Moog Music Forum

Hi, recent Sub Phatty owner here, and thoroughly enjoying it

I am sequencing it from my modular, specifically/usually the CV and trigger outputs from a Doepfer A-155 analogue sequencer.

Question: are the voltages from the a-155 safe to feed straight into the SP, or do they need attenuating? I have read rumours that they're too hot and might damage the SP over time, but I haven't read any comments from either Doepfer or Moog.

Thanks!

The Sub Phatty manual probably specifies the voltage range for the CV inputs.
You'll need to compare that with the CV voltage outputs of your A-155.

(Per the manual, the Minitaur is CV of 0 to +5 volts, with a Gate of +5 volts. I imagine all the current Moog synths are the same)

FWIW -

I have a Doepfer Dark Time.
By default, it provides the CV voltage levels required by my Moog gear, but it is capable of providing much higher, depending on the settings of a couple of jumper pins.

Best to check the manuals or measure the actual output, rather than risk damaging your new synth!!

From the Sub Phatty manual:

CONTROL VOLTAGE IN

The PITCH CV, FILTER CV, and VOL CV inputs each accepts an expression pedal (such as the Moog EP-2) or a control voltage signal from 0 to +5 volts. If you connect an expression pedal to VOL CV, you can use your foot to control the Sub Phatty’s output level. If you connect an expression pedal to FILTER CV, you can sweep the filter cutoff in the same manner. The PITCH CV and FILTER CV inputs are calibrated so that a one-volt change in the control voltage will result in a one-octave change in frequency.

The KB GATE input accepts a +5 volt signal, which causes the Sub Phatty’s envelopes to trigger.

I don't think sequencers are a problem. Usually, their voltage out is between 0 and 5V. But double-check with the manual.

The Doepfer manual states these voltages for the whole a-100 ecosystem:

Trigger/gates: +12v

Audio signals: -5v to +5v

Control voltages (e.g. LFO): -2.5v to +2.5v

Control voltages (e.g. ADSR): 0v to +8v

So, bearing in mind that there will be some wonkiness if I send it negative voltages, my only question, which I suspect only Moog can answer, is:

- Will the Sub Phatty be damaged in any way if fed with these voltages?

That's probably a good one to send directly to Moog tech support ~
Personally, I would be a bit hesitant without getting some feedback from them first!!

If you do correspond directly with Moog about this, please share what you find out.
That might turn out to be some good-to-know info for other folks on this forum.

Good luck with this!

Randy

Maine wrote:The Doepfer manual states these voltages for the whole a-100 ecosystem:

Trigger/gates: +12v

Audio signals: -5v to +5v

Control voltages (e.g. LFO): -2.5v to +2.5v

Control voltages (e.g. ADSR): 0v to +8v

So, bearing in mind that there will be some wonkiness if I send it negative voltages, my only question, which I suspect only Moog can answer, is:

- Will the Sub Phatty be damaged in any way if fed with these voltages?

Yes, that's in general, across the A-100 system. However, I doubt the A-155 can send all of those. Usually, a sequencer only sends gate info (0 or +5V) and note info (from 0 to +5V). That's it. But, again, I'm not familiar with the A-155. Check the specific outputs for the A-155. Other modules send other signals, with different voltages, as you point out. In any case, the Sub Phatty can only receive 4 CV's: gate, pitch, volume, and filter cutoff. To use it with a sequencer, just connect it to gate and pitch. I'm pretty sure it should be ok. If you want to affect the volume or the filter cutoff, using other modules, then yes, be careful what voltages you're sending.

Unfortunately Doepfer's manual for the a-155 is devoid of voltage level info.

I've emailed Moog tech, and will report back ASAP.

Good news! The answer from Moog is:

"Generally we advise 0 - +5VDC for Gate and -5 --> +5VDC for the Filter and Pitch.

However the CV inputs are buffered and can safely accept up to 12V probably, and will clip at anything above that."

Good to know - thanks for sharing the Moog tech support info!

Might be worth looking at the Moog CP-251 for you -
It might be able to address some of the voltage mismatch issues between the Doepfer & Moog gear.

I did try to measure the V out of the Doepfer, but sticking a multimeter across an output patch cable resulted in nothing. What's the best way to measure a momentary trigger voltage?

The 12v trigger/gate will work OK. It's used an on/off switch, not a wave that might be "distorted". Have at it!