BJFE Pale Green Compressor

[johnk]

since I just finished building the mad professor forest green compressor from IvIark's layout, I thought that i'd also build the simpler, yet, by many, considered to be just as good or better BJFE pale green one. I found the schematic online and looked at some posted gut shots so I drew up a vero for it and this one will easily fit in a 1590B.
after I build it, if it works like it's supposed to, i'll post my vero layout after it's verified.

[Jopn]

I have no less than 5 compressor projects started but not finished.  Yet I am strangely excited to hear this is coming down the pipeline.

Just took a peak at the schematic.  Is that a 20k dual lin for the tone pot?

[johnk]

I think that it's actually a dual 20K 'W" pot but i'm probably going to use a dual 20K lin for now.

[johnk]

well, I built it.  it fired right up and works perfect. I personally like this one better than the MP Forest Green comp. I used an NSL32 for the LDR/LED.

here's a pic of my test panel:



a pic of the vero:



...and the verified layout:

[IvIark]

Thanks for sharing John

[Jon Rep]

John,  I have built a number of compressors and my best is the Diamond Compressor by far.  Just wondering because I know you also built the Diamond Compressor , how does the BJFE Pale Green Compressor compare?  Thanks.  

[johnk]

IMO, the pale green is more transparent than the diamond and while the pale green is very, very good, the diamond is still my favorite. I also really like the Keeley 4 knob and the EMMA transmorgrifier.

[rocket88]

Hey john. I just started to put together an Emma transmorgrafier, since you've spoken really highly of it. Could you let me know of the changes you made to it for bass? I've been looking at a schematic of it, and trying to follow your advice on what to change for most pedals, so I figure I should socket the input & output caps, but wasn't sure if the coupling caps should be changed of if there were any other changes necessary. Also not sure of good starting values yet  hopefully that will come better with more experience.  

[johnk]

IRRC all I changed was the input cap on it to 100n.

[rocket88]

Really? Why didn't the output cap need to be changed? Is it because it creates a high pass filter that's actually ends at a low enough frequency? Also, I take it that the coupling caps are large enough to allow lower frequencies to be retained, since they're 10uF.

BTW, what do you look for in a compressor and make you like one over another? Until all this talk on the forum about compressors, I never really thought one. I mean I get the reason to having one on the board, and what it does, but since every one really is different I'm curious as to why you like one over another. Oh, and I read your description for each on your site, which is why this popped into my head.

Oh, and thanks for letting me know what you did the the transmorgrifier, I greatly appreciate it.

[johnk]

the output coupling cap is already a 1u which more than enough to pass freqs down to 20hz.

[johnk]

DONE!!!

[rocket88]

Ah, I thought it was the 10nF cap to lug 1 of the level control, the schematic I found didn't have it labeled so I was trying to figure that off the vero. BTW, the pale green comp looks fantastic as usual John. Amazing work.

[george01]

Hi, i' ve nearly finished my comp.
Bud One thing I'm in doubt,
The Nsl32 LED Kathode is signed with a dot I think.
Bud I'm  not sure which side on the schematic is
The Kathode? In my opinion the one which looks like
A dot, Triangel is Anode?
Thank's beforehand!

Regards, Gerd
(Outstanding Webside and Forum!!!)

[johnk]

the dot side goes to the bottom on my layout.

[george01]

Thank's alot John

[george01]

Hi John,

I finished the Comp yesterday,
I works ( I get a lot of compression out of it),
bud (like last time) one problem:

When I turn the tone pot fully counterclockwise,
I can here a loud humming, turn it a bit clockwise,
the humm is gone, sounds OK!

Can`t find a layout of the Dual Poti in the offboard,
Is stage A the one nearest to enclosure bottom?

Thank`s beforehand!

Regard`s
Gerd

[george01]

The Problem is caused by the A1 lwire,
When the tone poti is fully left, (0R, Ground to the Board)
The tone poti is oberloaded, and is getting hot and smokey.,
As soon as A1 is disconnected everything works fine
It seems the amperage is to high. I' ve double checked
Everything

[negativefx]

Hey John, not hearing any difference in tone when sweeping the tone pot.  I posted a description on the layout page.  Soldered the two middle lugs together and ran them to ground, post 1 of top row to A1 on board, post 1 of bottom row to B1.  A3 and B3 are disconnected.  Any idea?

[johnk]

take a look at this schematic to track it down (it's a simple circuit):



the tone pot should be very noticeable.