Cepheid chorus no efect and no leds

[mike_666]

Hi all, it's been many years since I had go at making a pedal, so thought I'd have a go at the cephoid chorus.

I fear I maybe being blindingly stupid here (trust me it happens a lot to me!), but I get the dry signal, but don't get any effect and the leds don't light up either, but they do work.

Any help would be most appreciated

 

[mike_666]

 

[swelchy]

I'm sure you tried adjusting the trimmer to find the sweet spot? also your breakout board has a wire looking a little wonky

 

[mike_666]

So today, I discovered I'd put the leds in the wrong way round! I know have the lfo working correctly, and I remade the dodgy soldering on the break out board.

I still don't have any effect, even after twiddling the trim pot. What I'm thinking is it's not getting power, as the led doesn't light (it works I double checked that), and when the switch is turned on I get no effect just sort of noise which does get louder if I use the trim pot.

 

[Locrian99]

Have you checked voltages at the ic’s to verify they are getting power?

 

[Stickman393]

Photos kinda make it look like your top jumper pad for the chip PSU rails isnt properly bridged.

You're building the MN3207 version, yeah?

 

[khanji]

Hi all, it's been many years since I had go at making a pedal, so thought I'd have a go at the cephoid chorus.
I fear I maybe being blindingly stupid here (trust me it happens a lot to me!), but I get the dry signal, but don't get any effect and the leds don't light up either, but they do work.
Any help would be most appreciated

Tutuapp​

 

[Nic]

Hi all, it's been many years since I had go at making a pedal, so thought I'd have a go at the cephoid chorus.
I fear I maybe being blindingly stupid here (trust me it happens a lot to me!), but I get the dry signal, but don't get any effect and the leds don't light up either, but they do work.
Any help would be most appreciated

You should start your own troubleshooting thread. Provide clear pictures of your board and all wiring connections.

 

[mike_666]

Hi sorry for the delay, it's been a bloody awful week at work.

Yes it's the mn3207 chip I'm using, I'll away and check the voltages and the jumper pad and get back to you kind folks.

 

[mike_666]

Here are the chip voltage, and sorry it's the V3207D chip I'm using not the MN3207

 

[Stickman393]

it's the V3207D chip I'm using not the MN3207

Same difference, the v3207d is a 100% drop-in work-alike.

 

[mike_666]

Ah okay, it was just the chip set it came with.

 

[Bio77]

Usually when an effect gives no sound engaged, it's the switch or a wiring problem. If that checks out: Use an audio probe and trace the signal through the clean path. You should get something even if the delay isn't working.

 

[Erik S]

Can you add a pic that shows your DC jack?

 

[mike_666]

Here's a pic of the dc jack, I've also ordered up a couple of bits to make an audio probe too.

 

[Erik S]

Here's a pic of the dc jack, I've also ordered up a couple of bits to make an audio probe too.

DC jack look good.

My first troubleshooting step is always to sit down with my resistor color band chart and go through each resistor and verify it’s right.

From what I could see it looks like a couple that should have been 12k are either 47k or 470k. The orange vs red in the 4th stripe multiplier spot are a little hard to make out.

 

[mike_666]

Excellent spot that man!!! Top of the class, cheers

 

[mike_666]

I'm going to say something stupid here, I can sense it.... but!

Looking at the diagram I have, and comparing it to the above, it's different.

The 12k ones are marked as 47k on my diagram and board too.

 

[Erik S]

I'm going to say something stupid here, I can sense it.... but!

Looking at the diagram I have, and comparing it to the above, it's different.

The 12k ones are marked as 47k on my diagram and board too.

You’re probably right there. I’d trust the build doc.

I was working off the image on the product page, @Robert probably just didn’t update the image to match the latest board revision.

 

[Robert]

Looking at the diagram I have, and comparing it to the above, it's different.

You’re probably right there. I’d trust the build doc.

I was working off the image on the product page, @Robert probably just didn’t update the image to match the latest board revision.

Yep, that's correct. Don't use the preview images on the website as a reference, use the build doc or the PCB itself.