Mr Tennis, I've not made a recommendation even though I appreciate thru your multiple posts that you are looking to change the balance of your system. You seem not to be able to find a single component which will do it for you which makes me think that perhaps you attacking the wrong part of the tonal spectrum.
I have found that a lot of stuff sounds bright to many folks, not because the highs are bright(too much high frequency signal) but that there is either, or both, an upper mid-range glare or a lower mid range suck out. Either will give an immediate impression of being highly detailed but over the long haul the former will become fatiguing and the latter will just make your system sound cool and un-involving.
It may just be time to re-think your entire system. I will give you an example based on surmise. Most folks who have Quad 63's put them on stands raising them off the floor from 6 to 12 inches. They are all taken by the clarity of the mid range in that position. What they fail to mention or observe is a concurrent upper bass suck out which gives the sound an over-all coolish tone which is enhanced by the natural tendency of the speaker to be on the dry side thru the upper mids and highs. These speakers were designed by Peter Walker to be used on the floor (actually when you start to raise any floor stander off the floor you start playing with the frequency response in the 200 hz area). Put these speakers on the floor, set them up properly!, and they really can sound warm and full range down to 32hz depending on associated equipment.
Now if you have in fact already optomized your Quads set up and remain convinced that one component can make the difference ditch the BAT (I have one and its a great CPD - I've had it 7 years and its not going anywhere). Get a Wadia 302. It has a very dynamic bass, very detailed mid range and smooth, non prominent highs. Overall it produces a sound slightly on the dark side of neutral once your are past a long break in stage (out of the box it sounds like a POS).
You asked about an amp. Independent of the comments I just made, and based on my personal experience with the product, if I were going to set up my Quads again I would get a Primaluna 3 pre-amp combined with a Primaluna 7 (I'm using a Primaluna 3/5 but I don't need the current or power that the Quads need but 70 good wts is enuf for the Quads). Excellent set up for the price.
