The Opamp thread

[ROBSCIX]

Hey guys, many of use test opamps in various equipment but it seems a great deal of the informaiton and discussion is going on in other threads or behind the scenes where people cannot find it. I figured this thread would be a great idea for those testing.

 

[Bilavideo]

I bought a Cmoy from BSG who installed an Opa 2227 and, for a few dollars more, sent me an LRM4562. After that, I got so excited about opamp rolling that I went through Ebay (bad idea), Digikey and AD for more. I've tested the 627BP, AD8599, AD8066, AD797, Opa27, AD823, AD825 and a few more. For single opamps, I went through Cimarron Technologies to order Browndog Adapters.

 

[ROBSCIX]

I just finished soldering up a bunch of new modules last night. All SOIC chips, some requiring two chips per module.
Looking forward to doing some testing tommorow. I would Avoid Ebay as many say they have gotten bad units or fakes etc. I would prefer to pay more and make sure I am getting quality opamps. I think more people are getting into opamp swapping now as more and more of the modern soundcards are coming equipped with opamp sockets.

 

[fzman]

without violating the TOS regarding selling in no for-sale forums, perhaps we could figure out a way for people to swap or pass-along orphaned opamps. anybody have an ideas-- chime in.

also, it might be nice to have people post fairly specific comments, e.g., component, position, general results, and likes/dislikes, so we have a firmer basis for comparison.

maybe even a forum/subforum/thread with links to data sheets in one, easy to search place.

robcsix -- good idea to start this thread

 

[hopeless]

Quote:

Originally Posted by Bilavideo /img/forum/go_quote.gif I bought a Cmoy from BSG who installed an Opa 2227 and, for a few dollars more, sent me an LRM4562. After that, I got so excited about opamp rolling that I went through Ebay (bad idea), Digikey and AD for more. I've tested the 627BP, AD8599, AD8066, AD797, Opa27, AD823, AD825 and a few more. For single opamps, I went through Cimarron Technologies to order Browndog Adapters.

For my 24V CMOY the best I've heard so far is 2x AD845KN. Tried also the OPA627BP, AD8620, TLE2082, OPA2111, AD797AN, and many more (not AD825 and AD8599 though).

Also 2x AD843JN was really good, but got really warm due to high quiescent current. Finally, I also loved the LT1361 there (about equal to the 2x AD845KN but different).

 

[ROBSCIX]

I just built two 8599's modules last night but I haven't tested them yet though.

 

[hopeless]

Please someone try the LT1355 (or the single LT1354) to support my impression that it is very transparent

It is a single stage opamp, and that probably explains why I like it and the rest of the series so much (as well as the LT1469). I like everything that sounds direct and emotional, yet subtle. The multiple stage opamps (like the LT1028 which is three-stage) tend to sound more artificial somehow. I bet that the LME's are also two-stage or three-stage.

 

[Pluto2]

Anyone has experience on LT1352?

Do you know where I can buy them, I need about 10 pieces?

 

[hopeless]

Quote:

Originally Posted by Pluto2 /img/forum/go_quote.gif Anyone has experience on LT1352? Do you know where I can buy them, I need about 10 pieces?

I would suggest that you rather use the LT1355.

 

[12Bass]

Quote:

Originally Posted by Pluto2 /img/forum/go_quote.gif Anyone has experience on LT1352? Do you know where I can buy them, I need about 10 pieces?

IIRC, Digi-Key has them. A decently clear-sounding opamp if low current is a requirement. I'm using one in the preamp for my 12-string bass.

Also, I've amassed a variety of chips over the past couple of years which others might be interested in.

 

[12Bass]

Of the chips I've tried so far, I've found the OPA211 preferable to most others (including the LM/LME chips). Hopefully the OPA2211A will be similar. OPA827 sounds pretty good too, IMO, if a FET is required. Heard lots of good things about the AD797 but haven't tried it yet... still sitting in the package.

 

[hopeless]

Quote:

Originally Posted by 12Bass /img/forum/go_quote.gif Of the chips I've tried so far, I've found the OPA211 preferable to most others (including the LM/LME chips). Hopefully the OPA2211A will be similar. OPA827 sounds pretty good too, IMO, if a FET is required. Heard lots of good things about the AD797 but haven't tried it yet... still sitting in the package.

I agree with you. Have you tried LT1357/1358 and LT1354/1355 ?


The AD797 is nice, especially for bass quality and neutral tonality. Sound(ed) a little dry for me though.


The AD8599 still remains a mystery for me (until I manage to hear it

).

 

[Pluto2]

Oh, I noticed that Jim Williams recommended LT1352 for filtering applications (which I need) since its input bias current is low (for BJT opamps) while LT1358 with high bias current is not suitabe there.....

Or any better suggestion other than LT1352 for filters?

BTW, any opamp has interesting quality for mid and bass?

 

[ROBSCIX]

Quote:

Originally Posted by 12Bass /img/forum/go_quote.gif Of the chips I've tried so far, I've found the OPA211 preferable to most others (including the LM/LME chips). Hopefully the OPA2211A will be similar. OPA827 sounds pretty good too, IMO, if a FET is required. Heard lots of good things about the AD797 but haven't tried it yet... still sitting in the package.

Yes, the OPA211 is a great chip had a quick listen to it a few hours ago and I am impressed. The OP827 is also a great new opamps that many are raving about. I built four of those and have done some quick tests also.
I have an AD797 but I found it was good but not as "amazing" as some say it is. Although it depends on the gear and position in the circuit. Hopefully I will get some time to test more thoroughly later today.

 

[Ashkii21]

I've built a couple of Cmoys, so my knowledge of opamps is limited.

I've tried the OPA2132, OPA2227, and the TLE2072. I am only using 1 9V battery and the best one for me that I've tried so far is the TLE2072. I was thinking of trying a TLE2082. Are there any other opamps that will work with just a single 9V battery supply? I would like to try a couple more.