[HamilcarBarca]

Quote:

Anyway,  I want to start swapping op-amps.  I am using this with HD650's.  Anyone know of a few posts I can reference that comment on the general consensus of rolling which op-amps produce accentuates what sounds?  I'd like to warm up the mids a little and tighten up the bass if possible, without buying a tube amp. 

 
Many tube amps create a warmer sound.
 
It's highly unlikely one will tighten up the bass on the HD 650. That's not the way tubes, amps, and headphones work.

 

[Xymordos]

I would say with the original opamps the m-Stage is already quite warm sounding for a solid state amp.

 

[kazaakas]

Quote:

So much for my genius theory! LOL
Maybe your Soundblaster outputs a very high level signal?

I suppose, it's known to have a pretty strong headphone out to avoid the need of an amp with semi-semi-demanding cans so to say, but I'm using the RCA outs..

 

[George_63]

I got my M-stage last Wednesday.It says v2.1 on the board.It came along with a power cord and EU adapter.



 
I was pleased to see how well built it is.The blue operation led on the front panel is quite discrete when on and not as bright as many have complained.It seems that there has been some improvement.I have the AKG K701 which as you all know are quite power hungry despite their relatively  low impedance.My Xonar STX head-amp is powerfull enough to drive them up to a deafening level but it lacks musicality and warmth,so I got a JDSLabs Cmoy v2.0.2 to give it a try.I must admit that it sounded unbelievably great.So musical,transparent,airy and warm like I had never heard before.My problem was that I couldn't raise the volume to an enjoyable level because of severe clipping.It was a matter of current rarther than  voltage as I was using an external psu at 18V.Soldering a second TLE2426CPL virtual ground solved my problem and I managed to raise up the volume to an audibly acceptable level.Then,having read all of this thread  plus the Headfonia review I decided to go for the Matrix being half the price of my initial pick,the Heed Canamp.
For the past 4 nights I have been listening to my favorite music(mostly jazz classical amd acoustic) playing 24-96/192 recordings ASIO Foobar >STX>Matrix>K701.Indeed it's a good amp and a real bargain for the money.I'm using the 10db gain and there is no backround hiss even when the knob reaches the 6 o'clock position.Music sounds quite clear and detailed.Highs come out clear yet not sibilant,Mids are a bit dark though and Lows well,I know it's the K701 but I was never a bass kick fan,so a 5db extra gain from the equilizer brings it in balance with the rest of the spectrum.It's not the bass quality,as it is nicely articulated and clear, but the quantity and I know that it's the phones' blame.
   To be honest,I expected a little more...It is not a complaint.I will say it again that it is a great amp for the money and I do know that many much more expensive gear sound worse.I should blame the Cmoy,for sounding as good as the Matrix at a cost of 4 times less!Amazing piece of equipment...
   As far as cabling  is concerned,using an Oehlbach NF1 showed no detectable improvement over the common 3.5mm-to-RCA IC provided with the Xonar.
   Now, about op-amp rolling, the only alternative I had for the time being since my LM4562 order will be here in a couple of weeks,was to use the OPA2227 of the Cmoy.Comparing it to the OPA2134 was not an easy task as they don't seem to have any profound differences.The 2134 has a slightly deeper bass,warm but not so well bodied mids.The 2227 on the other hand is a little more trnsparent and clear and that helps the mids which stand out more.It's as if it shifts the frequency spectrum towards higher values and the sound becomes less dark at the expence of some extra sibilance though.Since AKGs are bitchy with bass,and using some help from the equilizer seems inevitable in most cases,I decided to go for the 2227,at least until 4562 arrives.I will let you know about it when I get it.

 

[hifimanrookie]

I got my M-stage last Wednesday.It says v2.1 on the board.It came along with a power cord and EU adapter.




