The Opamp thread

[leeperry]

yeah, that's where I don't agree...discrete designs from A-GD/Burson measure very poorly, they WILL color the sound to death. Nothing beats a good IC opamp IME, these are pieces of highly engineered technology...just don't use many of them in a row, so you don't color the sound too much. And take your time finding your favorite opamp, it's where the fun resides.
 
Discrete isn't "better": http://www.head-fi.org/forums/f6/audio-gd-discrete-op-amps-reviewed-OPA-earth-OPA-moon-OPA-sun-v-2-a-397691/
 
Properly built discrete can be good, though. Look at the Neko DA100 AP measurements on their site: http://assets.head-fi.org/0/08/08ffecd6_DSC01272.JPG

 

[gwillys]

being old school, i think i'll be much happier not having to mess with opamps. besides, opampless is the best i've heard from digital audio so far.
 
a jumper across  pins 3 and 5 of the socket seems to work pretty well.
 
i have a bunch now, maybe i'll have a yard sale

 

[genclaymore]

I in up putting my OPA2111AM back in because 2xOPA228s made my Highs not sound right and got annoying to my ears after awhile and didnt sound fuller to me. I was hoping to find something that was netual that didnt have more bass While still having a big sound stage while still sounding fuller.

 

[Mad Max]

K702, huh?
 
You'll probably want opamps with higher output current, I think.
You'll probably like EL2125/2126.  Not sure if EL2228/2227 might work for you.  ISL55001/55002 is also excellent.

 

[leeperry]

"EL2125 is stable for gains of 10 and greater", which parts would you recommend from intersil? you know my tastes

 

[Mad Max]

That's why I suggested several for him to choose.  He didn't specify where they would be used.
 
You will probably like ISL28127 and 55001. EL2045 and 2126 are real nice, too, but might not be to your liking.  I've already forgotten how 2126 and 2125 compare, I think I liked 2125 better.

 

[ecclesand]

Quote:

That's why I suggested several for him to choose.  He didn't specify where they would be used.
 
You will probably like ISL28127 and 55001. EL2045 and 2126 are real nice, too, but might not be to your liking.  I've already forgotten how 2126 and 2125 compare, I think I liked 2125 better.

Hmmm...this is the first I have heard of these Intersil opamps.  What would you recommend for high impedance headphones like the 600ohm DT990 in the I/V and Buffer stage of a DAC?  I think the EL2045 might be the ticket for the buffer.  Can you recommend one for the I/V stage?

 

[genclaymore]

They would be used in my Bravura headphone amp op-amp socket,

 

[Mad Max]

So scratch EL2125/2126.
 
 

 
Quote:

 
Hmmm...this is the first I have heard of these Intersil opamps.  What would you recommend for high impedance headphones like the 600ohm DT990 in the I/V and Buffer stage of a DAC?  I think the EL2045 might be the ticket for the buffer.  Can you recommend one for the I/V stage?

I don't have a DAC that I can test them in I/V, only buffer.
Intersil has a bunch of real nice looking, and sounding, opamps.

 

[Avro_Arrow]

Hi All
 
I'm looking for op-amp recommendations.
I'm building a DAC based on PCM1794 and would like
opinions on which amp for I/V stage and Filter stage.
Schematic is just the standard one from the data sheet.
 
And no, I don't want to do a tube or discrete stages,
maybe in the next one.
 
I like the sound of LT1364 which I use in my PCM1793 DAC.
 
Thanks

 

[leeperry]

they recommend LT1028/1128 in the PCM1794 datasheet I think

 

[Avro_Arrow]

I know I could just use the amps recommended in the data sheet...but...
 
Quote:

they recommend LT1028/1128 in the PCM1794 datasheet I think

 

[leeperry]

well, LT1028ACN8 sounds very very good..together w/ LT1363, they're many ppl's favorite chips. I love both, but 1028 is too cranky to roll blindly.
 
If TI didn't recommend one of their crummy OPA____, there's a good reason.

 

[Mad Max]

Dunno if THS4081 would work in I/V.  Extremely neutral and transparent opamp, doesn't sound green like other video opamps either.

 

[jcx]

I've pointed out over on diyaudio that the new ADA4898 has unusual technical properties that could make a very good I/V op amp
 
a detail that doesn't appear on the data sheet is that it uses Gilbert's multi-tanh input linearization with a more recent patented twist
 
the ADA4898 multi-tanh linearizes the input diff pair to 1 ppm gm change at ~4 mV diff Vin - and I/V needs large linear input due to the I switching edge frequency content