which stompboxes invert the signal

[numpty]

Has anybody compiled a list of stompboxes which invert the signal or those which don't.

[petemoore]

  I have a bit of trouble with this too.
  One way that would handle all circuits is to figure out 'what inverts' and add the non-inverts and intverted stages to find whether it comes out as a '1' or a '-1'.
  see I don't know or know where exactly to look...
 

[Sir H C]

Most wahs invert, one transistor boosters invert, pretty much every common emitter gain stage inverts, so if it is an odd number the signal is inverted, even not.  So a fuzzface doesn't invert, nor the maestro fuzztone since one stage is a common collector follower.

Opamps and digital gets much harder to say.

[Johan]

why would it be important?..when recording vocals in a studio, wearing headphones..that I can understand, but for playing guitar?...if you're out of phase, take a half step back and you're in phase againg...classic Marshall amps are out of phase, classic fenders in phase ( and the fender bassman marshall copied, played out of phase, but had jensen speakers playing out of phase again, puting it back "in" phase, wich the marshall's celestion's didnt)...did you ever notice?....only situation I can imagine you would notice is if you run your pedals in parrallell instead of series or in an parrallell fx-loop...if you builld a high gain fx, such as a fuzz or a compressor, it is much easier to do it if it is inverting the phase...much less risk of oscillation and such problems...
I'm sorry if a come across as a wiseguy, but this is one of those things many people get obsessive over, when it, in a real world, doesnt matter...
j

[johngreene]

Unless you run two amps, one dirty, one clean and the box you want to use for dirty inverts. Then you have a problem with the two amps being out of phase.

--john

[Johan]

Unless you run two amps, one dirty, one clean and the box you want to use for dirty inverts. Then you have a problem with the two amps being out of phase.

--john

yes, but that would fall in the parrallell category...and you would have the same problem running a fender twin next to a marshall 1959...
j

[MarcoMike]

This tread gave me an idea... what if you run your signal parallel into a non-inverting octaver and an inverting booster, then mix them again. can you subtract the clean sound and leave just the octave? 

[numpty]

I want to run certain commonly used effects in parallel or mix the outputs.Its not a problem though as I will test each combination with an oscilloscope to see if the out put has been inverted or not and then decide whether phase inversion is necessary, I just though somebody else had maybe done this so i could save some time and play my guitar instead.
Thanks

[johngreene]

Unless you run two amps, one dirty, one clean and the box you want to use for dirty inverts. Then you have a problem with the two amps being out of phase.

--john

yes, but that would fall in the parrallell category...and you would have the same problem running a fender twin next to a marshall 1959...
j

Right, but a lot of people run two amps in parallel (of the same kind) to get a mix of clean and dirty. To them, it matters if a pedal is inverting or not. Other than parallel operation, or Eric Johnson, I don't think it matters much. Especially when you consider in a studio situation, the mix console has the ability to invert the phase of any channel...

--john

[petemoore]

Most wahs invert, one transistor boosters invert, pretty much every common emitter gain stage inverts, so if it is an odd number the signal is inverted, even not.  So a fuzzface doesn't invert, nor the maestro fuzztone since one stage is a common collector follower.
  Let me get this straight in my head, I have memory troubles...
  FF is non inverting, wah inverts.
  A gain stage [collector/drain output] inverts once.
  Emitter follower stages are Non Inverting.
  Omega is inverting [Jfet gain stage>mosfet source follower].
  ?opamps which have signal input to + are non inverting?
  opamps with input to - are inverting?
  I'll be having to figure this out soon, I'm planning a 2 amp system.

[oskar]

  ?opamps which have signal input to + are non inverting?
  opamps with input to - are inverting?

correctemente...   

[DWBH]

What's in and out of phase, anyway?

[Pushtone]

What's in and out of phase, anyway?

Wkipieda to the rescue

http://en.wikipedia.org/wiki/Destructive_interference



First graph show two signals IN phase. When they combine electronically you get more amplitute.
Second graph show two signals OUT of phase. 180 degree out of phase. When they combine they cancel each other out and you get almost no amplitute.

This only works this clearly with sine waves. With two amps and complex waveforms you will get some frequency that cancel and others that get boosted.  This is called comb filtering because the resulting waveform has many peaks and valleys like the prongs of a comb. The sound will be "hollow" and lack bass.


More from Wikipedia:
http://en.wikipedia.org/wiki/Comb_filter

[WGTP]

If it's a problem with 2 amps being out-of-phase, switch the speaker wires around on one of them.   

[DWBH]

Thanks pushtone.