I was pleased to see how well built it is.The blue operation led on the front panel is quite discrete when on and not as bright as many have complained.It seems that there has been some improvement.I have the AKG K701 which as you all know are quite power hungry despite their relatively  low impedance.My Xonar STX head-amp is powerfull enough to drive them up to a deafening level but it lacks musicality and warmth,so I got a JDSLabs Cmoy v2.0.2 to give it a try.I must admit that it sounded unbelievably great.So musical,transparent,airy and warm like I had never heard before.My problem was that I couldn't raise the volume to an enjoyable level because of severe clipping.It was a matter of current rarther than  voltage as I was using an external psu at 18V.Soldering a second TLE2426CPL virtual ground solved my problem and I managed to raise up the volume to an audibly acceptable level.Then,having read all of this thread  plus the Headfonia review I decided to go for the Matrix being half the price of my initial pick,the Heed Canamp.
For the past 4 nights I have been listening to my favorite music(mostly jazz classical amd acoustic) playing 24-96/192 recordings ASIO Foobar >STX>Matrix>K701.Indeed it's a good amp and a real bargain for the money.I'm using the 10db gain and there is no backround hiss even when the knob reaches the 6 o'clock position.Music sounds quite clear and detailed.Highs come out clear yet not sibilant,Mids are a bit dark though and Lows well,I know it's the K701 but I was never a bass kick fan,so a 5db extra gain from the equilizer brings it in balance with the rest of the spectrum.It's not the bass quality,as it is nicely articulated and clear but the quantity and I know that it's the phones' blame.
   To be honest,I expected a little more...It is not a complaint.I will say it again that it is a great amp for the money and I do know that many much more expensive gear sound worse.I should blame the Cmoy,for sounding as good as the Matrix at a cost of 4 times less!Amazing piece of equipment...
   As far as cabling  is concerned,using an Oehlbach NF1 showed no detectable improvement over the common 3.5mm-to-RCA IC provided with the Xonar.
   Now, about op-amp rolling, the only alternative I had for the time being since my LM4562 order will be here in a couple of weeks,was to use the OPA2227 of the Cmoy.Comparing it to the OPA2134 was not an easy task as they don't seem to have any profound differences.The 2134 has a slightly deeper bass,warm but not so well bodied mids.The 2227 on the other hand is a little more trnsparent and clear and that helps the mids which stand out more.It's as if it shifts the frequency spectrum towards higher values and the sound becomes less dark at the expence of some sibilance though.Since AKGs are bitchy with bass,and using some help from the equilizer seems inevitable in most cases,I decided to go for the 2227,at least until 4562 arrives.I will let you know about it when I get it.

Try the class a/ opa627 mod from tamaudio.com..u will be surprised how the sound will improve..
And pity u have the 701..as u cant switch cables on the set..That would certainly make a change.

 

[Chris J]

