The best sounding audio integrated opamps

[leeperry]

anyone care to explain please?

My ultimate DIY stereo soundcard - Head-Fi

[scott wurcer]

What's to explain, he's happy and that's all that matters. Those empty opamp sockets look cool.

[bichi]

Appears that he/she did:
- removed differential/LPF/buffer opamps.
- removed coupling capacitors.
- connected audio transformers to AK4396 DAC differential voltage outputs.
- routed transformer outputs to card's RCA audio output jacks.

In otherwords, transformer provides DC blocking/isolation, impedance matching, and LPF functions.
- guessing output level is lower than stock.
- typical transformer coupled topology. (of "no-opamp" ilk.)
- tradeoff appears to be increased noise and THD. (long signal wires in noisy PC environment.)

Power Section:
- replaced various power filter capacitors with OSCON.
- replaced onboard 5vdc voltage regulator(s) (for AK4396 DAC) with external shunt regulator.

Amplimo TM20 Signal Transformer:
- 30Hz - 25000Hz
- price: approx $114.00 USD

[Andrea:]

Originally Posted by scott wurcer

What's to explain, he's happy and that's all that matters. Those empty opamp sockets look cool.

hehhehehehe

[Andrea:]

I bought me a very cheap (on offer @ 19.90€) "Sansui DV1200" DVD player, whose sound (after burn in & connected with the always dependable VDH The Bay C5 interconnect) I definitely like, for its warmth and fluidity, although it certainly doesn't do anything extraordinary.. It looks like a perfect base for some modding, though

I will need to open it and see what DAC it has (provided it's even an independent DAC chip) to decide whether to use (most probably) OPA1642 or LME49725. Secondly, I guess I'll change coupling caps, and perhaps some power supply caps too.


I like the amount of goodness you can buy today for 20€.

[leeperry]

Originally Posted by bichi

transformer provides DC blocking/isolation, impedance matching, and LPF functions.
[..]
Amplimo TM20 Signal Transformer:
- 30Hz - 25000Hz
- price: approx $114.00 USD

ok thanks for the explanations!

so you can replace op-amps by pricey transformers huh

he's usually using Burson op-amps and already tried pretty much every op-amp in the book, I'd trust his judgment

[amparoytoni]

I have seen data from some small integrated amplifiers, fed at low voltage. the Max, tda, ... tpy

Are there any integrated amplifier that can be used as a headphone amp for hd595, with high audio quality (above all). Or is it better to go directly to operational amplifiers for this application.

The supply voltage would prefer that high, I have 22/0/22V in the transformer.

[Andrea:]

Originally Posted by amparoytoni

I have seen data from some small integrated amplifiers, fed at low voltage. the Max, tda, ... tpy

Are there any integrated amplifier that can be used as a headphone amp for hd595, with high audio quality (above all). Or is it better to go directly to operational amplifiers for this application.

The supply voltage would prefer that high, I have 22/0/22V in the transformer.

And this? Welcome to Audiophilechina


Anyway the HD595 was driven well by opamps directly in my experience. I remember it sounding really good driven by the LT1361 (or two single LT1360). The OPA132 (singles tend to be a better choice for this) is a good candidate as well. If you try the LT1360/1, pay attention to DC offset

[Andrea:]

And... I just bought the parts (some 105°C electrolytics) to fix my "Xenos 1HA-EPC" headphone amp.

As for the opamps, I'd already soldered an LT1358 in the stage that drives the transistor buffer; and this will remain. And I'll use the OPA1642 as the input and gain stage. I'm sure they'll pair well

That way I'll manage to try this OPA1642 that I'm curious about, and sooner than I would have in the said DVD.

[amparoytoni]

I have an old headphone amplifier circuit that employs the rc4558 dil-8, with a dc decoupling capacitors in and out. Gain 6. Could I use it with a more modern dual ao, what would you advise me?

I had given up using it because, from reading this forum, had figured that would work best to build a new circuit with two opa1611, and although more work (and money) might be worthwhile to design and build. (In order to improve the quality of sound.) The source I want to use is high quality and i want to make the best of it.

Furthermore, no stone seen your note on the Yulong a1000, which ultimately is based on another dual, the OPA2134 + bc377 at very reasonable prices. You just have to ask ...and paid.