NAD M23 Stereo Amplifier Review

[WaterFlame]

Where did I say to buy another amp? You claim, that you compared several ones.

How else do you want to compare amps unless you own them or have access to?


Again recording the output of each amp while attached to a speaker and running the result through Deltawave will tell you with much more certainty about audible differences than an error prone blind test. And if you don’t have the other amps anymore than record the one you have and obviously don’t run it through Delawave but simply post the FR and we can see if there is an audible load dependence. Plus you will have facts to post here and not anecdotes.

As it is very very doubtful that you heard differences btw all these amps you described but more likely have an error in your blind test (which once again is not even needed if you would have done what now several of us proposed multiple times). Do it right if you want to be taken seriously.

All seems like very weak excuses.

But I am wasting my time. I am out

Sorry, but I had to asnwer one last time.
I never mentioned that I wanted to test or share my blind tests. I was referring to already existing blind tests performed by Swedish LTS that are more robust than the tests I can do on my own, including your deltawave suggestion. You clearly did not study LTS in detail, otherwise you would have been very curious to understand how come quad 909, hegel, audioresearch and many others could not pass wire and gain test while Bryston passed. This would make you reconsider the dogma: "most amps that are not clipping sound the same".

As I mentioned, I no longer possess multiple amplifiers because I am happy with M23 for now also I have LS60w in another system that also was not cheap.
When I have multiple amps next time, I might do what you suggest but there are caveats:

1. obtaining a correctly calculated difference in deltawave is not walk in the park and most likely i will need to do blind test of recording with amp1 vs recording of ampt2 anyway
2. when listening to recordings, I will have to listen through my system. Those will go through my dac and amplifier again. I cannot guarantee that those are 100% transparent and will do nothing to the signal.
And of course, I would be running the test with preference scores and not with trying to correctly guess which amp is playing.
Found it much more discriminatory.

So I still believe a proper blind test rules.

p.s. anecdotal evidence can be informative sometimes

 

[WaterFlame]

This could also be interesting for M23 users: Link

Thanks for the link.
This is quite interesting because m23 supply is very good into any load but I have heard the same about 1 Benchmark Ahb2 vs 2x Benchmarks.
People also observed much less constrained and more open sound with better bass delivery and more grunt.
Also speakers there are Dali Epikore, right? It might be that bridging could show their max potential.

 

[pogo]

Also speakers there are Dali Epikore, right?

Yes.

 

[Julf]

You clearly did not study LTS in detail, otherwise you would have been very curious to understand how come quad 909, hegel, audioresearch and many others could not pass wire and gain test while Bryston passed. This would make you reconsider the dogma: "most amps that are not clipping sound the same".

I did read the full description of the LTS tests, and they are not very rigorous, nor have they been verified or replicated, so no need to change my views.

And of course, I would be running the test with preference scores and not with trying to correctly guess which amp is playing.
Found it much more discriminatory.

"More discriminatory" as in "produces the result I want".

p.s. anecdotal evidence can be informative sometimes

Yes, very informative about the belief systems of audiophiles.

 

[WaterFlame]

I did read the full description of the LTS tests, and they are not very rigorous, nor have they been verified or replicated, so no need to change my views.

"More discriminatory" as in "produces the result I want".

Yes, very informative about the belief systems of audiophiles.

Please be my guest and show me at least one study between an amp with 100+ sinad with excellent multitone and response into complex loads vs 80 sinad standard class ab with distortion that rises higher with frequency and poor imd. And that test should take into account short echoic memory as well as skill level of participants. As you say, it should be replicated at least once.

By discriminatory i mean fit for research question in test i,e not testing temperature outside with voltmeter. It is very easy to create poorly designed tests that have no chance of identifying smaller differences and then claim that no difference exists.

 

[WaterFlame]

I did read the full description of the LTS tests, and they are not very rigorous, nor have they been verified or replicated, so no need to change my views.

"More discriminatory" as in "produces the result I want".

Yes, very informative about the belief systems of audiophiles.

Also may I ask you to desribe the blind tests you personally did between amps or dacs? At least, i owned over 20 amps and compared many of them.

Also, on sbaf, there have been multiple successful attempts. People should be applauded for actually spending their time and coming that far with testing, much further than most people here who claim no diff exist. And instead of being applauded for their efforts, integrity of people like purr1n was doubted on asr.

 

[Julf]

By discriminatory i mean fit for research question in test i,e not testing temperature outside with voltmeter. It is very easy to create poorly designed tests that have no chance of identifying smaller differences and then claim that no difference exists.

And vice versa - see the Swedish tests.

 

[Julf]

Also may I ask you to desribe the blind tests you personally did between amps or dacs? At least, i owned over 20 amps and compared many of them.

Oh, I started back in my university days in the 1980's in the acoustics lab there. I have to try to find my old log books for all the ones I have done in the 40+ years since - there has been quite a bit more than 20. Fortunately I didn't have to own all of them...

 

[WaterFlame]

And vice versa - see the Swedish tests.

What do you mean? If you mean that difference with rotel, nad, quad, audioresearch or hegel in chain was due to some bias/ variable that is making it more likely to get a positive result, then they would have identified bryston in the chain too. Hence, your assumption is not valid here. Methodology has been unchanged between their tests, and if anything, they should have identified bryston in the chain as non transparent also by this logic. It actually makes their findings stronger.

 

[BDWoody]

Also, why do you insist on double blind?

