Once you get the subs optimized…
If you don’t mind my asking… what are you using under the PMG 800s? 
I assume you’re asking straightwire but I’ll butt in. I am using the solid steel S3 amp stands which were also used under the BHK 600s. The M800s just fit with about 1/4 inch overhang at each end. I did look for other options but nothing else was suitable.
Hi jerryd6, that’s just fine that you answered my question. I currently have BHK 300s but am looking hard at the PMG 800s. The 300s are on a hardwood floor but because the 800s are so much larger I may have to put them in a place that is covered with a thick area rug. I don’t know if ventilation/overheating/cleaning would be a problem but am thinking it may be good to get them up off the rug. I don’t really know what others do and just looking for ideas.
Because of your basic floor placement, as a start you could consider putting short wooden beams under the feet.
Having said that, next point of curiosity would be others’ experience with aftermarket footers under the new amp.
For reference the solid steel stands are, I believe, $300 each.
I did some looking online at that idea. Crutchfield sells the S3 but they show the length to be 23". The PMG 800 is 26-3/4" so there would be a couple of inches overhang on each end. It’s closer the narrower direction with a 1/4" overhang. It looks like Solid Steel makes a guitar amp stand (Vibestand BGS-XL) that is similar in appearance and close to the PMG in size but couldn’t find a US dealer.
Under my M800’s is slab of 17”x 24” 1 1/4” granite. It just covers the amp’s feet on all sides. Under the granite are Herbie’s large metal spikes that penetrate the carpet. I have Stack AUVA C3 pucks that I will put under the amps. I didn’t do this yet until I settled on a permanent location, and I wanted to see if they improve things, and I will report. The amps get warm, yes, but less than the BHK 600’s, if that helps as a reference.
I just checked and the front and back feet overhang by no more than 1/4 inch, less actually. The 26-3/4 I think is the chassis length.
I saw the Vibestand and also could not find a US source. The Solidsteel website in principal allows buying items but I could not navigate it at all.
The S3 works well and I don’t have any problems with the tiny overhang.
I found the same with the temps of 600s and 800s. The S400 is noticeably hotter though than the 800s.
Okay, good info – thanks!
How do they compare in the upper bass/lower midrange area, where most of the musical content lives - the power region? My BHK 600s struck me in that area in particular, as having a very full and round presentation that was much more forward than my previous amps, which were solid state.
Good question! The BHK amplifiers have vacuum tube inputs and mosfet outputs, which has a nice warming influence. Could that be what you hearing? As an aside, I have not heard what the new PMG amplifiers are using (other than they are solid state, of course).
Hello Folks:
I’ve had my M800’s a week now and this is my prelim reaction. I’ve only put about 20 hours of burn in. They are replacing the BHK 600’s, which are fine musical amps.
My gear is all PSA PMG except for the CD Transport. I have the PSA SACD. I also recently acquired 4 F12 Foundry Subs. My room is medium sized at 15x21 with a cathedral ceiling which eliminates standing waves in the floor/ceiling dimension. I’ve treated the room with absorbers and diffusors and measured T60’s or decay rates, which are within acceptable range and fairly linear for a small room. My first impression of the M800’s vs the BHK’s is in the bass response. The new amps go deeper and the bass is more dynamic. Low level percussive stuff jumps out. Imaging appears to be more pinpoint. Recently, I was able to move my FR-30’s further out from the front wall and things improved a lot. So far, the M800’s are keepers.
I second that emotion. What stood out immediately with the M800’s was the bass (deeper, tighter) and the imaging (more defined, airy). I’ve been slow to put back the 4 F12’s for that very reason as a best location for them still eludes me.
On the flip side, I still have some nostalgia for the BHK 600’s. Sub par recordings (aren’t they all 
) can benefit from an amp with a kinder disposition.
Ultimately less detailed, I think (sorry tube fans) but sometimes easier to love.