[Tribbs]

Quote:

So there is no difference of my cheaper OPA627AU versus the OPA627AP and OPA637AP?
Also upgrading to the OPA627BP, would it be a significant difference that would be notice-able? 

 
Unless you have a pair of infamous Golden Ears, I would say no.
 
Look, the OPA627 vintage was released in 1990.  The design is over 22 years old!
 
For about $15 you can put together a pair of stellar LME49990MA (2011 vintage) opamps on a Brown Dog adapter.
(On the same page for $33 they will build it for you.)
 
"My top three devices for serious analog audio work are LME49990, OPA1611 and OPA211. LME49990 is the only one capable of true 24-bit analog performance when powered with +/- 15 V supply (S/N = 159 dB,THD = 146 dB). As the THD of LT1028 is 96 dB, it is "only" good for 16-bit systems. NE5534A is even less linear, THD = 93 dB." (see comments)

 

[Chris J]

Quote:

So there is no difference of my cheaper OPA627AU versus the OPA627AP and OPA637AP?
Also upgrading to the OPA627BP, would it be a significant difference that would be notice-able? 

 
The OPA627B and OPA637B series have slightly better DC Offset Voltage and Input Bias Current, really not too useful in audio applications.
 
B series has slightly better noise characteristics, I really doubt we would hear a difference.
The A series and the B series (627A vs. 627B) are the same design, they would be selected by the manufacturer for low DC offset voltage and low input bias current.
 
The other important audio characteristics are unchanged:
 - Slew Rate
 - Distortion
 - Bandwidth
 
So I don't see why the difference would actually be noticeable.
 
As Tribbs pointed out, the other letters refer to packaging.
 
If you want to try something different, try the LM4562MA.  You will only need one for your M Stage. 
 

 

[Oderi]

I'm the guy who had a problem with hiss a couple weeks back.
 
I thought I had the gain set to 0 dB. Turns out it was set to 20 dB since in the pictures that are in the manual white parts are the switches (quite logical seeing as they're white in reality). Just wanted to report this here in case anyone else is dumb enough to have the same problem. No hiss whatsoever with 0 gain.

 

[headhog]

Quote:

I'm the guy who had a problem with hiss a couple weeks back.
 
I thought I had the gain set to 0 dB. Turns out it was set to 20 dB since in the pictures that are in the manual white parts are the switches (quite logical seeing as they're white in reality). Just wanted to report this here in case anyone else is dumb enough to have the same problem. No hiss whatsoever with 0 gain.

Not very reassuring you hear hiss at 20 db.
 

 

[Oderi]

Quote:

Not very reassuring you hear hiss at 20 db.
 

Isn't that then headphone-dependent? I'm using M-50's with Windows & uDac volumes set to max; with 20 dB gain anything past ~7:30 was unlistenably loud anyway. At 0 I can go to 9:30 or 10.

 

[Chris J]

Quote:

I'm the guy who had a problem with hiss a couple weeks back.
 
I thought I had the gain set to 0 dB. Turns out it was set to 20 dB since in the pictures that are in the manual white parts are the switches (quite logical seeing as they're white in reality). Just wanted to report this here in case anyone else is dumb enough to have the same problem. No hiss whatsoever with 0 gain.

Yep,
I did that a few times.
It took me a while to get used to it even though I know that 20 dB is louder, 0 dB is quieter.
Personally I've settled on 10 dB, but occasionally set it to 18 dB when using 600 ohm Beyers or 2,000 ohm Sennheisers.
I've never tried 0 dB.
 

 
 

 

[genclaymore]

Which gain setting should I set for DT880 pro-250s.

 

[Satellite_6]

The lowest gain setting that gets them loud enough. 

 

[Mad Max]

 
Quote:

Which gain setting should I set for DT880 pro-250s.

You will probably be setting the M-Stage to 10 gain.
 

 

[headhog]

How long does the seller usually take to provide a  tracking number?
 
Thanks

 

[genclaymore]

Quote:

 

You will probably be setting the M-Stage to 10 gain.
 

When I got my Matrix M-Stage from a user here, it was aleady on 10 gain, but I didnt know it. As the label under the amp was wrong. I in up putting it on 18 gain thinking I was putting it on 10.

 

[ByAnyMeanz]

Will an OPA627 A-biased from a MStage work with an Audio GD NFB5 ?
The Audio GD also uses the OPA2134 for Amplification.
 
I would like to try it as i got no Sun, Earth, Moon or other opamp for rolling neither experience with OPA Soundcharacteristics
 
@Chris J
What effect does the LM4562MA have ?
I need a real good opamp, neutral, detailed but not boring or cold.. 

 

[Mad Max]

OPA627 will work but it is not neutral.  With NFB-5, it would be best to go with opamp bypass mode.  Any opamp will just color the sound and reduce detail to some extent.

 

[Chris J]

Quote:

Will an OPA627 A-biased from a MStage work with an Audio GD NFB5 ?
The Audio GD also uses the OPA2134 for Amplification.
 
I would like to try it as i got no Sun, Earth, Moon or other opamp for rolling neither experience with OPA Soundcharacteristics
 
@Chris J
What effect does the LM4562MA have ?
I need a real good opamp, neutral, detailed but not boring or cold.. 

I'm not good at describing sound but I'll try................
I prefer the LM4562 over the OPA627 (class A and non Class A) and the stock amp because it gives me a bit more clarity, a bit more openness, slightly less mud. I think it just sounds "right".
I think if you are looking for neutral and detailed you will like the LM4562.
 
I usually listen at 10 dB gain.
I find with 0 dB gain, with some very dynamic CDs I have to crank the volume up to about 3 o'clock to get a reasonable volume out of my Q's.
Other than that, 0 dBs is very good.  
Avoid 18 and 20 dB.  I've had a change of heart, the more I listen to it, the less I like it, even with my Beyer DT880 600 ohms!  Weird, 18 and 20 dBs sound thin. 

 
Hats off my fellow Head Fi-ers for turning me on to 0 dB and turning me off 18 and 20 dB

.
 
I'll shut up now.............
 

 

[Zombie_X]

I don't hear difference in OP amps at all. I tried many varieties in my Cmoy and none of them changed the sound. So My verdict stands that OP amps don't do anything to the sound.