Wurlitzer 200a Vibrato?

[Fuzzard]

This would be cool to replicate the Wurly Vibrato in a pedal format - anyone into making a stripboard diagram? Bless. http://www.bustedgear.com/images/schematics/Wurlitzer_200A_series_schematics.pdf 

[Fuzzard]

This might help

[Travis]

Before somebody creates a layout they have to design the pedal for you. The two sections of interest in your schematic are the oscillator and output stage. Most likely you need some sort of buffer or gain stage at the front

I’m not sure who here has the time to do this for you, so it’s best to DIY and bring us a schematic

[Fuzzard]

Hey Travis - does this help?

[Fuzzard]

[Fuzzard]

Thank you for patience as this is my first time posting to  requests and I am nervous asking for this request - my undying appreciation to whomever will take this on

[heuermh]

From what I can tell, this isn't actually vibrato, it is a tremolo (VCA).  My son has been going over the schematics for a different home organ we used to own, and the vibrato in that thing is a true vibrato (FM), because it modifies the frequency of the top oscillator, which all the keyed note frequencies are divided down from, instead of modulating volume.

[Fuzzard]

Right like how Fender labeled it “Vibrato” but it was really a Trem. Thanks for chiming in, good luck to your son on his quest.

[Travis]

I had misread the schematic before. I was thinking the oscillator modulates the output but it is going to the input circuit

The more I have thought about your idea the more I like it

[Frank_NH]

Interesting circuit.  I looked at the Wurlitzer schematic and the tremolo appears fairly simple.  There are some videos online of people playing the organ with the tremolo engaged, and it sounds as you would expect.

To be honest, if you simply want a flexible LDR-based tremolo, the Tremulus Lune is a good project.  Also, we have a more recent vero layout here for the VFE Old School Tremolo.  I would check that out as well.

However, if you just have to have the Wurlitzer circuit, let me recommend creating a breadboard version first and, if you like the sound, then finalize the schematic after some tweaking.  We can convert a completed schematic to vero here pretty quickly.

[Travis]

I get the appeal. The Wurlitzer is a CLASSIC and I have always loved its sound.

The Eagle schem is looking possibly good to go, but definitely one to breadboard first

[Fuzzard]

Thanks for taking the time to check it out.

[Axldeziak]

I spent some time looking into this circuit and found a few interesting bits. The transistors are 2N5088. The original number on the vactrol is 21L251. There appear to be two modern reproductions of the board. The older one (red) uses a Vactec VTL5C1, the more recent repro (blue) uses an Xvive VTL5C3.

I also found this Bing cache of a deleted page that explains the organ's circuit and what each part does and how it interacts.
Wurlitzer 200a

[Fuzzard]

Thank you for you’re interest and research. I am really intrigued with this effect.

[Fuzzard]

I wish I had a proper setup for breadboarding - it’s on the list

[Fuzzard]

Anybody wanna take a crack at this?