best used amp for 300- 400

I have a system composed of a rotel rcd970 cd player, rc990 preamp, rt940 tuner, acoustic reasearch turntable with denon mc cartridge and old infinity Qe speakers and am looking to replace my amp an old dying adcom gfa-2. I have heard a rotel rb 980 in the system and it was decent but not great i am trying to find an old bryston 3b but any suggestions would be welcome, my price range is less than $400 including shipping so closer to $350 would be ideal. I listen mostly to classic rock and ska, so i want power and good bass but also want good upper frequency perfomance as well. Thanks
Have a look at the Acurus stuff. Very, very nicely made and good punch.
Try and find a AMC by Weltronics. Unbelievable for the money. I'm not sure who sells them but worth investigating. Sounds like amps costing 4-5 times as much. They make a tube hybrid that blew me away. I think it was the 2030. Had about 60 watts a channel. I could be wrong on the exacy power rating. but is truly remarkable. I bought one for my fiance (now my wife).
I found their web site. It is You can buy direct although you can probably find used for a real good deal. The model is 2100. 80 watts per channel hybrid. See my above post for superlatives.
The Anthem MCA-2 would fit your needs very well. 200 watts into 8 ohms. SE and Balanced inputs. I used a pair of them to biamp Maggie 3.6/Rs with no problems and with very acceptable sound quality for the price.. I have one remaining unit,in your price range, listed here. Anthem products are made by Sonic Frontiers.
" so i want power and good bass but also want good upper frequency perfomance as well. "

Well if this is possible ( at this price ) then all of us who have spent more than this, are wasting our money :)
Try on a B&K at this price, they're about as laid-back as a low price SS amp gets. I found the Acurus amps harsh and with lousy soundstage.
I'll second the recommendation for the B&K amps. I you shop around for a ST-140 or ST-202, you'd be able to come in under your budget, and with a nice sounding amp.
thanks for the responses, after reading some reviews the b&k sounds like the best because my system tends to be a little too bright .
I own/have owned B&K ST140, ST1400mkII, Reference 4420 amps, and all are excellent. If you do investigate the ST140, there are two versions cosmetically (one with blue racing stripes, other black with gold rack handles - I like this one better). The ST140 is a minor classic, hard to go wrong. I believe the 202 is from the same series so would be a solid amp as well.

Interconnect/speaker cable choice can also tame a bright system.

Used PS Audio amps (200, 100cx, etc.) run in that price range. They can sound a little hard at times however (although Paul McGowan claimed to have been using ARC electronics to voice his equipment). The Bryston is a good choice, too - I used a 3B for years with my M-L Sequel IIs and (now-extinct) GNP 220s. I'd also look at the Marantz MA-700 blocks; they're pretty cheap, come recommended (haven't heard them myself) and you can save $$ on speaker cable by putting them right next to your speakers.
Nix on the B&K stuff. The bass is soft and does not meet your criteria. The ST-140 seems to have trouble with lower impedances to boot. But nice midrange, good soundstage and a bit soft. Caters to the "solid state like tubes" crowd.
Viridian is correct about the ST-140 having trouble with lower impedances, I have experienced this in extreme cases. I wouldn't pair it with a 4ohm speaker on a bet. The bass is not as big as "muscle amp" bass, but I find it voluminous with correct speaker matching. I can't speak to the Infinitys you own. "solid state like tubes" - this guy is right on. Probably explains why I moved up to a CJ Sonograph 400 in my main rig.

There's also a Mccormack DNA .5, just listed for $550 (steal)... out of the pricerange, but damn!
I would buy the VSP Labs Transmos-150 for sale here on A-gon. I had one in my home a year ago and passed it on to a friend. The description is apt. A superb value!
I bought a used ST-202 and had it Modified from Sound Unlimited in Bristol,CT..I had Magnepans which are a difficult load to drive and there were no issues.
Matched with a Rotel Pre-Amp it sounds exceptional.I would like to try having a Tube Pre-Amp next.

I am using it to drive Mod. NEAR M15's at the moment and the M15's which drop to around 5 ohms I believe!

You can find Modified Models on A-Gon for around $400.