Clever Hans

 

[Julf]

What do you mean? If you mean that difference with rotel, nad, quad, audioresearch or hegel in chain was due to some bias/ variable that is making it more likely to get a positive result, then they would have identified bryston in the chain too. Hence, your assumption is not valid here. Methodology has been unchanged between their tests, and if anything, they should have identified bryston in the chain as non transparent also by this logic. It actually makes their findings stronger.

You don't seem to understand why single blind testing is invalid, and proper tests require double blind.

Ah, @BDWoody already provided a link to Clever Hans.

 

[WaterFlame]

You don't seem to understand why single blind testing is invalid, and proper tests require double blind.

Ah, @BDWoody already provided a link to Clever Hans.

No, i understand. If a person who was switching amps was in some way not knowingly hinting to participants/ they could read his emotions whenever an amp was in the chain, it would have biased towards correctly guessing which did not happen with Bryston and makes the finding even stronger. Basic logic. Next time when you state something, please explain how exactly it invalidates results and reduces tha cause and effect relationship and not blindly repeating: «basic controls», «double blind».

Edit: i have now reread the last few pages and see that m23 was not the main topic of discussion there. Apologise for that. Will create a new topic if i decide to discuss lts ot blind testing procedures further. Thanks for the discussion. Now lets focus on m23. Any comments on the effects of bridging mentioned by pogo? Does it improve power delivery during transients?

 

[Julf]

No, i understand. If a person who was switching amps was in some way not knowingly hinting to participants/ they could read his emotions whenever an amp was in the chain, it would have biased towards correctly guessing which did not happen with Bryston and makes the finding even stronger. Basic logic. Next time when you state something, please explain how exactly it invalidates results and reduces tha cause and effect relationship and not blindly repeating: «basic controls», «double blind».

Clearly there was no need to explain, as you did understand the basic idea, but keep blindly repeating the faulty argument "it would have biased towards correctly guessing which did not happen with Bryston". That is not how it works - it all depends on what people believe is "correct" guessing. Maybe the people involved in the test share the belief that only the Bryston is transparent?

Was that clear enough?

 

[WaterFlame]

Clearly there was no need to explain, as you did understand the basic idea, but keep blindly repeating the faulty argument "it would have biased towards correctly guessing which did not happen with Bryston". That is not how it works - it all depends on what people believe is "correct" guessing. Maybe the people involved in the test share the belief that only the Bryston is transparent?

Was that clear enough?

Belief of those who answer does not matter in this case because we are not going to doubt their integrity here.
Belief of the one who is switching is important because of the give aways due to his non verbal reaction. In case he was biased towards bryston being transparent, it would have made guessing bryston easier due him getting emotional when bryston was in the chain. So my point stands.

 

[Julf]

Belief of those who answer does not matter in this case because we are not going to doubt their integrity here.

It has nothing to do with their integrity. We are all affected by subconscious cues.

Belief of the one who is switching is important because of the give aways due to his non verbal reaction. In case he was biased towards bryston being transparent, it would have made guessing bryston easier due him getting emotional when bryston was in the chain. So my point stands.

Please explain why you believe that.
Let's say the one doing the switching sends (without being aware of it him/herself) a cue indicating "now you should hear a difference" for all other amps, but not the Bryston (that he/she believes to be the only transparent one). How does "not guessing" Bryston (as in not being able to tell it from a straight line) proves anything?

 

[WaterFlame]

It has nothing to do with their integrity. We are all affected by subconscious cues.

Please explain why you believe that.
Let's say the one doing the switching sends (without being aware of it him/herself) a cue indicating "now you should hear a difference" for all other amps, but not the Bryston (that he/she believes to be the only transparent one). How does "not guessing" Bryston (as in not being able to tell it from a straight line) proves anything?

This would happen only in case he would get excited and emotional about all other amps that lts has tested but very unemotional and indifferent only when they tested Bryston which is very unlikely. Even if he had certain amp he was excited about, lets say Audioresearch, this could have skewed findings about bryston vs audioresearch but since all of the previously tested amps were shown to be nontransparent, your argument assumes excitement about absolutely all the amps except for Bryston.

You still have not shared research with a better method that compares cheap, more expensive, poorly measuring, well measuring amps, just picking on any data i presented.

Feel free to present better studies/ data but lets do it in another topic.

 

[WaterFlame]

This could also be interesting for M23 users: Link

Julf, better focus on this post. You might find it interesting.

 

[Julf]

This would happen only in case he would get excited and emotional about all other amps that lts has tested but very unemotional and indifferent only when they tested Bryston which is very unlikely.

How so?

Even if he had certain amp he was excited about, lets say Audioresearch, this could have skewed findings about bryston vs audioresearch but since all of the previously tested amps were shown to be nontransparent, your argument assumes excitement about absolutely all the amps except for Bryston.

They were not shown this or that - for reasons I (and others) have explained a number of times - and why would one have to assume "excitement"?

 

[Julf]

Julf, better focus on this post. You might find it interesting.

The one that starts by stating "I had the same experience"? As in subjective, personal...

 

[Snowbuffalo]

Cool excellent however the lower tier c298 actually has variable input sensitivity.
Amp should at least have some gain settings imho , this totl product omits that feature ?

From the manual: "The Gain Level of the M23 can be set to any of the following - LOW (19dB), MEDIUM (24dB) and HIGH (29dB)."