[TheKisho]

Quote:

I'm listen LC with MBQuart 450 PRO. Don't know how the sound would be with AKG. But MBQuart has the best sound with the 2134 (stock OPAMP). The most comfort and slightly more dark sound with 627 class A mod. I also have tube amplifier Laconic HA-02, and I think LC with stock OPAMP sounds more naturally. But tubes is tubes, your favorite songs which gives you maximum pleasure with your tube amp will never sounds exactly the same way with transistor amp.

I hear they [OPA2134] are muddy, bloated and have limited sound stage, I rather avoid it [The OPA627 I hear kind has a muddled mid range at times as well].  The AKGs would make the flaws dead obvious as well.
It's a hybrid.  Beside the tube doesn't add much to the sound (unlike the cheap chinese 6N11).  While I cannot get the exact same sound I can achieve something similar with a good op-amp and a much better amp (the original indeed circuit isn't perfect).
 
 
 


Quote:

Originally Posted by BlaBlaBla /img/forum/go_quote.gif
Maybe you need too much.

You should try OPA2107. If it is too bright and wide then you can put it into A class and get stronger mid range. OPA627 is too expensive.
 

Maybe.  But I would like to get close to that on my first few attempts.  Playing it picky usually helps to get the majority of the way there.
 
I'm fine if it's bright.  Does it have good extension of highs and lows?  Can you describe it any farther?  Is it drop in able without pin rerouting or biasing to preventing being unstable oscillating?  I don't like the OPA627 or most BB op-amps how they are described, they all seem to be described as sounding layed back, slow, bloated, and colored.
 
 
I might get a LT1364 and OPA2107 for starters.  Can somebody tell me how to bias the LT1364 for class-A with bias that is just right for it (or my likes).  Sorry, I'm new...
 
Any more suggestions before I start buying? [Post #490]

 

[ringer]

 
Quote:

But beware! Maybe you have problems with rectifier? If input capacitors are too warm after few minutes of work, then you should check rectifier diodes. Maybe they are leaking too much and your capacitors are negatively polarised for a short time. I always check diode resistance in both ways. (I know this is not good enough but it tells me if diode is a bad product or not). In open direction It has to be in miliohm range, and in a close direction in a megaohm range. Input capacitors have to be cold for a long time, after turn on. And became warm only because of heat of rest equipment (pick up the heat - not making it).

No, there is no heating problem with input capacitors. They are slightly warm.

 

[CrucifixationOfFaith]

Is there any justification in using BD140/BD139 and not their equivalents with lower voltage ratings ?

 

[BlaBlaBla]

 
Quote:

I hear they [OPA2134] are muddy, bloated and have limited sound stage, I rather avoid it [The OPA627 I hear kind has a muddled mid range at times as well].  The AKGs would make the flaws dead obvious as well.
It's a hybrid.  Beside the tube doesn't add much to the sound (unlike the cheap chinese 6N11).  While I cannot get the exact same sound I can achieve something similar with a good op-amp and a much better amp (the original indeed circuit isn't perfect).
 
 
 



Maybe.  But I would like to get close to that on my first few attempts.  Playing it picky usually helps to get the majority of the way there.
 
I'm fine if it's bright.  Does it have good extension of highs and lows?  Can you describe it any farther?  Is it drop in able without pin rerouting or biasing to preventing being unstable oscillating?  I don't like the OPA627 or most BB op-amps how they are described, they all seem to be described as sounding layed back, slow, bloated, and colored.
 
 
I might get a LT1364 and OPA2107 for starters.  Can somebody tell me how to bias the LT1364 for class-A with bias that is just right for it (or my likes).  Sorry, I'm new...
 
Any more suggestions before I start buying? [Post #490]

I think that BB opamps are the most stable and easiest to drive in the class A. I tried five of them and never had any problem. AD opamps are just opposite they are very sensitive to power supply and capacitors.
OPA 2107 is more wide than OPA 627 but has less pronounced vocals. Laid back? Depends. On your entire setup and on type of music that you like to listen to. With AKG K701, OPA2107 has less synergy than with ATH or Grado. That is because AKG K701 have enormous soundstage and it becomes too wide. With Grado, situation is opposite.
I will say (with ATH) that OPA2107 is excellent for listening to music genre like Enya, soundtracks made by Jablonsky and something that needs big and spacey soundstage. Here OPA627 does not come even close.
But... If someone wants to listen to rock, violin concerts, guitar concerts where there is need for concentration on one instrument and where "magic warmth" must exist - OPA627 wins.
Also I tried AD797 and was driving it successfully (without oscillation), but it is not worth time and effort. Too sterile and to plain (without soul). This opamp is not good for amplifiers, but for DAC (where high precision is most important fact). After disappointment with AD797 I did not try another AD. I heard that all ADs behave the same. They sound clinically (too much). Not my type...
 
