Cold Mac Ideas

[tttttom]

I ended up getting this on a recommendation from a photographer friend who’s also into Eurorack and, while it did nothing at all to help with my Cold Mac, it turns out it’s a great tool to clean up dust on your panels I heard back from Whimsical Raps: turns out my knob needs a replacement, so I’ll have to send it in for repair unfortunately.

[Auguste]

Ah nice thank you for the recommendation!! I defintly need something for dusting in tight spots even if it’s not going to help my cold mac. Ah no, I thought it may be the case, mine doesn’t look as though its improving either so looks like I will also have to send Whimsical Raps an email. Thankyou for your updates!

[kinggrump]

Hi hijacking this comment with a noob question Lol, but is it possible to use cold Mac as a standard vca as in patch a envelope into it to control Adsr of a vco? Considering getting one for my small system.

[mutedial]

Yes! You can use it as a VCA.
You could look at COLD MAC: A Technical Map which is a great guide or this thread which has lots of neat things you can do with it.

[kinggrump]

Thnx!!! I’ll check it out

[claasp]

i’ve got a scratchy pot on my CM and was wondering if the B10K will work ?

[midouest]

It should! I am planning on replacing a pot on my Cold Mac and AFAICT it uses the same pot as Three Sisters. I think all of the Mannequins pots are B10K: https://www.whimsicalraps.com/pages/support-faq#scratchy-pot

[claasp]

ahhh wonderful thanks:)

[license]

I’m not sure if anyone has posted this patch yet, but I just stumbled on this oscillator patch. Seems to only like a pretty narrow, farty frequency range. The frequency changes with the knob and is only audible from about 10:30 to 1:00.

• OR to SURVEY
• MAC to OR 1
• Listen to CREASE

Could be specific to my case, too, if it’s picking up some noise from somewhere.

Edit: Just tested, and as I suspected, this also works using AND1 in with AND out. This also gives a slightly wider pitch range, and in this case the knob enables sound from noon up.

There’s actually all sorts of similar patches, I think the significant part is getting CREASE involved in some kind of logic loop. Plugging into OR1 to start is handy because it’s normalled to AND1.

I don’t know why but I’m really into these “wrong” sounds. Coming out of a utility, they’re that much tastier.

[andrew]

can a comparator be mac’d ?

i.e. +5v when a signal is higher than another signal, 0v when low ? or any other way to get gates out of continuous signals ?

i’m a big cold mac baby!

[renegog]

As far as I know the answer here is—no. The logic section will give you the higher of two signals at the OR out and the lower of the two signals at the AND out. Depending on the signals this could theoretically make gate-y behavior I think? but not exactly what you’re talking about.

More usefully maybe—I have successfully used the crease output to give me a sharp rising edge for triggering things. There is a comparator in the crease circuit I believe! but obviously not what you’re talking about exactly either…

[eblomquist]

Can you say more about this? I have had a hard time grokking some of those aspects of CM …

Thanks!

[mdoudoroff]

I’m hesitant to ever say Cold Mac can’t do something because then somebody contrives some (sometimes convoluted) way to make it do it, at least sort of. But there’s certainly no binary/gate generation circuitry in Cold Mac. An entire fourth column of comparator outputs (gates) might’ve been an interesting expansion of the Cold Mac concept.

Cold Mac’s domain is really the continuously fluctuating voltage (audio or CV), and it excels at translating one fluctuating voltage into one or more others, with or without additional input signals. In that respect, Cold Mac is theoretically an ideal companion to a comparator module that depends on external voltages to compare, such as the best-in-class Joranalogue Compare 2. Cold Mac might derive one or both voltages for comparison (and/or it might provide the CV over the comparison window, in the case of a comparator like Compare 2).

[desolationjones]

Not quite what you asked, but if you patch A into OFFSET and B into FADE, then patch RIGHT OUT into CREASE IN, you should get a sharp rising edge from CREASE OUT whenever A exceeds B.

If your signals are relatively devoid of high frequency content (smooth CV), then this same patch might also give you a reliable trigger out of MAC by patching CREASE OUT to SLOPE IN and maxing SURVEY.

[mdoudoroff]

@desolationjones

Not quite what you asked, but if you patch A into OFFSET and B into FADE, then patch RIGHT OUT into CREASE IN, you should get a sharp rising edge from CREASE OUT whenever A exceeds B.

Love this. Just tried it, and it’s enough to trigger Maths or NG, but it can be tricky to dial in. Basically, we’re just exploiting CREASE’s discontinuity at 0v, and to a more limited extent, you can do so by patching straight into CREASE. (One variable is how sensitive the trigger input is on whatever you’re triggering.)

[renegog]

Well put simply, CREASE takes the voltage above zero and offsets it below, and the voltage below zero gets offset above—this causes sharp discontinuities (which are depicted on the front panel) that can be used as triggers (as @mdoudoroff points out, they’re not necessarily triggers that all modules will accept, so requires some experimentation). Sometimes, with nothing patched, if I want a manual trigger I will plug crease to something and simply turn survey past zero.

@desolationjones 's version of using crease this way is interesting because it uses FADE’s inversion at RIGHT output to give you the difference between two signals. This can maybe be understood more easily in audio terms because this is also how you get mid-side decoding out of Cold Mac—plugging stereo audio signals to FADE and OFFSET gives you FADE + OFFSET (mid) at LEFT output, and FADE - OFFSET (side) at RIGHT output. Maybe it’s more confusing to put it in audio terms but I’ve found that the easiest way of understanding the relationship between there.

As far as the AND and OR circuits I think the drawings in the technical maps are the easiest way to understand those, but I realized you can’t create gates or triggers out of nothing with those, it’s more a case of gate/trigger manipulation, because you’re not doing anything to manipulate the rising edge other than whatever rising edge you’re putting into the circuit… A sine wave in there with SURVEY at noon will give you discontinuities, but I don’t think they’d trigger anything that wouldn’t be triggered by the sine wave alone…

[crunchydrums]

Not sure if this is the right thread, but mine just came in today! Awesome back panel… Which side is the -12v?

[renegog]

red stripe towards where it says “-12” faintly in the green (not the white print—the other side)

EDIT: because of the type of header your power cable should only go in one way and it will be the right way.

[crunchydrums]

I totally didn’t even see this til you mentioned it! Haha thanks so much, hopefully I can spare someone else from asking the same.

[otaro]

Today I discovered a simple patch inspired by two patches from earlier in this thread that I had written down in my notebook: @praffensperger’s MacTimbre and @ghost’s Wavefolder. It generates high pass filter or PWM-like timbres through what I believe is a coupling of wave rectification and the crease circuit. To call it MacFilter is perhaps a bit of a stretch – but I do think it sounds pretty good!

CV in → Survey
Audio In → Left In
Right Out → Crease In
MAC → Slope In
Slope Out → Audio Output

Audio example here. First is a sine wave, then saw wave through Cold Mac to DPLPG, then the same but modulated by Channel 1 of Maths into Survey. Note that the saw wave sounds an octave lower.