ring mod stompbox

vmgas · Post by **vmgas** » Thu Jun 07, 2012 1:53 am

friend of mine was looking to build a stompbox ringmod..she was borrowing a frequency analyzer from somebody and had to return it
she asked me if was aware of any kits or anything to build a ring mod
any tips?

fonik · Post by **fonik** » Thu Jun 07, 2012 3:24 am

as a stompbox? then you would need an internal oscillator, i guess?

what about the MFOS ringmod? it is AD633 based, a classic ringmod. however you wold need to accomodate the input impedance to match guitar levels, i guess. and the PCB may be a little bit on the large side for a stomp box?
anyways: MFOS RingMod (AD633)

valis · Post by **valis** » Thu Jun 07, 2012 10:57 am

The PAiA CA9 balanced modulator might also work for you. It's a balanced modulator and not a real ring modulator but it may work better for your applications.

J3RK · Post by **J3RK** » Thu Jun 07, 2012 11:04 am

Funny you should ask this. I just finished up a small board layout for a ring-mod last night. It uses an LM13700, and is roughly based on the one in the datasheet, and this one here: http://experimentalistsanonymous.com/di ... %20mod.pdf which is a modified version of the one from the datasheet. It's extremely simple, and should work off of a variety of voltages. (though it would need a bipolar supply)

I'm working on a way to use the second half of the LM13700 so it doesn't get wasted though, so a rev 2 is in the works now. (possibly some form of additional CV input or internal oscillator) I'd be happy to share my schematic/board layout for the rev1 if you'd like.

haiku-ish · Post by **haiku-ish** » Thu Jun 07, 2012 11:06 am

i did one for a friend

half passive one (transformers and diodes)
and a negistor as oscillator one input, and a transistor preamp as the second input for guitar. and a buffer at the output

RealDudes · Post by **RealDudes** » Thu Jun 07, 2012 11:26 am

J3RK wrote:I'm working on a way to use the second half of the LM13700 so it doesn't get wasted though

distortion/tone control?

J3RK · Post by **J3RK** » Thu Jun 07, 2012 11:29 am

RealDudes wrote:
J3RK wrote:I'm working on a way to use the second half of the LM13700 so it doesn't get wasted though
distortion/tone control?

That might be fun. I hadn't thought of that really. I was thinking about either an additional CV function, since the OTA is well suited to this, an internal oscillator, or trying to mimmick the low-noise (distortion cancelling) that is in the FadeX design.

Adding a bit of distortion or color might be more fun though, and would be something new for me. I typically do everything I can to clean up a signal.

vmgas · Post by **vmgas** » Thu Jun 07, 2012 5:05 pm

J3RK wrote:Funny you should ask this. I just finished up a small board layout for a ring-mod last night. It uses an LM13700, and is roughly based on the one in the datasheet, and this one here: http://experimentalistsanonymous.com/di ... %20mod.pdf which is a modified version of the one from the datasheet. It's extremely simple, and should work off of a variety of voltages. (though it would need a bipolar supply)

I'm working on a way to use the second half of the LM13700 so it doesn't get wasted though, so a rev 2 is in the works now. (possibly some form of additional CV input or internal oscillator) I'd be happy to share my schematic/board layout for the rev1 if you'd like.

yea thatd be cool
internal oscillator is going to be a must for a box..she was using a ring mod for vocals..my suggestion to her was to build a paia balanced mod, preamp, vca, and really simple diy vco and a plague bearer or something for a tiny little vocal processor but i dunno how invested she is into doing all that

J3RK · Post by **J3RK** » Thu Jun 07, 2012 5:49 pm

vmgas wrote:
J3RK wrote:Funny you should ask this. I just finished up a small board layout for a ring-mod last night. It uses an LM13700, and is roughly based on the one in the datasheet, and this one here: http://experimentalistsanonymous.com/di ... %20mod.pdf which is a modified version of the one from the datasheet. It's extremely simple, and should work off of a variety of voltages. (though it would need a bipolar supply)

I'm working on a way to use the second half of the LM13700 so it doesn't get wasted though, so a rev 2 is in the works now. (possibly some form of additional CV input or internal oscillator) I'd be happy to share my schematic/board layout for the rev1 if you'd like.
yea thatd be cool
internal oscillator is going to be a must for a box..she was using a ring mod for vocals..my suggestion to her was to build a paia balanced mod, preamp, vca, and really simple diy vco and a plague bearer or something for a tiny little vocal processor but i dunno how invested she is into doing all that

I believe a triangle-wave linear VCO would be extremely easy to build with the other half of the LM13700. (looking at the datasheet, half of the LM13700, an op amp, a cap or two, and some resistors.)

I have a little bit of work to do tonight, but I'll try to add this if I get a few minutes. Otherwise, I'll post what I have anyway. It would be fairly trivial for anyone to take the tri-portion of the VCO in the data sheet, and hack it in.

J3RK · Post by **J3RK** » Fri Jun 08, 2012 10:55 am

Sorry, I ran out of time last night, but will try to get the docs up tonight, and try out the VCO idea.

vmgas · Post by **vmgas** » Fri Jun 08, 2012 12:27 pm

jonah · Post by **jonah** » Fri Jun 08, 2012 10:06 pm

http://www.synthrotek.com/store/passive ... 09123bcc3d

The optical theremin as oscillator source might be a really interesting if it's for live use.

Another thing might be cool is making a feedback loop to go into the oscillator in.

Or you could wire up two cheap speakers on to the top and bottom of a wah style pedal and as you pressed down on the pedal they would create a feedback loop.

J3RK · Post by **J3RK** » Mon Jun 11, 2012 9:48 pm

Here's my very slightly modified version of the datasheet version, and the one I linked above. I'm trying out some ideas for using the other half as a VCO now, and will try to post those soon.

vmgas · Post by **vmgas** » Tue Jun 12, 2012 2:38 pm

sweet

monstrinho · Post by **monstrinho** » Wed Jun 13, 2012 10:52 am

vmgas wrote:friend of mine was looking to build a stompbox ringmod..she was borrowing a frequency analyzer from somebody and had to return it
she asked me if was aware of any kits or anything to build a ring mod
any tips?

There'a a kit here:

http://www.delptronics.com/ringmodulator.php

and here:

http://www.paia.com/proddetail.asp?prod=CA-9&cat=14

MUFF WIGGLER

MUFF WIGGLER

ring mod stompbox

ring mod stompbox

Re: ring mod stompbox