About 6 years ago I bought a pair of JBL 4365 thinking I wanted a large format speaker. Efficiency is 93 dB or so, and I had run amps at that spec with my 300B based amp before. Well I found out the hard way that my Eletraprint could not do this. Eventually I went hybrid with a Musical Fidelity integrated, and then pure solid state. I did try an amp based on 811B tubes and it was still a no go. I kept thinking I wanted a tube option again. I am waiting for a top tier solid state integrated to get sent my way, but I don't know when that is going to actually show. I saw a pair of Audio Mirror Reflections amps on USAM and decided to buy them. When shipped apparently a solder joint got damaged, so they went back to the factory for service and I had resistors and tube wiring updated to current spec. I got them back and hooked them up and was underwhelmed. It had Sophia 6SN7 and 6SL7 driver tubes, and I did not have a lot of replacements. I tried one pair of old mismatched Sylvania 6SN7 I had, and the sound moved the right way. I decided to order tubes. I got RCA and GE 6SL7 and Sylvania, Tungsol, GE, and Raytheon 6SN7, finally RCA5692 So far I have found the Raytheon and GE combo to be my preferred pairing, and the sound is excellent! It is amazing what the right pre-driver tubes does in this amp. The output tubes are a paralleled pair of 6c33c tubes, and they are good for 42 wpc. That is a lot of power in SET land and what drew me to them. The biggest and baddest of transmitter tubes are capable of more power, but this is on pair with many other types of transmitter and big triode tubes. They are affordable too, I just ordered a new 1980s era quad of tubes for a total of $140 from the Ukraine. The amplifiers have an auto bias system that also checks the health of each output tube and shuts the amp down and lights the tube that is at fault, happens during a 90 second warm up delay. The amp uses a pair of toroidal transformers on each amp, one is the output transformer. Never had an amp with this as the output transformer, and the monoblock feels a bit light compared to most SET amps I have owned in the past. The chassis is made of stainless steel, and most seem to find it quite attractive. The heat sinking for the bias circuit is the previous generation, and to be honest I think it looks better and is easier to handle than the current heat sinks on the side of the amp. The sound? It's hard to pinpoint, and you can vary it a lot with the driver tubes. It has that relaxed flow that tube amps should have, the top end is extended but never calls attention to itself, the bass is well defined so far but I have not ran it to the ragged edge. The soundstage is expansive, and performers are well formed. It is a great amp to listen to. Is it better than my AVM Audio monoblocks? It is a different presentation that some may find more appealing, it is more limited in power and thus macro dynamics and SPL level, but for a normal listening session its fabulous. When no one is home I plan on flogging it like a rented mule and see what kind of SPL levels can be hit. Not cheap, but worth the money in my opinion, and very much worth what I paid for them off the used market. Disclaimer: I stole these images off the net. I don't have my own photos on a hosting site that I can link to this forum. So these will have to do.