Upgrade Nakamichi PA 7All power amp with mono blocks

Current System:

Acoustat 1+1 speakers

Rythmik pair F12SE subwoofers

SPL Crossover (German Brand.  This separates the signal and reduces the demand on the Acoustats.  It helps bring out the mids and highs on the 1+1's

NAD C165BEE pre amplifier (plan to upgrade long term)

Technics SL-1500 C with AT 540ML cartridge in a RigB housing (think AT740ML+)

Marantz 8003 SACD (essentially retired with all CD's on digital card)

Eversolo DMP A6 streamer (occasionally use the DAC, but find it is too bright for extended listening

Schitt Bifrost 2/64 R2R DAC

Nakamichi PA 7All Power Amp (Nelson Pass Stasis design)

I am currently considering replacing the PA 7All with mono blocks, but am also willing to consider a  higher end stereo power amp.  I am looking for improved stage and instrument separation (already very good.  just want more).  I stream Amazon HD (60%), use the digital card for CD material (20%), and vinyl (20%).

These are the power amps I am currently considering:

PS Audio M 700 Mono Blocks ($3498 for pair)

Schitt Audio Tyr ($3198 for pair)

Buckeye Amps ($1550 for pair).  Worried about missing the low level Class A sound (70% of listening is done at low to mid level with 80% primarily background sound).

I would love to test these at home, but with a bad back and restocking fees I am inclined not too.  Once I get a new unit I will A/B it with the PA 7All to confirm it is an improvement.  Trying to minimize bringing too many units into the home.

I would love to hear the community's thoughts on these and potential other units to consider.  I am willing to try used, but it needs to be essentially a lock.  (I purchased the Acoustats and Nakamichi used.  Everything else was purchased new).


Thanks, Ralph


@thriftyaudio given your existing investments so far, I like your plan for yourself on next steps. Since you indicated having just refreshed your PA-7 amp, go for it. Can’t think of a good reason not to try it with either unit you’ve narrowed it down to so far.

Fwiw, I normally run tube pre & mono amps on my main system. Late last year I picked up an older Pass/Forte amp, had it refreshed and upgraded. I’ve been listening to it swapping back and forth since. Channeling your own PA7 lineage that is. I like it well enough to keep it in play, and the tube gear has been sitting idle on the side. And as you know, some of this decision making also has to do with your speakers, but I can share without a doubt, a good preamplifier can really help the amplifier and your speakers to perform differently, hopefully better when you find a nice match and synergy.

As you may be aware, Darren Myers designed that Stellar Gold preamp before he left PS Audio to go join in at Parasound. I was eyeballing the internals and design on that unit, seems kind of like a unique and different design for PSA, lots of "other stuff", regulators, and discrete amplification stages fed by a big transformer in that unit. It might be worth a call over there to PSA to ask them what kind of serious demo they’d let you do, for 30-45 days, ensuring its a "good match" for you and your PA7 before committing to follow through on keeping it. Demo required imo!

Interested in hearing what they do for you. Would be nice to see PSA put their money where their mouth is on this one for you, if you decide to demo it. Best of Luck on whatever you decide.



decooney thriftyaudio OP PSA gives you 30 days in home trials- no questions asked. Even longer if you request. I’ve bought many products from them...

thriftaudio: They also take trade ins. They will discount up to ??% of the price of your purchase if you trade in that NAD! Sometimes more if you have a history with them or under certain circumstances.  For best results, don't buy online.  Call and speak to one of their sales reps.

I have the NAK PA-7A MKII with the CA-7A pre.  Both fully refurbished 2 years ago also.  

Fact is it's a tough combination to beat no matter what your budget is.

"Fact is it's a tough combination to beat no matter what your budget is."



Reading back over this. Another thought along the same lines of thinking...

Yep, levarage the existing amp as-is, keep it for a few more years, at least.   Having owned the BF 2/64 myself, its an ok DAC for the money - yet more to be gained with a 1 or 2 level up dac for sure if you are looking for more lush velvet and musical sound.  Some dacs are "overly precise", too analytical for me, or imo.  

A really good DAC, nice Digi Coax cable, nice output interconnects to the PA-7 II, and you'll hear the existing amp and Acoustats in a new way.  Demo 3-4 more dacs first.  Try this for a while, might be pleasantly surprised.  

Then, after this is set up well, IF the new-amp-itch is still there for a set of "monos", start demoing (buy/return/keep) and comparing decent monos to see who can dethrone the recently refreshed PA-7 II.  Would not be suprised if it holds its own.  



We seem to have similar taste.

I am picking up a used Benchmark LA4 preamp this weekend.  I leveraged the purchase to also pick up a pair of PS Audio M700 power amps used.  I suspect the LA4 will be my long-term preamp, but I will do some a/b testing with the NAD just to comfirm.  I have some interested parties in the NAD so it will be easy to sell.

I will also do some a/b testing with the M700s with both preamps just because the equipment will be here.  I expect I will leverage them into something else, but if I love them then I will leverage the Nak into something else.

My streamer/DAC journey was a mess.  I started out with a Cambridge CXN v2.  The sound was just OK and the app was not user friendly.  Never could get it to work consistently.  I returned it to the dealer and tried the Node N130.  The app was a little better and the sound was about the same.  I upgraded the N130 with a PD Creative SMPSU in a LPSU interface.  The sound improved dramatically.  Really loved it.  While this was happening I ordered an Eversolo DMP A6 based on all the great reviews.  By the time it arrived the upgraded Node was working great.  I was going to return it, but decided to go ahead and do an a/b test.  Turns out the streamer portion of the Eversolo worked better than than the Node.  Additionally, the app was amazing (still is).  The DAC portion was a bit shrilly, but it had very good stage and instrument separation relative to the Node.  I kept the DMP A6 and moved the Node to a secondary system.  The Node is still very good.

I listened to a friends Lumin D2 and liked it, but didn't love it.  The sound was great but the app was not as user friendly as the Eversolo.  It was also too expensive for me at the time.  My friend suggested the Bifrost 2/64.  He had one on his 2nd system and said the DAC was the equivalent of the D2.  I listened in his system and liked it so I ordered one.  I was prepared to return it if I was not blown away in my system.  I was.  It was a huge improvement over the DMP A6.  

So, what did you try in terms of DACs and where did you end up?  Did you try the Schiit Yggdrasil LIM or MIL?  Any suggestions for the future?  Did your try different streamers too?