This amp is very musical and harmonically rich...with a good source and preamp, you will hear things you never heard before. It is dead silent with no signal. Bass is sufficiently controlled, but it is not the amp's strongest traits -- there are other amps that exhibit much more authority in the bass department. But midrange and treble is to die for. It is not sweet tube sound, but just so pure and clear without being clinical or solid-state sounding. Really good tonal balance. Soundstage is so wide and deep it will breathe new life into your speakers.

Build quality is very good, but there are signs of cost cutting compared to their current and former top end amps like the A-65, A-60, A-50V, A-50. The top cover is a bit thin and flexes. The meter window is plexiglass instead of real glass. The benefit is the weight is manageable at 68lbs (versus 100lbs on the higher model.)

Considering that it is a pure class A amp that doubles in power (45W into 8 Ohms, 90W into 4 Ohms, 180W into 2 Ohm, and 360W into 1 Ohm), it is as cheap as a high end class A amp comes. What turns this amp into a true bargain in the high end world is when you use a pair in bridged mode: 180W of pure class A into 8 Ohms, 360W into 4 Ohms, and 720W into 2 Ohms! This is one of very few amps that does not have degraded sound when running in bridged mode. If anything, I think sound gets even better in bridged mode -- more clarity, definitely more dynamic and slam, and not a hint of harshness. It might have lost a bit of golden glow, liquidity and 3-dimensionality, but so little as to be not noticeable. Tradeoff for the better dynamics is definitely worth it.

Don't let the low power rating fool you. This is a very high current amp, and will drive most speakers with no issues. I'm using it with the very power hungry and wild impedance curve Gallo Reference 3.5, and no problem whatsoever.

This amp is of such high resolution that for the first time, I can hear differences in interconnects and speaker cables, something I never believed in nor could reproduce before. Music is never congested and presented in layers so you can pick out each instrument and their location, both within the stereo field and depth.

I love the fact that it sounds great right after power-on -- no need to warm up.

A-45 is great with any kind of music, but really stands out with Jazz and Classical.

Beware of the fact that the XLR pin assignment is according to Japanese standard, so hot and cold are swapped from standard pro audio or Western world equipment. If your preamp or source does not have phase inversion, no problem --- just swap the + and - speaker wires, as this is a fully balanced amp.

It is best to run this amp using balanced inputs (XLR) with the gain set to lowest position. And of course if you can, run a pair as monoblocks -- then they really come alive. Also, I find that using isolation transformers or even a high quality (that is, with Faraday shield) step up/down transformer with same output voltage as input, will yield better soundstaging and resolution. So it seems to be somewhat sensitive to AC line noise.

Give her a listen -- I think you will fall in love with this amp.

Great musicality,pure tone,microdynamics.It can easy drive my 3-and a halfway floorstanders even in big
orchesteral works of Mahler and Bruckner to very high sound levels.

Börje