Nakamichi PA-5 vs. PA-7

[Brent Powers]

I'm including all revisions. I've already got a PA-5 on the way. Version 1. I am using Vandersteen Model Ones. Now, I could, if I decided to make a serious investment in hard emiricism actually bid on a PA-7AII that is up on eBay right now and make a subjective comparison, decide which one is better, and sell the loser. Or. I could wait. Dig the PA-5 for a while. If I like it, just live with it or, I don't know ... I have been moving up the Stasis line from the SR-2A receiver, which I REALLY like, to the SR-3A, which I don't like as much, to the Nak. PA-5 amp, which hasn't arrived yet, settling for that, even though I know the PA-7 has more power, hence more headroom. See, I've had a Rotel RB-991 with a Conrad-Johnson PV-10 going into the Vadersteens for years and I have been perfectly happy. Then I started getting a whiff of the OS of the Nelson 9000 via Nakamichi hand me downs, research, and emailing the Master himself. Now, rather than continue to bother him, I'm gonna throw it up to the DIY community. Whaddaya think?

[bethelcat]

I had a PA5 and PA7 at the same time, both mark Is, so was able to make direct comparison

They were used to run a pair of Infinity RSIIB speakers from a Proceed CD source

In my view, the PA7 was in a different league than the '5, not just in terms of power output but also the quality of sound. I thought the speaker drivers were poorly interfaced as the sound quality from them was very different - untill I swapped the '5 for another '7

The difference was night and day

Incidentally, it is well worth replacing the bias and dc offset pots for better quality multi turn types and also replacing rectifiers with faster low noise variants