The Opamp thread

[Charminbaer]

Quote:

Hi everyone!
 
I want to make a DIY project with a Creative Sound Blaster Live 24bits, SB04100
 
I found this thread, great info, but I would like recommendations for opamps and capacitors, and I saw this opamp thread, but since it started more than a year ago and has 222 pages, I got desperate after some reading.
 
My current favorites based only on reviews and recommendations are:
 
 
LM4562
AD8066
OPA2211A
ADA4627-1
 
But I don't even know if I can place all of them at my card, open for suggestions.
I think I enjoy, in decreasing order, soundstage, detail, mids, bass, treble.

Hi,
 
good electrolytic capacitors are for example Nichicon KZ , Nichicon FG , Elna Silmic RFS II. Maybe this is the right tread for you:  http://www.head-fi.org/forum/thread/284863/orgy-of-capacitors-the-cap-thread#post_3646129
 
LM4562 has very strong treble, too much for my taste. Sometimes grainy. Soundstage is okay.
I have read somewhere in this thread that ADA4627-1 should have a good soundstage. But don´t rely on that ,i have never heard it myself.
Some people think OPA128SM is one of the best opamps, even superior to OPA637SM. But the cheapest i have seen is 80$ for a pair on ebay.
AD797BR has a superb soundstage and is very neutral over all audio frequencies, but it´s a pain in the ass to get it stable.
 

 

[leeperry]

 

LM4562 has very strong treble, too much for my taste. Sometimes grainy. Soundstage is okay.

I'm afraid things are more complicated than they seem. LM4562MA in the PCM1793 Spitfire DAC is not bright/shrill and has very solid bass. I hate the SS, though. it seems to dig deep to impress, but it's too colored and brings to the front stuff that should stay where it is. Very impressive for a few hours, then dead boring IME.

 

[Charminbaer]

Quote:

 

LM4562 has very strong treble, too much for my taste. Sometimes grainy. Soundstage is okay.

I'm afraid things are more complicated than they seem. LM4562MA in the PCM1793 Spitfire DAC is not bright/shrill and has very solid bass. I hate the SS, though. it seems to dig deep to impress, but it's too colored and brings to the front stuff that should stay where it is. Very impressive for a few hours, then dead boring IME.

hm okay, i´ve only tried it in the m-stage and on my Auzentech Prelude. On both it sounded a little bit harsh.
I can imagine it could sound different on other equipment.
I agree that SS is strange at stock, but as soon as I did some powersupply bypassing with 0.1uf ceramics and 4uf mkps it got much more realistic. Bass did also improve a little bit, but on my setup it is still not very deep.

 

[SpudHarris]

Hello Guys,
 
haven't posted here in a while but have been checking back periodically to see if there is a new FOTM
 
Well if you guys haven't tried it you really must get the ADA4637-1. I believe only the ARZ version is available at present which I got a few days back. The ADA4627-1 has been a favorite of many for a while (me included) but I like the 4637 more.
 
I'm not 100% sure how to explain how they differ. Ryuzoh of Fi-Quest fame says a more detailed version of the 4627 but I think the differences are more than this. Yes there is maybe a tad more detail but resolution is far better and vocals are just beautifully rendered, probably one of the best chips I have heard in terms of vocals...... Obviously circuits will play a part in results and I personally found my P3+ yealded better results than my Fi-Q.
 
Let us know what you guys think, its been a while on this thread since we had new chips to try.

 

[K3cT]

4637 is just a decompensated 4627 right? 

 

[murrays]

Hmm, from the specs it looks like the ADA4627 is meant to be a direct competitor for the OPA827. What do you think?
Look at the graph for THD vs output level, on p8 of the datasheet. It goes through the roof above about 0.8 V Rms. That must be where the class A bias ends and it starts getting crossover distortion.

 

[Mad Max]

4637-1A's warm haze is very pleasant.  I still like 4627-1B better.
Either is an awesome chip.

 

[LuciferX]

Hi! Quick question:



I orderer LT1364CN DIP8 samples, how i should combine it with OPA2107 in my Claro Halo?

U8+U10 = OPA2107AP - U9+U11=LT1364CN



or



U8+U10 = LT1364CN - U9+U11=OPA2107AP



U8+U10 are LPF and U9+U11 final buffer?



The circuit should be: DAC >> U8+U10 >>> U9+U11 >>> RCA OUT / HP OUT?





Thanks!

 

[Theodore]

Hi.
I saw the following original Asus item.
[size=x-small]ASUS Xonar Op AMP Upgrade Kit for Essence ST/STX[/size] .
Does some guy know something about it?

 

[Charminbaer]

It´s two LME49720NA. They are almost similar to LM4562NA.
 
http://www.newegg.com/Product/Product.aspx?Item=N82E16800998157

 

[LuciferX]

Hi, I need a quick comparison between OPA2107AP and LT1364CN (Both DIP8) ... I have a Claro Halo soundcard (C-Media Oxygen HD CMI8788 Audio Processor - 24-bit/192kHz AK4396VF (120dB-part spec.) DAC), with 4 OPA2107 right now .... I want to combine OPA2107 with LT1364, but I dont know wich of them works better like LPF or Final Buffer ... Can somebody help me?

 

[Avro_Arrow]

OPA2107 and LT1364 are apples and oranges, they are not directly comparable.
 
OPA2107 is a low noise JFET op amp.
LT1364 is a high bandwidth, high slew rate Bi-Polar op amp.
 
With OPA2107, you will not receive the full benefit from LT1364.
 
If the circuit will handle the Bi-Polar input op amp, I would go
with all LT1364. I use one in my PCM1793 based DAC.
 
A better (safer) part might be OPA1642 but you will have to solder it
to an adapter for DIP8

 

[LuciferX]

So, I cant mix them? I only have 2 LT1364 ... My others OPAMP are LM4562NA, LME49720NA and LME49860NA ... What do you think about using them with LT1364 in combination?
 
The circuit in my soundcard is: DAC >> U8+U10 (2 dual opamps) >>> U9+U11 (2 dual opamps) >>> RCA OUT / HP OUT

 

[Avro_Arrow]

The three LMs you mention seem pretty close in their specs.
One of them would be a better choice than the OPA2107 in my opinion.
 
I would try the LM in the LPF and the LT1364 in the buffer.
 
Make sure to test for DC offset. The LT1364 draws about
100 times as much bias current as a JFET op amp.

 

[Daemos]

I'm looking at some Opamps are there anything that is better than the OPA128? I know they are expensive, but from what I've read they are supposed to be one of the best.