Audio-GD Master-1 Fully Balanced ACSS Pure Class A Preamplifier

Amazing reviews !  This is one of the best preamplifier that I ever owned! You can look at the reviews.  Very neutral and musical.  Never aggressive and very detailed.  All the small inflections and nuances in the musical message are rendered.  I was mostly impressed with the current power it has to control the low frequencies.  They are rendered with clarity and detail... in all their nuances. No muddy sounds, only high precision.  The air and space between all the instruments is also quite outstanding.

Fully balanced class A design built by discrete analog stages without any OPA or coupling caps in the signal channels.
Non- feedback ACSS analog output stage.
Uses three R-core transformers (135W total) with separate power supplies for the digital components and right and left channels.
More than 50,000uf audio grade NOVER capacitors are used to ensure ample and smooth power delivery.
A total of 8 groups of high-quality class A parallel PSU's, four double-stages for dedicated DC supply. To achieve a high S/N, the control circuit is powered with separate regulators.
Uses high grade parts and exactly matched transistors.
Four-channel 99 steps digitally controlled relay-based volume control avoids channel imbalance and improves sound quality.
5 analog inputs:  RCA X2, XLR X2, ACSS X1
Preamp output:   XLR / RCA / ACSS