Best Amp for Quad 989's?

I'm a recent owner of Quad 989's. I have them paired with a YBA Passion integrated @100wpc. It sounds very good, but compared to what??? I'd like to hear some recommendations on matching amps to these speakers. Tube or solid state could work. I heard them at CES with the Quad tubes and wasn't overwhelmed. It could've been the setup. Let me hear your thoughts?
I have a pair of 989s in a room that's about 21 x 19' and about 3200 cubic feet. I've had them only about 2 months. I am NOT a golden-eared audiofile, but I still hear and love the 989s' transparency...'see-thru-edness'...and cohesion, their all-togetherness.

I listen to classical and film music and a little 'lite-duty' jazz. In 2-channel mode my subwoofers don't operate; I drive the 989s full range all the time. I do not listen at very high levels; I've never triggered the 989s' protection circuitry. I drove them initially with a (tubed) c-j Premier Eleven (70WPC) from the (default) 4-Ohm taps. They sounded quite good. I then bought a pair of tubed monoamps that use 4 KT-88s for a claimed 100 Watts (in ultralinear), but I use them switched into triode (from the 8-Ohm tap). I GUESS they have around 40 Watts, but they drive the 989s VERY nicely.

Everything I've read indicates the 989s are NOT hard to drive and that they don't require high current with their nominal-8-Ohm impedance.

If I were looking for poweramps, I'd look for the highest-quality tubed amp I could afford, in the 35- to 100-Watt range. If you prefer solidstate (I have no idea what the YBA Passion is), I'd look in the 75- to 150WPC/8 range. I'd sure stay away from anything that anyone thinks is a tad brite, grainy, gritty, etc.

Pls let us know about what you audition.
My response is based on owning Quad USA Monitors, not the beautiful 989s. Regarding your CES comment. Although I did not hear that system, the few shows that I've gone to did not leave me thrilled with the sound from systems with Quads. But get those puppies home, sent them up right, and you are talking about some magic.

In my experience, my Quads loved power. I would not go with anything too whimpy unless it has an excellent and beefy power supply. I drove my Quads with an OTL tube amp from Atmasphere and with a nice Rowland solid state amp. The Rowland sounded quite good. The Atmasphere, when it worked and the planets were aligned correctly, took the musical experience up several levels.

I'd recommend a tube amp. The OTLs from Joule Electra, one of which I've owned, would be a superb match. And they are solid and reliable. Maybe a beefy SET amp would be worth evaluating.
...or the Berning ZH270??
Agree that making switch to a SET like and 845 based tube where you could get 20 plus watts might be better than just going with push pull amp but it depends on room size and how much volume you want.Think you would better off with tube in any case and there are many class push pull and depending on maker and tube you could get 40-80 watts at reasonbale price.One caution I tried my own advice with a Bel Canto 845 based amp and with my 94 db sens german semi horn didn't have enough volume so I went back to my EAR 834 40 watt (proably closer to 50) since the BC's (I think) 27 watts didn't get loud enough.Great amp might be the new McIntosh with KT88's at 75 watts.Once you get into tubes remeber you not only have the sound of the amp but you also get diffent sound out of tube type and vintage.Regardless of the power output a KT88 will have more balls (dynamics( and bass than a EL34 which will best it in midrange.If your into classical or rock than KT88 would be better but small ensemble jazz or folk (especially voices) go better with EL34 creamy midrange.6550 inbetween with a cheap price on replacement with good Soviet tube.Than you could roll sound by replacing input tubes with New Old Stock drivers (outputs would be much more expensive).Last suggestion is a hybrid like the 70 watt Pathos Logos with tube pre and solid stae output stage.Great reviews less upkeep with replacing output tubes down the road.But you have maybe the best speaker for midrange and tubes would be great.
MFA M-120s with the Citation II transformers running off the 8 ohm taps - pure magic!
MFA (Moore, Franklin & Associates), haven't read anything about Bruce and Scott's stuff for a long time. I was an MFA dealer (Two Jeffreys Audio) in the mid-'80s and sold a few pieces. They were VERY well designed with octal-base frontend tubes (6SN7 and similar types); their top-line Luminescense preamp was full of those things.

Wish I had a pair now.
I use Quicksilver M 135 monos with my 989's and have been happy with them.