(TAU PIPE) Stereo outputs from mono delay-based fx

[funkyfarm]

With chorus and flanger, I know two methods to output stereo from a monophonic process :

- panning DRY signal full Left and WET signal full Right (btw it doesn’t have to be always full…)

BOSS CE-3 uses this method.

- mixing these two sounds with three desk tracks : DRY set to Centre, WET panned to the left and –WET (phase opposition) panned to the right.

I dare some formula like :
Left = WET+DRY/2 and Right = DRY/2-WET


I guess BOSS CE-5 uses this method, and leads to a rather different effect (with no mono compatibility at all… notice Left + Right = DRY)


I’m quite lost concerning the JH-20 Phaser output configuration, in phasing mode. (which can be seen as delay based fx)

MAIN OUT mixes what I would call –DRY (Input signal inversed by input stage U1A) and the processed sound from U3A (WET) ; this output also feeds the audio feedback circuit (via RESO pot)

Setting the IC into a inverting mixer (+in to ground, etc), we can imagine output formula to be : MAIN OUT = -(-DRY+WET) = DRY - WET

AUX OUT

The same as above “–DRY signal” goes to –in of U4B, mixed with RESO signal.
WET sound goes to +in of U4B, via a set of 10k/56k resistors.
Does it mean lower the amplitude of WET signal by two ? then adding it to the two others ?

AUX OUT = -(-DRY+RESO) + WET
AUX OUT = DRY + WET – RESO ?

Can it just be seen from this point of view ?
Am I just real ridiculous with this kind of formulas ?

i've just noticed fx cancelation when those outputs are simultaneously set to centre.

[jhaible]

Most of these pseudo stereo FX devices start with something like positive mix on one side and negative mix on the other side. And then some of them (like the Tau) change that scheme slightly, to avoid loosing the stereo balance for extreme resonance settings; that's why with resonance turned up, the mix is different.
Doesn't avoid cancellation when mixed to mono, though.

JH.

[funkyfarm]

[jhaible]

[funkyfarm]

Thank you very much.
for all.

[funkyfarm]

The vibrato mode provides a really great effect.
I will use it further more.
But now i need to put back the potentiometers on the panel to compensate the level loss

("the loop is looped", i promised no more question)

PS : I also like to have a switch to slow down lfo rate ; will throw a sample of a slowly evolving sequence...

[jhaible]

[funkyfarm]

yes, i put another 470nF cap, via a switch, and it's slow cool !

[numbertalk]