The best sounding audio integrated opamps

[danielwritesbac]

If your op amp is set for a heck of a lot of gain and/OR if its circuit is in inverting mode, then decompensated may work well or even better. It IS more dynamic, but in the wrong circuit that would be unpleasant noise. Decompensated shouldn't be used as a buffer--it is a powerful preamp.

If your op amp is a buffer or low gain or low gain non-inverting then you need the compensated version. If a compensated op amp was set to higher gain, then its possible (not guaranteed) for it to be a bit dull or even rear numbingly dull. It may also simply be "laid back" maybe (or maybe not) with possibly lesser dynamics. Its also possible or even probable that the lesser dynamics are less shout.

These factors depend a lot on which circuit supports which opamp. However, it may be possible to identify the type of circuit just by differences in reaction to the opamp. That's unnecessary because its very easy to measure the resistors (located at point blank range) with an ohmmeter.

For instance if between one of the opamps inputs and its output is a short (ohmmeter reads same as leads crossed "0") then you must have a compensated opamp because that circuit is a buffer (doesn't amplify).

And, if you find a resistor between one of its inputs and its output then it is amplifying. Find its partner resistor that attaches to the same input and measure it too. Divide them with the calculator and you have a very close approximation of the gain factor.

A single channel op amp has two inputs, inverting and non-inverting. One of these inputs is used to set the gain factor. The other is used to input the signal from the source and that will tell you what kind of amplifier it is (inverting amplifier uses inverting input to put in signal from the source).

[Andrea:]

The LT1126 is stable in gains of 10 or more... Not for your soundcard(s), leeperry. Maybe you should give a try to the OPA2228, instead...

And the LT1124 looks good. I was tempted to try it a while ago. I don't think it has a chance to challenge two LT1028 though...but it could be a fine dual opamp.



BTW... I just bought myself a new digital interconnect... Supra TRICO-RCA - From £39.50 - HiFiCables.co.uk

And I want to break out that Audioquest King Cobra (analogue interconnect) that I'd bought myself some time ago...for the better times.

[leeperry]

ok thanks Daniel for the detailed technical explanations!

can I still try it? or might it kill something?

and Andrea, do you think LT1013ACN8 is worth a shot?

even w/ fresh ears, LT1124 is really AMAZING...it does everything the LM4562 promised, but failed. totally amazing, so many details!

[Andrea:]

No... at .4 V/uS of slew rate it's kind of slow for audio

Muuuch better to try the LT1632...

[Andrea:]

I have received & wanna try the THS4631... but not in my DAC (for obvious reasons ) but in my 24V "cmoy". Hopefully it's stable... if so, it will sound good because it has a lot of output current. Otherwise, I might try the THS4601 which was a good FET opamp to me, again with a good output current.

[danielwritesbac]

Originally Posted by leeperry

ok thanks Daniel for the detailed technical explanations!. . .

That was more of an application note.

Next step is HeadWize - Breaking News and pick out a fun opamp project to put together. Perhaps a preamp or buffer type would be helpful?

After that is another opamp project, except that the opamp is larger and can make use of the previous preamp/buffer project. Next up. . . Its the LM1875 power amp. This works quite well with 90+db speakers (like Tang Band W6) and its capable of authentic hi-fi sound, very, very easily. Its also expandable. . .

And, no chip makes as much pretty bass and sharp mids like the LM3886; so, naturally this can be well employed to power a pair of 10" or 12" woofers to add powerful clear bass to the previous LM1875 project.

Well, there's a short description on a high quality multi-amp system that uses nothing more than simple opamps. Your experience with preamps and buffers gives you a head start, because larger scale opamps aren't different except that they're larger.

[Andrea:]

The LT1028 is the closest thing to true transparency that I've ever heard.

[danielwritesbac]

Originally Posted by Andrea:

The LT1028 is the closest thing to true transparency that I've ever heard.

In that case, it would be nice to know what the supporting circuit looks like so that everyone could enjoy the LT1028 as much as you do.

[Andrea:]

Originally Posted by danielwritesbac

In that case, it would be nice to know what the supporting circuit looks like so that everyone could enjoy the LT1028 as much as you do.

I showed it through an image one page back...

Don't know if those are precisely the component values though (as I said in that post).


Also I've replaced the 220uF power supply electrolytic shown, with a Rubycon ZL 680uF 16V + Wima MKS 330nF + Wima MKS 100nF. All the caps in the signal path are film.

[Andrea:]

The OPA827 could be on par with the LT1028CS8... if it only had the same level of tonal fidelity. Unfortunately, it kind of superposes its greenish/brownish curtain on all colors