But it can be bypassed with a switch for fixed gain.
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NAD M23 Stereo Amplifier Review
- Thread starter amirm
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WaterFlame
Member
True, but input sensitivity will be 1,43v which is not a good match with 4,2v from my dac that I used as a preamp - could hear hissing from the speakers from 0,5m
Channel imbalance would not affect the decay of notes.
WaterFlame
Member
Not sure that investigation of the reasons for what I heard is needed since it was not a proper blind test or even an a/b comparison with matched volume. Could have been just my bias or mood during that period. It was my purely subjective opinion.
I would put more weight to the comments from Kal Rubinson where he found c298 less clear, transparent, and detailed in the upper midrange than benchmark ahb2. I know it is not apples to apples comparison but an interesting observation nonetheless.
PJ 1
Member
6 years! Nice. I'm still unsure if I go separates for my 2ch listening or with an all in one like the NAD M33. That's been favorably tested and has a lot of customers who attest to its reliability. (Yes, before we get sidetracked, I am aware there are some who are very vocal about "NAD QC issues" and would take issue with my statement.) I'd most likely pair the M23 with an M66 (if it ever gets released) and Perlisten S7t. My longing for a multichannel/Atmos theater died with going to movies and buying physical media. (Besides, nobody but me appreciates the rumble of "Edge of Tomorrow" or the overhead sounds in "Pearl Harbor". They do however, love the nostalgia of putting on a record from the 60s/70s and enjoying the crackles over drinks.) The fact I get the best of both worlds (ease of HDMI w/fantastic audio reproduction) while watching my Judge Judy is a bonus.
Understood. I suspect that pinning the control at either extreme will minimize tracking differences. FWIW, when I used that control on the C298, I check for interchannel differences with a voltmeter on the output terminals.
And, yet, I still kept the C298s and used them with the Benchmarks in multichannel.
WaterFlame
Member
Debating between m33 and m23+m66 is a nice problem to have
I had m33 around a year ago in the hope to cure my audiophool syndrom. I wanted to stop trying new dacs, amplifiers etc. I liked the sound of m33 but not Dirac. Of course, I limited correction to around 250hz but it still affected impulse response / time domain. It made my room less lively I felt. I tried to measure a larger area and that reduced the negative effect to some extent. I had better results with a simple peq. Room perfect and ARC Genesis were also excellent. Also I did not use a sub or a phono stage and hence felt I was paying for functions I was not using.Regarding nad m33 use in HT environment, i heard its ht bypass has significant latency that can be an issue.
Why? He also used no basic controls to determine this dubious conclusion.
WaterFlame
Member
Interesting that there exist other methods in academia to confirm/ reject a hypothesis or answer a research question but here I see that only a blind test (controlled experiment) being considered the only valid approach on this forum (edited).
There may exist useful information in reviews of people such as Kal. If I read 10 random reviews on the internet of people not influenced by each others opinion and they describe the sound of an amplifier or differences between amplifiers in the same way, with purifi being smoother than Benchmark, it takes care of the lack of controls such as being blind or not having perfect volume matching. Some of those 10 people had benchmark with higher volume, others nad c298 but the conclusion about the sound they made was the same.
I do not mind experiments, usually they have the highest internal validity, however, with less obvious and smaller differences, an experiment should be constructed such as to maximize chances to discriminate between options. In other words, i have yet to see a blind test of amplifiers or dacs on this forum that went all the way to address this issue. Ok, some address the switching time issue but i have not seen the test with 2-3 second repeating extracts from a song. Most just switch at random place in a song while the song continues. The extract heard with one amplifier cannot be then repeated after 3 seconds because next amplifier gets the next extract.
Also there is an issue of correctly guessing vs preferring. To correctly guess an amplifier, a participant needs to be extremely skilled and should correctly formulate the difference in his head before the blind test. It is much easier to do 20 runs between 2 amplifiers and ask which one is preferred. If preference scores are significantly different, this will confirm that 2 amplifiers sound different.
In sensory science (as well as most other science involving human response), double blinding as a basic control is an absolute necessity, whether in academia or industry. If you think it's only at ASR, you really need to get out more.
You DO need to get out more.
In any case, the software to do this is free, get off your lazy butt and do it instead of complaining that your hand-wavey objections aren't being met.
How do you know that the people haven't read each other's (or some common other) opinion/review, and been influenced by it?
I am sure we are all very keen to see the results of your tests that "go all the way".
WaterFlame
Member
If I understand you correctly, you are referring to foobar? To test amplifiers, do I then need to both switch the output on the abx switcher while at the same time switching on the foobar for another loop? Sounds like a lot more than just «getting off your lazy ass». In any case, whenever somebody here runs a half-baked blind test that is very poorly designed to be discriminatory for amplifier differences, noone is criticising the design but whenever a positive result is presented, a person who has performed the test is being grilled.
I am sharing general consensus here that it is room and speakers that have the largest effect on sound but I do not like black and white approach to amplifiers, especially when there have already been tests (guessing whether amplifier is in the chain vs not in the chain) by swedish audio society where only Bryston 4b after some modifications (to have fully flat frequency response) passed the test. They tested rotel class ab, quad 909, nad class ab, hegel to name a few but so far, no other amplifier has been fully transparent. That test is more sensitive than a typical abx test suggested here. So no, I do not share a consensus that all amplifiers with sinad over 80 and not clipping sound the same. The number of truly transparent amplifiers is not that high.
Your personal dislike has been noted.
Any links to the test? Have the results been independently verified or replicated?
Again, your personal opinion/belief is noted.
But much higher than most audiophiles think.
Even if you use 80 SINAD as the benchmark for transparency, I disagree with your statement. Most, if not all amps SINAD are power, load and frequency dependent. I don't believe even the Hypex is 80 SINAD from 20Hz to 20kHz regardless of load and power before knee.
You can of course disagree. On the other hand, I believe SINAD at 20 kHz is irrelevant. You won't hear the distortion nor the noise.
WaterFlame
Member
If you check the thread started by pma, it was observed that hypex started to oscillate at a lower switching frequency and all that rubbish post 20khz came inside the audio band. Of course, the load was too extreme, and no speakers exist in real life that would pose such a load on to the amplifier. However, it begs the question of how the distortion profile would look like with realistic but still very complex load. Nilai performed better but in the Audioxpress test, still saw a large increase in thd.
I disagree with that statement as well.
And I believe I read somewhere that Amir stated 110 sinad is what is needed to achieve transparency. If that is the case, then I triple disagree with your statement.
WaterFlame
Member
Sure, here is the link to LTS that performs such tests.
Ljudtekniska Sällskapet
Ljudtekniska Sällskapet är en oberoende förening som verkar för högsta möjliga kvalitet såväl i fråga om hifi-anläggningar som musikproduktioner av alla slag...
It was 14b sst model, not 4b.
Found a link in English:
Here is an interesting post from ASR member Blumlein 88 who found Spectral amp transparent while other amps not:
Limitations of blind testing procedures
Do you think there is something that can't be electrically measured that distinguishes one amp from another? Its more the definitive interpretation of the data, where comprehensive test data is actually available, and its relation to sound. This is not relevant and continuing down that line...
audiosciencereview.com
If you wish, but it wouldn't be my first choice. @pkane 's software is far better and more versatile. Transparent high-quality recordings of amplifier outputs are trivially easy to make these days to make a file.
Any clips you wish can be made using any standard editor.
Stop making excuses about why other people aren't chasing your uninformed objections. Go put in the work.
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