Single ended = large images?

@montaldo Completely slipped my mind, but in thinking about that much Rel sub power it came to me that one very important aspect of Rel subs is how they affect sound staging and imaging. I have only two of the T9x, adding these brought an easily noticeable expansion in sound stage and image size. I can only imagine how your stack of subs would far more greatly expand upon what I'm hearing. My room similar size to yours, I presume your stack with my 300B SET monoblocks would completely overwhelm my room.

Yes the six pack goes well beyond two subs, in some small ways on soundstage, etc. I found the biggest benefit of the six pack to be how it makes each instrument and each voice sound more like the real thing in real space. The texture, the timbre, and the ambience around it... Like good vinyl does. The six pack was the first step in my realization that I could get good, musical sound from digital. After getting an audio note UK DAC and a Grimm AU-1 streamer, I decided to sell my analog rig and take a break from analog. This coming from a guy who only a year ago listened to 80% vinyl!

I would recommend you look at Triode labs-Finale Audio out of Toronto, they make some of the best SET’s I’ve heard. I’m not sure though if they make one powerful enough for your 91db-8ohm (4ohm min) speakers though.

You mentioned 89db but the manufacture states on their web site 91db, either way not overly efficient for a SET IMO.

You may want to consider a parallel SET to get more power. I really do not think your speakers are efficient enough for less than 20watts and IMO probably still pushing it, you may actually need closer to 50-60 watts, if as you mentioned you listen at moderately loud levels. Subs you have will help in this regard if you cut the low frequencies from the main speakers. Not sure if you have that ability.

I’ve owned some moderately easy to drive 94db, 8ohm speakers that really did not come alive on a 300b SET amp @8wpc. They needed 25wpc to wake up. Not sure if the 20-25wpc of the 805-811 will be enough for you. Remember SET’s tend to start distortion earlier in their power envelope than in a push pull configuration. Really 60-70% of their power rating is about all you’re going to have clean.

I’m hopping your successful but if it was me, I’d loan one for a few weeks to see if it meets your expectations. And definitely consider parallel SET. one more thnig in your prce range you may want to consider one of the chinese amps that are well reviewed like the Wilsenton, etc. good value for the money. another option is the gallion amp. 

Thanks. I think you all provide good advice. Unless I can get a loan to try, I may just try some tube rolling ing v4 amps, such as trying kt-120 or kt88 tubes. Or think about one of my lost loves, the vac Renaissance 300b amp, which is pure magic and would achieve some of what I want to try. But need the 30/70 or 70/70 versions, and it's a lot of 300b tubes.

My Parsifals are early models and I believe are 89dB. Later models like the anniversary, and maybe the ovation, have higher efficiency.

I cant imagine an amplifier increasing the perceived size of instruments. Normally this is the results of speakers and interaction with the room. SETs are very quick to clip and do so in a very subtle fashion so what you are experiencing might be the result of overdriving the amps. P.P. type designs tend to sound a bit fuzzy or confused however by comparison which is why I settled on OTLs.