Help me find my next amp for my newly adapted "scientific mind-set"

[Mehdiem]

If you want to go down the sub optimization rabbit hole, you can get a UMIK-1 to measure your bass response and flatten the frequency response with the parametric EQ filters which are available in the ADI-2.

Is this mic good for regular EQ response room measurement as well? or it's only good for Sub? Because I'm actually looking to buy a mic to use with REW, I thought I should have paid much more than this, but this priced very reasonably.

 

[TurtlePaul]

Is this mic good for regular EQ response room measurement as well? or it's only good for Sub? Because I'm actually looking to buy a mic to use with REW, I thought I should have paid much more than this, but this priced very reasonably.

The UMIK-1 is the recommended USB microphone for REW.

 

[Mehdiem]

The UMIK-1 is the recommended USB microphone for REW.

Sweet. I was contemplating UMIK-2, but you made my job easy. Thanks a lot.

 

[MaxBuck]

Perhaps. Here is one that is not as enthusiastic regardning NAD C 298 :

Morello:

Note that the measurements on this Class-D device are performed with the low-pass filter (fo = 25 kHz) Audio Precision AUX-0025 connected between the output of the NAD C 298 (amp) and the input of the analyzer, so all THD measurements are irrelevant above about 6 kHz. It surprises me that Atkinson does not limit the graphs to just this.

The reason for the measurement procedure is that the analyzer from Audio Precision that Atkinson uses does not handle the copious amount of high-frequency debris typical class-D throws out. What I object to is that the THD data is still reported up to 20 kHz, even though the data is not relevant above 6-7 kHz. It is also obvious that very many readers of tests have not reflected on this, which of course is fully understandable.

THD is a measure of an amp's nonlinearities - quadratic, cubic and higher order terms in the transmission characteristics. The same terms lead to intermodulation distortion. If you want a correct picture of that amps distortion, the bandwidth when measuring THD up to 20 kHz must be at least 80 kHz, which means that harmonics up to and including order four are included.

Nad C298 shows high THD at treble frequencies above 10 kHz, even though the numbers are "beautified" due to the low-pass filter used in the THD measurement

I'm not an audio engineer, but this seems to me to be so much bullshit.

You've gotten some great advice in this thread. I think the NAD C298 is a superb amplifier, but the March Audio and Buckeye amps should be audibly indistinguishable from the C298 and cost less. Boxem is another manufacturer I'd consider.

Best wishes!

 

[DanielT]

I'm not an audio engineer, but this seems to me to be so much bullshit.

You've gotten some great advice in this thread. I think the NAD C298 is a superb amplifier, but the March Audio and Buckeye amps should be audibly indistinguishable from the C298 and cost less. Boxem is another manufacturer I'd consider.

Best wishes!

I'm not an audio engineer

But he I quoted is an audio engineer.

It was just a view of it all. Whether it's just bullshit or not, I do not know. You get to ask that EE Morello/Gustav (which also constructs amplifiers) that. Or any other knowledgeable EE here.

Here is his contact information:
(no secrets he reveals himself in his avatar)

Sybarite Audio

Sybarite Audio. 451 次赞 · 1 人在谈论. 电子产品

www.facebook.com

Well, you look at that. He has constructed a new amp. I did not know that.
(see attached picture)

Edit:
You get to decide for yourself. Here he performs various measurements on a tube pre amp he designed.
(he actually hates tube amplifiers , he did it mostly for fun to have something to do in his spare time). If he can measurements that is:

faktiskt.io • Visa tråd - GDS-projekt: rörförsteg - LEVERANS!!

The construction:

Index of /Morello/Tube-preamp

Edit:
Note, Morello's critique concerns the measurement in Stereophile. It has nothing to do with audibility. That in itself can mean everything, or nothing at all (it is subjective and depends on the conditions, mainly volume and speakers / headphones) . I do not hear any distortion with my vintage receiver HK 330C, which I have as an amplifier in the bedroom. As long as I do not push it into clipping.

This is nothing new or strange. Measurements regarding amplifiers and class D.You're at ASR. The guiding light is objectivity, so why categorically dismiss what Morello writes?

Edit 2:
I can take a little more from that thread. Belker, who sometimes writes here:

Belker: Absolutely, the level of knowledge here has high peaks, but so does the one at ASR. A much larger forum with many designers and educated people. That's why it's so strange that there is no consensus.

