Listening Test Part 2. Active Circuitry.

Mooly · 2014-01-28 10:32 am

This is the second of two listening tests and is for active powered circuitry, the other thread is HERE and is for passives.

PLEASE READ THE OTHER THREAD AS THAT GIVES FULL INSTRUCTIONS ON HOW THE TEST WORKS.

The links to the files are at the end of this post.

What is this test about ?

This test is between two different opamps, an LM4562 and an FET TLE2072. For those of you that have seen and taken part in previous tests I can assure you that the equipment used here is NOT the Sony CDP790 but a Philips based DAC using twin TDA1540 convertors and with supplies of -/+12 volts for the analogue stages.

Your results.

Please read the other thread for full instructions and mark your results "OPAMPS" for this test.

And above all, ENJOY

Barleywater · 2014-01-28 8:16 pm

Any audible change has measurable differences.

TLE2072 hack is clear example.

SY · 2014-01-28 8:30 pm

Barleywater said:
Any audible change has measurable differences.

That's certainly true, but many people claim otherwise, or (equivalently) claim that our measurement protocols are not sophisticated enough to pick up the differences that their immaculate pinnae can.

Mooly · 2014-01-28 8:31 pm

Barleywater said:
Any audible change has measurable differences.

TLE2072 hack is clear example.

So easy to pick out then ? Have you determined which files are the TLE2072 and which the LM4562

Barleywater · 2014-01-29 5:42 am

That's what Frank is for.

fas42 · 2014-01-31 1:01 am

Just downloaded and had a bit of a listen to X and Y ... for me, these two versions are much closer than the Passives reference tracks, the clues, cues are quite a bit more subtle. Yes, I hear a difference - but the sorting of the samples into 2 bins will require considerably more focus, I suspect ...

abraxalito · 2014-01-31 1:10 am

What's a TDA1450? I tried googling, no chips meeting that description. Did you mean TDA1540?

Mooly · 2014-01-31 8:59 am

abraxalito said:
What's a TDA1450? I tried googling, no chips meeting that description. Did you mean TDA1540?

I do... apologies. Too many years as a TV tech with all those TDA chips rattling round my head

(first post amended)

Mooly · 2014-01-31 9:06 am

fas42 said:
Just downloaded and had a bit of a listen to X and Y ... for me, these two versions are much closer than the Passives reference tracks, the clues, cues are quite a bit more subtle. Yes, I hear a difference - but the sorting of the samples into 2 bins will require considerably more focus, I suspect ...

Interesting that you find these a tougher test. Out of the passives and actives, this was the one where I felt differences would be most apparent, particularly after experience of the other opamp tests. The TLE2072 seems an oddball chip (which it shouldn't be) and I didn't want to dismiss it out of hand despite the previous tests.

As before... thanks

You are one of the few to be approaching these tests in the true spirit they were offered... which is to give them a listen.

abraxalito · 2014-01-31 9:13 am

Thanks for the clarification

So are these chips operating as I/V converters for the TDA1540 or are they line stages after another chip (inside the CD player presumably) has done that function? Just curious to know how much ultrasonic stuff they're being subjected to here.

Mooly · 2014-01-31 9:45 am

abraxalito said:
Thanks for the clarification

So are these chips operating as I/V converters for the TDA1540 or are they line stages after another chip (inside the CD player presumably) has done that function? Just curious to know how much ultrasonic stuff they're being subjected to here.

Pretty much identical to this. Yes I/V conversion and the usual anti aliasing filter arrangement

fas42 · 2014-02-01 3:00 am

Inspired by Jay's comments,

, I'll grab the samples of this one, and go through the exercise ...

abraxalito · 2014-02-01 3:19 am

Mooly said:
Pretty much identical to this. Yes I/V conversion and the usual anti aliasing filter arrangement

Thanks Mooly - unless I'm kidding myself that looks to be something very similar to a Philips CD104 player with SAA7030 4X oversampling digital filter.

Classic model indeed

Mooly · 2014-02-01 7:59 am

abraxalito said:
Thanks Mooly - unless I'm kidding myself that looks to be something very similar to a Philips CD104 player with SAA7030 4X oversampling digital filter.

Classic model indeed

Yes the picture is actually of a CD303, and the one in the test is a CD150 with virtually identical signal processing circuitry. All these Philips players were pretty similar electrically I seem to recall.

Mooly · 2014-02-01 8:00 am

fas42 said:
Inspired by Jay's comments, , I'll grab the samples of this one, and go through the exercise ...

Frank. Your a star

Mooly · 2014-02-03 6:56 pm

It would be good to have some more votes on this one. Frank is the only one brave enough to put a full set of results forward so far together with interesting comments on the sound differences as he heard them.

Mooly · 2014-02-06 8:12 am

Well interest in this one was lacking unfortunately with only one complete set of results submitted (thanks again Frank), so with that in mind here is the key and the result.

Participant. File. Actual. Match choice Result. (Yes for correct, no for incorrect)

fas42 Test01 TLE2072 X Yes
fas42 Test02 LM4562 Y Yes
fas42 Test03 TLE2072 Y No
fas42 Test04 TLE2072 X Yes
fas42 Test05 TLE2072 X Yes
fas42 Test06 TLE2072 Y No
fas42 Test07 LM4562 Y Yes
fas42 Test08 LM4562 Y Yes
fas42 Test09 LM4562 X No
fas42 Test10 TLE2072 X Yes
fas42 Test11 TLE2072 Y No
fas42 Test12 LM4562 X No

Copy and paste of key.

Test_01 = TLE2072
Test_02 = LM4562
Test_03 = TLE2072
Test_04 = TLE2072
Test_05 = TLE2072
Test_06 = TLE2072
Test_07 = LM4562
Test_08 = LM4562
Test_09 = LM4562
Test_10 = TLE2072
Test_11 = TLE2072
Test_12 = LM4562

Standard reference files.

X = TLE2072
Y = LM4562

Copy and paste of your results:

X: 1, 4, 5, 9, 10, 12
Y: 2, 3, 6, 7, 8, 11

PMA · 2014-02-06 8:27 am

Purely random result. Same as in your passive test, same as in my test cap1, cap2, cap3: Mundorf x Roederstein.

fas42 · 2014-02-06 9:20 am

Consistent with the number right, at least,

.

Jay felt he had no trouble distinguishing the 2, shame he didn't submit a try. Overall, my feeling is that inconsistencies in the state of the electronics between takes, and the characteristics I focus on to separate the samples don't tie in with what is being tested for, hence the meaningless outcomes. Electronics varying in their subjective capabilities from one time to the next is what I've been 'battling' with for years now, so I'm not at all surprised, in retrospect.

The cap1, cap2, cap3 test is a classic example of where nominally the same hardware produces different results, at the subjective level - and no clear reason why ...

PMA · 2014-02-06 9:22 am

fas42 said:
The cap1, cap2, cap3 test is a classic example of where nominally the same hardware produces different results, at the subjective level - and no clear reason why ...

Which applies to your hardware sound impression, only

I have seen NO positive ABX result to support this opinion.

Listening Test Part 2. Active Circuitry.

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