[Bonthouse]

Hmm, ah well, I soldered the AD797ARZ's in my Corda Meier Move just now and they make the Grado SR80 sound amazing!

 

[leeperry]

where did you get them? what price?

 

[Bonthouse]

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif where did you get them? what price?

I contacted Analog in The Netherlands and requested some sample opamps.
They sent me two (I asked for six total) and I didn't have to pay a thing

Try to contact AD in your country for some samples that aren't available at the site.

 

[fzman]

Google Translatefound these in my web travels, and think they would be interesting for finicky opamps. this is the english translation, if i got it right. any thoughts, help from anyone in sweden re: pricing and availability? reputation of this company??

 

[leeperry]

@Bonthouse: ok cool, I'll do that! by email?

BTW, what's the diff between U and UA on TI op-amps? Precision Amplifiers - Low Offset Voltage - OPA228 - TI.com

they don't say anything in the PDF, and they only offer the cheaper UA as free sample.

and AD doesn't say anything in the PDF about the different grades of the 797 : AD797 | Ultralow Distortion, Ultralow Noise Op Amp | Military/Aerospace | Other | Analog Devices

more expensive = better, but why?

I've also called LT to know why it was taking a month to get samples, and they told me that they receive them from Singapore...and then they have to package them and ship them from your local country, so it takes forever...plus they don't bother putting the DIP8 parts in plastic holders, so they're completely mashed up and require pliers to unfold them

and when you read stuff like this, you realize that rolling op-amps on a board you know nothing about...and without an oscilloscope, is a terrible hit & miss :

 

[Bonthouse]

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif @Bonthouse: ok cool, I'll do that! by email?

I went at them like crazy! Email, phone and even snailmail!

 

[majkel]

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif and AD doesn't say anything in the PDF about the different grades of the 797 : AD797 | Ultralow Distortion, Ultralow Noise Op Amp | Military/Aerospace | Other | Analog Devices

It does. Look at the charts.
Quote:

more expensive = better, but why?

Spec-wise, sound-wise.

 

[leeperry]

ah right! there's the AD797A and the AD797B...and the B seems to drift less, hence it's higher grade

but 797B has a min gain of 2, where 797A is 1...isn't that better

still TI is not clear on the diff between U and UA ?! Precision Amplifiers - Low Offset Voltage - OPA228 - TI.com

 

[murrays]

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif @Bonthouse: AD doesn't say anything in the PDF about the different grades of the 797 : AD797 | Ultralow Distortion, Ultralow Noise Op Amp | Military/Aerospace | Other | Analog Devices

What datasheet do you have? I have rev. E and it shows specs for the 'A' and 'B' as well as the other codes for packaging (N/R) and lead-free (Z). The order codes are on the last page. Are there other special grades?

 

[leeperry]

I think the diff between A and B is the same as between the LT1469-1 and LT1469-2, -2 is faster but requires a gain of 2 or more...so I think AD797A will be more "universal" than B

ahhh, these datasheets are giving me headaches

and anyway I think I love the LT1358IN8, I don't wanna lose my sanity in all that op-amp mumbo jumbo

I believe I need the gain bandwidth to be as low as possible(nothing more than 30Mhz or so, considering the stock 2114D were 15Mhz, and that my soundcard has crappy sockets), and unity gain stable at 1(not the case of the AD797B

)

 

[majkel]

You don't read carefully, guys.

It's a minimum open loop gain which is a strictly op-amp parameter, not a circuit parameter. The higher, the better. Just look, it's V/uV which means minimum is 1,000,000 and 2,000,000 V/V respectively. 'B' series is suitable for unity gains, too.

 

[Apocalypsee]

Guys, I would like some opinion, I just bought X-Fi Elite Pro, the stock sound is excellent, but only a bit muddy because stock caps and opamp, but I do have some spare opamp to replaced, which is LME49720, LME49723 (slightly worse than the former), LT1364. Which one is the best choice?

 

[ROBSCIX]

Quote:

Originally Posted by Apocalypsee /img/forum/go_quote.gif Guys, I would like some opinion, I just bought X-Fi Elite Pro, the stock sound is excellent, but only a bit muddy because stock caps and opamp, but I do have some spare opamp to replaced, which is LME49720, LME49723 (slightly worse than the former), LT1364. Which one is the best choice?

With that card many have been using the LM4562MA for upgrading the circuit,
The LME49720 you have are the same unit. Those opamps should give you a noticable upgrade in sound quality.

 

[SpudHarris]

I have been doing this all wrong for ages

and I've only just found out. I have a Ibasso P3 & P3+ and never thought to put the supplied dummy adapters in the ground channels on either one. I did this a few nights back and realise I haven't been purely listening to the actual opamps in L/R as the ground channel adds something.

The upshot is I am loving opamps that I never really rated before because for want of a better word their sound was 'tainted' by what ever was in ground or Virtual Ground (usually AD797's). Now don't get me wrong there are a few opamps that benefit from the addition of opamps in ground but I'm using the amps without at the moment and for the forseable future.

Humble pie time for me I'm afraid, one of the finest sounding opamps to my ears NOW is the OPA211 but I also find the LME49722 real nice also. These 2 are my favourites at present. For anyone interested I'm using BUF634's (Hi-C) but no opamps in G/V. More isn't always better!! just took me a while to discover that.

 

[ROBSCIX]

Atleast you figured it out and now you can go back to testing all over again. Sounds like fun to me!

The OPA211's are nice, if you can try out the LME49710HA's. I am unsure if your application is dual or single channel but the 710HA's are single channel TO-99's.

The OPA211's are nice though as you said, I have been testing alot latley with a bunch of new opamps I built a couple weeks back.