Blend control with 100% dry + 100% wet

[petemoore]

  On that circuit fragment of Blue Box mixing, a resistance between the R20 wiper and ground...wouldn't that make it act more like a 'more of this on one side' when switched in, and fully wet or dry [depending on pot setting of CW or CCW]/
  I'm suggesting that circuit with a switched resistor [whatever still gives enough of the perception of 'bit more' of one side] be put right under R 20, then you'll have ... and we could use a bit of nomencalture..let's see...
  "Partial mix-out-er" [ie mixes 'deeply' enough to make one side heard pretty good with only a hint of the other side [thereabouts].
  And a 'Dead Sides' mixer [completely ground-shunts the signal on one or the other side when Cw or Ccw.
  Also would 'boost'..by raising resistance to ground from signal paths.

[kvb]

Not trying to step over Pete's point of using switches to adjust mix levels . . .
If that idea was used then a stomp would allow for two mix settings -

two separate volume knobs would be better
Any thoughts?

Some time ago I noticed people working on the clean-blend idea for a simplified version of a certain overdrive.
And the DIY common sense says that a bass distortion/fuzz needs a clean blend.

Now, the pile of wires that I posted in the pictures thread is a splitter blend with two dedicated circuits - one is a fuzz the other is a two stage booster (to retain polarity).

Each circuit has its own volume knob > then to the buffers > then the 25K mix pot.  There is no need for a master volume. Each effect is loud enough and levels between the two are easily controlled with the three knobs. I can bypass (shut off) the fuzz - or switch to a different effect - and retain the clean sound.
The whole thing can be bypassed as well.

So, I know the real question is about how to do all of this with one knob. Moog does it, but I'm sure it's more complicated than a splitter-blend.

[kvb]

OOOH, OOOH    Mista' Cottah  I think I have an Ideeuh . . . wait, wait

Back when I first started thinking about this, I thought that LEDs/LDRs could come into play somewhere.
I was working on the Tremulous trem/pan at the time.

So, I figured that the junction of two LDRs could be the point of output. But, this set-up, LEDs controlled by a dual ganged pot, would have the same problem as the pot all by itself.

But, what if the pot that was controlling the LEDs was this StewMac 0R when at its center pot.

At the center position, the R would be 0 and both LEDs would be full on (grounded through the pot). The R through the LDRs would be low and the signals would be allowed to pass at whatever level had been predetermined by the two parallel circuit's designs.

When the pot is rotated to one side, one of the LEDs will start to dim and the LDR will attenuate that side's signal.

As I type this, I realize that I don't really know exactly how this particular pot acts. But I figure it must be like my bass. When the pickup selector knob is in the middle, both pickups are on. when rotated to one side the opposite pickup is attenuated.

This could be a one knob solution, If I am correct. 

It would suck some juice, though.  Couldn't it also be done the other way around? LDRs with low resistance when dark? Then the blend would be with an LED being lit as the other stays dark.

Hmm.

[ihattwick]

Yes, you can wire up the stew-mac pot to work backwards, so at the center both sides have either minimum or maximum resistance. Unfortunately, these pots only come in 250k and 500k so they won't be useful with LEDs.

[kvb]

some very low, parallel resistance across the lugs might get us much closer to what might have the proper effect on an LED. Plus if things still do not work out in a direct relationship, the pot could be controlling something else that would control the LEDs.
Using LDRs might end up being a bit complicated anyway.

The Tremulous panner acts like a mixer when both LEDs are lit. 

If someone had two different circuits for the front half >  then the second half of the tremulous circuit with the LDRs, all we would need is a way to control both LEDs with one knob. Turn it one way, one of the LEDs starts to dim and chokes off that signal.

If the large value pots were used to control the LEDs indirectly, this would probably require a a circuit similar to what would be used for a voltage contolled amplifier.

A stereo, voltage controlled amplifier is probably what most EEs would suggest anyway.

Then I'd be at square one, needing to do a ton of reading.

I still like the LDR idea. Just need a way to get the two way pot to work.

Anyone know who manufactures this type of pot?

[kvb]

It would be possible to use the values of either 500k or 250k as part of a voltage divider such as what is found at the front of an LFO circuit.

If these op amps were not configured to be LFOs then they would just be supplying a constant voltage to the LEDs - in a way that is similar to what we see in the tremulous panneur.

It will take me a while to try this. I've got things I should finish first.