Magnatone Vibrato circuit

[jojokeo]

Has anyone here made one from scratch or is it not possible w/out the type of special "silicon controlled varistors" the Maggie's used? I can't seem to find any info on anyone building a true vibrato circuit here.

[phsyconoodler]

Tried it but I guess  don't have the patience.They are called 'varistors' They have capacitance and resistance.The original type aren't available anymore but there are some available that have the same specs.
  Frankly I don't get all frothy over the magnatone sounds,they have too much thump and are problematic.
 I developed my own vibrato on my V-Verb amps.It sounds quite a bit like the Univibe.
  Have a listen on my website. www.claramps.com
Lots of work and really not too much different from some.

[sluckey]

dinkotom built several within the past year or so. Search for magnatone.

[jojokeo]

Very nice vibe effect - I liked #4 since it has some sustaining to actually hear the effect better than Johnny V's syncopated playing. He seems to be very rhythmically influenced by it. This is meant to mean my complements to the chef! Thanks. Nice site too.

I saw the varistors on the Maggie site but they're no longer available. It makes me wonder what's the replacement or maybe it's not worth it? Just by a pedal instead or make something like what you did. Also, I've seen a lot of people build in tremolo but nobody err hardly anyone builds in a true vibrato. It's a little surprising.

[Merlin]

The alternative is the Vox AC30 vibrato circuit, which works on a very similar principle, but does not use varistors. I built a standalone version of the Vox.
(Contrary to what is implied on the Magnatone website, the Vox vibrato is also true vibrato.)

[eleventeen]

Many many years ago I built a true vibrato outboard circuit that appeared in probably a 1957 or issue of Radio Electronics. I'm afraid I can't supply much coherent info on it. It used 2 tubes, 12a_7, no special components other than R's and C's, and it worked! It was subtle, but it definitely worked.

[jojokeo]

The alternative is the Vox AC30 vibrato circuit, which works on a very similar principle, but does not use varistors. I built a standalone version of the Vox.

Would you be willing to share any info on this? The schematics I've seen are hard to make out values and poor copies very blurry. Thanks Merlin-

[Merlin]

Would you be willing to share any info on this? The schematics I've seen are hard to make out values and poor copies very blurry. Thanks Merlin-

Well, here is my old schem
http://s81.photobucket.com/albums/j207/merlinblencowe/Vibrotron/
However, I would do it slightly differently now. There will be a good Vox schem out there somewhere.

You should also read:
http://thermionic.info/dorf/Dorf_TheUniversalVibrato.pdf
http://thermionic.info/dorf/Dorf_TheWurlitzerVibrato.pdf

[jojokeo]

Thanks a bunch Merlin. 

[Jack_Hester]

You should also read:
http://thermionic.info/dorf/Dorf_TheUniversalVibrato.pdf
http://thermionic.info/dorf/Dorf_TheWurlitzerVibrato.pdf

I have the '54 issue that the 'Universal Vibrato' was published in.  Enjoyed the other article, too.  I'm going to scan the schematic from my magazine, just to get a clearer image to save.  I will put the scan in my photobucket album, so that others can have a clear schematic and BOM to work from.  Thanks for posting.

Jack