I was pleased to see how well built it is.The blue operation led on the front panel is quite discrete when on and not as bright as many have complained.It seems that there has been some improvement.I have the AKG K701 which as you all know are quite power hungry despite their relatively  low impedance.My Xonar STX head-amp is powerfull enough to drive them up to a deafening level but it lacks musicality and warmth,so I got a JDSLabs Cmoy v2.0.2 to give it a try.I must admit that it sounded unbelievably great.So musical,transparent,airy and warm like I had never heard before.My problem was that I couldn't raise the volume to an enjoyable level because of severe clipping.It was a matter of current rarther than  voltage as I was using an external psu at 18V.Soldering a second TLE2426CPL virtual ground solved my problem and I managed to raise up the volume to an audibly acceptable level.Then,having read all of this thread  plus the Headfonia review I decided to go for the Matrix being half the price of my initial pick,the Heed Canamp.
For the past 4 nights I have been listening to my favorite music(mostly jazz classical amd acoustic) playing 24-96/192 recordings ASIO Foobar >STX>Matrix>K701.Indeed it's a good amp and a real bargain for the money.I'm using the 10db gain and there is no backround hiss even when the knob reaches the 6 o'clock position.Music sounds quite clear and detailed.Highs come out clear yet not sibilant,Mids are a bit dark though and Lows well,I know it's the K701 but I was never a bass kick fan,so a 5db extra gain from the equilizer brings it in balance with the rest of the spectrum.It's not the bass quality,as it is nicely articulated and clear but the quantity and I know that it's the phones' blame.
   To be honest,I expected a little more...It is not a complaint.I will say it again that it is a great amp for the money and I do know that many much more expensive gear sound worse.I should blame the Cmoy,for sounding as good as the Matrix at a cost of 4 times less!Amazing piece of equipment...
   As far as cabling  is concerned,using an Oehlbach NF1 showed no detectable improvement over the common 3.5mm-to-RCA IC provided with the Xonar.
   Now, about op-amp rolling, the only alternative I had for the time being since my LM4562 order will be here in a couple of weeks,was to use the OPA2227 of the Cmoy.Comparing it to the OPA2134 was not an easy task as they don't seem to have any profound differences.The 2134 has a slightly deeper bass,warm but not so well bodied mids.The 2227 on the other hand is a little more trnsparent and clear and that helps the mids which stand out more.It's as if it shifts the frequency spectrum towards higher values and the sound becomes less dark at the expence of some sibilance though.Since AKGs are bitchy with bass,and using some help from the equilizer seems inevitable in most cases,I decided to go for the 2227,at least until 4562 arrives.I will let you know about it when I get it.
[/quote]

Hi,
The LM4562 is a nice Op Amp but you will find the differences between Op Amps is very subtle.

 

[George_63]

Quote:

Hi,
The LM4562 is a nice Op Amp but you will find the differences between Op Amps is very subtle.

 
  I already have ,as it took me more than 30 times of switching the 2227 and 2134 to verify their differences.
 
 
Quote:

Try the class a/ opa627 mod from tamaudio.com..u will be surprised how the sound will improve..
And pity u have the 701..as u cant switch cables on the set..That would certainly make a chang

 
Some electronic engineers claim that class A biasing reduces the lifetime of the op-amps.Can anyone confirm that?

 

[Chris J]

 
  I already have ,as it took me more than 30 times of switching the 2227 and 2134 to verify their differences.



Some electronic engineers claim that class A biasing reduces the lifetime of the op-amps.Can anyone confirm that?

I'm not surprised you had to swap the Op Amps again and again to hear the difference. LikeI said, real subtle, ain't it?

True, you are running the Op Amp a bit hotter, so the lifetime will be a bit shorter, but in actual practice, this is rather academic as the Op Amp will outlive the electrolytic capacitors.

 

[clams]

Quote:

 
Many tube amps create a warmer sound.
 
It's highly unlikely one will tighten up the bass on the HD 650. That's not the way tubes, amps, and headphones work.

That's just a generalization of tube amps. In the case of OTL amps like the Bottlehead Crack, the increased voltage output actually made the bass on the HD650 more controlled than the m-stage. I actually preferred the Crack over the matrix for that pair of headphones although its obviously personal preference.

 

[HamilcarBarca]

Quote:

Quote:

 
Many tube amps create a warmer sound.
 
It's highly unlikely one will tighten up the bass on the HD 650. That's not the way tubes, amps, and headphones work.

That's just a generalization of tube amps. In the case of OTL amps like the Bottlehead Crack, the increased voltage output actually made the bass on the HD650 more controlled than the m-stage. I actually preferred the Crack over the matrix for that pair of headphones although its obviously personal preference.

 
It's an inherent characteristic of how tubes operate. If the tube audio sound isn't desired by the designer, it can be worked around. Nothing prevents the use of tubes in (say) an excellent Class A amp. Voltage doesn't make the "bass [...] more controlled", in theory or practice.
 
You like the sound of the Crack better than the M-Stage. I like the sound of the O2 better than the M-Stage. I think we both got what we wanted. This is a good thing.

