Orange Squeezer - Pseudo Side Chain

[agschaid]

Hi there,

I want to build an Orange Squeezer and have a question regarding a minor mod I am planing to do.

The very short version of my question:
Refering to this schematic ( http://generalguitargadgets.com/pdf/ggg_osq_sc.pdf ) would it "just work" to insert two jacks between R11 and D1 so I can insert some other effect there?

Ok. Now a bit longer.
According to this nice explanation ( http://www.diystompboxes.com/smfforum/index.php?topic=54308.msg414842#msg414842 ) "R11, D1, R12, and C7 form an envelope detector". Makes sense to me. Now my idea is that if stuck some cheap EQ pedal between R11 and D1 I could do things like boost the signal to make the circuit "think" I play harder than I do. Or I could cut the bass frequencies (having something that works quite like a side-chain HPF).
So with my limited knowledge I am thinking this should "just work". But is there something not so obvious I might be missing? Are the envelope follower and the signal path decoupled enough by R11 to do this?
I'll just go for it and try it. But it would be nice to know about potential trouble ahead 

[garcho]

there are way better advice-givers here, but you'd want to be able to attenuate the signal before the diode, and maybe switch out the op amp output?

the AC is coupled by C6, resistors resist, they don't couple, or decouple

if you stick some other pedal in the side chain, it should be AC coupled with a capacitor at the output as well and shouldn't leak DC into the post C6 audio signal. the envelope DC is after the diode. sounds like a good idea, dig the side-chained HPF. oh yeah, and WELCOME TO THE FORUM!

[Transmogrifox]

You should put a buffer ahead of D1 and add another 1k5 at the output of the buffer so that the drive into the diode rectifier looks the same.

IC1(B) (which is unused) is already shown as a buffer.  Just disconnect pin 3 from ground and tie it to a network identical to what is formed on IC1(A) with C4, R4, R8.  That will be your sidechain input.

Final thing should look like this:
R11 -> Output Jack -> Input Jack ->0.047uF DC blocking cap -> 390K/470k Junction -> IC1(B) + -> 4.7uF cap -> 1k5 Resistor -> D1

Your basic idea is correct, but as stated you rely on your "sidechain" effects to maintain DC blocking and also have enough output drive.

As Garcho mentioned, you may also want to be able to add some attenuation.  In that case you may want to do this:
R11 -> 10k Pot (just like R13) -> Output Jack -> Input Jack ->0.047uF DC blocking cap -> 390K/470k Junction -> IC1(B) + -> 4.7uF cap -> 1k5 Resistor -> D1

[agschaid]

Hello there,

first of all, I am very sorry it took me three years (almost exactly) to respond  . . . I didn't have time that day, then I forgot, then my second child was born 

I'll try to make it up to you by posting a lengthy report/review (and hope that somebody is interested).

So.
The original plan with the EQ died quickly. As you hinted, the output of the OP was just too much for the EQ. It heavily distorted, resulting in almost no compression at all (which again resulted in a distorted sound of the OS). Frankly I was just too lazy to follow your advice to attenuate the signal before the EQ and then boost it afterwards. So that was the end to that.

BUT I went for a lower hanging fruit and just stuck a capacitor in series between R11 and D1. Actually it is a 3 position switch with two capacitors now (I'll try to come up with the values I used soon).
The idea was to let the envelope detector "see" less bass frequencies. I am a bass player and some dedicated bass compressors feature that kind of sidechain filtering so that's where I got the idea.

Back then I was not overwhelmed with the result. I thought it was too subtle.
But revisiting the pedal years later with a set of fresh ears (and more experience with compressors) I think this is a very very valuable mod. As far as I can trust my ears it affects the sound in multiple ways:

• first of all the string-to-string balance is improved. At least on bass I always felt that the stock OS squashed the E String far too heavily. With less bass in the sidechain the low strings do not get compressed that much and are (at least almost) as loud as the higher ones.
• overall there is a tad less compression, even on the higher notes
• There is more low end punch. My theory here is that the punchy transient in the low frequencies is slower than the zing in the high ones. So now, while the compressor is already clamping down because it was triggered by the high zing, we still get a little envelop bump from the slow punch that basically goes unnoticed by the sidechain (and thus doesn't cause the compressor to work harder). This is quite noticeable when playing with the band.
• The tone gets a little bit darker. Again I think this is because the relatively untamed low punch dominates the restrained high zing, resulting in a darker sounding attack.

Now the switch position with the bigger capacitor (=less filtering of the side-chain) is definitely a keeper! You still get that funky (or chicken picken') OS effect but the whole package is much more bass friendly. And even a little bit up the fretboard, the notes just get a more lively powerful feel. I think some guitar players might like that mod too.
The position with the smaller capacitor is interesting too but probably too much. The OS loses a lot of its funkyness and sounds rather "normal" (not bad though). The OP is overdriven much easier and the sound is noticeable darker. If you increase the gain of OP you might be able to mod the Squeezer into an interesting "compressed overdrive" that way.

If I should ever need that switch for something else (C7-switch for example) I am deffinitly going to hardwire the bigger capacitor in.

So once again: a very nice and easy mod that you really should try. Actually I am wondering why I have never seen it before . . .

[GGBB]

The high-pass filtering idea works well - it was one of the better features of the orange smoothie. You might find a way to do the side-chain with the smoothie as it separates the signal path from the envelope detector. You may also want to have a look at the tangerine peeler by Mark Hammer.