External oscillator via Audio In?

The Moog Forum Little Phatty & Slim Phatty Forum
1

Hi there.

I’m pretty new to all of this, so any help would be appreciated.

I’m trying to connect an external sound source (in this case a Poly Evolver) as an extra oscillator via the Audio In on the Slim Phatty. Shouldn’t it be pretty straightforward? Poly Evolver audio out/headphones → Slim Phatty audio in. This should add a note as an external sound blending it with the internal Phatty oscillators before it hitting the filters, right? Nonetheless, no sound comes from the Phatty. What am I doing wrong?

On a similar note, I would also very much like to try playing through the Phatty from a poly source. Here is what the Slim Phatty manual states:

"The SP’s Audio Input is not limited to processing monophonic signals - it can work well for processing polyphonic signals, too. For example, connect the MIDI Out of the SP to the MIDI Input of another polyphonic keyboard, then feed that audio output back into the SP through the Audio In jack. Now you have a POLYPHONIC source that is being affected by the SP’s Filter, Overload and EGR circuits. "

This I don’t get. Why the MIDI from the Phatty back to the poly source? I obviously haven’t tried this yet, but shouldn’t it function somewhat like above: poly audio out → Phatty audio in, or would that not work when playing several notes (poly) at the same time?

2

You can only hear external audio when a note is being pressed.

With the keyboardless Slim, this would normally be a note signal from an external keyboard, such as your Poly Evolver. In other words, there should be a MIDI cable connecting the Evolver’s MIDI out to the Slim Phatty’s MIDI in. The Slim won’t know or care whether the incoming audio signal (separate from the MIDI signal) is monophonic or polyphonic. I apologize if I’m spelling this out in too much detail. Someone who has an Evolver already knows more than I do; I’m just trying to help troubleshoot, and sometimes it’s the simple things that trip us up.

If you want the Phatty to process audio without holding down a note key, you can plug a a dummy cable or patch cable into the KB GATE jack on the back of your Phatty. Don’t connect the other end of the patch cable to anything else. When you do this, the amp and filter envelopes are bypassed.

Forgive me if I’m missing something; I agree that the manual’s description of connecting a polysynth is a bit odd. Since the Slim Phatty doesn’t have a keyboard, maybe this was originally written for the Little Phatty and not completely revised.