 

[Chris J]

That's just a generalization of tube amps. In the case of OTL amps like the Bottlehead Crack, the increased voltage output actually made the bass on the HD650 more controlled than the m-stage. I actually preferred the Crack over the matrix for that pair of headphones although its obviously personal preference.

No.

Voltage = volume.

If you are listening at the same volume, the two amps would be outputting the same volume.

Hey man, just sayin'

 

[Mad Max]

Quote:

...
Some electronic engineers claim that class A biasing reduces the lifetime of the op-amps.Can anyone confirm that?

 
Probably because of the increased heat due to the class-A biasing?
Plus a lot of opamps don't need class-A biasing anyway, and the change in sound is probably due to mildly increased stability - the class-A biasing also reduces HF oscillations to a small extent, I've read.  Still, it is better and simpler to add ceramic/film psu bypass caps right on or next to the opamp(s)' power pins instead for the improvement in stability and sound.  Preferably C0G/NP0 ceramics and polypropylene film caps with the ceramic cap being no more than 1/10th the capacitance of the film cap and yet being greater than or equal to 0.01 uF (10nF) in capacitance.
 
Here I've got an OPA209 module with a 21nF ceramic and two MKP416 caps that add up to 241nF:
 

 
Well, I also have a matched pair of 100.5-ohm resistors added in parallel to the 50-ohm output resistors after the opamps, but that creates instability with all of my opamps except OPA209 and AD8510 which improve in sound instead.

 

[the search never ends]

Quote:

 
Probably because of the increased heat due to the class-A biasing?
Plus a lot of opamps don't need class-A biasing anyway, and the change in sound is probably due to mildly increased stability - the class-A biasing also reduces HF oscillations to a small extent, I've read.  Still, it is better and simpler to add ceramic/film psu bypass caps right on or next to the opamp(s)' power pins instead for the improvement in stability and sound.  Preferably C0G/NP0 ceramics and polypropylene film caps with the ceramic cap being no more than 1/10th the capacitance of the film cap and yet being greater than or equal to 0.01 uF (10nF) in capacitance.
 
Here I've got an OPA209 module with a 21nF ceramic and two MKP416 caps that add up to 241nF:
 

 
Well, I also have a matched pair of 100.5-ohm resistors added in parallel to the 50-ohm output resistors after the opamps, but that creates instability with all of my opamps except OPA209 and AD8510 which improve in sound instead.

Ok, seriously Max, did you take this picture?  I could never take a picture that well, too many nerves shot maybe, anyway, if you did take it, kudos bro.

 

[Chris J]

Probably because of the increased heat due to the class-A biasing?
Plus a lot of opamps don't need class-A biasing anyway, and the change in sound is probably due to mildly increased stability - the class-A biasing also reduces HF oscillations to a small extent, I've read.  Still, it is better and simpler to add ceramic/film psu bypass caps right on or next to the opamp(s)' power pins instead for the improvement in stability and sound.  Preferably C0G/NP0 ceramics and polypropylene film caps with the ceramic cap being no more than 1/10th the capacitance of the film cap and yet being greater than or equal to 0.01 uF (10nF) in capacitance.

Here I've got an OPA209 module with a 21nF ceramic and two MKP416 caps that add up to 241nF:



Well, I also have a matched pair of 100.5-ohm resistors added in parallel to the 50-ohm output resistors after the opamps, but that creates instability with all of my opamps except OPA209 and AD8510 which improve in sound instead.

The hotter the Op Amp runs, the lower the lifetime will be.
The difference will not be very pronounced, but it is there.

Will Class A biasing reduce HF osciilations? I don't see how. Maybe someone can explain.

The Op Amp was designed without Class A biasing, I suspect we may be hearing more distortion with the Class A biasing, but can't confirm that.

Why did you add 100 Ohm resistors in parallel with the 50 Ohm resistors? What are you trying to improve? Remember, the current driving the headphones is actually derived from the discrete output transistors.

 

[PanamaHat]

Anyone here think the m-stage would be overkill for a Sennheiser HD558?