got clock, it should be a square wave. When it suddenly drops below ultrasonic frequencies, you can hear the noise recorded in mp3 n°2
@ 4047's pins 10-11 you got clock, it should be a square wave. When it suddenly drops below ultrasonic frequencies, you can hear the noise recorded in mp3 n°2