There is indeed an NAD 2600.
Also - when you say you turn it up to 4 - I'm not sure of the gain of that preamp - but a lot of receiver or integrated amps have a preamp section which will hit full power on the amp well before you go halfway. This is a trick to sell amps and make the consumer think "Well, it goes to 4 and my god - what incredible power this thing must have!" Not the case at all. It's not unlike amps you've heard that "go to 11" (okay, it's a movie amp but that's the point. The numbers don't mean anything.)
So, was it loud?
I've had NAD 2200 (used two in bridged mode) which were amazingly reliable and sounded surprisingly good. I've had them for years. Literally. Still working. HIGHLY recommend one or two as back up amps for your seriously expensive and probably tweaky gear. You can pick them up cheap and they sound pretty great. Still.
Also - when you say you turn it up to 4 - I'm not sure of the gain of that preamp - but a lot of receiver or integrated amps have a preamp section which will hit full power on the amp well before you go halfway. This is a trick to sell amps and make the consumer think "Well, it goes to 4 and my god - what incredible power this thing must have!" Not the case at all. It's not unlike amps you've heard that "go to 11" (okay, it's a movie amp but that's the point. The numbers don't mean anything.)
So, was it loud?
I've had NAD 2200 (used two in bridged mode) which were amazingly reliable and sounded surprisingly good. I've had them for years. Literally. Still working. HIGHLY recommend one or two as back up amps for your seriously expensive and probably tweaky gear. You can pick them up cheap and they sound pretty great. Still.