Preamp Noise with High-Efficiency Speakers

Yingtonggao, just set the input impedance of your FL100 to the max, which is 57kohm and feed your AMR DP-777 straight in and use it's volume control, which quote is a "Direct-Coupled Analogue Volume Control." No extra caps in the signal path.
This will be the most transparent/dynamic sound you will get PERIOD! As it is basiclly then a straight wire from the 777 to the fl100 then (no impedance mismatches). And you will have bags of gain left over still on the AMR's volume control.
If after that you still prefer an active preamp, then it's the colouration/distortion of it you like, which is a bandaid fix for something else that's wrong. Remember it is impossible for an active preamp to extract any more music than what is on the disc and being presented by your DP777, it can just add artificial things, as it does not make music itself.

Cheers George

Just got an email from the maker of the FL100 and your amp is also dc coupled. No caps in the signal path from your DP777 volume control all the way to the speakers, that is a big plus always.

If it sounds like white noise, then the signal to noise ratio on your preamp is not high enough to use with the AG horns. If it sounds like 50/60Hz harmonics, then it may be due to your power supply/transformer saturation/DC offset etc.
Finding high quality pre and power amps to run with ultra high efficiency speakers like the AGs is hard. I have a pair of Duos and run mine with TRON amplifiers (www.tron-electric.co.uk).
TRON amplifiers have been specifically designed to work with ultra high efficiency speakers. The designer, Graham Tricker, is the Uk distributor for Avantgarde and has a pair of Trios in his listening room. Ralph Cessaro uses TRON as his preferred amplifiers for his Liszt speakers.
TRON are distributed by Jeff Catalano at Highwater Sound in NYC. Thomas Woschnick (TW Acustic turntable designer) uses TRON for his own personal system.

If after that you still prefer an active preamp, then it's the colouration/distortion of it you like, which is a bandaid fix for something else that's wrong.

Its not a bandaid- an active line section can control an interconnect cable and reduce its artifact. A passive cannot.

Amen Atma!

It is a banaid fix because his AMR has to drive the input of a preamp through the same interconnects and pre amp inputs are usually 47kohm (industrie standard), his FL100 is acually higher and easier to drive at 57kohm through the same interconnect and 1 pair less as well.
And gain doesn't even come into it as he has an abundance. and as a bonus it's all direct coupled, no "masking" capacitors in the signal path as it would be with many preamps.
A preamp in this case in the path can only add colouration/distortions that some may like because it's masking a problem elsewhere.

Like I said Nelson Pass's quote says it all, to contradict it is almost blasphemous. read again carefully.

Cheers George

A Quote from the master Nelson Pass

We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.
Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up.
Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control.
What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.
And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp.

Cheers George