Phono Cartridge Spring Reverb

[heatwalk]

Here is an interesting one from the bench I recently had come in. Vox Conqueror, one of the early solid state Vox models. Among the issues it was in for was non-working reverb. Instead of those tiny transformers and broken tinsel leads, this amp instead used two phono cartridges instead, weird! Anyone else seen something like this before? One of the casings to the cartridge had cracked so some superglue got the reverb back. Hopefully it lasts, its been a few months so far so seems like its held up, finding that particular cart looks all but unobtainable.

 

[JohnRoberts]

I can imagine using a phono cart as a pickup, but not as a send to wiggle the wire.

JR

 

[NOON]

I don't remember where but somewhere over the years I've seen a design for diy reverb using a small speaker as a driver and a phono cart as the pickup.

 

[heatwalk]

I can imagine using a phono cart as a pickup, but not as a send to wiggle the wire.

JR

If you look in the first picture there is a transformer connected to the input on the left main chassis. Your guess is better than mine as to how it actually works. I just found the break and found that fixing that brought it back. Admittedly not a great reverb sound.

 

[soapfoot]

Farfisa Compact combo organs did the same thing—Acos GP71 phono cartridges to be exact. Does anyone have a good workaround?

I’ve got a Farfisa with a non-working reverb

 

[fazer]

I read on a Vox Denny or the engineer did not want to pay hammond the patent fee so he developed a reverb spring with a cartridge to not infringe on the patent. It was a bad choice and prone to problems. The circuit can be rebuilt to use a standard spring but then it’s not original. But I wouldn’t want bad original anyway. I would probably just use a pedal. This is the amp that has built in distortion circuits so pre input reverb also has its problems. Sorry I’m not more helpful

 

[the groke]

Danelectro spring reverbs as well! I have a broken Farfisa reverb and a broken Danelectro reverb!

 

[the groke]

This old post on theGearPage details a repair on a Danelectro made amp:

Vintage Danelectro reverb unit - help needed

Attaching the picture in case it doesn't load (I had it saved on PDF).

 

[the groke]

Also check out Enzo's posts here: AMPAGE Archive - search results

Enzo ( )
Tue Mar 2 01:41:27 2004
I have repaired a couple of the godawful things. I took a piezo disc out of a piezo tweeter. The original disc was two sided, and the metal parts that held it made contact on either side. SOme of the newer piezo discs have three layers, and the outsides are connected together with a separate lead for the center. If you stick this in the old holder, it shorts the two sides together. I had to add a layer of insulating material and a wire to get it electrically to fit. But it works. Sounds like doo doo, but it works.

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Enzo ( )
Sat Jul 17 00:10:05 2004
Sounds like the same one as the Sears amp, which they made.

I have fixed those before using a piezo out of one of those cheap tweeters. I carefully broke off a piece ro fit, and it jams down into the mounting little bracket. The basic Moto piezo was a double sided job, so both exterior surfaces were electrically connected. I had to add some insulation since the original was one side each, but otherwise piezo is piezo. They just stick up into the spring windings.

I give them credit for originality, but they sure soiund like crap. If you can't find the Dano drawings, look on a Sears amp drawing. I forget the tube complement.