Ampmaker P1800 footswitch mod: done

paulnb57

Now you have done it, has it met your expectations?, and will you be releasing details/an idiots guide to achieving it

Fatfingers

Yes it's great. Most of the details are in this thread but if you want help with it I'm more than happy to talk you through it. I used a little channel switch relay board from Weber in the States. It runs from the valves' heater supplies. I think it was 10 bucks, although the postage was more than the board if I remember correctly.

paulnb57

Thanks for the offer, I need to buy and build the amp first!.....

Fatfingers

Well, I recommend that you do.

paulnb57

Wisdom!

Fatfingers

Finished it off with a little footswitch. I spent ages trying, unsuccessfully, how to work out what value of resistor I needed to go with an LED to indicate when the hot channel is selected.

Eventually I just stuck one in series with the switching circuit and it glows, but not too brightly, so I guess the switching relay's coil is about the right resistance!

paulnb57

So, what is the difference when you switch between inputs…...

Fatfingers

The hot channel switches in an extra gain stage - half an ECC83. It gives a lot more crunch and a handy volume rise. Perfect for solos, really.

paulnb57

Proper job, I'd better bookmark this thread.....