Any Magnatone vibrato builders?

[cgiff]

I just discovered these amps yesterday. Took a look at some schematics, downloaded a couple of Mr. Bonhams patents that explain the operation. Pretty funky circuit!
I have an interest to build up a vibrato circuit. Has anyone worked out a Voltage Dependent Resistor replacement (FET circuit)? Any Recommendations for replacement VDR's Thanks

Cgiff

[John_H]

I've got a Magnatone amp. It's on the left in the picture. My daughter is using it for her Farfisa electric organ currently. The vibrato works great for this. I recently woke it up from a 2 year nap in storage. I located the short that had put it to sleep years earlier, replaced the 6L6's that were rattling, and put new filter caps in it. For a fifty year old amp this thing rocks.

I can't help you much with the circuit. I read a couple articles about it, but never got into it.

[soundmasterg]

You might be able to get the varistors for the vibrato circuit from Zach at Vibroworld. He's on tour right now in Europe, but he should be back in a couple months and get his site back in operation again within a couple months after that. I got some myself from him (enough to do 3 amps) and they are just like what was used in the Magnatones. If he doesn't have any more, he may be able to tell you where to find some or what kind of replacement parts to try. Good luck.

[Paul P]

Try here

I was also looking at this circuit a little while back. I found one
source for varistors :

http://www.moyerelectronics.com/inde...bin/WorkMan.pl

They list the FS308 that Vibroworld does not sell but not the FR1039. They
have a bunch of others, though.

I know nothing about this supplier.

[dinkotom]

I was also looking at this circuit a little while back. I found one
source for varistors :

http://www.moyerelectronics.com/inde...bin/WorkMan.pl

They list the FS308 that Vibroworld does not sell but not the FR1039. They
have a bunch of others, though.

I know nothing about this supplier.

So which varistor is correct for the Magnatone, FS308 or FR1039?
Which (if any) of the FS308 could be used in a Magnatone-there are three different voltages and also, part FS308 is not labeled as a varistor?
Also, I have a circuit board from some old PA amp with a couple of FR1039 (listed at Vibroworld, but not for sale). Could I use them?

[rocket]

VDR Datasheets

Are there data sheets available for FS308 and FR1039?

[Elbow Swamp]

Magnatone Varistors are available on eBay ?

NOS Varistors