Circulator no effect

markseo

New member
Hi!

I have just finished my second Circulator build (the first one went really well except some minor stuff).
I have now finished a second unit but I am getting no effect when the pedal is engaged.
The pedal does activate as the LED turns on and blinks to the rate of the frequency control (also reacts accordingly to the rate switch).
It just sound exactly the same wether its on or off and the knobs are doing nothing to the sound.
I don't have my multimeter with me right now, so cannot do too much testing :/ But any help will be great! Should get my multi back on Tuesday
 

markseo

New member
Yeah!

Hope these are good enough. Let me know if you need anymore.


The pedal's behavior is as follows:


When not engaged, it passes clean signal.
When engaged, the LED turns on and flashes to the speed set by both the RATE switch and the frequency/speed control (therefore I am assuming the LFO is working). It also stops moving when set to position 2 (park filter).
When engaged the sound has no change at all. It doesn't matter where I set the knobs, the sound is as clean as when in bypass mode.
If I set the mode to Vibrato, the sound stops (I am assuming the Vibrato circuit only sends wet signal, which there is none, so there's no output).

I guess it has something to do with the DEPTH section of the circuit. I might just replace that pot. I will get my DMM back tomorrow in the afternoon, should I measure anything specific? I don't know much about using DMM for troubleshooting except for checking continuity and power, which in this case I would imagen are OK as the pedal is turning on when engaged and I do get signal passing through the entire circuit.

Thanks in advance! Hope the images and info are of any help :)


IMG_20210308_213928 (1).jpgIMG_20210308_213909 (1).jpgIMG_20210308_213853 (1).jpg
 

Betty Wont

Active member
It looks like one of your power supply wires isn't soldered in. And some cold looking solders around your pot pins.
 
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markseo

New member
I got everything from a kit from Musikding. I already built another Circulator kit from them. Both came with old PCBs which have some differences with the actual ones (mainly around the LED, as some had a bicolor LED).

Ill check those caps (as they came with the kit, I went straight to soldering without checking with a DMM, should have waited to getting mine back, damn).

And yeah, I was in a bit of a rush and soldered the pots backwards by error (on the components side). Desoldering them was a bit of a PITA and might have damaged something in the process. I know the rate pot works as the speed changes, but don't about the rest.


I have a bit of a broader question regarding troubleshooting. If I built an audioprobe, it would not work for this project, right? Cause I do get signal passing through.
 

fig

Well-known member
The caps are correct value, but in a rather large package for that board.

Does the other build function correctly?

An audio probe is a great asset. If you are planning more builds, I am certain many folks here would suggest putting one together.
 

Mcknib

Well-known member
An audio probe would work you could for example check if you are getting wet signal etc it certainly sounds like or doesn't depending on which way you look at it! You're getting no wet signal

Obviously the first thing to do is visually check all component values and orientation are correct and all your wiring and solder joints look good no dull, ball like dry joints or solder bridges

All your values and orientation that I can see look correct can't see R2, 30 or 102
 

markseo

New member
Yeah, Musikding sent caps way too big for this PCB, but I managed to get them in both builds.

The first one I built did work, and I actually love this pedal soooo much I wanted to do a second one as a gift to a friend.

Components wise, both pedals are identical. So I am assuming I might have a broken wet pot, so I cannot get any effect through. I do have an audio probe, but I have never used it, I thought it only helped when there was no signal in order to find where the sound was cutting.

Im going to triple check all my solder joints and do some cleanup of the whole PCB. Lets see if I can find something
 
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Mcknib

Well-known member
You can probe where the wet signal gets mixed with the dry if you get nothing you can just probe back till you find where it's lost

Could be anything even something as simple as a dry solder joint
 

markseo

New member
Thank you so much to everyone! Im loving this community!

I hope Ill have some spare time this weekend to check with an audio probe.
 

Mcknib

Well-known member
You're correct with the PV switch that does indeed stop the clean signal going on to be mixed with the wet and just sends it straight down to C3, R7 to be 'wetted'

It looks like your wet signal would go to depth lug 2 and up to be mixed I'd check from there up to IC5.2 pin 6 as you know you wont get any audio through the LFO so initially I'd check audio from depth 2 and through the components up to pin 6 then if you get none from Depth lug 2 back the way
 
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