The Opamp thread

[hopeless]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif Really should state the PURPOSE of the opamp you are recommending. I/V - I've heard great things of the OPA1632 for I/V - TwistedPearAudio uses it and I must admit, I love their stuff.

For I/V it's much simpler to use the LT1468. I've heard great things about it for THIS

purpose. Otherwise, I'd try the OPA827.


Quote:

Driving headphones directly - AD8397 is pretty damn good and rail-rail.

Been using it both at 12V and at 24V; sounded better at 24V, but I still preferred 2x AD845KN and later 2x OPA228P to it. That's with my 32 ohm phones, HD238 and HD485.

The AD8397 is powerful but: 1) lacks some body on vocals despite its current 2) sounds dryish in the mids 3) lacks a bit of color. At 24V it was less dry and a bit more natural.

Quote:

Behind a buffer, I like AD825, AD8065, LME49710 among with a few others.

Myself, I really disliked the AD8066 a lot when I tried it (yup, behind a buffer). It had rough mids and was white sounding.

Instead, I do like the LME49710 quite a bit (despite my criticism to it

) inside my DIYEDEN SVDAC05. Nonetheless, the LT1355 sounds just as good (if slightly different) inside the other DAC and at a lower supply voltage. The same is true of the LT1358 I'd used before.

 

[Pluto2]

Hi hopeless,

Decided to try out the LT1469 & LT1358 combination, and about to order a bunch of LT1469s for the filters (too bad only SOIC is available at digikey

).

Will swap around later with the LMEs I have.
Thanks for the advice

 

[leeperry]

so I like the uber-transparent and pretty much distortion-free upper spectrum on the 49720NA, but the bass is a bit too hollow and distant to my taste....what would be a good prescription(in DIP8 or TO99 if any possible) for I/V you mad professors?

thanks!

 

[FallenAngel]

Yuk, hated the OPA228 at 9-32V, unbearable highs without buffer, just as bad behind one.

Haven't tried LT1468 or AD827.

Don't know much about all of these LT chips, not much info on them (except the insane ravings of andrea).

I also really have to say the LME49710 is nice, but certainly not "very good". It's a good chip when restricted to certain voltages (which is why I use it behind a buffer in my portable amp), but I definitely wouldn't drive headphones with it, nor would I put it into something other than a line driver when I had absolutely no choice - such as TwistedPearAudio IVY).

 

[hopeless]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif Yuk, hated the OPA228 at 9-32V, unbearable highs without buffer, just as bad behind one. Haven't tried LT1468 or AD827. Don't know much about all of these LT chips, not much info on them (except the insane ravings of andrea).

Don't know... inside my (evolved

) CMOY the OPA228 at 24V sounds great and treble is very well controlled. (I don't use Grado's...just in case)


Regarding LT opamps... yes I like them. Shouldn't I? They're a sweet spot between the strengths & weaknesses of the other offerings I know.

 

[hopeless]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif I also really have to say the LME49710 is nice, but certainly not "very good". It's a good chip when restricted to certain voltages (which is why I use it behind a buffer in my portable amp), but I definitely wouldn't drive headphones with it, nor would I put it into something other than a line driver when I had absolutely no choice - such as TwistedPearAudio IVY).

Still inside the SVDAC05 it performed better than: TI NE5534, LT1028ACN8, AD797, LT1363, OPA211, OPA827, when living with a certain sound was concerned. That's why I removed the sockets and soldered it in.

Have you tried the TO99 version?

 

[hopeless]

Quote:

Originally Posted by Pluto2 /img/forum/go_quote.gif Hi hopeless, Decided to try out the LT1469 & LT1358 combination, and about to order a bunch of LT1469s for the filters (too bad only SOIC is available at digikey ). Will swap around later with the LMEs I have. Thanks for the advice

I think you'll love it. Let us know how you find the LT1469 to be in your application.

 

[FallenAngel]

If you got the AD797, you're something special, it's a VERY hard opamp to get to work. OPA211 is no slouch either, also a terrible bipolar to stabilize.

Since you're asking about TO99 package vs DIP8, hi Andrea

 

[hopeless]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif If you got the AD797, you're something special, it's a VERY hard opamp to get to work. OPA211 is no slouch either, also a terrible bipolar to stabilize. Since you're asking about TO99 package vs DIP8, hi Andrea

The AD797 worked just fine, didn't get hot or anything. It sounded fine, tonally pleasing, with solid fast bass, but it was a little too dry in the midrange, which is common to all of the AD chips I know of (have yet to try the AD8599).


The OPA211 (tough to stabilize!?) was my other favorite for the SVDAC05, thus I'll try the OPA2211 very soon in the modified Super Pro where the LT1355 is sounding so good that I may also keep it forever (but I guess I won't

).


Regarding the OPA228, I have to agree with majkel regarding its ability to spatially separate instruments better than most opamps. Even in a CMOY. Will try 2 of them inside the Super Pro next.

Did you try 2x AD845KN unbuffered? It drives headphones very well, too, with less dryness & more musicality than the other AD's I tried in the CMOY (including AD8620 and AD797).

 

[Pluto2]

hopeless your findings on LT1355 vs LT1358 conincides with someone else 's I found on web (a Japansese site)

Should I also get the LT1355s (4 pc).....hmmm, wondered the difference would be just subtle....worth to get them....

How would you say about LT1356 (vs the above chips)? The gentleman found it a nice match with LT1469 in a preamp....

 

[hopeless]

Quote:

Originally Posted by Pluto2 /img/forum/go_quote.gif hopeless your findings on LT1355 vs LT1358 conincides with someone else 's I found on web (a Japansese site) Should I also get the LT1355s (4 pc).....hmmm, wondered the difference would be just subtle....worth to get them.... How would you say about LT1356 (vs the above chips)? The gentleman found it a nice match with LT1469 in a preamp....

LOL, funny!


The LT1356 is the quad version of the dual LT1355, no more no less.

Sooo.... LT1355 and LT1469 should make a nice match.

 

[hopeless]

I'm tooo curious about the OPA2822 (just received 5 of them) in my 12V DAC. It might turn out as the ideal solution, even. Adapters pleaaase coooome...

 

[Pluto2]

Quote:

Originally Posted by hopeless /img/forum/go_quote.gif LOL, funny! The LT1356 is the quad version of the dual LT1355, no more no less. Sooo.... LT1355 and LT1469 should make a nice match.

Oooops, typo, it should have been LT1346, rather than LT1356....

 

[Bonthouse]

Another question from me; what's the difference between the 'AD797BRZ' , the 'AD797BRZ-REEL' and the 'AD797BRZ-REEL7' ?
I seriously can't find the differences..

 

[majkel]

Bunch packaging method only. Does not apply to the chip directly.