shawn. Back up, slow down, start over. Which tube EXACTLY. What pin was the cap on, and what was the value of the original and the value of the one you replaced.
and then step by step detail exactly what you did and what happened with the unit.
I presume the 1000A was running before this excursion into the AUDIO VACUUM?
The more detail, no matter how silly sounding to you, the easier it is for us to troubleshoot and help diagnose a problem. The only DUMB QUESTION is the one you DON'T ASK. We've all BTDT. Most of us have the T-Shirt. Some have read the book, and watched the Movie.
The only .003uf cap (C-96) in that area is in what's known as a Packaged electronic component or PEC(CRS-02). One of those Tan squares with 3 to 10 leads that looks like a ceramic cap on steroids. And you can't replace it with out ripping the PEC out and buildin a new one on a board. There is a .03uf (C-99)between V14 (12ax7)and a PEC (CRS-10A). I don't think the replacement with a .3uf would cause a loss of channel however, under ideal conditions (ie: no leads are crossed, or miswired).
Check for
1.) Flying leads touching other area that they aren't supposed to. like the chassis or another cap or resistor.
2.) Solder bridge between tube socket pins where the part connects to.
3.) Solder bridge between terminal strips where the part connects to.
The Sansui 1000A is really a triple canopy jungle underneath. You need to be absolutely specific in details for location and part number. "a .003 cap near a 12ax7" isn't good enough, although there are only 2 12ax7's in the whole thing. Think if you had 7 12ax7's in it.....See what I mean? Use the template for future questions with regard to parts.
Copy and Fill in the blanks
Tube......
Pin # that the part connects or is connected to.......
Part # replaced
Value and voltage of original part
Value and voltage of replacement part......
Exactly what happened when you put power to it. Snaps?, Crackles?, POP's?, all of a sudden no sound?? , Smoke?? blown fuse?, house lights went dim, etc ..........
Using a signal tracer work from V14 thru the pec's, up to the 6AN8 and then to the 7591. Where you lose the signal is just past the bad component. Hopefully it's not one of the pec's. If so you'll need to build one based on the components inside the dotted lines for that part. The caps inside are pf values. The resistors are most likely 1/8 or 1/4 watt. The part#'s are listed separately in the parts list and also say they are part of CRSxxx"
Check the 6AN8's on a tube tester. You could have blown the tube on that side. OR swap side to side. Note the results.
Swap the 7591's by pairs side to side. Note the results.
Larry