should I upgrade my amp

The Musical fidelity amp is killer for the used price. If you like the 545 sound you'll love the MF amp and preamp. I agree that the preamp is as important as the amp, when funding allows I would upgrade both to MF gear. If you don't need the extra power I would avoid the Adcom 555 like the plague, the 545 sounds so much better from top to bottom, but on power hungry speakers it does clip easily....

I use a Jolida 1000a integrated tube amp with Spica TC 50’s. Give tubes some thought, I find tubes takes some of the glare out of the Spicas.

I agree and second bob bundus's comment concerning the pre-amp it is the most important component in your system.

Chuck

I don't know for sure whether I would go preamp or amp. If I were to change the amp I would consider going with a Forte 4a and maybe even two of them.

What ICs, power cords and speaker wire are you using? These may make a bigger change in your system than the amp or preamp depending on what you are usig now. I compared 12 amps over the past four months and there wasn't that big of an improvement over better cables.

I used to have a pair of the Spicas with matching Hercules stands...and an older Class A MF intergrated...and this was the best combination I came up with...huge soundstage,and ofcourse...legendary 3-d imaging which the Spicas are famous for...dont know if this helps...a tube pre would be a nice addition as well...

I have an adcom 450 pre-amp and 2 adcom 555II amps bridged mono. I like the sound of the two 555's bridged a lot better than just the one. The 555 is 200w times two. Bridged they put out 600w per. I know this is not the most liked amp on the site, but for the 1k i paid for the pair i don't think i did that bad. And if you don't like them i'm sure you could sell them on ebay for the same price you bought them for. They seem to sound alot smoother than just the one. But then again i'm really just starting out so what do i know.

good luck
tommy

agree the preamp should be upgraded first - pre is the most important component. Its quality, or compromise thereof, determines a great deal of the overall systems' performance. Perhaps it's time to consider a quality intergated amp & put the Adcoms' out to pasture.