Champ micro as a reverb driver?

[Len058]

So I've got a champ micro and a 4 input Bassman micro. What if I plugged the guitar in the low gain input 2, then jumper the other input to the champ. Then instead of a speaker, a reverb tank and connect the output of the tank to input 1 of the Bassman micro?

Am I an Idiot for coming up with this?

 

[FenderLover]

Nope. There were standalone reverb units that took an amplifier output to use as the reverb driver, and had it's own SE amp and speaker with the tank.

Ampeg also did it on their Echo Twin. Speaker drives the tank, recovery side goes to channel 2 on the amp. They call it fold-back reverb. Supposedly Frampton's favorite amplifier.

 

[Phrygian77]

I don't see why that wouldn't work. However, it will probably be noisy because of ground loops, and you'd really want some more high passing in the Champ Micro circuit. You could swap the first coupling cap for a 500p, and that would probably work.

 

[Len058]

Great! Thanks

I'll start soldering the cables tomorrow, to test it. Looking at the original 6g15 schematic doesn't make me think I need another coupling cap for the driver. Plugging the output in the treble input is probably more important.

 

[Phrygian77]

Great! Thanks

I'll start soldering the cables tomorrow, to test it. Looking at the original 6g15 schematic doesn't make me think I need another coupling cap for the driver. Plugging the output in the treble input is probably more important.

No, I'm talking about reducing the lows going into the tank. The tank impedance isn't fixed, it slopes up with frequency. You need more drive at higher frequencies and less at low frequencies. This is the reason for the 500p cap and 1M grid leak arrangement for the reverb driver in the Fender AB763 and AA1164 circuits. The 6G15 has a 2000pF cap and a smaller grid leak of 220k, which creates a similar high pass filter.

 

[Len058]

I get it, thanks for the explaination. I'll have a look in my stash and probably look at e few more schematics, before I blow up my reverbtank.

 

[Paul G.]

Nope. There were standalone reverb units that took an amplifier output to use as the reverb driver, and had it's own SE amp and speaker with the tank.

Ampeg also did it on their Echo Twin. Speaker drives the tank, recovery side goes to channel 2 on the amp. They call it fold-back reverb. Supposedly Frampton's favorite amplifier.

My first quality amp setup was a Gretsch amp with an Ampeg "EchoJet" for the reverb. The EchoJet was similar to the Jet amplifier, you could plug an instrument right in, and it acted as an amplifier (no reverb). But -- it had a cable with alligator clips. If you connected the alligator clips to the speaker terminals of your main amp, it acted as a Reverb unit, with the delay coming out of the EchoJet speaker. The controls now worked on the reverb. Weird but quite effective.

 

[Len058]

I've got some caps on the way and I'm thinkingabout making a true springreverb unit out of the Champ. Maybe the TubeTown version, with an EL84 instead of the usual 6*6.

Still pondering