Musical Fidelity A300 or Rega Mira 3 for Rock?

Greetings All -

Here's my situation and I really need some advice. I purchased the Cambridge Audio 640A integrated and matched it up with my existing Rega P5 turntable, Rega Exact cartridge, and Polk Audio RTi6 speakers about a 2 months ago.

I was immediately hit with how thin the setup sounded, so I ditched the RTi6's and replaced them with Polk's LSi-7s which resulted in much better bass response and way better high end control, although the bass is not very controlled and becomes "boomy" at times. I really can't go to floorstanding units in the room this is in - the wife would kill me!

I'm thinking this lack of control over the bass has to do with the amp not having enough power to deal with the 4ohm 88db LSi7s. I know the LSi7s are capable of dishing out very controlled and tight bass - I've heard them perform perfectly.

So, I've sold the 640A and the CIAudio VPP-1 phono stage I had with it and am now looking at a used Musical Fidelity A300 or a used Rega Mira 3; both of which have built in phono stages. The A300 concerns me a bit because I like controlled yet clear and crisp highs and I've read some things about the highs being rolled off to a degree on the A300 - although I've also read that after break in this isn't a problem. I can find almost nothing on the Mira 3 although I love my P5!

Let me know your thoughts on either of these amps and which would work best. Thanks!
Don't know the Musical Fidelity, but I have a Mira 3 with a P25 and don't get a huge amount of bass thru Linn Katans. The sound is good but my next upgrade is probably a subwoofer. I can't say the sound is thin but it could do with a bit more on the bottom.

I bought the system new and found that it improved a lot after breaking in, and also my dealer set up the cart with only 2 bolts and I found using all 3 made a difference in bass too.

I also have the jupiter CD which gives great bass thru the mira/katans so it's capable of it. I also think the Rega carts probably are brighter than others.
Thanks for the response!

Well, I purchased the Musical Fidelity A300 here on AudioGon, so we'll see what that yields, it should be here tomorrow. I figured it was a safe bet since it's got a healty re-sale value and I can quickly get back what I've put into it if it doesn't work out. The positive reviews on this amp are almost too good - we'll see if it works for the type of music I listen to.

I'm holding out hope as I found an article on the 2001 Canadian Hi-Fi Show where Polk had their LSi-15 powered by the A300 at the show which indicates to me that at the very least Polk feels the LSi line is a good match to the Musical Fidelity equipment.
Well, I've been playing with the A300 for around 5 hours now and all I can say is that it's simply an amazing piece of equipment! I am hearing things I've never heard before in my music, especially in the bass - it's cleaner, tighter, and way more detailed. Simply astounding and I couldn't be happier. It's built like a tank, has to weigh 45 pounds or so and sounds smooth, detailed, and with just the right amount of punch. Seriously, I'm as giddy as a little school-girl!

I read some online consumer reviews at that spoke of a high-end rolloff and all I can imagine is that this was an issue while the amp was breaking in becasue I hear none of it, it's perfect. I've also read that it takes around 200 hours for the amp to really break in and start to perform, especially in the high end - another benefit to buying used. Another winning purchase via Audiogon!