The best sounding audio integrated opamps

[Andrea:]

Originally Posted by Mooly

They look like that for two reasons, the absolute upper limit of 20khz... which means that the harmonics that make up the squarewave are lost, and the action of the filters that cause "ringing"
Put a 6khz squarewave (analog input signal) into a ADC/DAC convertor and you will see a triangular wave emerge because the harmonics are lost.
So designing for perfect squarewave response at 100k is academic when CD is the source.
IMO it is better to sensibly tailor the response to gentle roll off outside the audio band (well outside of course) and I find that gives the best results very often.

Edit... I am refering to a typical ADC/DAC as in domestic equipment.

Yup, often CD players have a gradual upper treble roll-off... I guess this is often preferable to a very strong digital filtering, in terms of impulse response. Right? Or something like that

[Mooly]

Just for interest on "how things sound" that shot of the 1 khz from a cd player.

It doesn't matter whether the player is a 10 £€€$ portable or a 10000 £€$ one... it looks the same. They don't (hopefully) sound the same though.

Have you tried (seriously) the TLO71 in your listening tests

[Mooly]

Originally Posted by Andrea:

Yup, often CD players have a gradual upper treble roll-off... I guess this is often preferable to a very strong digital filtering, in terms of impulse response. Right? Or something like that

Last post before lunch

I don't know about a gradual roll off. If it's designed into the player then it's not related to the action of the filters as such (I think you are talking of perhaps 0.5db down at 20 khz at most).
A gradual roll of while inaudible at a single frequency can (possibly) be audible as it reduces the whole spectrum of energy at hf, but it's very slight. Drawing the curtains makes far more difference

If you replace the opamps in a player with 741's that 1 khz squarewave looks essentially the same.

[Andrea:]

Originally Posted by Mooly

Just for interest on "how things sound" that shot of the 1 khz from a cd player.

It doesn't matter whether the player is a 10 £€€$ portable or a 10000 £€$ one... it looks the same. They don't (hopefully) sound the same though.

Have you tried (seriously) the TLO71 in your listening tests

Yeah...and it's always a square wave. That's one of the measurements I never look at (in magazines).


I used the TL072 years ago... I remember preferring the NE5532 at that time.

Have you tried the TLE2071/2072/2081/2082 ? These are the newer, improved (and faster) versions of the TL07x and TL08x. The TLE2082 sounds quite nice, while the TLE2072 it too cold tonally. They're nothing to write home about, though.


Edit: And the TLE2062 with its about 80 mA of output current is quite good for cmoy headphone amps

[Mooly]

I found the TL072 (and 71) a pretty good performer, exceptionally so when price considered. It was the first opamp change I did on my Micromega Stage 2 which had NE5534's and gave that "small" but indefinable worthwhile improvement.
Have since come to like the OPA604AP... I just like the sound... and it works well in the Stage 2 as the I/V convertor with an AD845 as the filter/buffer.
Haven't tried the ones you mention
Would like to try the OPA1611 and 1612 sometime... see they (OPA1611) doesn't have the offest null pins connected... which are used in the Micromega... you can trim the output to 0.000000 vdc or near offer

It's an interesting subject with no right and wrong answers... it's what works for you and what works in your particular application as much as anything.

[Andrea:]

Yeah, well, anything audio is like that. No surprise it's so with opamps

Then again, we have to make some use of these public boards, no?


Anyway, I believe that the findings of one can be shared with others to some extent. I'm not a total subjectivist. I'm partly that, and partly an objectivist too


P.S. The OPA2604 sounded good for my ears in a AD1852 DAC I had for a while. And I definitely like the AD845, since it's musical & dynamic...though it's not quite at the level of transparency of LT1028ACN8, OPA1611, and some others.

[fastvideo]

Originally Posted by Andrea:

P.S. The OPA2604 sounded good for my ears in a AD1852 DAC I had for a while. And I definitely like the AD845, since it's musical & dynamic...though it's not quite at the level of transparency of LT1028ACN8, OPA1611, and some others.

LME49720 metal case, does sound better than lm4562 in my rotel rcd-855. Will get some OPA1611 to test later.

[Andrea:]

Originally Posted by fastvideo

LME49720 metal case, does sound better than lm4562 in my rotel rcd-855. Will get some OPA1611 to test later.

I really liked the LME49720HA, along with the LME49723 -- funnily, the two opposite extremes of the National line of dual audio opamps, as far as ambition & cost

Instead what's in between I liked not enough... LM4562NA, LME49720NA, LME49860, LME49722...

Next (and last) for me to try is the LME49725, about which I have a good feeling


Right now, I think my absolute favorite is the OPA1611. It simply sounds the most natural, musical, balanced... and crystal clear too...

[Andrea:]

I think I'll get the Poppulse PCM1796 DAC, if I will buy one more DAC

The Super Pro is from Poppulse too, and I find they're good at making good things


So I can play a little longer with my favorite opamps, LT1028ACN8, OPA1611, LME49720HA, maybe ADA4898-1 when I try it...

[Andrea:]

This morning I've repaired & improved my C&C BOX headphone amp.

Now it's got 2x LME49721 (gain) + 4x AD8532 (buffer). The AD8532 were stock (totalling 1 mA of current output per channel); the LME49721 is a rather new 6V rail-to-rail CMOS opamp that has substituted the stock AD822.

Besides, I've used Rubycon ZLH and YXH capacitors, plus a pair of Nippon Chemicon's (due to size requirements).


Sound is awesome... the LME49721 is a great CMOS audio opamp. There's definitely a better smoothness and solidity to the sound, as compared to my cmoy (even if we're talking of 24V vs. 6V supply voltages).