Fulltone Deja-Vibe MDV-2 factory error

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
Post Reply
User avatar
TWSpedals
Information
Posts: 47
Joined: 30 Dec 2020, 23:48
Has thanked: 15 times
Been thanked: 46 times

Post by TWSpedals »

Hello everyone. I have a 2009 fulltone MDV-2 in for repair and the symptoms were: the chorus setting was full volume, and the vibrato setting was much lower in output. I've seen this complaint on the web before with no solution provided.
Both settings the modulation wasn't strong and got weaker when the rate was maxed.

I have found the cause: fulltone built their pedal wrong.

In this unit at least the chorus/vibrato switch was labeled backwards, and the output mixer had very 'none original' values in it. Causing the dry mix in the chorus setting to be unbalanced and weak in modulation and the vibrato setting to be quieter. Attached is a pencil drawing of the issue

Not a clue where these values came from as they are not on any schematics attached to the original Uni-Vibe at all.

As an aside this was a simple repair made difficult by the narrow PCB hole sizes and thick PCB. It's a very crowded board with no labeling either. Also the Bulb was covered in hot glue and touch the roof of the shield so it was resoldered to be in the middle of the box
Attachments
20230610_213624.jpg
20230610_213619.jpg
20230610_213615.jpg
20230610_213555.jpg

User avatar
FuzzMonkey
Breadboard Brother
Information
Posts: 118
Joined: 28 Dec 2009, 22:10
Has thanked: 43 times
Been thanked: 26 times

Post by FuzzMonkey »

I'll have to check this out on mine. Haven't used it in ages so I have forgotten what it sounds like.

Post Reply