(Note: This started with a question, but as is often the case the more I got into exactly I was trying to ask the closer I got to just answering the thing myself, which I believe I did. So here is my thought process open for correction, notes, questions, or other critique/discussion.)
So I love this forum but one thing that I'm not sure is super clear is just how good is good. Of course, that clearly depends on budget and power when it comes to amplifiers, but I have 3 amps that I'm trying to decide between for a particular set of speakers. All 3 are reasonable and affordable, but the highest priced one is nearly twice the price of the lowest (I'm naturally inclined towards "cheapskate"). I think it's in the spirit of this forum to discuss how much SINAD is worth in tangible and intangible assets. I think the general and reasonable consensus is that it's worth a lot up until the point where it's not really worth anything.
None of the three have specifically been tested here, but the 2nd and 3rd have tests of the modules in different applications. If it matters the particular brands are Emotiva PA-1 for 1 and the Apollons for 2&3. I need rack mountable units so if you have better recommendations please make sure that criteria is hit.
Speakers will be the Revel M126Be, 86dB sensitivity. "Recommended power of 50-150 watts", whatever that means. 150W is 110.77dB@1m.
Listing the modules and not the manufacture, I'm choosing between the
1) ICEpower ASC300, $639 USD (after discount), .two 135w @8 ohm channels (.1%THD)..................... SNR 112dB (135W) 91dB (1W). SINAD 86dB(1W 4 Ohms)
2) NC252MP, ...............$959 USD (shipped).............. two 200w @8 ohm channels (125@91dB SINAD). SNR 113dB (246W)....................... SINAD ~86dB(1W 4 Ohms)
3) NC502MP, ...............$1042 USD (shipped).............two 350w @8 ohm channels (270@ 87dB SINAD).SNR 127dB (445W?)..................... SINAD ~94dB (1W 4 Ohms)
So 1&2 are so close in measurements that I may as well get 1, but 2&3 are so close in price that I may as well get 3. So what's the audible difference between the 1 and 3? Given the similarity in specs can we approximate 2 for 1?
For 2 minimum distortion occurs at 100W 8 Ohms and is -100dBFS THD+N. For 3, the same spec is 2W and -101dBFS. However, at 100W 3's distortion is ~ -90dBFS. 100W is 110.77dB@1m.
Full 16 bit resolution is 96dB peak. Using the Homestead calculator , near a wall, and at an insanely large 20ft distance, 96dB happens to be 100W. That's convenient...
Thus, minimum distortion at maximum practical output levels can best be achieved with amp 2 which has similar stats to amp 1, which is considerably less expensive than amp 3. Caveat is that distortion curves are similar. NC252MP distortion curve appears to be typical. It is unlikely that ASC300 distortion curve is atypical. Consequence of atypical distortion curve is low. Risk of incorrect assumption is negligible. Risk of spending 1.6x more is unlikely to be parity.
So I love this forum but one thing that I'm not sure is super clear is just how good is good. Of course, that clearly depends on budget and power when it comes to amplifiers, but I have 3 amps that I'm trying to decide between for a particular set of speakers. All 3 are reasonable and affordable, but the highest priced one is nearly twice the price of the lowest (I'm naturally inclined towards "cheapskate"). I think it's in the spirit of this forum to discuss how much SINAD is worth in tangible and intangible assets. I think the general and reasonable consensus is that it's worth a lot up until the point where it's not really worth anything.
None of the three have specifically been tested here, but the 2nd and 3rd have tests of the modules in different applications. If it matters the particular brands are Emotiva PA-1 for 1 and the Apollons for 2&3. I need rack mountable units so if you have better recommendations please make sure that criteria is hit.
Speakers will be the Revel M126Be, 86dB sensitivity. "Recommended power of 50-150 watts", whatever that means. 150W is 110.77dB@1m.
Listing the modules and not the manufacture, I'm choosing between the
1) ICEpower ASC300, $639 USD (after discount), .two 135w @8 ohm channels (.1%THD)..................... SNR 112dB (135W) 91dB (1W). SINAD 86dB(1W 4 Ohms)
2) NC252MP, ...............$959 USD (shipped).............. two 200w @8 ohm channels (125@91dB SINAD). SNR 113dB (246W)....................... SINAD ~86dB(1W 4 Ohms)
3) NC502MP, ...............$1042 USD (shipped).............two 350w @8 ohm channels (270@ 87dB SINAD).SNR 127dB (445W?)..................... SINAD ~94dB (1W 4 Ohms)
So 1&2 are so close in measurements that I may as well get 1, but 2&3 are so close in price that I may as well get 3. So what's the audible difference between the 1 and 3? Given the similarity in specs can we approximate 2 for 1?
For 2 minimum distortion occurs at 100W 8 Ohms and is -100dBFS THD+N. For 3, the same spec is 2W and -101dBFS. However, at 100W 3's distortion is ~ -90dBFS. 100W is 110.77dB@1m.
Full 16 bit resolution is 96dB peak. Using the Homestead calculator , near a wall, and at an insanely large 20ft distance, 96dB happens to be 100W. That's convenient...
Thus, minimum distortion at maximum practical output levels can best be achieved with amp 2 which has similar stats to amp 1, which is considerably less expensive than amp 3. Caveat is that distortion curves are similar. NC252MP distortion curve appears to be typical. It is unlikely that ASC300 distortion curve is atypical. Consequence of atypical distortion curve is low. Risk of incorrect assumption is negligible. Risk of spending 1.6x more is unlikely to be parity.
Last edited: