Champ 600 Built-in Reverb

Champ 600 is very compact amp, but it sounds better with a little reverb. There are many reverb pedals/units available, but I like the idea of built in reverb in this very compact amp so I added a accutronics BTDR-2 digi-log reverb to a Champ 600. The brick robs some gain, but with the amp converted to a 5F1 type circuit it sounds pretty nice. I haven't got any experience with the older Belton bricks, but this Accutronics branded one looks smaller and fits very well in the small chassis.

First I tried to get the 5vdc needed by the brick from the filaments; I converted the filaments to DC and added a regulator for the brick. The reverb sound was very ugly and metallic, the regulator needed more voltage than the rectified filaments could supply. Then I took apart a 110-240 ac-to-usb adapter (1€ from eBay); the innards fit in the chassis and it supplied the needed 5vdc 100mA. I grounded the brick power supply to the volume pots ground leg and it worked nicely without any noise problems.

I tried to keep the component count as low as possible, so everything could fit inside the chassis. The trimpot in series with the brick input sounded best at about 91kΩ, smaller than that the reverb got a little "slappy". The delays got more pronounced, which I didn't like.

The reverb pot is connected parallel w/ the volume so I can get "reverb only" sound like in some Gibson amps.

The overall reverb sound cannot be compared to a real spring unit, but for this amp its good enough IMHO and makes a really compact package without a need to haul a reverb pedal and extra cords for low volume playing situations.

I attached the schematic and a little sound clip if anyone is interested.
http://www.youtube.com/watch?v=ZebaPMhm5nM
http://www.youtube.com/watch?v=ZebaPMhm5nM

What a timely post, this afternoon I was looking at a reverb pedal kit wondering to myself why I couldn't just build it into the amp instead of a pedal.. . I like how you think! :mrgreen: