Mixer Volume Taper

Hi. This is my first post to the forum. I have been using my Kinotone Ribbons and really love this device. I make experimental music using mostly “cracked” electronics. I especially love the touch effects available in this pedal. My favorites so far are the degradation loop and the magnetic dace effect.
I have noticed that with the mixer knob centered I hear about 50% volume levels for each. With the mix knob completely to the right or left I get 100% volume level for either wet or dry. This leads me to believe the taper is linear from left to right and vice versa, resulting in the 50% volume levels when the mix knob is centered. I’m wondering if it’s possible to adjust the volume taper to be more curved – like a DJ crossfader – so that both signals are near 100% when the mixer knob is positioned in the center. I hope all of this makes sense. Thanks!

Hi @toner ! Thanks for sharing your thoughts on this. You are spot on in that we use a linear crossfade.

In general, Ribbons is a guitar pedal so my assumption was that the dry/wet mix knob would mostly be used to obtain a chorus effect when used in combination with the tape effects.

I thought it would best to use a linear taper for this because the dry and wet signals are correlated, so you end up with about equal perceived volume as you crossfade between dry and wet.

Now, Ribbons is a little different because the mix knob also serves as a global volume control for magnetic dance, loops, etc. Those signals are uncorrelated and so an equal power curve might be more suitable.

Orange is the current crossfade approach, dotted blue is a fast approximation of an equal power curve.

I don’t want to go the DJ mixer route because that could lead to a +6dB boost when at the mid point. I haven’t ever looked at a DJ mixer schematic but I think they might do something like an equal power curve too.

I’ll play with some things in the firmware and get back to you.

Thanks for the response. Here is an article I found about the history of the DJ crossfader. It looks like there are some variations as well as some mixers that have multiple options.

I started wondering about how my Red Panda Tensor pedal’s “blend” knob works as this “seems” to have a curved taper. I don’t actually know the taper, but after digging into the manual, the volume mix “blend” knob seems to depend on the bypass option you’ve selected.

OK, that’s all I’ve got for now. Thanks for the discussion and thoughtful response.

Jaak,

It’s nice for the chorus/flange at around noon for the MX controller 50/50 mix. (green page top right knob) But that particular chorus/flange effect sounds way to dull so I run my ribbons on MX=100% or 5 o’clock all the time. It reminds me when you use any DSP effect in sent fx loop. the 10ms always get you the flange/phase effect. And this is not as simple to solve. I suppose choice of mono WOW and FLUTER are direct results of this phenomenon. I suppose you do the mixing in the DSP domain thus both clean and wet are not delayed to create flange/phase effect. So the chorus I hear is contribution of Wow, Flutter to the wet signal ? I need to check if I still hear flange/phase effect if both page2 and page3 effects are disengaged. IF yes then I’d just add delay (10ms or what ever the DSP for the wet needs) on the clean channel to “remove” the flange while mixing then you could perhaps enable stereo on Wow and Flutter :slight_smile:

Real-time DSP will always have some tiny amount of latency from input to output - in the case of Ribbons, this is 1 millisecond. We do the dry/wet signal mixing in software because if we did an analog dry/wet mix it would result in a fixed comb-filter / flange effect that can’t be dialed out.

Pitch modulation effects require additional latency, so we add extra depending on the depth knobs of the various modulation parameters. So there should be no chorus/flanging effects with the mix knob if wow, flutter, dropouts, and crinkle are set to 0.

We don’t do separate processing on the left and right for wow and flutter because it’s not something I really observed on the tape players I studied and in some situations created undesirable phasing issues. Stereo everything is not always better (IMO). :slightly_smiling_face:

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