ROG Condor - Blanket over Amp tone - WTF?

[mydementia]

Hi guys.
I built a Condor (http://www.runoffgroove.com/condor.html) a few weeks ago and the first time I plugged it in, it was absolutely awesome...the recording sounded VERY much like the sound out of my amp.  The output level was low, so I tried a couple recommendations (from you guys here) to get the output up and nothing ever worked right.  After I stripped the booster and the power mods out (back to stock), it's never sounded as good as the first recordings.  I would describe the recorded sound as 'amp with heavy blanket over it'.  I figured I screwed up my original circuit (perfed) with all the soldering and de-soldering so I had a guy make me a couple boards.  I just finished my first PCB Condor and it sounds exactly the same as my 'hosed' original - WTF?  I made zero substitutions from Pablo's project file... I trimmed the Drain of the j201 to 4.6V (~1/2 Vinput).
Any clue what's going on here?  Only thing I can think is that I need to futz around with the drain voltage (it's the ONLY variable in the circuit)...isn't 1/2Vin right?

I'm running Guitar --> Pedal Board-->Condor-->ART V3 Tube Pre (to get recorded volume up cleanly)-->EMU 0404 Sound Card->CuBase SX

Let me know what other information I can provide that will be useful in this troubleshooting venture...I'm stumped.

Thanks for looking.
Mike

[mydementia]

BuMp

[Coriolis]

Could it not be something like a bad solder causing resistance or capacitance, where there shouldn't be any?
I have had problems along those lines before - solder joints that looked ok, but something was still wrong. Reheated the joints, and stuff sounded different...

C

[MartyMart]

I have been using one for a while now, built on stripboard using Torchy's layout and the
schematic for ref.
I made a couple of changes, so it's more like a 2X12 cab sound ( see ROG site for details on this )
I run it through a Mackie desk, pre mac and Logic for recording and have used it a lot, also for some
of my sound samples hosted here.
Point 1 - I have plenty of output, so am not "boosting" it through the desk at all
Point 2 - I dont have a "blanket over amp" tone, but do roll off a touch of low end ( 80-100 Hz )

My guess is that you have an error somewhere, which has also been translated over to your
PCB version too !
I used a J201, biased at around 4.5-5.0 volts and both opamps are NE5532AN's
I've found a few "horrific" errors on some of my builds, which I've only discovered after
tracing through the whole build with a DMM and the schem, such things as mistaking
47k resistors for 470k's etc etc are easily missed !!
Dont give up on it, it's a great cab sim and I Guarantee that you have either a wiring/part
error somewhere ....

MM.

[mydementia]

MartyMart - are you making fun?  (I couldn't get my Q5 to bias on my JCM800 emu build - come to find out I had a 470k resistor in place of the 470 ohm resistor - now I'm back to measuring EVERY part before I solder!  I guess we all screw up from time to tim, eh?).   

I'll definitely go back through the whole thing...again - but I used the ROG layout and PCB which (I believe) is verified.  The odd thing is that my first build was based on the ROG perf layout and my second is from Pablo's PCB/Part List/Layout.  I used LM833's in the perf build and TL072's in the PCB build.  I also used J201's in both builds.  The kicker is that they both sound the same and both have low output. 

Anyone out there successfully build from Pablo's PCB?

Thanks for your help.
Mike

[mydementia]

Hi guys.
I just spent a couple hours with this circuit and haven't made any progress...but I put this purdy page together: http://www.freewebs.com/mydementia/DIY%5FStompboxes/Condor.htm
(Aron's site was down 20 minutes ago when I tried to add to this post...I'm just lazy and figured you wouldn't mind wandering over to my site).  The page has images, commentary, and voltages.  Please have a look and let me know what you think I'm screwing up!

Thanks in advance.
Mike

[MartyMart]

Well , all the voltage readings look OK to me !
I took a quick "look see" in mine and found the following mods :
The Hi rolloff network around Op amp 2 on mine is like this,
the four 22k's are all 15k's and the pair of 3n9's are 2n2's .... so
I'll have a lot more hi frequency content than you will.
Perhaps it's just a bit too "dark" sounding the original way ?
Worth a try, also perhaps worth changing the two 47n caps at
opamp 1 to something smaller, 33n or 22n.
There's recommendations for these values at the site, I guess mine
is sounding more like a 2X10 cab or something, but I like the tone a lot
and I have more than enough low end going on.
Your two mistaken V-ref resistors shouldn't be a problem, so long as
they are both of the same value, I try to use higher value pairs, to make
things a bit more accurate, pairs of 1% metal film 47k's work for me !
Make sure that those two Huge caps are not 10X the value that you suspect they are !!
( been there done that )
MM.

[mydementia]

MartyMart - Thanks for checking yours...
Yes, the big orange guys are 0.0039uF (3.9nF, right? ) - you can read it on the picture (uncompressed original - it's definitely clear!).

<Yes, Q1 is backwards in the picture - that's where my last act of troubleshooting desperation led me!>

My confusion is with R15/R16 (vertical Red Red Orange Gold to the left of OpAmp1).  It's not that I used the wrong values...the oddity is that when I measure across the resistor, I get 7k below their values (15k instead of 22k).

Also, you said before that you had no problem with your output level...I wonder what else I have going on.  Do you have a link to Torchy's vero layout?  I don't see it in the gallery. 

Thanks again. 
All input is appreciated as I'm about ready to go back to using my Vox Tonelab for recording...
Mike