Nakamichi PA-5 driving NHT 2.5i

Thumbs up to this combination.

I have tried to power the relatively demanding NHT (86db, 3.6ohm lowest impedance) with different units which i thought were "good value": Acurus DIA-100 (100wpc), Carver Premiere AV-705x (185wpc in 2-channel), even CJ Sonographe SA250 (125wpc). The CJ came quite close, but I have always felt that something's missing - the voices would turn harsh at elevated volumes, the bass was emphasized and muddy (to my ears). Based on other feedback on NHT i kept thinking that it has to do with room placement (sure enough the bass output can be tuned with room placement, but could never get it to clear up).

I even wanted to sell the 2.5i - with the intent to get something "less demanding".

Boy am I happy i didn't.

In comes PA-5 which i got because it was "too good to pass up". Did not think I would actually need it... First I hooked it up to power the tweeter/midrange drivers of the NHT 2.5i while keeping the Carver for the subwoofer. The highs cleared up nicely, but the subwoofer still felt somehow underpowered and muddy. Oh well - room placement, I said, but on a whim i removed the Carver and hooked both posts to the PA-5 only.

And I was in for the most pleasurable surprise.

Gone were the "room placement" issues. The highs and mids kept their newfound clarity while the subwoofer now presented a taut and fast bass with flawless integration to the overall sound envelope. Gone was the perceived "dip" in the mid-bass - which i previously thought is a "given" of the design - now i understand that it was artificially created by the lower bass over-emphasis and sluggishness.

What did i learn?

1. 100wpc is "less" than 185wpc. However if the speaker feels underpowered - throwing more power in might not help.
2. The quality of the power component is more relevant.
3. Room placement issues might sometimes be a reflection of inability to power appropriately one driver or another.

I can now confirm that the NHT 2.5i is a worthy speaker of a great design - and I'm happy to have found the Nakamichi gem to drive it with.
I think that is one of the Nelson pass designed Ss amps.

For cost effectiveness with second hand gear, I suspect it would be hard to do better. I've come close to trying one of the better Nakamichi amps myself in recent years. Nakamichi was an affordable high quality audio brand for years. A shame it is no longer around. I had a Nakamichi car stereo about 10 years ago. It was somewhat delicate but was by far the best sounding car gear I have had and for only a nominal additonal cost compared to other brands like Alpine which it blew away IMHO.
Congratulations, you've discovered Nelson Pass. As mentioned earlier your amp is using his earlier design that was licensed to Nakamichi. There is a nice upgrade path from his later designs when you are ready for an upgrade.