I'm now using the C320bee as a preamplifer with an O&B power amp. but using it as a preamp, I don't notice a big difference. So as a preamp, I don't recommend. When I connect 320 as an integrated amp, here is the "wow" factor.@hifimaddy, kindly share some light on Rowen Swiss Edition with reference to your NAD C320BEE amplifier (used as a preamplifier)
Basically, Rowen used their own techniques and modifications to improve the "stability and musicality" of the standard NAD amps; they changed some parts or tuned according to this. I don't know much about the modifications they have done.
I have heard the sound signature of normal 320 very few times. but the rowen basically feels very powerful. I have compared side by side with O&B; the sound signature and stereo separations are very noticeable in Rowen. Even above 50-75 percentage volume, there are no distortions or fades.
I have brought it from an audio equipment collector in Switzerland. When I was buying this amp, I didn't know anything about Rowen Editions. He explained it to me, and I thought he was giving some fake information, but later I realized this was worth the purchase. If you have a plan to own one, don't hesitate; this will be worth buying, but find a Rowen edition, which is very rare and also very expensive compared to normal NAD amps.