Audio Research LS25MKII

The LS25 MkII very high quality, places stiff challenges to all of the known competition.
Sound stage is huge and 3-dimensional with lots of detail, stereo imaging is excellent, one can actually hear the positioning of the instruments and voices as they were recorded. The music has weight and dimension. The bass is deep and well defined, bass lines can be followed naturally (it’s right in front of you) without being mushy and rounded. Mid’s are incredibly realistic and non aggressive, gives the real sensation of the musicians and instruments being there. The treble is smooth but very detailed.
Overall the sound is smooth without loosing detail and being fatiguing. I found myself listening for hours and hours.
And, what’s most important of all, the timbre of the instruments and voices are faithfully reproduced.
This pre-amp has the best of both worlds solid state (FET stage) and tube (output stage).
Like all tube pre-amps the sound can be easily transformed with a different set of tubes and since there are only 2, experimenting will not ruin your bank account.
Controls: this pre-amp has a control for everything - sensitivity of each input, balanced or single ended, etc., it’s a luxury that once you get used to, you can’t live without. It’s something highly appreciated.
It is built to very high standards, solidly and with the highest quality parts.
Customer Service at ARC is very helpful. Leonard is always ready to help when there is any question or issue. They also sell direct the original tube sets (always good to buy direct and avoid distributor fees) and take credit cards for payment.
On the con side: the unit is very sensitive to mains fluctuation. It can mute outputs and go completely unresponsive with a variation of voltage above 10%.