Morello:Consensus on specifically what?

I do not think you understood what I wrote. If an amplifier has a THD of 1% at 20 kHz with a dominant third tone, it means that the third tone has a frequency of 60 kHz. If you measure with 25 kHz bandwidth, the third tone will be attenuated by, for example, 40 dB (depending on the flank attenuation of the filter) and the measurement will show THD of 0.01%. The measurement thus gives a false result. Do you mean that it is something you can like?

faktiskt.io • Visa tråd - NAD C 298

..and with all that now said. I like class D. Here and now and also in the future.

 

[guisess93]

Before C298 I used NuPrime IDA-16. Alternatives considered before purchasing NAD: NuPrime AMG STA, Benchmark AHB2, VTV EVAl-1. Check this thread, I think there was a link to C298 testing and measurements in Polish. Then there is always this: https://www.stereophile.com/content/nad-c-298-power-amplifier-measurements

Sorry for digging this up. But is buying a pre-owned Nuprime Ida16 in 2022 worth it, for around $500?

 

[Cooltool]

Well, it is really hard to say… I think it would all depend on what would you want to invest into

 

[peng]

I'm not an audio engineer

But he I quoted is an audio engineer.

It was just a view of it all. Whether it's just bullshit or not, I do not know. You get to ask that EE Morello/Gustav (which also constructs amplifiers) that. Or any other knowledgeable EE here.

Here is his contact information:
(no secrets he reveals himself in his avatar)

Sybarite Audio

Sybarite Audio. 451 次赞 · 1 人在谈论. 电子产品

www.facebook.com

Well, you look at that. He has constructed a new amp. I did not know that.
(see attached picture)

Edit:
You get to decide for yourself. Here he performs various measurements on a tube pre amp he designed.
(he actually hates tube amplifiers , he did it mostly for fun to have something to do in his spare time). If he can measurements that is:

faktiskt.io • Visa tråd - GDS-projekt: rörförsteg - LEVERANS!!

The construction:

Index of /Morello/Tube-preamp

Edit:
Note, Morello's critique concerns the measurement in Stereophile. It has nothing to do with audibility. That in itself can mean everything, or nothing at all (it is subjective and depends on the conditions, mainly volume and speakers / headphones) . I do not hear any distortion with my vintage receiver HK 330C, which I have as an amplifier in the bedroom. As long as I do not push it into clipping.

This is nothing new or strange. Measurements regarding amplifiers and class D.You're at ASR. The guiding light is objectivity, so why categorically dismiss what Morello writes?

Edit 2:
I can take a little more from that thread. Belker, who sometimes writes here:

Belker: Absolutely, the level of knowledge here has high peaks, but so does the one at ASR. A much larger forum with many designers and educated people. That's why it's so strange that there is no consensus.

Morello:Consensus on specifically what?

I do not think you understood what I wrote. If an amplifier has a THD of 1% at 20 kHz with a dominant third tone, it means that the third tone has a frequency of 60 kHz. If you measure with 25 kHz bandwidth, the third tone will be attenuated by, for example, 40 dB (depending on the flank attenuation of the filter) and the measurement will show THD of 0.01%. The measurement thus gives a false result. Do you mean that it is something you can like?

faktiskt.io • Visa tråd - NAD C 298

..and with all that now said. I like class D. Here and now and also in the future.

I am curious to know what your point is? Are you saying JA of Stereophile should have included the inaudible harmonics in the THD?

 

[DanielT]

I am curious to know what your point is? Are you saying JA of Stereophile should have included the inaudible harmonics in the THD?

I do not say much. I referred, quoted. In any case, it is not about the inaudible above 20 kHz. However, one needs to have large bandwidth when measuring class D amplifiers because what happens above 20 kHz affects down to and below 20 kHz. What is audible or not 20Hz-20kHz is another question.

It is a common discussion, regarding measurement technology and class D amplifiers. Here are those who are more knowledgeable than I am about it in this thread:

On Class D Amplifiers Measurements

Class D amplifiers have defined a new discipline in audio amplifier design and parameters, similarly as digital CD audio after its arrival in 1980-ties. After some time after its arrival, it was apparent that CD measurement methods would need something else and more than previous, purely analog...

audiosciencereview.com

By the way, I like class D amplifiers.