Audio Research 300.2

TAS - Audio Research’s $3995 model 300.2 power amplifier is a 300Wpc design based on Tripath Class D (or as Tripath would have it, “Class T”) amplification technology. At its best, the 300.2 is one of the most musically satisfying amps I’ve ever had in my system.
I found that this amplifier needed to be powered up for 24-to-48 hours or more before its sound fully gelled (and even then, improvements continued to accrue).
It is true about the warm-up time. I left mine on all the time if I’m planning on listening within a few days. It only gets slightly warm.

ARC sounds so expressive and full of life, it is more engaging on an emotional level than most other amplifiers. Instead of presenting “good sound” in a vacuum, the 300.2 gives listeners the sense of participating in musical conversations. In that context, the ARC’s ability to convey emotional content makes all the difference.
This amplifier is in good condition and was modified by Tripath engineers for optimal sonic performance (XLR input has been disabled and works in Single-Ended mode only). The ARC 300.2 produces 300 watts per channel into 8 ohms, 500 watts per channel into 4 ohms, both channels driven, 1% THD. (600 watts into 4 ohms, one channel driven). with very little heat. Made-in USA.

I prefer that the buyer audition the amp to their satisfaction and hence will not ship.  I have the original boxes.
Serious inquiry only.
Price is fair and firm.
CASH only

NOTES FROM ENGINEER
Main bridge Rectifier looks good
Other diodes for rectifiers are good
Nothing visibly wrong / not connected or loose
Summary
⁃ To improve the overall noise performance, the differential preamp was
bypassed. So the only usage UNBALANCED via RCA JACKS.
⁃ Noise level for both channels is now sub 400uV-A weighted at startup and
increases to ~500uV due to line harmonics (mostly) and some TA0105A
self-noise
⁃ Fsw (left_ch) = 520kHz, Fsw(right_ch) = 567kHz
⁃ Trimmed output offset via RV1 and RV2 to less than 3mV
Modifications / Improvements
⁃ Bypassed differential preamp (to lower noise level and hum pickup) by
disconnecting TA0105A input caps from drain of Q1A/B and Q2 A/B
⁃ Wired C8 || C10 || C12 (left channel input caps) and C7 || C9 || C11 (right
channel input caps) directly to left and right RCA jack, respectively.
⁃ Replaced R50 (10ohm isolator between RCA GND and AGND) with 0ohms.
Improved noise and line harmonic pickup, especially of right channel.
⁃ Added 65.5k resistors across each RCA input to AGND to minimize pops
from hot insertion of RCA cables
⁃ Changed feedback cap, C19 (originally 10pF) to 5pF to maximize switching
frequency delta between left and right, so as to minimize high frequency
noise floors
⁃ Star connected the AC IEC module ground at same location as transformer
ground as opposed to at chassis bar inputs
⁃ Add star washers at each screw point on bottom of the amplifier to
improve chassis integrity to minimize noise pickup
⁃ Add star washer at back middle of the top where paint had been masked
off to ensure good chassis connection. Noise floor is lower with top on as
compared to off by about 50uV