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WIGGLING 'LITE' IN GUEST MODE

Lopass gate
MUFF WIGGLER Forum Index -> 5U Format Modules  
Author Lopass gate
snoop
Hi!

Been trying to get hold of a single or double lopass gate(s), ready made module, but no luck yet. Is there anyone who makes them in 5U (Motm, .com, or modcan connectors). Tried bridechamber but no luck yet.

Not that familiar with lopass gates. But i suspect this module would be great for making percussion sounds?

Best,
Roger
essex sound lab
Cynthia made a limited run of them in Dotcom format. I don't know if she has plans to do it again...might be worth asking.
snoop
Ok, thanks. Mailed cynthia
snoop
Seems the Cynthia one is without resonance. But they have a production run with modules ready in about one month. I been looking at some youtube videos and the ones with resonance seems more usable to me

Roger
dude
a doepfer beauty case never hurt anybody... twisted
sandyb
the only resonant 5U low pass gate i know of was the diy one. pcbs are sold out it would appear (which is maybe why you've had no luck with bridechamber):
http://www.naturalrhythmmusic.com/lopass.html
the cynthia one is fairly good - especially if you run a couple together. i've never felt the need for resonance in an lpg. you could always patch it though if you end up with one that doesn't have it built in.

sandy
essex sound lab
sandyb wrote:

the cynthia one is fairly good - especially if you run a couple together. i've never felt the need for resonance in an lpg. you could always patch it though if you end up with one that doesn't have it built in.


I find Cynthia's Quad LPG to be more than adequate, but I must admit I'm no West Coast aficionado.
sandyb
essex sound lab wrote:
sandyb wrote:

the cynthia one is fairly good - especially if you run a couple together. i've never felt the need for resonance in an lpg. you could always patch it though if you end up with one that doesn't have it built in.


I find Cynthia's Quad LPG to be more than adequate, but I must admit I'm no West Coast aficionado.


they're absolutely fine lpgs no doubt. i have some plan b ones in my euro system. i prefer them to the cynthia lpgs a bit although they were both afaik designed by the same person. the plan b have a bit more ring and woodiness about them to my ears anyway. the cynthia ones ring pretty well for that classic lpg sound but i find they need hitting with a pretty sharp envelope to do so, certainly more so than the plan b.
imho, ymmv etc...

sandy smile
Peake
essex sound lab wrote:
sandyb wrote:

the cynthia one is fairly good - especially if you run a couple together. i've never felt the need for resonance in an lpg. you could always patch it though if you end up with one that doesn't have it built in.


I find Cynthia's Quad LPG to be more than adequate, but I must admit I'm no West Coast aficionado.


There is a bit of brassiness in it not occuring in the Buchla. And I believe that there is naturally a bit of resonance in the circuit.
snoop
Just bought one from thomas white. Anyone have opinions on using dual vactrol or 2 x single vactrol? Any difference? He could make it anyway i wanted it
Peake
Two single vactrols may have slight differences in response as there are two light elements involved instead of one, but all things are possible..

I don't know if I've ever seen it described. A dual vactrol is a single light source and a pair of receiving elements, correct?
snoop
Ehhh... personally i have no idea how these things are built. Just know that i like the sound. Gonna use it for percussion sound, specially fast percussion. So wondered what would be the best option and if there is a difference. Have heard very nice wooden sounds, and wet tamblalike sounds from these things
doctorvague
Peake wrote:
Two single vactrols may have slight differences in response as there are two light elements involved instead of one, but all things are possible..

I don't know if I've ever seen it described. A dual vactrol is a single light source and a pair of receiving elements, correct?


Yeah a dual one has the same LED but 2 photosensors in the same pkg. Vactrols vary a lot one to the next, I'm not sure technically why that is, but they do. I can attest to that after measuring some. Plus there are different types made with different materials that have widely varying response/recovery times, curves and different on and off resistances. It's reasonably a deep rabbit hole once you start down it.

I think of all the LPG variations I've heard demos of I gotta hand it to the QMMG for the most organic woody tone. Just one guy's opinion. I've thought about re-paneling one of those in 5U more than once...
Thomas White's sounds great too. Certain classic designs like this- it would be nice to be able to re-panel easily. In other words if the QMMG guy (sorry don't know the name) would sell a populated board that you could slap behind a dotcom or MOTM panel or whatever. Seems like something like that would sell, but what do I know. Maybe most of those kinds of DIY'rs already have the Thomas White one. Just a thought.

I had the Cynthia LPG and sold it. It just didn't do anything for me but maybe I wasn't using it right or something. I seem to recall STG saying that they wanted to see 10V vs the usual 5V to really make them sing.
bwhittington
essex sound lab wrote:
Cynthia made a limited run of them in Dotcom format. I don't know if she has plans to do it again...might be worth asking.


For what little it's worth, Cynthia told me she was out of the LPG business a few months ago, because of all the competing products. It doesn't hurt to ask, of course.

Cheers,
Brian
J3RK
dude wrote:
a doepfer beauty case never hurt anybody... twisted


I don't know... One may have... I know this guy....
doctorvague
J3RK wrote:
dude wrote:
a doepfer beauty case never hurt anybody... twisted


I don't know... One may have... I know this guy....


hurl anything hard enough
thermionicjunky
doctorvague wrote:

I think of all the LPG variations I've heard demos of I gotta hand it to the QMMG for the most organic woody tone. Just one guy's opinion. I've thought about re-paneling one of those in 5U more than once...
Thomas White's sounds great too. Certain classic designs like this- it would be nice to be able to re-panel easily. In other words if the QMMG guy (sorry don't know the name) would sell a populated board that you could slap behind a dotcom or MOTM panel or whatever. Seems like something like that would sell, but what do I know. Maybe most of those kinds of DIY'rs already have the Thomas White one. Just a thought.


