Walco Compressor???

[markm]

Hi fellas,
Just wondering if anyone got the hiss issue resolved in the Walco comp?
Is it worth doing a layout for or, is this circuit relatively useless.
   MarkM

[RickL]

I built one of these a while ago and I also have an original one. I think I tacked a volume control onto the one I built. I think I used a hand drawn layout that I found somewhere on the net, maybe here, but I may have just done it on perfboard.

This puppy has got some serious squish. I don't think it would be much good as a general use compressor but for special effects it's pretty cool. I do remember that it was pretty noisy and I doubt that much can be done about it. It's a pretty simple circuit with no provision for noise reduction. I think anything that was done to reduce the noise short of adding a compander section would also reduce the amount of compression it has. I think the super heavy compression is what makes it cool, in a cheesy sort of way.

[markm]

Thanks for the info.
I wonder if Mark H. took a look at the schem, maybe he could point out the resistor that controls the squish and change that over to a pot.
Perhaps to make it more useful?

[Fret Wire]

Are we talking about the Chord and Note Sustainer. Isn't that the ckt with the 3SK30b with dual gates?

[markm]

Yes it is.
I was under the impression that the dual gate Mosfet in this circuit could be subbed by a standard Mosfet due to the fact that one gate was grounded out and not used.
Maybe I am wrong here, I'm not sure.
Anyone have any other info??

[Fret Wire]

If I remember right, gate 2 was grounded.

[markm]

Yes,
I did a search of the board here and it seemed that quite a few built this circuit but, hiss was a problem.
According to some of the posts, MPF102's were used but, I can't seem to remember.
Here's the schem

http://experimentalistsanonymous.com/diy/Schematics/Compressors%20Gates%20and%20Limiters/Walco%20Chord%20and%20Note%20Sustainer.gif

[Fret Wire]

That looks like one of Dan N's schematics. You could try searching his user name for posts around the same date as the rev. to the schematic. Maybe he had something to say about trying the dual gate jfet. Also, it looks like Rob Strand had a hand in it also. The Tonefrenzy clip sounds cool, but you can sure hear the hiss in the ckt.

[markm]

The Tonefrenzy clip sounds cool, but you can sure hear the hiss in the ckt.

Yeah, you're not kiddin'!!
I drew up a layout for it and figured I'd give it a whirl but, I'm a bit uncertain at this point.
Thanks for your help and info too BTW.
It does sound good though so, it's tempting.

[Fret Wire]

You're welcome. Here's another thread I found, not much help though.
http://www.diystompboxes.com/smfforum/index.php?topic=22367.msg140750#msg140750

[markm]

Yes, I did read that one myself.
Appears there was some initial confusion over the circuit.
I beleive the one that I posted is correct at this point and oh yes, Looks like it was DanN's work.
I think they were looking for Rob to give it a look but, he's missing.

[Dan N]

Hi guys. Yes, I did trace that thing and got follow up help from Rob Strand and jneely.

Here is a killer thread on the subject:

http://www.diystompboxes.com/smfforum/index.php?topic=25846.msg170872;topicseen#msg170872

JC knocks me out!

I have never built one. If I can find the original, I'll try a J201 in it. I suspect the fancy dual gate fet is not essential.

[markm]

Hi guys. Yes, I did trace that thing and got follow up help from Rob Strand and jneely.

Here is a killer thread on the subject:

http://www.diystompboxes.com/smfforum/index.php?topic=25846.msg170872;topicseen#msg170872

JC knocks me out!

I have never built one. If I can find the original, I'll try a J201 in it. I suspect the fancy dual gate fet is not essential.

DanN,
Thanks for the info and thanks for stopping by,
Much appreciated!
  MarkM