I have a Stack in a box that I got from Paia years ago and I've been trying to make it sound a little better.  My idea was that I would change the pot in the feedback loop of the first opamp, the "crunch" control, to get more gain going into the tube.

I was trying different pots out and then the volume faded in and out a couple of times, and then nothing.  And still, right now, nothing.  It seemed to fade in when I hit the strings but it might have been unrelated.  I took the gain from ten up to 250.  Was that enough to fry something?  The tube maybe?

Well this wasn't my favorite thing I don't want it to not work at all...

Any thoughs??

Quote from: LeftrightsAny thoughts??

oh dear.

:?

I don't know the circuit, it's likely that you've driven it to the point were the waveform squared off SO MUCH that it became essentially a switched DC.  Something may have latched on and overheated?!

Have you put the original part back in to try it?

put the original pot back in.

the resistor 2 change is the 680K in the effects send.
put a 100K in it's place so that the output of the 1st
stage goes thru the 100K the back to the top of
the *crunch* pot.

here's where i got the idea--
http://fclarke.softwareballistics.com/Distortion/DualTubeStackinaBox.html

my article, (tonyb's) , details a little about the mod Frank used 2 have
on his old site.   now all he has is the Dualtube SIAB.

First put all the original stuff back in and get it working normally.
Check 2 C if U blew out the inverter making the HiV.
U should have at least 38-42VDC.

i'v e added a compressor & headhphone amp 2 mine.
it rocks!

email 2/PM if U need more detailed help
afn
tone

Thanks, that makes me feel alot better.  I've been working like a dog since I wrecked it so I havn't got a chance to check the 4049.  I wish I had seen that site before I started fooling around... but it's great to know now.  Learning process right?

Anyway thanks alot for the link toneman, and thanks even more for the offer to give more help, hopefully you won't be hearing from me though:wink:

I have a SIAB that I fiddled with 4 YEARS and never got it to sound the way I liked, even with Frank Clarke's mods.

I got better results with Aron's Shaka tube: I've only had to fiddle for about a year to get that sounding the way I wanted (almost) ...

I have a SIAB that I fiddled with 4 YEARS and never got it to sound the way I liked, even with Frank Clarke's mods.

I got better results with Aron's Shaka tube: I've only had to fiddle for about a year to get that sounding the way I wanted (almost) ...