Compression Sustainer

Ahhh...a Sunday where you actually have off....uh...

...right, what do you do?










There's Markus beta testing

Really prefer this one to the Orange Squeezer, getting a Squeezer right has a
lot of little pitfalls like radio, matching FETs and stuff, though it is way nice
if you hammer it right. But this one has a timing network like the SSL and just
works.

And a selectable two-position diode clipper for some real distortion.

But the fun happens when you set it on clean compression with endless
sustain and stick that up a Fuzz Face with some matched old Germaniums, yahaa...

DimmuBorgirSez="hi"

Makes me wanna design a double box and send it to a friend


Here are some sound samples (direct into DAC nothing on master bus, channels EQ/Rev/PPD)

Basic clean guitar

Standard diode distortion

And with the Fuzz Face, this happens.


Ah right - here, clickable for ye olde etchtank:



Dude who shared el schemo is mictester from over at freestompboxes.org, cool guy

It was once an original developed part of a bigger device but then got abandoned
by its mama...too bad but what the hey? It's alive

Nothing against stray kittens...

...heeere kitty kitty...have some milk.


And now....ROAR!


Isn't he just adorable?

Ah TL072 btw...I used an 082 I had floating around.

Looks coll. I'll have to try this one if I ever get a day off. 

You guys got jobs?
Very cool.
Thanks for this.

my OS doesn't work so good  and i'min the market
for a good gtr comp , are you selling boards ?

Yah sure - any and everything you find that the author's ok with, I sell

But I'd wait a while still because I'm not quite satisfied with this thing yet-
gonna rearrange headers on the layout so that I can do the groupheader
thing on it, and not have wire mess...ey Keith? (el hero)

add some transformers to make it balanced and turn it into a 500 series comp ala levelloc effect...

This is the circuit from freestomp.... forum, right?

For use with guitar, I would change the input cap to somewhere between 100nF and 10nF and the 1k resistor at the input to 10k. You can test it without actually messing with the board itself - just in-line it with the existing board, "insert" it instead of the "hot" input wire.

Similar compressor (a different design, but same basic principle) I used "always on" on the 2-bus in very early 90's, but in a "less serious" setup (jingles and such stuff). The results sounded quite good when played on the radio, especially considering the fairly low-end setup..

I used a DC coupled FET in the FB loop (BF245A) with slightly different biasing and CV circuit. Less capacitors seeing the signal..

Darn-it lukas....

Etch me a board, and I'll wire you a patchbay!!!  ;D

-looks fabulous, by the way!

I really ought to register at DIYstompboxes...

Keith

Yeeha! Now I'm really doing another rev.

The relay and effect boards go together, and all you need is el ribbon cable, bam.

That'll be Keef-spec wiring for sure 

Ha! -I'll come up with a way to make it even tidier!  ;D

Seriously though, send me one, with a bill.

Keith

Excellent! I'm finishing up all the small design jobs today, I'll just put it in the cycle.

Anybody else want one, gimme holler!

SMD relay included.

Have you tried to change the input cap? Does it "play" better?

Are we allowed to have the schemo without joining the stompbox forum?
I just don't like to join any club that would have ME as a member...

Haw

Well - mictester said "and be sure to share it with your friends..." so I guess he
is doing the free license thing consciously. He's also one of those guys who is
way into helping people learn and develop, so, you know - nobody's worried about
DIY kids having their fun...

Going to try the cap thing right on the next version - this one's gonna get a TL062
for experimentation, and some fun for PSU too...got something cool at Conrad
(and saw a really cute girl)

TL062 is passable for onboard tone-controls, but in circuits with variable gain or distortions, it will hiss. Stay with 072 or 082 or use an OPA132 if you want to record parts that "stick out"..

Ah ok - didn't know that...what's the difference between them otoh?

062 is more suitable for low-power devices like bateries-powered tone controls etc. It has cca 0.2..mA current draw per opamp.

Compared to 062, a 072 has ten-times bigger current draw and more than twice better noise performance. Also, it has cca four times better slew rate than a 062.

072s are practically everywhere... except in audiophile stuff.
For guitar circuits, there is probably a reason that 072s are in almost every ss amp or preamp - they have some sort of "fluid" midrange that sits well with guitars and are cheap to buy (as well as "watery" bottom end). Compared to 072, a 062 sounds "cheaper", also slightly weaker but lasts longer.

theres some musings on a 072...
http://www.joemeek.com/faq_frame.html

(If in doubt, just use an OPA132.)


if you are really persistent with "guitar" circuits I can try to "re-animate" some of my long-forgotten circuits from 80's and 90's. I have some of these leftovers in a shoe-box that accidentally didn't get thrown into garbage (another box full of "good" boxes went instead - what a bummer).

Oh sure, that would be great (at least it won't have all been for nuts). I had noticed that things which draw more
current are more "conducive" to "wow check that sound out" in general, with the old "water analogy" it makes
intuitive sense, because you can't disturb it as easy and you get kindofa gaussian-stochastic thing going on in there
the more electrons are flying around - i.e. the more buckshot in the barrel, the more you hit the actual target.

I got this pretty cool 10x AA battery case that terminates in a 9V connector, think I might just give kittycat 15V
instead and see what happens. It's also totally inherent with these rechargeable 9V cells that they suck hard.

It's the biasing current (output class AB stage ... as well as VAS and input pair) that somewhat determines how much "pull" will an opamp have.

That's one of the reasons why low-current opamps usually sound more "watery" compared to higher-current opamps, with less "impact".

Since you now have an opportunity to swap opamps and compare, you can test it by yourself and compare your findings to what I said. The words arent so good at describing sounds..
http://www.paclink.com/~ascott/they/tamildaa.htm

Many people say that "upgrading" and 072 in a guitar circuit isn't an upgrade really.. however, back in days I had a different favorite chip.

Re. my circuits: it wasn't "all for nuts" really - a good portion of my stuff has actually seen radioplay.. and tv-play here. If you are really interested I can hunt some links (I know some stuff was put on youtube and whatnot) and send them in a PM or email. But I'm really not a "grave digger".