freestompboxes.org

Hi everyone !!! In new here so i have a couple question about preamp !!! I've built 3 point to point amp but never one all by myself !!! So... My question is : I'm building the P27 100W ss Amp but i want to have 2 chanels ( one like the Engl 530 and one like the SLO already have the schematic + keeping a clean one !!! So if someone can explain me how to do it and what do i have to understand, i will be very greatful !!!!

So thanks

The way I do it is to take the input jack to a buffer stage, then to a CMOS switch IC (I use the 4066 mostly). The CMOS switch can then be used to route your signal to either pre-amplifier. The output end of each preamp should be matched in level - I use two Volume pots - and then through another couple of 4066 gates to select the preamp to the master volume control. The control lines of the 4066 can be buffered with transistors, and you can have an external switch for channel change - one on the front panel of the amp, and one on the floor.

Thanks for the info !!! Do you have a sort of schematic to do that ????