Pre Amp break-in balance issue

My plinius sa100 xlr right channel is weaker after I over drive my Martin Logan request many yrs ago.Thinking maybe the fuse inside are the issue. Replaced the fuse still the same. But on rca no problem.I am not sure what’s the problem.

I am sure it’s not a break in issue on your amp.

please clarify, you say the amp is pre-owned, i.e. it was/is your existing amp, worked properly, OR, you also just bought it used?

preamp is new, warranty?

cables/speaker wires: still using yours? worked properly previously? solid connections?

as mentioned, you can figure some stuff out by swapping l to r, at preamp, at amp, speaker wires from amp.

leave preamp balance control in the middle, what moves l or r, when, what changed,

my memory sucks I draw diagrams and write stuff down, things get confusing, you end up repeating things .....

Thanks for the replies, after a sleepless night racking my brain I decided to try something. I have 2 Synergistic Research UEF devices that plug into unused rca connections that I used to great effect in my 509X and had plugged them into the pre outs on my new preamp. Today I removed them and plugged them into 2 inputs instead and VOILA great balance. I have no idea why they would have altered my balance into the pre outs but not inputs but I'm learning in my old age that I don't have to have all the answers. I started with these devices installed into my SR ethernet switch and have enjoyed the soundstage improvements with my modest Shiit Yiggy/Aurender N100H. Then adding 1 and then another into my 509X things just got better and better. They are certainly worth a 30 day money back trial. So far the C700U/Sanders combo sounds great with my ML ESL11As and the pre is not broken in yet. Another shout out to Albert Sportis at PAV in Chicago who has given my great advice and deals for years, a real gentleman. I have been enjoying the 509X and didn't think I would ever move on from it but having heard that the Sanders was made for ESLs finally took the plunge. So far so good. Thanks again for the thoughtful replies. Joe. rca

Yes there is a break in on SS devices, but it’s for both channels equally.  If one channel is softer than the other, something is wrong. Send it back and get another one.

All the best.