CA Ring Modulator

[damnableman]

So Derelict78 (as Satan) gave me a Montreal Assembly CA Ring Mod for Christmas. It's awesome.
One question arises:
How loud is the carrier supposed to be? I understand it is not gated, but it is quite loud. I know this is normal in some ring mods, just not sure if this is the case with this guy. If this is its true nature, I'll carry on and learn to love the drone.

[multi_s]

iirc there is a trim pot on the pcb? i might be wrong, its been a minute, but i think there is a trim and you can try to null the bleed, but even in the best position it will not eliminate it. it looks likr someone at Michigan state has the pdf of the book, you can find the project at about page 98 of the pdf. https://msu.edu/~dougl126/Electronic%20 ... icians.pdf

CA states carrier bleed -40dB so that's not amazing but its hard to say what "quite loud" is in dB.

[damnableman]

Right on. I'm fairly certain the bleed is much more than -40 dB. Perhaps a previous owner got curious about the trimpots inside and cranked the carrier. I'll investigate. Thanks for the link.

New question: I tried throwing an M-Audio expression pedal in the Probe socket. That led to somewhat concerning static crackling as I swept the treadle. I'll not do that again. What resistance were the LDR probes that accompanied the first batch?

[multi_s]

honestly i do not know at this point.

my guess is somewhere around 10k min/bright . you could use a pot to see what is a good range. iirc you need a trs plug, then take like a 1 meg pot or 100k and put the wiper to tip and ccw lug to ring. do not connect the third lug. do not connect anything to the sleeve of the trs. now just dial the pot and see if it is a good range/ stop dialing when the resistance is too large and measure what that resistance is. etc.

an expression pedal will not work.

[damnableman]

Excellent. Thanks for the info. I'll investigate further.

[Jwar]

I had one of these back in the day. I liked it and that's saying a lot because I fucking hate ring mods.

[damnableman]

Update: "quite a bit" may in fact equal -40dB. The carrier was MUCH louder when adjusted in either direction.

Time to learn to love the wave.

[Jwar]

Update: "quite a bit" may in fact equal -40dB. The carrier was MUCH louder when adjusted in either direction.

Time to learn to love the wave.

Would it help putting it in a bypass looper? I know that helps with noisy stuff but I have no clue on carrier bleeds.

[damnableman]

Nah, it only bleeds through when the pedal is on, so the bypass looper would be redundant. Something like the Zvex Loop Gate would probably work to minimize the bleed between notes. Or a noise suppressor with a very high threshold.

Either way, I'm not worried about it. Sometimes we must learn to love the world as it is.

[LaoWiz]

I had a couple of boards for these. Reminds me that I still have the second one unhoused.

I remember adding another 500ohm trimpot in series with the one called out for in the schematic or Scott's part list and was able to whip out the carrier completely. That's pedal has always been one of my favs because of the effects loop. Sticking a Noise Ensemble circuit or any fuzz with delay in the loop with the ring mod frequency at one certain setting is one of my favorite sounds ever. Super haunting and fucked up sounding!