SOLVED Abider drive J201 Issues???

PaulPauliePabloPaolo

PaulPauliePabloPaolo

Member
Hi again Gang,
So having built an abider before and liked it a lot, a friend of mine wanted one. Just building one now and the pedal is fine when 'off' but when I engage the foot switch all I get is a quiet white noise. I changed the chips to see if it was them as they were the only thing's I didn't 'test' before soldering them (socketed).

Im now wondering if the switch could be the culprit?. Good quality Gorva. Do you think I burnt it out by soldering it. I don't think I applied excessive heat to it but this is the first time Ive really had a problem like this...
Can you help?.
I did try to upload a small audio file(mp3 ~ 700b - 10 seconds) but alas it wouldn't let me when I tried to attach file.

Anyone!?!?!?!
 

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Solution
Robert
Where'd you get those 4558 opamps?

They look a little odd.

Do you by any chance have another set of known good opamps?

While we're on that subject, where'd you get your J201 transistor?
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swyse said:
I can't quite tell in the picture, the capacitor should go in line with the input wire to block the DC, so make sure its between the jack and the wire.
Click to expand...
Ok I can insert guitar signal to the input tip only????.

All the test points sound the same as previously described?. I can hear the guitar tho when I connect the tip to the insert jack when bypassed.

I will freely admit I have no idea what that means?.
 
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That's a bit surprising, just noise coming through? I really expected you to get something going at at least one of those points. Can you get signal through the output if you put some guitar into any of the pins of the treble pot using your probe? That's basically the end of the circuit.
 
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swyse said:
That's a bit surprising, just noise coming through? I really expected you to get something going at at least one of those points. Can you get signal through the output if you put some guitar into any of the pins of the treble pot using your probe? That's basically the end of the circuit.
Click to expand...
Yea, when the pedal is on just noise at all test points. But when bypassed I can hear the signal when I inject it to the input tip.
 
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I don't see anything obvious with the soldering. You could flip the operation and see if you're getting signal out of the circuit by using the probe as the output to the amp instead and see if that yields any different results.
 
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swyse said:
I don't see anything obvious with the soldering. You could flip the operation and see if you're getting signal out of the circuit by using the probe as the output to the amp instead and see if that yields any different results.
Click to expand...
I like your thinking but same results...
You guys think I should get another J201 and swap it out?.
 
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Hey Ya'll...
It 7am here and im still trying to figure this one out... ;(

I have now ruled out the IC's as I have an old Jan Ray build from another company which uses one 4558.
Ive tried all the chips I have in that and they all sound great. In fact the chip that was supplied with the Jan Ray build is exactly the same as the ones I got from BitsBox so at least I know where they get theirs!..

Also...
The white noise can be controlled when the pedal is 'on' by the control knobs, by that I mean they all do what they are supposed to.
The noise can be turned down with the volume knob and disappears when the vol is all the way down... same with the gain(except when in conjunction with the volume). The tone controls also seem to effect the white noise in the way that they would a 'normal' signal, increasing and decreasing the treble and bass appropriately.

Do any of you think im right in guessing I have a faulty J201 transistor?, I still can't figure out why I can't get 18v out of any of the pin3's of the chips.... I thought one of them was a charge pump?... Im really struggling!.

Id really appreciate a little assistance if there is any going spare around here...

I may not respond until I get a few hours sleep... but I'll back at it in a few hours.
I hope you can help!.
 
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The voltages you measured earlier on your ICs are helpful, but not very. We really need voltages for every pin on the ICs. From what you posted we can see that they are getting a bias voltage OK, but we can't see the actual power. For dual op amps that would be on pins 4 and 8, but just give us all of them.

With your audio probe, let's be a little systematic. With some form of audio playing into the input jack, and the pedal engaged, probe the input jack signal, the input into the PCB (where it connects from the switch), IC1 pin 3, IC1 pin 5, IC2 pin3, IC2 pin 5, IC3 pin 3, the output from the board, then the output jack. That breaks the circuit up into discrete chunks. The area between where you last hear signal, and where you have none will tell us where to look for the problem. Report back on where you hear signal and where you lost it.

Edit: Also, I can't read the markings on IC3. None of your ICs should be charge pumps. The build doc says they should all be JRC4558s, so if you have stuck something in IC3 that is not a dual op amp that could well be your problem.
 
