Cold Mac Ideas


It’s the gift that keeps on giving - the more you look, the more you find.

I’d recommend Cold Mac first. For Reasons.


Ok, here’s a video.

This covers about 90% of what we went through on Wednesday at Control, but does so in about half the time. :slight_smile:

Hope I got it all mostly right!


Oh I have 44 minutes of shear pleasure possibly stumbling into new insights for the Cold Mac.


Class was insightful and informative. Thank you! I am going through the video to reinforce what you taught us and I’m excited about cold mac :slight_smile:


Just finished watching the new video and…


thank you so much for taking the time to do this video! super helpful! :raised_hands:


As only being 2 months into modular,
The biggest thing i learned was how normalling worked on Coldmac, and I guess on every module.

EX: when putting a bipolar LFO into FADE, I knew that the SURVEY knob would then be broken from LEFT & RIGHT But for some reason, I thought the survery knob would still effect the off set from where the LFO would modulate from. Its always dead center with a equal bipolar LFO.

this helped simplify Coldmac a little more.


Right! Alternatively, you could connect your LFO into the SURVEY jack, instead, and use the knob to offset the LFO. Moreover, you could also attenuate and offset the LFO in some other module (e.g., MATHS, Triatt, and a zillion others) before connecting to FADE. It all depends what you want to do and how. These are essential fundamentals of modular.


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Is this correct for a ring modulator?

OSCc --------> [L IN] ----> [L OUT] -->
            \–(-)-> [R IN]
OSCm ------> [FADE]

I don’t have a ring modulator in my rack to compare.

edit: cleaned up diagram.


Hi guys, recently I got a Coldmac as my Christmas gift and really enjoy it a lot!

However I noticed a phenomenon of signal bleeding in the MAC output while the survey knob turned all the way down (CCW) if using coldmac as VCA mixer. Same phenomenon is also seen in the crossfading circuit too. There seems some replies mentioned this before.

I really curious if this kind of VCA circuits that controlled by bipolar signal cannot be fully closed and this is its nature. Because this phenomenon can also been seen in Xaoc Praga mixer module. (Although this is not as significant as Coldmac because it appears only when the gain at my external mixer is opened to almost maximum.)

Figure1: from the manual of Xaoc Praga mixer module. When attenuator knob is all the way down, the gain always still has -55dB if it’s in bipolar mode and accepting -5V control voltage to close the VCA circuit.

Figure2: if it’s in unipolar mode (accepting 0 to +10V) and attenuator knob all the way down, the gain is approaching negative infinity, even if 10V CV is applied.


I think during the Coldmac lecture at Control, we tested that if you put some voltage into the OFFSET, you can push it beyond the +5 and -5 range on SURVEY. That might help close it all the way. Not by my system, but give it a shot. I think we had to push +10 or -10 through 2nd channel on MATHS.


20 characters of that should work!


On my particular Cold Mac, I get no bleed at all on MAC: turning Survey fully CCW fully shuts it off, even if I load up the inputs with signal.

However, my crossfader bleeds quite badly on the left channel for me (fails to fully attenuate the RIGHT input with SURVEY fully CW). My right channel seems well behaved. Dunno if this is a calibration thing, a tolerances thing, or a spiritual matter. Additional offset voltage through SURVEY or FADE from outside doesn’t seem to have any affect in this situation for me.


Cold Mac Idea for 2019: explain the origin of the name “Cold Mac.”


Tangent here: ADDAC has just released their model 306, which presents a comparatively straightforward and focused take on the “patch surveillance” concept. In comparison to Cold Mac, you get to directly dial in the voltage ranges that surveillance traverses. The 306 would complement Cold Mac for some, although the ADDAC is unipolar only, posing an integration inconvenience. The 306 appears to have jumpers to individually configure the voltage ranges of the five channels between 0-5v and 0-10v.


just got a cold mac! can anyone verofy the proper way to connect the PSU? my build is the one with the cabin on top of the tower on the back. there’s no red line and both -12 and +12 are on the same side of the image


Hullo! The cable should be prevented from being attached the wrong way because of the notch. But mine’s like this:


The header is shrouded, so there shouldn’t be any ambiguity, but I suppose you can’t completely trust that. Actually, if you look really closely, a tiny black “-12v” should be visible on the dark green side of the house. Red stripe to left.


thank you my friends :)))