Reckhorn Mini-Sub – Preamp

For those interested, here is schematics and gerber files ready for use, for non commercial purposes of course. I have corrected the two small mistakes, so should work perfectly.
Can be powered from the AMP PSU you use directly (must be a split supply with a positive and negative and a GND, of course).

I lately use JLC for pcb’s: only 2 USD for 5 PCBs!
It is dead easy, just upload the zip file and do the order; just drag and drop the zip file. …. pretty smart 😉

Schematics should be straight forward. Input pot needs to be Log and Xover Freq should be lin. Chose through hole components to make it easy for anyone to assemble.

For mounting on a back plate, use the pots, but I also made a hole in the PCB wher you can attach a smal metal brace which can also double function as a heat sink for the two transistors.
I’ll show later.

For the input highpass filter, you can calculate other values here:
Multiple Feedback High-pass Filter Design Tool
I chose 25 Hz with a small peak of +2 and +4 db. Really easy to calculate for other freq and more or less peak.

Schematics can be found here here

Gerber files can be found here