Home Made Mixers
One of the things we found out early on was that recording straight into the tape machine sounded enormously better than a microphone (or two) stuck in the room which, obviously, contained the tell tale acoustic signature of living room (or bedroom) boxy reverb, coupled with lost high and low frequencies.
But once we had more than two things to plug in we needed to combine the signals and control the levels.
The first mixer was a handful of jack sockets on a board with variable resistors to dampen down the more powerful signals. To restore the lost signal level a head-amp from a car 8-track cartridge player was used. We were ferociously skint. I'd wait a week for my pocket money and then buy a jack plug, then wait another week and buy a jack socket.
Things picked up once we both got paid employment in the autumn of 1977.
I bought some faders from a surplus electronics supplier and designed an eight channel mixer around 741 op amps. Forgot to reverse the layout when etching the circuit board and had to mount all the components on the same side as the copper. The etching went all wrong where there were greasy finger prints on the board and bald patched where the etch resist pen ran too thin.
Once I'd bodged the board into shape with the necessary links and cut-aways the mixer seemed to work, in a lacklustre kind of way. One day I forgot to connect the batteries and noticed it worked exactly as well. I'd obviously strayed from the text book somewhere in the use of the op amps as the thing was effectively passive. Hey ho.
No photos exist but if you imagine a tatty circuit board with cheap components fixed on in a wonky way and oddments of recycled cable leading off to unmatched jacks and sockets then you have the picture.
The next mixer was a kit, as I concluded that - greasy fingerprints notwithstanding - my forte was assembly and modification rather than design.