Based on the Aiwa pocket cassete player (walkman) preamp parameters. The waveform seems like the one what Korg AX100G calles american hi-gain sound. There the Treble pot causes the same edge as the second pot here.
If you turn pots here, "no solution" state can come. Than just restart by "t" and go on. ;)
Does anybody in Prague need english speaking czech electrician?
Call: 724511405
I think i have wide spectrum of skills. Just pride... 8-D