I auditioned the Pathos InPower at the dealer's shop and later on in my listening room.
I was intimately familiar with the Pathos sound since I owned a Pathos TT for a couple of years.

Design and Appearance:
Nice size amps considering that they are monoblocks, but they are back-breaking heavy.

It is designed according to the Pathos Acoustics Design Philosophy, where the voltage-gain blocks use tubes and the output stage uses the pateneted InPol Technology where a passive current source is used in conjunction with the output transistors.

The Inpower monoblock output stage is essentially two Single Ended current amplifiers in one, and therefore unable to sink current below zero. This inevitably leads to clipping if connected to low impedance speakers at hight voltage amplitudes (playing loud).

The manufacturer recommends speakers having a min input impedance of 6 ohms.

As always with Pathos, the exterior appearance and design is extremely pleasing to the eye. The amp is beautifully hand-made and feels very luxurious.
The thick, polished, aluminum front panel along with the Pathos-red ( Ferrari-red? ) capacitors - sandwitched between the chromed InPol devices help create a dazzling visual effect not very soon forgotten.

Setup and Use:
Not very big amplifiers but they more than make up for it with their weight. They should therefore not be placed in a hifi rack, and because of their producing A LOT OF HEAT, there should be a lot of room around them.

They have a lot of gain, making the use of preamps unnecessary. If you have the opportunity to directly connect them (as I did) to your source or use a passive preamp, you will hear these amps at their very best.

I also noticed that they are queiter than Pathos TT units. Since they are more solidly built, I would assume that they would be more reliable than the TT's.

A very important factor is that the output stage is DIRECTLY COUPLED, with no caps in the direct signal path of the speakers -- bravo! -- and consequentially there is no pop in the speakers when amplifier is turned on or off.

Sound:
Once properly connected and setup, they produce a sound that is immediately recognizable for those familiar with the Pathos products.

High frequencies: realistic and VERY extended, a bit sharper sounding and slightly grainier than for example Aleph 3, or TT for that matter. Symbols are recreated with a sharper harmonic content which tend to make them slightly over-emphasized. There is a lot of air around the instruments.

Midrange: very palpable and dimensional, however slightly grainier than many SET's out there.

Bass: this is where Pathos Inpower truly shows its superior qualities. The low frequencies are reproduced with such extension, articulation and speed that I have not heard any thing, regardless of the price, quite being able to equal it. Its bass response is beyond anything that I have heard and is absolutely reference class.

Soundstage: Very good, but not as panoramic and deep as for example Aleph 3. Dynamics are slightly more congested than say Aleph 3 and the presentation of its soundstage not quite as colorful.

It is not as emotionally stimulating as the Aleph 3 or as or romantic as the Pathos TT.

There is very little information on the internet on this amp, and no one seems to have reviewed it.

During the one week I had this unit in my listening room I did not experience any mechanical problems. As stated earlier, this is a much more solidly built unit than the TT, including much larger heatsinks, a huge transformer for each channel, TWO passive current regualtors PER CHANNEL, however its price tag limits its appeal. It draws a lot of current and can quickly turn your listening room into a sauna.

It is an expernsive unit and the competition is very tough, even from the manufacturer itself. I believe Pathos has released the second and third generation InPol circuits that might be more interesting than Inpower which features the first generation InPol Circuit.

As wonderfull as this amp is, check out the other models from Pathos first, in particular the Pathos Inpol2 which has gotten rave reviews. If you however decide to go for this one, I don't believe you will be disappointed...

Good luck