Nakamichi PA7 versus PA7 II

I have a PA-7Aii. I've run it with Magnepan MG3a's and Martin Logan CLS's -the first generation that are difficult to drive. It runs warm, not hot, but drives both speakers very well. It is a little cold blodded and sounds best after it's run for 45 minutes or so and sufficiently warmed up.

I bought my Nakamichi PA-7A mkII in 1990 for $2200, and it’s still one of the best amps I’ve ever owned. After about 20yrs tho, it was sounding dark and sluggish, so I took it to a Threshold expert, and he recapped the whole thing (not cheap! $1400) but what I got back was like a $5k Threshold! It sounds glorious, and adds a certain glow to the music. I had to stop using it many years ago due to a nasty turn-on thump, and I’ve actually just taken it to a tech to get it fixed.

I recently got a pair of Cornwall IV’s and my Bryston 4B-SST2 is just too harsh and brutish for them (not surprised). I tried a Schiit Aegir2, and it sounds REAL nice on the Cornwalls... very smooth and easy, but ultimately still not quite right. THEN I pulled out my old Nakamichi, and it sounds FABULOUS on the CW’s! Yes it’s way too much power, but it simply has a certain magic to it. I can’t wait to get it back with the turn-on thump fixed.

For those that claim... oh it’s a hot amp, or oh, it’s a cold amp.... well.... it is however you set the bias! It runs many watts into Class-A. The guy that recapped mine set it so it runs pretty warm, and I can attest it’s smooth and dynamic! BTW... he also replaced the bias pots, as the originals, after 20+ years will be noisy and impossible to adjust smoothly. This is a great amp, worthy of fixing up.

The Threshold tech also told me that the MkII version is THE one to have. Nakamichi addressed many issues in the revision. Just look at the wiring in the first version vs. the MkII. They really cleaned up the power supply.

This is a great amp, worthy of fixing up

I spent about as much as you did in 2021 to refresh my MKII.

Absolutely worth the investment.  

The factory set bias of 40 mA will allow approximately 16 watts in Class A and, yes, it will be warm at idle but not hot. Unlike the Threshold's of that era where bias was set at 100 mA allowing 25% of rated power to be in Class A, however they were hot to the touch at idle and component reliability/longevity suffered greatly.

My tech also prefers the the MKII vs. the original and prefers the Naks over Thresholds for build quality and component selection.