Carlin Compressor

[Freppo]

Here's a layout for the "Carlin Compressor" (AKA "Carlin Compressor / Fuzz") - verified!

It's a swedish cult-classic and was made by Nils Olov Carlin in the 70's.
Read the background to the compressor by the creator here
This is by far my favourite compressor (though I've only built a few)!



It was kinda tricky to make a layout for this one..
Many sections of the schematic are interconnected, which translated into many links.

Note: It's important to set the trimmer just right, there is a small sweet spot -
Set the pots to maximum sustain and minimum fuzz and adjust until it's not too noisy.
Turn it up if you want more agressive compression/fuzz (at the expense of noise)



I noticed after I had finished the layout that Moodysounds has a DIY kit for this
They also sell the PCB separatly. Check out moodysounds.com

Cheers
/ Fredrik

[johnk]

nice compact layout Fredrik!
the only thing I'm wondering about is the +9V only going to the 1N5817. the schematic shows it directly connecting to 4 of the BC548B collectors, and the 22K, 8.2K,270K and 470K resistors.
is there something that i'm missing?

[Freppo]

Thanks :) You are right, R22 is supposed to be 47 ohm (for DC-filtering) not 47K.. Ops! :P I used the correct value (47 ohm) when buildig it and didn't even read the BOM since it was my own modification so I didn't spot that.

The diode is for polarity protection. So +9v - diode - 47 ohm, then the rest follows the schematic. If you want to you could connect 9v directly to the top row or put the diode between +9v and ground insted of in series (on the last column alongside the 100uF cap)

I will update the layout next weekend when I get back home. I'm in a studion out on the countryside all week.

Cheers / Fredrik

[johnk]

that's cool. I omitted the 47R and added a 4K7 for the led in it's place.

[johnk]

I built it last night and it works great. thanks for posting it Fredrik!

[Freppo]

Well, sharing is caring ;)

I updated my layout now with a few small changes.

How do you like this compressor John? I know you have built alot of compressors. :) I'm not using compressor pedals much, but this one stood out among the few I've built - Orange squeezer, a byoc compressor and the engineers tumb (which I also really like)

I have a Lindell Audio 17XS compressor (inspired by 1176 rev D) in the studio which I love and I also had a DIY Hairball 1176 rev A, but I sold it to a friend.

cheers
/ Freppo

[johnk]

i'd love to se a layout or schematic for the DIY Hairball 1176 rev A.

as far as comps go, I think that the Carlin is pretty good, although the distortion feature in it leaves a bit to be desired (to me, it's a bit too artificial sounding and fizzy). IMO, It could also use a clean blend since the compression is always on and effects the attack of the signal even at minimum settings.

I like the pale green comp, the forest green comp and the keeley four knob more though. and the diamond is my favorite of the bunch. I also own an origin effects Cali76 which is an awesome compressor that sounds basically identical to my Urei 1176LN's.

[Fuzzard]

I built this the other day. Curious thing is that the toggle switch in the down position delivers the effect - in the up position the signal passes through with no effect

I also see that the earlier layout listed a spst switch and second layout listed a dpdt switch - any help would be appreciated

[fx-fidden]

I guess that DPDT switch is for the bypass indeed. Not true bypass, but buffered bypass.