Hires 96/24 listening test of opamps

Which of the files do you prefer by listening?

  • rr = LM4562

    Votes: 1 4.5%

  • ss= OPA2134

    Votes: 2 9.1%

  • tt = MA1458

    Votes: 2 9.1%

  • uu = TL072

    Votes: 9 40.9%

  • vv = OPA2134

    Votes: 1 4.5%

  • I can not hear a difference

    Votes: 7 31.8%
  • Total voters
    22
  • Poll closed .
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PMA

PMA

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billshurv said:
Pavel: Not sure I understand your use of 'integrate' there. I wasn't looking at the single tone test wrt the miniDSP, just that, with a real world signal and my real world listening levels, that noise is below the room noise floor and therefore not a priority to address, vs say getting a better power response from my speakers which has a real impact on the stereo illusion.
Click to expand...

What I mean is that you may not read noise directly from noise floor at some frequency. You need to know spectral noise density. E.g. if you know spectral noise density in nV/rt(Hz), then you get noise by multiplication of noise density by root of bandwidth (root of 20kHz = 141). This is valid if noise bottom is "flat". To get spectral noise density you need to know sample rate and number of samples in the FFT record. Divide sample rate by the number of samples and you get binwidth. This re-calculate to rt(Hz). So to get anything about noise from spectrum, you need to know what level corresponds to 0dB, sampling frequency, number of samples in FFT and then you may make the calculations of noise.
The only information you may directly read from the spectrum is the amplitude of peaks in spectrum. This in dB is related to 0dBFS level.
 
Mooly

Mooly

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Thanks Mark :) Its probably something I should experiment with, and I'm partly blaming unfamiliarity on my part as the only time I seem to do this kind of thing is for our listening tests on here.

I was pleasantly surprised how much better the MP3's were on the Marantz vs the native files on the laptop/s. A big difference actually.
 
PMA

PMA

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billshurv said:
Ah gotcha. But that was an IMD plot, not a noise plot. The 'hash' is mainly distortion products not noise was my assumption.
Click to expand...

I know it was multitone IMD plot, but the result is noise-like with spaces between the original lines filled with intermod products. Look at the time record and you will see noise-like signal. And the contribution of the single components adds similarly as for the noise, which is the integral of spectral noise density over the bandwidth of interest. Similarly for the multitone intermod products. You will hear them as noise with non constant spectral noise density.
 
PMA

PMA

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So far, there are 3 members who contacted me with their preferences through PM. These 3 opinions are quite different. There is also one member who contacted me with the message that he does not find any difference. And then we have a poll with unidentified voters, but for the reason that anyone can click in the poll, I do not take poll results as very serious.
So, no valid conclusions at the moment. Except for one - not much differences (in fact almost no differences) were confirmed in a statistically valid proof.
 
M

Markw4

Member
Joined 2016
Maty, perhaps some combination of equipment performance and a lack of ear training and practice are all involved.

Would you mind describing your equipment and listening background?

I have stated at times that I am using a Benchmark DAC-1, 20-year old Bryston 4-B, NS-10's, and Primacoustic Recoil speaker pads. They all help some, IMO. First started taking listening seriously about 45 years ago, when I got a job as a sound man. Did that for 7 years then moved on to other things for a living, but sound and mixing have remained an on and off serious hobby.
 
maty tinman

maty tinman

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Joined 2012
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The key of my systems are the measures to fight the ALL types of noise, interferences and DC mains (yes, I have almost an incredible 3 Vdc).

A lot of Würth 150 kHz ferrites (8 mm and 12 mm)

-> 74272733 - WURTH ELEKTRONIK - Ferrite Core, Split, 150 kHz, 30 MHz, 8 mm | Farnell element14 Ireland

ATL Hi-Fi DC & Ripple Blocker x4 ME (aka Maty Edition)

-> http://www.diyaudio.com/forums/solid-state/279794-toroidal-transformer-noise-12.html#post4463624

and more cheap tweaks inside the amps, speakers and headphones. And inside/outside the ODAC.

My W10 x64 is very optimized to play multimedia. The same with the soft players. And yes, with Linux I have not gotten better sound :(

and finally, to eliminate my last bottleneck, the jitter generated inside the PC (CPU, registers, memory and HDD) I defragment the audio files with Rewrite Data.

-> Bug head
 
maty tinman

maty tinman

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Sorry, and a lot of RFI/EMI filters: Schaffner FN9244B

-> http://www.mouser.es/ProductDetail/Schaffner/FN9244B-3-06/?qs=%2fha2pyFaduizvpSn1rUp%2fhCeqfVzEXqxiooWwv4TR5mv9p1P2yZfKA%3d%3d

An externally hosted image should be here but it was not working when we last tested it.


Likew I always say, I have "tons" of interferences (mains and atmospher)..

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.

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