The Opamp thread

[K3cT]

I want to order some AD843 from Farnell for experiments. Which versions should I go with, the AD843JNZ or AD843KNZ? Also, their descriptions say that they come in PDIP8 package, that's the same with normal DIP8 yes?

Thanks in advance for the help, guys.

 

[ROBSCIX]

Yes PDIP = Dip8. Also verify that is has the right amount of channel you need as DIP opamp can come in 1 or 2 channel versions. Usually coding after the product number varies from company to company but many times it has to do with environmental concerns such as no lead...etc. The coding legend should be in the products spec sheet.

 

[ROBSCIX]

Quote:

Originally Posted by Pluto2 /img/forum/go_quote.gif How close is OPA827 compared to it's second place, OPA211 would you say 12bass?

I have tested both of these units...If I had to choose one though I would go for the 827.

 

[SpudHarris]

Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif I have tested both of these units...If I had to choose one though I would go for the 827.

I've also tested both and although our applications vary the 827 comes out on top with me also, it sure is a nice Opamp.

 

[ROBSCIX]

Quote:

Originally Posted by SpudHarris /img/forum/go_quote.gif I've also tested both and although our applications vary the 827 comes out on top with me also, it sure is a nice Opamp.

Yes, People there that have actually tested the unit all have positive impression of it. According to the posts in this thread.

 

[12Bass]

Quote:

Originally Posted by Pluto2 /img/forum/go_quote.gif How close is OPA827 compared to it's second place, OPA211 would you say 12bass?

Hmmm..... My experience is that they are more similar than different, when compared with other chips. A lot will depend on the circuit, and personal taste. If you're replacing a FET device in a high impedance circuit, then the OPA827 is the obvious choice. I tried the OPA211 in a high impedance section and it sounded weak and somewhat noisy. However, in the proper circuit, it sounds very good, IMO. Overall, I've found that the OPA827 can have a little something extra that some may or may not like.... sort of a euphonic presence in the midrange area, while the OPA211 might be a bit less colored. Bear in mind that I've done no proper testing to confirm any of this... just based upon subjective listening.

 

[leeperry]

LT1361 is nice too

it's like a LT1364 with less 2nd/3rd order THD, it leaves more room to the Earth to express itself...so far so good

 

[ROBSCIX]

Quote:

Originally Posted by 12Bass /img/forum/go_quote.gif Hmmm..... My experience is that they are more similar than different, when compared with other chips. A lot will depend on the circuit, and personal taste. If you're replacing a FET device in a high impedance circuit, then the OPA827 is the obvious choice. I tried the OPA211 in a high impedance section and it sounded weak and somewhat noisy. However, in the proper circuit, it sounds very good, IMO. Overall, I've found that the OPA827 can have a little something extra that some may or may not like.... sort of a euphonic presence in the midrange area, while the OPA211 might be a bit less colored. Bear in mind that I've done no proper testing to confirm any of this... just based upon subjective listening.

Personally, I find the OP827 makes a very good I/V opamp. I have tested the 211 for buffer but in a different circuit.
IIRC, both opamps were released around the same time.

Have you had a chance to test the 161X series?

 

[12Bass]

Made mention of the OPA1611 here: http://www.head-fi.org/forums/f6/opa...ml#post6140712

Haven't done any exhaustive comparisons, though from a limited audition, it sounds very much like the OPA211.... which should be no surprise.

 

[leeperry]

Quote:

Originally Posted by 12Bass /img/forum/go_quote.gif it sounds very much like the OPA211.... which should be no surprise.

a while ago, you said that there was no in-house sound for each brand...well today I've rolled from 1364>1361>1213acn8, they still carry a lot of similarities. identifying 1361 and 1213 in a DBT would be pretty hard, 1364 is more distorted and very colored so this one would be easy.

1213 was nice but too clean before, but w/ the Earth as final buffer it's nicer by the hour! SS is wider than the 136x serie.

I wonder if 1211/1213/1215 would sound any different...basically it's the same chip w/ 3 different kinds of specs?!

and Earth makes sure that you get some killer bass, good chip

 

[12Bass]

Well, from all appearances, OPA1611/12 are (practically) the same chips as OPA211/2211A, but with relaxed DC specifications, so it isn't exactly surprising that they sound similar. They're not like OPA2604/2132/34, however, so I can't say that they confirm the notion of a TI/BB "house sound". One of the problems is that people tend to base such conclusions on a limited sampling.

 

[leeperry]

hummm I thought going discrete would stop this rolling frenzy...but I'm now looking for the best ones to feed the Earth

Earth brings fantastic bass, balanced mids/trebles and very clear SS...all the layers are nicely laid off like cards on a table, so get some good cards in the first place...and you're in!

LT1213 is great stuff...definitely a LM4562/49720 killer, it does everything the same...just better in every aspect. "you may not be able to fight like a samurai, but you can at least die like a samurai"

the 24bit TrueHD track of "Up" sounds amazing on the 1213+Earth combo...such a wide and clear SS

 

[Wfolio]

Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif Using brown dogs? are you using two single TO-99 adapters with single channel to dual adapters? I am just asking because I have never seen the proper dual TO-99 adapter made from Brown dog. You can use a few to make one though. I have 627 and 637SM and they are some of my favorites, but I have other SM version on my every growing list of units to build. Seems I am building new opamps modules every week or people are sending me units to test.

I don't have a proper dual TO-99 adapter now. But I can find below two Asia suppliers

diyrealaudio, have not buy anything from them yet, can accept paypal

taobao is the largest 'eBay' in China, has all sorts of things including many DAC at unbelievable prices. Payment could be a problem for foreigner. I had once asked a China colleague to order a toy for me (deliver to Malaysia).

about US$1/pc
diyrealaudio


about US$0.5/pc
taobao

 

[ROBSCIX]

Quote:

Originally Posted by Wfolio /img/forum/go_quote.gif I don't have a proper dual TO-99 adapter now. But I can find below two Asia suppliers diyrealaudio, have not buy anything from them yet, can accept paypal taobao is the largest 'eBay' in China, has all sorts of things including many DAC at unbelievable prices. Payment could be a problem for foreigner. I had once asked a China colleague to order a toy for me (deliver to Malaysia).

Sure, they are out there. I was just wondeirng if you were using the setup I mentioned. Using the single TO-99 adapters conencted to a dual DIP8 to single Dip8. Just curious. Whatever works!

 

[ROBSCIX]

Quote:

Originally Posted by 12Bass /img/forum/go_quote.gif Well, from all appearances, OPA1611/12 are (practically) the same chips as OPA211/2211A, but with relaxed DC specifications, so it isn't exactly surprising that they sound similar. They're not like OPA2604/2132/34, however, so I can't say that they confirm the notion of a TI/BB "house sound". One of the problems is that people tend to base such conclusions on a limited sampling.

I have tested all in the above statment and personally, I wouldn't say the 161X or the 211 series has that typical Burr Brown soudn that others seem to exhibit. That may also be based on my limited testing though...