inbuilt feedback loop...

[kissack101]

Hey,

I was thinking of building a Big Muff and had the idea of building a TSA style feedback loop into the body. Is there any way of doing this so that when the 'level' pot controlling the TSA is set to its lowest level, the feedback loop is effectively 'turned off'? (i.e. without the need of another switch? I'm not too bothered about being able to switch it 'on the fly')

As I understand it, the way the TSA circuit works is that the pot acts simply as a resistor controlling how much signal goes back round the loop? So it 'turn it off' you'd need a very, very high value? Only, I was hoping to use only a small range for the TSA pot, a feedback loop without the craziness that occurs at the higher setttings.

Is this possible? With diodes? Chips? I'm a willing learner but unfortunatly still just that, any help would be appreciated.

Thanks

Adam.

[Bernardduur]

I build a great feedback loop in my BMP by puttin a wire between the collector resistors of the first and third transistor. I turn it on with a simple switch and control it with a LDR I placed in the wire.

The sound is quite diverse. On my 1981 BMP I got "Nintendo" sounds, on my triangle BMP (clone) I got "perfect" octaves down

[petemoore]

  Well, that is interesting enough, and EZ nuff' to test out too !!! Thanks for cool idea Bernardduur ! Something to try out !
  The trick to TSA, IIUC, or something I tried with input sorta tied to output, is getting the exact right amount of resistance that doesn't just make it freak out. Freak out is cool too. I tried that on a DS-1 with a pot [I forget the value of..], and adjusting it for usability was..touchy..I would say 1 meg resistance should be large enough between I/O to restore 'normal' sound, Of course I'm just ramble-writing here.
  A schematic always helps visualize, perhaps some voicing in the FB loop'd be cool