Fixing a faulty Devi Ever Soda Meiser

[jimladladlooklike]

Whats up!

First of all, sorry if this isn't the correct place to post about fixing pedals. Please point me in the right direction if so!

I've been asked by a friend to see if I can fix his Soda Meiser pedal and I thought I'd found the problem: Using an audio probe I noticed that the audio signal wasn't passing through C1. Figuring the cap was spent I changed it for another of the same value... Still, the pedal sounded the same as before. Now I'm unsure what to do so I though I'd seek some advice before continuing as I don't want to be removing working parts from someone else's pedal if there's no need to...

Please see schematic below:


Cheers everybody.

[R.G.]

There is a sticky posting that appears at the top of the forum entitled "Debugging: what to do when it doesn't work". It's there for a reason.

It would help us help you a great deal if you'd read and follow that.

[jimladladlooklike]

I do apologise.

It's a Devi Ever Soda Meiser. The pedal isn't making the right sound. It's fuzzy, but lo-fi sounding. Certainly not right anyway.

Here are the voltages:

Q1
C: 2.37v
B: 0.6v
E: 0v

Q2
C: 3.1v
B: 0.59v
E: 0v

Q3
C: 1.06v
B: 0.61v
E: 0v

Q4
C: 1.06v
B: 0.61v
E: 0v

Tah very much!

[jimladladlooklike]

Hello! Sorry to have to bump this post. Would love if someone could shed any light on what may be the problem here.

Thanks in advance!

[amz-fx]

Turn the Intensity control all the way up to the max.

Use the audio probe on the collector of Q1 and see if there is a sound. If so, move to the collector of Q2 and check it.

Fuzzy, but lo-fi sounding is normal for this pedal (by design). Here is a demo of how it normally sounds: https://youtu.be/eViXPhlBkoo

Best regards, Jack

[thermionix]

If there's no sound past C1, and C1 is known good, then maybe Q1 is shorted and grounding out the signal.

[jimladladlooklike]

Turn the Intensity control all the way up to the max.

Use the audio probe on the collector of Q1 and see if there is a sound. If so, move to the collector of Q2 and check it.

Fuzzy, but lo-fi sounding is normal for this pedal (by design). Here is a demo of how it normally sounds: https://youtu.be/eViXPhlBkoo

Best regards, Jack

Thanks for the reply. It definitely doesn't sound right. It sounds almost 8 bit.

There is signal at the collector of all 4 transistors. I'm stuck!

Thanks again in advance

[jimladladlooklike]

So I've noticed that the signal at the collector of Q1 is quite weak in comparison to the input jack. I would have thought that it would be a little louder if anything. Does this seem like it could be the problem?

[antonis]

So I've noticed that the signal at the collector of Q1 is quite weak in comparison to the input jack. I would have thought that it would be a little louder if anything. Does this seem like it could be the problem?

Try to lower C2 NFB cap value (to 10nF or 1 nF) or set it completely off to see if signal on Q1 Collector gets more strength..

[amz-fx]

So I've noticed that the signal at the collector of Q1 is quite weak in comparison to the input jack. I would have thought that it would be a little louder if anything. Does this seem like it could be the problem?

I agree with Antonis; the C2 capacitor is much too large in value. I would remove it entirely for testing to see if the signal increases, and then I would try 100pF once it is established that there is a good signal on the Q1 collector.

regards, Jack

[BetterOffShred]

I don't have much to add, but the Soda meiser is a really fun fuzz IMO.   Isn't this a "factory" unit?  Has someone been poking around in it before?   I know it's hard to tell sometimes with Devi stuff, but if it is indeed a production unit the likelihood of components being wrong is slim. 

Also if you're handy with a soldering iron it might just be easier to make a new board  .. just sayin.

[jimladladlooklike]

It is a factory unit. As far as I know it had never been opened since the time my friend purchased it, so I doubt the cap is too high in value. Plus, looking at schematics and layouts online also tells me it's the correct value. The guy says it's as thought there is something wrong with the input... what does this sound like to you guys?