Changed circ.breaker-vocals became shouty:why?


Hi
I live in pre-war apt.building.The circuit breaker that was feeding my system was an old 15 amp gadget that was long ago discontinued.When i noticed that it was 15 amp i went and bought a $25 30 amp replacement for it.After installing it in the box i noticed that vocals and solo guitars became shouty and flat even though the rest of the spectrum became more dynamic,especially bass.After i put back the old breaker,the sound became 3-D and warm again,even though the system was straining at high volumes.Is it a circuit breaker burn in factor or something else at play here?My power amp is Pass X 250,5 driving 86db/4ohm Snell type B speaker (6 drivers per side,3 of which are 10 inches).
Outlets by PS Audio.Any ideas?Thanks a lot.
overhang
Ignoring your question, but you can't just up the amperage of the breaker unless you've upgraded all of the downstream wiring in the walls to match. Big fire hazard if you don't.

No idea why the sound would change.
Thanks for your replies.
The wire is 12 gauge.I will step down to 20 amp breaker.
The dynamics changed a lot with a 30 amp,a lot of headroom and the lights on my Panamax power conditioner are not flickering on the border of underpowering anymore.But fire hazard is something i don't want to play with.Once again,thanks to your advices.
Hello Again. You said nothing about the Panamax in line before. Take that piece of ?&$# out of the system. I am a Panamax dealer and that thing doesn't belong on anything above a $400 theater in a box. That is cutting the sound quality of your amp down about 30%. You need to be in a line canditioner above $2500 on that amp OR nothing at all. (my favorite is Shinyata. (don't know how to spell it because I am not a dealer. LOL)
No,the Panamax if for cd player and preamp only,the amp is plugged into the wall.They do share the same outlet though.
Btw,the Panamax in my experience is way better than the current Monster/PS Audio stuff.As i understand Panamax had several owners in the past 5-7 years,mine is mid 90s model with upgraded cord and outlets.