Q&D Compressor plus "Tweaks" OMG !! - build report& mp3's

[MartyMart]

I'm hyperventilating  !!

Jeez, this is such a superb circuit, I'll get to some details but first off a HUGE thanks to
Jack Orman for making the circuit and app notes into something very buildable.
MarkM for bringing it to our attention ( recently )
Mark Hammer for ( as ever ) some superb tech tips on getting the most from this
and also "Theman" for some nice circuit "twists" that have made the gain control
very usable and sensible 

Build and tweaks :
Got the SSM2166 from smallbear and the 78L05 from Mark - thanks chaps !
I made this on vero and kept it quite small, 5.5cm X 3.5cm so it may just squeeze
into a 1590B but more "pot" room in a 1590BB.
Input to a Jfet buffer using a J201 then 100n to pin 7
Gain adjust follows theman's idea of a 220ohm to the 10k pot with a 10k across
the outer pot lugs, a 4k7 pot would do the same here.
Joined pins 5&6 and took an RC network for some high end boost off pin 6 using
a 10k and 10n cap to ground.
Comp ratio pot becomes a 50k for slight ratio increase.
1M noise gate pot wired in reverse to the schem, so noise gate threashold increases
as the pot is turned CW
"Limit" pot or rotation adjust also reversed to operate correctly when turned CW
Got a little confused with my pot wiring so my gain pot now works backwards 
I'll rewire that one ....
All other components as per the schematic, just used a 1uf poly output cap.
First time power up worked great, no issues at all or hum or noise

Operation :
Works beautifully as a compressor with gentle to quite extreme settings available.
I'm pretty sure that I got the RC network to give me a boost at around 2 -3k and there
seems to be a nice "sheen" to the tone with no typical comp treble loss.
Noise gate setting is OK and set to come on just on very light "brushing" of guitar strings at
almost quater vol on gtr pot, could be a bit smoother but works fine.
Limit, well here we can have some fun, when used at quite extreme settings along with
suitable comp/gain you can get almost "slow gear" response  !!  .... I know  ... I know
calm down.
What you have to do is hold chord shapes with your hand and "bang down" on the strings
with the whole palm of your other hand, this causes the unit to very quickly "clamp down"
on the "bang" and slowly "release" the much quieter following chord ring, which sounds
reversed and swells in 
Kind if hard to describe, but if you do this every 1/2 second to 1 sec apart, you get a real
nice reversed kind of "david torn" guitar sound like it's reversed on tape  ... LOTS OF FUN 
I will make a sound sample asap, possibly later today. have to get back to some work now.

In summary :
Q&D comp is just wonderful, and will probably become a commercial effect if any one gets
there eye's on it .... or is there one now ??
Build one, sell your grannie to get the parts .... just do it NOW  !!!!

Again, huge thanks to all those concearned .
Marty.
EDIT : sound samples :
http://aronnelson.com/gallery/albums/Martys-layouts-and-photos/Q_D_Comping.mp3
http://aronnelson.com/gallery/albums/Martys-layouts-and-photos/Q_D_Reverse.mp3
http://aronnelson.com/gallery/albums/Martys-layouts-and-photos/Q_D_reverse_delay.mp3

[snoof]

sounds very cool!  I did a quick search, but couldn't come up w/ any info on this circuit.  any links??

[MartyMart]

http://www.diystompboxes.com/smfforum/index.php?topic=47389.0

http://www.diystompboxes.com/smfforum/index.php?topic=47713.0

http://www.diystompboxes.com/smfforum/index.php?topic=17230.0

http://www.diystompboxes.com/smfforum/index.php?topic=38837.0

[snoof]

Geez, don't i feel stupid   I guess my searching skills leave much to be desired

[JonFrum]

I like that "reverse" sound. I've been listening to The Byrds Younger Than Yesterday recently, and there's one song with a very similar sound on it - it might be Time Between. I was going to ask if anyone knew how they did it.

[alfafalfa]

Marty ,

Don't choke please !
This reverse sound is awsome , quite some find, must build it !!

Alf

[markm]

Glad ya got it built Marty!
The Q&D is a great comp.
Congratulations! 

BTW, to all whom are interested, I got to meet Roger McGuinn from the Byrds back in the early '90s......He was great to talk music and guitars with!!

[theman]

hi marty,

glad you like the comp and my mods.   i love the fact that i can get a comp, limiter, noise gate, and boost -- all in one mxr-sized pedal! the only downside i see is the noise gate doesn't work as well on extremely noisy, hi-gain circuits -- at least not as well as the isp decimator, but those are extreme cases anyways.

[petemoore]

  "Wait a 1/2 a second while I catch my breath"...
  "Dippy' compressors are lots of fun to play with and listen to".
  Pretty extreme volume dipping there MM.

[markm]

Q&D comp is just wonderful, and will probably become a commercial effect if any one gets
there eye's on it .... or is there one now ??

I think somebody has put this out as a commercial pedal but I can't for the life of me seem to recall who it was....
I could be mistaken but, I'm sure I saw something about this somewhere. 

[bluesdevil]

Wow!! Sounds like it's time for me to start digging into compressors finally!!
Marty - I have a question about the input buffer. Did you use this configuration?:
http://aronnelson.com/gallery/TheBigMan-Layouts/fetbuffer
Or like this:
http://www.generalguitargadgets.com/pdf/ggg_buffer_jfet_sc.pdf

[MartyMart]

Hmm, not quite like either :
100n to gate with 1M to ground
9v to drain
4k7 from source to ground and out here to circuit input cap.

MM.

[bluesdevil]

Thanks for that info Marty. I'll give it a shot soon!!!!

[MartyMart]

Thanks for that info Marty. I'll give it a shot soon!!!!

It seems to work well, I thought that it came from a "buffer/wah" schem, but I can't find it
so it's just something that I had jotted down on paper ( still use that sometimes )
Perhaps the other examples would work better ! but it looks right to me ...

MM