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DIY Stompboxes => Building your own stompbox => Topic started by: numpty on July 26, 2011, 02:34:59 PM

Title: twin channel preamp wah type treadle type panning pedal
Post by: numpty on July 26, 2011, 02:34:59 PM
I have built a 2 channel tube pre-amp.Each preamp has different tonal characteristics. I would like to use a wah pedal with a stereo panning pot to mix between the two channels. They will feed a stereo tube power amp.I this a feasible idea? what problems may I encounter?The set up would be the guitar would feed two sets of pedals on a pedal board in to the stereo pedal which would feed the preamp.
Title: Re: twin channel preamp wah type treadle type panning pedal
Post by: numpty on July 27, 2011, 05:23:04 AM
I was unable to find a balance pot, the sort found in commercial hifi stereo amplifiers, but I think this circuit should do the job:
http://i783.photobucket.com/albums/yy113/sausage1953/pots-f9.gif (http://i783.photobucket.com/albums/yy113/sausage1953/pots-f9.gif)
Can anybody care to comment?  -I am aware that both signals need to be in phase.
Title: Re: twin channel preamp wah type treadle type panning pedal
Post by: joegagan on July 27, 2011, 01:20:45 PM
a buffer ahead will do nicely to even out response and send a nice signal to the amps. not sure if it is possible to do phase reversal with one trans / fet tho. i did some experiments for this a long time ago, lost the notes.
Title: Re: twin channel preamp wah type treadle type panning pedal
Post by: numpty on July 30, 2011, 03:33:49 PM
Sorry -a bit late but:
What would be the best for this sort of configuration, to avoid unwanted distortion/colouration/"tone suck", -Jfet or opamp? any schematic suggestions?
Title: Re: twin channel preamp wah type treadle type panning pedal
Post by: LP Hovercraft on July 31, 2011, 12:02:29 AM
The Splitter Blend from Runoffgroove does this very nicely and does have a switch for phase reversal in case one of your channels is inverted from the other.  I've built A/B faders into Ernie Ball vol pedals and they worked great.