Yeah, I have my heart set on the QMMG, but I would prefer to limit my Euro expansion to things that would be too much of a pain in the ass to convert. It's the VC damping that sold me. It appears to employ a panel component board connected to a main board with headers and Tony told me when it first came out that it should run well on +-15v. I would love to see the main board for sale.
Peake
Thanks doctorvague. So the answer would be, use a dual vactrol if you want (probably) tighter, more closely-matched performance, and two singles if you want/don't mind potential variation.

IIRC, the three VCAs on my old Buchla 212 module all sounded slightly different. You find which one is best for filtration, for VCA work, and go with it.

Yes, the vactrols do need a large voltage to get ringing. I don't have one to test right now but IIRC the Buchla envelopes put out 15V signals (I'm probably wrong). If you apply a smaller signal, it slews significantly. Try a sample and hold output and see that very large, sharp changes are unslewed, and what happens to the smaller. Part of the charm, but it prevents using a keyboard for tracking purposes, which is something I demand in a multiple-filter resonator. In a single filter, it's no harm.

I do remember, when controlling the Buchla via computer/CV conversion, to have to add a "note/gate" just prior to the one with which I wanted to begin recording on. The first note didn't fully open the filter/VCA. I didn't measure if it was the output of the Buchla envelope or not, or if said envelope required different/higher gating.
snoop
Thanks for all the information! I learn a lot around here. Thomas White was kind enough to solder a dual vactrol on the PCB + include 2 x singel vactrols in the package. That way i can check out the difference between the two myself. Exciting
doctorvague
I'm not an EE by any stretch, but I'm guessing you would need to change a resistor or 2 when going from 2 vactrols to a double one or vice versa. Twice as many LED's to light up with 2 separate vactrols vs 1 double one. I could be wrong about that - just a guess. It may not make any difference at all.
Peake
I remember seeing layout artwork on White's 292 PCBs for single or dual Vactrols, but I haven't checked his notes on whether it requires any change in the surrounding component values. My offhand guess is that none would be needed, but I'm not always right. lol
Funky40
i swapped from single to dual vactrols on a fonik LPG, no partchanges where needed.
bf
Peake wrote:
I remember seeing layout artwork on White's 292 PCBs for single or dual Vactrols, but I haven't checked his notes on whether it requires any change in the surrounding component values. My offhand guess is that none would be needed, but I'm not always right. lol
I have built the White LPGs both ways. There is no change in surrounding components necessary.

emdot_ambient
Yeah, no component changes needed...I haven't built mine yet (I've got 2 boards), but I'm planning on using 2 dual vactrols, one fast and one slow...then add a switch to flip between them.
Peake
Thanks for the info.

Now to test my Vactrol stock for the ringiest ones...

hmmm.....
haricots
I built one of these a while ago and love it but I'm not sure I understand the concept of the 'ring'. Are you referring to the loosness of the decay? Is it more common to inject a straight gate into it or an enveloped signal like you would with a filter or VCA?

BTW, it's a really easy build even for a hack like me. I have two more pcbs sitting around in hopes of building a dual at some point.
megaohm
haricots wrote:
Is it more common to inject a straight gate into it or an enveloped signal like you would with a filter or VCA?



By all means, slap it around with triggers!
It's one of the coolest things about using vactrols.

p.
sandyb
haricots wrote:
I built one of these a while ago and love it but I'm not sure I understand the concept of the 'ring'. Are you referring to the loosness of the decay? Is it more common to inject a straight gate into it or an enveloped signal like you would with a filter or VCA?

BTW, it's a really easy build even for a hack like me. I have two more pcbs sitting around in hopes of building a dual at some point.


i usually use a short(ish) length AD envelope. i like being able to vary the attack and decay separately to get the sound i'm after. triggers work well but don't give you this option.
pugix
I have two of these.

http://pugix.com/synth/resonant-lopass-gate/

Has anyone else used the VTL5C4 vactrol for it? It's slower response makes it less 'slappable'. I might switch.
sduck
I've built 4 of these - and used the vtl5c4 in one of them. I prefer the ones with the 3 most of the time, but sometimes the 4 is fun and cool sounding.
doctorvague
haricots wrote:
I built one of these a while ago and love it but I'm not sure I understand the concept of the 'ring'. Are you referring to the loosness of the decay? Is it more common to inject a straight gate into it or an enveloped signal like you would with a filter or VCA?


Yeah there is a natural decay they have- even if hit with a short square trigger it sounds like it adds a decay stage. That's part of that 'bongo sound'. Different vactrols have different ring (and attack too for that matter) - there's also a short non-instantaneous attack rise that contributes to the sound and there's the overall response curve too.
It's common, especially in Buchla land, to hit these with triggers and let the vactrols make the 'envelope' but you can also use an AD or ADSR of course. The LPG can be the filter, VCA and sort of an envelope all in one. applause

My favorite sounding vactrol is the Silonex NSL32-SR3. It's pretty fast as far as vactrols go. As a slower alternative to the VTL5C3 I always thought one of the common choices was the VTL5C2, not necessarily the VTL5C4. I've messed extensively with the others but have never used the VTL5C4 myself.

When I first read about the dual vs single vactrols I thought you were replacing the dual with 2 singles, not one single, that's why I thought the LED circuit might need tweaking (doubling the number of LED's). But according to the diagram, if you're swapping one single for one dual then it makes no difference. What's changing is only the photocell/resistance side of the circuit. Unless I'm misunderstanding something.
snoop
The deal was to replace one dual with 2 single vactrols, yes. My LPG should arrive anyday now. Will post some demos. I only make percussion and loops with my modular, so it will be... percussion sounds :-)
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