Project: Preamp Number 2
The board is a single stage OPAMP, but it can use a dual OPAMP or two singles.
I have modified the board and removed the switchable gain, and also made some changes to the feedback loop.
It's currently running two genuine NOS NE5534 OPAMPS from signetics.
The input relays were purchased off Ebay and are switched by a rotary switch on the front panel.
The volume is an Alps pot with IR control provided by an Arduino NANO.
Everything has it's own PSU fed from the single toroidal with multiple windings.
As soon as I find the schematic I'll post it!
I also have some RMAA test results somewhere as well.
This board has since been replaced by a heavily modified MBL6010 clone board
It now has the same board as Preamp Number 1