can I switch TS808->TS9 with a SPDT?

[Dimitree]

hi everyone
can I switch the 2 resistors in the tube screamer circuit to alternate between TS808 and TS9 by using a simple SPDT as shown here?



my doubts is, when the switch is in any position, the 3 parts not connected to the outputs are loading in some way the rest of the output buffer? or are them in a "true bypass"?

[FiveseveN]

Yes, the "unselected" part would still be connected. It might still be possible to do what you want, but you might want to take a look at this topic first: http://www.diystompboxes.com/smfforum/index.php?topic=108501.0

[Dimitree]

thanks for the link, btw I still need to switch the 2 circuits (as a request made to me)

my doubt was: when TS9 is connected, since R17 is still connected to ground, would that still create a path to ground from Q2/R13/R14? (and of course the opposite situation when TS808 is connected).

[mremic01]

I would just use a DPDT and switch between the two sets of resistor values. For what it's worth, you probably won't hear a difference between either. It's worth doing as an experiment to see whether or not it affects the tone. It's not worth doing if you think you're going to get a TS808 and TS9 sound on a switch.

For extra cool points, see if you can get a 6PDT and switch between opamps.

[PRR]

Let me know if that switch has ANY effect.

IMHO: the transistor swamps the 100/470 difference, 10uFd is 10uFd, and either 10K or 100K will pass far-far-far below the audio band (like 2hz versus 0.2Hz).

[antonis]

edit: I haven't seen the R.G. Keen's analysis so I double posted about output impedance..