Headphone amp to replicate Quad

Hi everybody,
I have question. Would anyone have a suggestion how to replicate, in a headphone amp, the sound of a Quad 99 amp, Quad 11L speakers combo? I LOVE this sound, and my current headphones, headphone amp set, sounds watery and unengaged by comparison I think. I have a Rega Ear headphone amp, and Sennhesier HD650 headphones. I would like to work with the headphone amp, more than with the headphones. Would prefer to keep these. Thanks a lot! (More than an audiophile, I think I am more of a Quadiphile).
--- My complete regular system consists of a Quad 99 CDplayer, Yamaha TX-497 tuner, Conrad Johnson PF-R preamp, Quad 99 amp, and 11L Quad monitors.
I use a Creek with my 600s but haven't heard current Quad line.
Thanks, I see there are some Creeks now in Audiogon. Will perhaps give them a try. Thanks,
I can't say that they will sound like the Quad system but they are reasonable and very good quality. They can be used with a passive preamp to add gain or with devices with a volume control as a preamp. Their volume control does not control output level so they can't be used alone.
Here are some options
Lots of others if you look on www.head-fi.org or www.head-case.org
Thanks Stanwal, Tom,
What I´ve noticed these last days is that the Rega Ear sounds actually much better, less hollow in the middles with the Rega Planet CD player. I was using it before with the Quad 99 CD player. Perhaps the problem was that the Quad favors the middles, which are the strenght of the Quad amps.
Passive preamps- that´s just what I am getting into now. I just purchased a pair of Quad 12L actives, and apparently I would need a passive preamp between it and the CD player.
Thanks again,
I use the 99 amp (and I also own the Quad 909 amp)with my Harbeth C7 speakers and also own Spendor s3/5 speakers and had 988s on long term loan.

I specifically like my headphone set-up because of its "similarity' to the Quad/Harbeth speakers- I use the Benchmark DAC1 as my headphone amp (as well as source) with Beyerdynamic DT 880 and AKG 701 headphones (The Beyers are closer to my speaker sound.)

Obviously the DAC1 is more than you may need, but in any event this was the solution I devised for myself. (As CD was my only source in my audio room, I ran the DAC1 directly to the Quad amps.)
Thank you. This is really useful. I had noticed the Benchmark DAC a while ago. I am glad to have somebody´s take on them. I am tempted to consider getting it because I just received my new Quad 12L Actives --I am SO impressed-- and it looks like the DAC can go straight to your active monitors, without having to use a preamp. That way I could have a backup preamp.
What´s amazing of these active speakers is that it´s like you were quad-amping so to say. Each speaker bi-amped. I am totally converted now to the benefits of bi-amping.
These speakers are awesome.