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music6000 said:
He has taken it out of the enclosure & it still behaves the same.
Click to expand...
Yea that's correct!... sorry was just trying to get all the voltages from the iC's together.
Thanks for the reply though, its always one of the first things I check... and as well, when the pedal is 'off' I get the clean signal perfectly.
At this point it doesn't seem to be a 'grounding' issue... leaning more towards a dodgy J201.... But I will be pulling my hair out until I know for sure!... haha
 
Last edited:
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music6000 said:
A genuine JRC4558D should only look like this.

View attachment 32431
Click to expand...
Yea thanks... I looked up what they are supposed to look like... I know there are two in that pic that I bought of eBay that are certainly not genuine JRC4558's even though they have it written on them... I also cracked open my TS808 to have a look at a real one!. ;)
But Im sure that the ones I have are good equivalents and do the same job...
 
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PaulPauliePabloPaolo said:
Hey Ya'll...
It 7am here and im still trying to figure this one out... ;(

I have now ruled out the IC's as I have an old Jan Ray build from another company which uses one 4558.
Ive tried all the chips I have in that and they all sound great. In fact the chip that was supplied with the Jan Ray build is exactly the same as the ones I got from BitsBox so at least I know where they get theirs!..

Also...
The white noise can be controlled when the pedal is 'on' by the control knobs, by that I mean they all do what they are supposed to.
The noise can be turned down with the volume knob and disappears when the vol is all the way down... same with the gain(except when in conjunction with the volume). The tone controls also seem to effect the white noise in the way that they would a 'normal' signal, increasing and decreasing the treble and bass appropriately.

Do any of you think im right in guessing I have a faulty J201 transistor?, I still can't figure out why I can't get 18v out of any of the pin3's of the chips.... I thought one of them was a charge pump?... Im really struggling!.

Id really appreciate a little assistance if there is any going spare around here...

I may not respond until I get a few hours sleep... but I'll back at it in a few hours.
I hope you can help!.
Click to expand...

If the ratio control makes a difference in your noise I wouldn't be surprised if its the jfet or switch, as its very early in the circuit. Every IC in this pedal is a dual op amp, no charge pump, I see the lower 2 are labeled 4558, what IC is in the top socket?
 
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PJS said:
The voltages you measured earlier on your ICs are helpful, but not very. We really need voltages for every pin on the ICs. From what you posted we can see that they are getting a bias voltage OK, but we can't see the actual power. For dual op amps that would be on pins 4 and 8, but just give us all of them.

With your audio probe, let's be a little systematic. With some form of audio playing into the input jack, and the pedal engaged, probe the input jack signal, the input into the PCB (where it connects from the switch), IC1 pin 3, IC1 pin 5, IC2 pin3, IC2 pin 5, IC3 pin 3, the output from the board, then the output jack. That breaks the circuit up into discrete chunks. The area between where you last hear signal, and where you have none will tell us where to look for the problem. Report back on where you hear signal and where you lost it.

Edit: Also, I can't read the markings on IC3. None of your ICs should be charge pumps. The build doc says they should all be JRC4558s, so if you have stuck something in IC3 that is not a dual op amp that could well be your problem.
Click to expand...
Thanks for having a look at this for me...
IC1
PIN 1 - 4.49
PIN 2 - 4.49
PIN 3 - 4.48
PIN 4 - 0
PIN 5 - 4.47
PIN 6 - 4.49
PIN 7 - 4.49
PIN 8 - 9.08

IC2
PIN 1 - 4.49
PIN 2 - 4.49
PIN 3 - 4.49
PIN 4 - 0
PIN 5 - 4.41
PIN 6 - 4.49
PIN 7 - 4.49
PIN 8 - 9.08

IC3
PIN 1 - 4.57
PIN 2 - 4.57
PIN 3 - 4.32
PIN 4 - 0
PIN 5 - 4.48
PIN 6 - 4.49
PIN 7 - 4.49
PIN 8 - 9.08
 
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swyse said:
If the ratio control makes a difference in your noise I wouldn't be surprised if its the jfet or switch, as its very early in the circuit. Every IC in this pedal is a dual op amp, no charge pump, I see the lower 2 are labeled 4558, what IC is in the top socket?
Click to expand...
I admittedly don't know anywhere as much as you Gents, but I think its the J201.
Just got a msg that Im being sent another one...

With regards the chips

RC4558 [QU088] - £0.59 : Bitsbox, Electronic Component Suppliers UK

Bitsbox RC4558 [QU088] - High Performance Dual Op-amp.
www.bitsboxuk.com
 
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