Well, had it up and running for a couple of days now. I've been quite surprised by the amp, it leans towards the brighter end of things more than I anticipated. Partnered by my trusty old 752s and Marantz SA7001 KI, there is a very open presentation, quite airy to some degree and with a good soundstage to the music.
The speakers benefit from a little toeing-in, which I haven't done for some time, they normally point straight ahead, but this has tightened up the bass which seemed to sit back in the mix.
Detail is very good, much better than I expected; the NAD is a very musical little amp, but forensic isn't a word you'd apply when describing the sound. The Sansui is much nearer this but retaining a good grip on the music. I've found myself looking up at times and realising there were elements in the music I'd not really heard of late - a good thing IMO. Voices are well presented and retain a lifelike touch. Bass lines are followed accurately and bass pedals accurate without becoming boomy.
The trade-off (yes...!) is that treble; music with a lot of high frequency stuff going on starts to get a bit unruly. The amp can do volume well enough (40/wpc) but gets a bit shouty/screechy depending on the amount of high frequency going on. There are tone controls and a high frequency filter, though I haven't really used either and are set to neutral or "off" accordingly.
Build quality is excellent - no quibbles here, the amp is weighty and the tone controls are satisfyingly solid in operation. Condition is well above expectation given it's over 30 years old now in this example. There are no options to add a separate power amp alas.
If you're like me and on a very tight budget, or just interested in older kit, this is well worth shortlisting and trying out. Mine cost me £33 including delivery and for that money it's a steal. Performance is up with the Marantz PM6010-KI, so think around the £400 mark. Not too far off the Audio Analogue Puccini SE I tried a few months back either, and that one clocked in at the £800 mark or so, but the treble on that model is very sweet.
This amp would work in a set-up where either the source or speakers are a little on the warm side. I might avoid earlier Cambridge Audio CDPs for instance given their tendency to brightness. All that said, the 217's punchy, has a good grip on the music and makes an excellent used buy. There's plenty of them out there currently and the n17 series is worth checking out given you're likelyu to clock this one in for less than £50. Get one in decent shape and you're definitely on to a good thing.