General Asylum: REVIEW: Audio Refinement Complete Integrated Amplifier (SS) by klaus

For two years I use A.R. as the only amp for music and video. The unit s/n is an early 00026, and judging by two many empty slots on the board, it might differ a lot from the newly made ones.

The sound is warm, open, and very comfortable. A/B tests with other amps (other things equal) show that A.R. somehow compresses the sound without losing too much detail or imaging. The voices sound more in harmony than they do on other equipment, and when the sudden loud solo on the other amp stands out and breaks the picture, with the A.R. it still stands out but as a part of the cohesive total. This applies not only to loudness and tonal harmony, but to tempo as well, believe it or not. The amplifier as a second conductor? I'd say, the designer sacrificed some fidelity in favor of musicality, or - to the critics - in favor of plain ear comfort. Euphonics, is it the right word?

Before you read further (for the bad news): this is a good amp that I'd keep for at least a few years more.

One thing where A.R. obviously fails, in my opinion, is how it renders string attack. It over-empasizes the attack, double bass, or violin pizzicato - and sometimes it sounds as if the recording was made close-mike in a small club while in fact it was a huge hall.

As for the other glitches. The most obvious two are related to the automated source selector and motorized volume - this is the weakest part of a design.

1. Volume returns to zero at each power off. I'm not using a remote, so I simply disconnected motor wires. You'd need a 2.5mm hex key to get inside.
2. Too much crosstalk from unused audio inputs to output. I'm thinking of re-wiring it completely, placing reed relays on separate daughterboards for each input - I need only three, with decent cables to source units running directly from the daughterboards - bypassing the rear RCA jacks.
3. The other side of #2, poor channel separation. Doesn't this explain in part the cohesive sound picture?
(being an EE in the past, I couldn't help digging inside and deciphering the board. Here is the schematic: http://klausmobile.narod.ru/arcomplete/r2_schdetail.GIF
and my description of what's there, in Russian: http://klausmobile.narod.ru/arcomplete/arcomplete.htm).
4. The pre-output follower transistors have no heatsinks and yes they get quite hot in less than three minutes (about 80C on tab with top cover removed). The main heatsink is mounted neatly but, again, can be not good enough for proper convection. I'm not sure if it could be a problem in places warmer than mine, or at higher output, - good ventilation is a must - not only above the case, but especially UNDER the case, where colder air is inhaled.
5. It bumps on power-on and breathes on power-off, not too loud on my speakers but might be painfully loud on high efficiency ones.
6. There is NO protection of any kind for the amp (short circuit kills) or the speakers.

REVIEW: Audio Refinement Complete Integrated Amplifier (SS) Review by klaus at Audio Asylum