input boost for passive ring modulator?

madstringbean · December 15, 2009, 10:45:49 PM

Hi, I am making a simple passive ring modulator and in the archives of another forum I found this bit of advice regarding boosting the inputs with an LM386:

" Try, for both inputs, an LM386 wired like this:
Ground to 2 and 4
Input to 3
Electro cap from 1 to 8
output from 5
6 to 9v battery "

This is obviously just a start, and also I am going to be plugging all sorts of things into this and want to have a wide range in terms of how much the signal is boosted, from a lot of boost to almost none. How can I achieve this, short of building two entire Little Gems into the pedal?

PRR · December 15, 2009, 10:51:36 PM

> a wide range in terms of how much the signal is boosted

Put a audio-taper volume pot in front. Gain from 200 to nothing.

Top Top · December 16, 2009, 02:38:45 AM

essentially you will be building two little gems - give or take a few parts.

I built one of these (passive ring mod) and used the "beginner project" booster from this forum as the boost on the inputs. It works well.

madstringbean · December 16, 2009, 11:31:03 AM

Quote from: PRR on December 15, 2009, 10:51:36 PM
Put a audio-taper volume pot in front. Gain from 200 to nothing.

I think I'm going to go with this approach since I have the LM386s on hand already. may I ask though, why audio taper and not linear? I have some 5k linear pots on hand already and was planning to just use those.

the Little Gem has the gain pot between pins 1 and 8, would it make sense to put it there?

thanks.

madstringbean · December 17, 2009, 09:33:43 AM

Quotethe Little Gem has the gain pot between pins 1 and 8, would it make sense to put it there?

well, that didn't work. help, anyone?

PRR · December 17, 2009, 06:50:49 PM

> didn't work

Use more words.

T1bbles · December 17, 2009, 08:57:36 PM

Quote" Try, for both inputs, an LM386 wired like this:
Ground to 2 and 4
Input to 3
Electro cap from 1 to 8
output from 5
6 to 9v battery "

This makes a passive ring modulator? Really

Sounds too easy to me

madstringbean · December 17, 2009, 10:34:04 PM

no, the ring modulator is made out of transformers and diodes. the circuit described above is supposed to be a boost circuit to put before the inputs of the ring modulator.

I gotta try a few more things...

dr.benway · March 07, 2010, 11:51:57 AM

Hope someone can help me out on this. Didn't think it was worth starting a new topic. I've boxed a passive ring mod with boosts before and after the effect and a dpdt true bypass and I'm wondering if the true bypass should be placed before the boosts or after ? IN other words when the effect is off should the boosts remain on ?

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input boost for passive ring modulator?