Ahm, it meets the 2 volt spec. It does nicely with the:
Apt Power Amplifier 1
Apt Power Amplifier 1
(1979-1987)
8 ohm setting:
1V in = 117.9 W out
1.03V in = 125W out at 0.1% THD (still green)
1.04V in = 127W out at 0.41% THD (still green)
1.045V in = 128W out at 0.6% THD (just turning red)
1.27V 10mS peak = 54.5V peak = 38.54V RMS = 186W RMS burst power
And with the:
NAD 2200 Power Amplifier
Date of manufacture : Jan 87 - Feb 89
POWER AMP SECTION
Continuous output power into 8Ω * 100W (20dBW)
Rated distortion (THD 20Hz - 20kHz) 0.03%
Clipping power 140W
(maximum continuous power per channel)
IHF Dynamic headroom at 8Ω +6dB
IHF dynamic power 400W (26dBW)
4Ω 600W (28dBW)
Here is actual results:
(Hey, that doesn't meet specs either, but is it adequate)? And I can drive anything with much less sensitivity. So what if it exceeds specs? That just opens up more options...
It is power measurements where the magic of this amplifier comes to life so let's look at that with 4 ohm load first:
We can see a kink in distortion when we hit 200 watts as the unit sails past that to produce whopping 337 watts per channel, both driven! Per design characteristics, you can have much more during momentary peaks:
Wow, we have one kilowatt of power coming out of this amp in short duration!
Switching to 8 ohm we see similar results as 4 ohm:
Sweeping the power test at 4 ohm with different frequencies shows a well-behaved amplifier:
You do loose power in higher frequencies but that is fine since music spectrum has lower energy there anyway.
Due to the long duration of this test, the protection circuit likely backed off the high voltage rail, producing lower output levels.
EDIT: adding Lab Input Measurements
Lab Input Measurements
I was surprised that the frequency response was not flat but was relieved to see later in the thread that this is due to insertion of low and high pass filters. So here is the frequency response with Lab input that doesn't have such a filter:
Response now (in green) as it should be, ruler flat to below 10 Hz, and well extending past the 40 kHz limit of this measurement.
I figured the filters may be adding some noise/distortion so re-ran the dashboard again:
Distortion doesn't change but if you look at the noise floor at 20 Hz, it is down by some 10 dB. That improves SINAD a couple of dBs, making the amplifier stand out even more!
Zoomed:
And signal to noise ratio:
Conclusions
Nice to see innovation like this from equipment that is over 30 years old! Shame on manufacturers that produce amplifiers for much less power, more distortion and higher prices these days. No, you don't get a fancy case here and sheet metal is strictly budget category. But you are not going to sit on the amp. The guts are where it matters and NAD 2200 delivers.
NOTE: the output relay on stock 2200 gets corroded and fails over time. There are videos and DIY threads on how to upgrade the relay there to fix the problem. The unit tested here has that fix. Other than that, there are not reports of many other reliability issues even though NAD products are often said to be less reliable than other brands.
Overall,
I am happy to recommend the NAD 2200. I almost gave it the highest honors but given the upgraded nature of the test unit, and the fact that used amps may have issues, I avoided that. But you could have easily pushed me to give it the golfing panther.
I think that you may have jealousy issues and just have to say something negative to make yourself feel good.