Right now I have plans for using a new LME49720HA (to put into new amplifier). But I do not have big expectation. This opamp has good technical specification. But quality of sound does not relly only on pure technicall spec. All opamps today are far above that we need for listening to music. Sometimes, very slow opamp can be better, than ultra fast one. Do not judge the opamp on technical spec. It depends where you want to put it, and what do you want from it.

 

[francisdemarte]

My advice is to stop reading all these opinions and listen to the amp with stock op amp first then decided for yourself. The sound of an amp is more than the just the opamp.

 

[ringer]

Quote:

My advice is to stop reading all these opinions and listen to the amp with stock op amp first then decided for yourself. The sound of an amp is more than the just the opamp.

 
Agree.

 

[BlaBlaBla]

Quote:

 
Agree.

I do not agree.  Stock opamp is mainstream crap.
Avoid at all costs.

 

[TheKisho]

Quote:

My advice is to stop reading all these opinions and listen to the amp with stock op amp first then decided for yourself. The sound of an amp is more than the just the opamp.

True.  An amp adds it's own sound and character but a tube or an op-amp is still 1/3th of the sound.  If you have a poor sounding op-amp or tube your going to hear it.  Knowing my own tastes I most likely will not like the stock sound.

 

[gwikse]

There are too many opinions on these things but I`m going to start with the stock parts since there are no "only op-amp" sound. The Op-amp has a large impact on sound yes but the sound will vary from one type of amp to another. Having a swappable op-amp socket makes it easy to swap out and more often than not I have been surprised at wich op-amps have led to the best sound in different equipment. A piece of tape covering the top of the op-amp makes a blind test easy. And op-amps we can afford having lying around
 
Ordered my lovely cube today. Will make a balanced amp with two boards and a stepped attenuator. The amp will also be used as a pre-amp in my main rig. Will be paired with: BuffaloII DAC, IcePower1000ASP mono`s, Audiophysic Virgo V speakers. 3dmodel of the lovely cube will be posted when done hopefully later today.

 

[ringer]

 
Quote:

I do not agree.  Stock opamp is mainstream crap.
Avoid at all costs.

I like stock op amp. Beautiful sound with my headphones. Besides, I doubt that Lehmann Audio think about saving money on op amps when they made Black Cube. They made one of the most famous headphone amplifier...

 

[ringer]

 
Quote:

There are too many opinions on these things but I`m going to start with the stock parts since there are no "only op-amp" sound. The Op-amp has a large impact on sound yes but the sound will vary from one type of amp to another. Having a swappable op-amp socket makes it easy to swap out and more often than not I have been surprised at wich op-amps have led to the best sound in different equipment. A piece of tape covering the top of the op-amp makes a blind test easy. And op-amps we can afford having lying around
 
Ordered my lovely cube today. Will make a balanced amp with two boards and a stepped attenuator. The amp will also be used as a pre-amp in my main rig. Will be paired with: BuffaloII DAC, IcePower1000ASP mono`s, Audiophysic Virgo V speakers. 3dmodel of the lovely cube will be posted when done hopefully later today.

Оne thing I'm absolutely certain  - sound signature of op amps is nothing depends on sound signature of headphones.
If headphones is bassy, then you probably like OPA2111. If it is bright, then you might prefer OPA627... But the stock one is good

 

[JiggaD369]

I think the end result of the sound signature is the sum of ALL parts.
 
Sextetts are known to have the best midrange known to man kind and my setup does a fine job of doing everything else right.

 

[ringer]

Quote:

I think the end result of the sound signature is the sum of ALL parts.
 
Sextetts are known to have the best midrange known to man kind and my setup does a fine job of doing everything else right.

Noob question from Russia - what is Sextetts?

 

[BlaBlaBla]

 
Quote:

Noob question from Russia - what is Sextetts?

 
AKG Sextett. Famous headphones from AKG. Almost like AKG K1000.
 
 
Lehmann Cube linear is the most famous headphone amplifier because:
 
- it is German (quality)
- it has simple circuit (low losses)
- it can handle AKG (people think that it is the best)
- it can be easily bought (Yamamoto can not)
 
- and its opamp sucks
 
 
 
 

 

 

[BlaBlaBla]

Quote:

I think the end result of the sound signature is the sum of ALL parts.
 
Sextetts are known to have the best midrange known to man kind and my setup does a fine job of doing everything else right.

Agree. Even signal resistor can change sound signature...
 
 
But stock OPA 2134 is crap...