Stompboxology Ring Modu-Matic

soggybag · June 12, 2009, 01:13:36 PM

Hey Morocotopo, I did build the Tremolo-Matic X from your PCB. It seems to be working pretty well. I like the sounds it makes. I have not boxed this up yet.

I get a little bit of harsh noise when I hit a loud note with humbuckers. I think this is over driving the 570. There was a mention of this in the notes. The notes suggest this can be fixed by reducing the gain of the input buffer by reducing R14. There seems to be a voltage divider on the ouput, so the gain could be brought up by playing with R16 and 17.

One mod that I did was to change R25 to 100K. Which gives a much better range on the slow speed. I'd like to get the fast range to get a little faster. I think this might accomplished by reducing R21.

There is a Tremolo project in the Stompbox Cookbook that uses a very similar design. This adds an extra adjustment called Static gain. This looked another easy mod that could be added to this design.

This project gave me some great ideas.

Trem Fuzz. This is not finished. I wanted to change the input to a non-inverting arrangement.

Tremolo with FX Loop. This was an extension of the Trem Fuzz. You could put your favorite fuzz/distortion in the loop.

Morocotopo · June 12, 2009, 03:36:41 PM

Soggy, great to hear my PCB is of use to someone. Yes, I also got some distortion with humbuckers. Seems to be a problem of most circuits using the 570, like the DC2 dimension chorus, etc. I tried all the mods suggested, but never got the noise floor low enough to where I wanted. Did eliminate the distortion, though. Oh, I also did something to extend the speed max/min range, switched resistors in series with the pot as I recall. I think I´ll retrieve this from the semi-finished circuits box...

Nice schems!

Gila_Crisis · June 18, 2009, 05:35:33 AM

any news about the ring modu??

soggybag · July 02, 2009, 12:35:38 AM

I just finished the board and gave it an initial test. The oscillator seems to be working but. The dry signal is weak and the oscillator doesn't seem to be shuttin off. I suspect an error somewhere in the input buffer.

So far it sounds like a ring modulator. The low pass on the carrier frequency has a nice effect on the ring mod sound. Fix the problems and test again...

Taylor · July 02, 2009, 05:34:03 PM

Do you think your PCB is right? I was going to make one, but wanted to know whether you think your problems might stem from a PCB error, or construction/parts error.

soggybag · July 02, 2009, 05:56:45 PM

I'm not sure where the problem is. I'm going to break out the audio probe and test tonight.

soggybag · July 03, 2009, 12:56:01 AM

Stop the presses! Looks like swapped the + and - inputs on U4B. Updated and corrected schematic and PCB coming up...

soggybag · July 03, 2009, 09:58:14 PM

Here's an updated version. This fixes the problems that I found. This is still untested.

Gila_Crisis · July 05, 2009, 06:03:44 AM

good good, let us know if the new version works better.
if you can dosome sound samples it would be awesome, i'm really curious to hear this in action!

soggybag · July 05, 2009, 10:47:35 AM

I haven't had time to make a new board yet.

I did modify the first one I made to fix the input buffer. Now it's sounding more like it should. I think there still is a problem around U3A.

Taylor · July 07, 2009, 07:05:03 PM

It may still be too early for you to say, but how would you characterize the sound of this ring mod? I want a clean RM to complement my Ring Stinger (which is slightly distorted even at its "cleanest"). Would you say this is along the lines of the EHX Frequency Analyzer sound? Having a triangle carrier generally means it's more buzzy and full of extra harmonics - using the lowpass, are you able to get it relatively mellow (as much as can be done with ring modulation, anyway)?

I'm definitely going to build this once you get it worked out.

soggybag · July 07, 2009, 07:27:13 PM

I would say this makes a good clean Ring Mod sound. I this is due to the low pass filter on the carrier frequency. I suspect this rounds off the triangle wave into more of a sine. The signal going in is clean also. The Ring Stinger has some diodes in the feedback loop of the input buffer. The arrangement is similar to a Tube Screamer, though not exactly the same.

Taylor · August 27, 2009, 08:49:29 PM

Er.... anybody notice anything strange about this thread? And all others which mention the name of the book by Mr. Boscorelli? If I try to write the word which would mean "the study of stompboxes", it comes out www.diystompboxes.com.

What happened here? Is that word now off-limits for some reason?

soggybag · August 27, 2009, 09:10:53 PM

That's pretty weird. I wonder what the logic of that is? Maybe Mr. Boscorelli has been found...

Let's test it out: stompboxology should say ompboxologystay if remember my basic pig latin.

Taylor · August 27, 2009, 09:53:42 PM

Nope, redacted. Aron must have put in a word filter, but why? Is Boscorelli on the "ZVex List" now?

soggybag · August 27, 2009, 10:27:23 PM

That is very funny. Why filter stompbox-ology? There haven't been any flame wars related to it. Mr. Boscorelli has disappeared so he must can't have complained.

Looks like someone has done something with the site com.ygoloxobpmots take a look. Looks like the domain name is now owned by Tim Reid from Texas. The plot thickens...

soggybag · August 28, 2009, 10:47:54 AM

And the next day everything is back to normal, very mysterious.

oldschoolanalog · August 28, 2009, 11:48:42 AM

Quote from: soggybag on August 28, 2009, 10:47:54 AM
And the next day everything is back to normal, very mysterious.

Hmmm...

The Tone God · August 28, 2009, 03:01:05 PM

I think it was a leftover from the April fools prank.

Andrew

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Stompboxology Ring Modu-Matic