[Chris J]

Bipolar Junction Transistors can have lower noise than JFETs."

Depends of the resistance before the opa, depends of the schema, I had had a bad experience with the remplacment of a JFET with a Bipolar.

The noise was not realy a probleme, but the continus curent was...I have changed the resistance before the opa and it's ok, sometime we have to change the schema for the opa.


The oscillation is not the only risk, and it's can be corrected if you study the theory and the datasheet (adding caps etc..).

Some opa can remplace similar opa without any risk, we can find the right match on inernet.

Generally I think it's more safe not to inverse JFET and Bipolar, but I am not electronician...

I would just explain than rolling amp can be dangerous, and the opa are rarely at there best in a schema not made for them.

But we can experiment the sound of an opa on several schema, it's always the same nature, and we can find the sound than we prefer.

The matrix can be safe for a lot of opa, I don't know.

All of this is more or less true, but there are always exceptions
i'm 99% sure that the LM4562 has BJT inputs.........

In theory, you can usually get lower noise with a BJT input stage than with a JFET input stage.

 

[Magicman74]

can you describe the sound? smooth? warm? nice treble/highs? cause that what i am into. 

Do you have a LM4562? The LT1364 sounds almost the same, just a little bit deeper in the Bass and a little more refined in the Treble. A tad more air all around.
These are the only 2 opamps I use in the M-Stage. They sound the best to me, I have an older one that came stock with the LM4562, I haven't read the whole tread, but I have no hum issues or anything some posters were talking about. My Stage is dead silent, no hum notta...The only thing is the LT runs a little hotter, but the stage is a bit hot anyway. For my Senns, I use the LT, Denons and others the LM. LT used to send samples, so you can get the LT's free...Don't know if they do it anymore..But they are cheap, a few bucks maybe?, shipping is most likely more.

 

[proton56]

I prefer the sound of the LT1364 to the lm4562, the sound is one of the more neutral for me.
Its fast sound, with a lot of détails, but it's not my prefered, some new chips are better, with lower distorton.
His spec. are good, It's  very fast amp (high slew-rate), it have low distortion.
It can load some hard resitances, it's powerful.
he become hot in normal functionnement.
 
But it's not a drop in replacement, It will oscillate in many circuits that are stable with the more common audio op amps. Mine is burned...
 
It can be a good opa if it's safe with the matrix.

 

[Shini44]

Do you have a LM4562? The LT1364 sounds almost the same, just a little bit deeper in the Bass and a little more refined in the Treble. A tad more air all around.
These are the only 2 opamps I use in the M-Stage. They sound the best to me, I have an older one that came stock with the LM4562, I haven't read the whole tread, but I have no hum issues or anything some posters were talking about. My Stage is dead silent, no hum notta...The only thing is the LT runs a little hotter, but the stage is a bit hot anyway. For my Senns, I use the LT, Denons and others the LM. LT used to send samples, so you can get the LT's free...Don't know if they do it anymore..But they are cheap, a few bucks maybe?, shipping is most likely more.

 
lol! i've just ordered the LM4562 , wish you typed about the LT1364 yesterday the problem is that i live in dubai -.-''

so the treble/highs are crispier on the LT? or? i like the treble/highs the most :3
 
LT1364CN8-ND or LT1364CN8#PBF-ND
 
will test it for sure after the LM4562 , also i need one to replace the opamp right? 

how long to burn in the M-Stage + LM4562? so i know when to test the LT1354

 

[proton56]

 
I don't know if the LM4562 have BJT inputs, I have read it's a bipolar.

When I have use it instead a JFET, the source resitance was hight, (3.3M), and I had a problem of cc.
 
I have change the resistance, the cc was lower, but I never heard any difference.
I have read that bipolar have bad noise spec. with high source resistance.
I imagine that the noise is not so important for the sound.
 
I think we could do some simulations with TINA etc.
 
 
I just try to explain what is dangerous, as I would like someone has explained me before I had made a mistake....

 

[Chris J]

   
I don't know if the LM4562 have BJT inputs, I have read it's a bipolar.
 
When I have use it instead a JFET, the source resitance was hight, (3.3M), and I had a problem of cc.
 
I have change the resistance, the cc was lower, but I never heard any difference.
I have read that bipolar have bad noise spec. with high source resistance.
I imagine that the noise is not so important for the sound.
 
I think we could do some simulations with TINA etc.
 
 
I just try to explain what is dangerous, as I would like someone has explained me before I had made a mistake....

 
BJT = bipolar
 
BJT means Bipolar Junction Transistor.
 
An Op Amp with JFET inputs will have a very high input impedance and negligible input current: I think that is what you are referring to when you talk about the continuous current?
 
The whole noise thing is very complicated,
Op Amps have a noise current spec and noise voltage spec.which interacts with the input resistors and feedback resistors used in the Op Amp circuit.
So what has less noise? JFET input or BJT input Op Amp?  It's complicated and it depends on several factors. JFETs often have more noise in the lower frequencies.
There's a guy named Walter Jung who wrote a book called "The Op Amp Cookbook".
It's a reference standard on the whole subject of Op Amp circuits.
Lots of detail on this subject in there!
 
But you are correct, you can't just substitute any Op Amp for another one, there are lots of pitfalls................

 

[DaemonSire]

Any further feedback on the LME49710HA X2 + Adaptor opamp? http://www.ebay.ca/itm/LME49710HA-X2-Adaptor-/180872434827?pt=US_Amplifier_Parts_Components&hash=item2a1cd6548b&_uhb=1
 
A few pages back there were some excellent opinions on this opamp compared to both the LM4562 and OPA627 (which I currently have both).
 
Just wondering if it is worth shelling out the $30 or should I just be happy with what I have...this is Head-Fi though so that never happens does it?

 

[Chodi]

  Any further feedback on the LME49710HA X2 + Adaptor opamp? http://www.ebay.ca/itm/LME49710HA-X2-Adaptor-/180872434827?pt=US_Amplifier_Parts_Components&hash=item2a1cd6548b&_uhb=1
 
A few pages back there were some excellent opinions on this opamp compared to both the LM4562 and OPA627 (which I currently have both).
 
Just wondering if it is worth shelling out the $30 or should I just be happy with what I have...this is Head-Fi though so that never happens does it?

 
Small price for a noticeable improvement. The positive comments I made earlier stand. I listen mostly to classical music and this combo does it for me. I never thought I would find a $300 ss amp that worked this well. I own some good tube amps and I find I enjoy listening to the Matrix just as much. Never thought that would happen.

 

[elwappo99]

  Any further feedback on the LME49710HA X2 + Adaptor opamp? http://www.ebay.ca/itm/LME49710HA-X2-Adaptor-/180872434827?pt=US_Amplifier_Parts_Components&hash=item2a1cd6548b&_uhb=1
 
A few pages back there were some excellent opinions on this opamp compared to both the LM4562 and OPA627 (which I currently have both).
 
Just wondering if it is worth shelling out the $30 or should I just be happy with what I have...this is Head-Fi though so that never happens does it?

 
I believe a bit back someone state the LME49720 is the same as the LME49710. They can be had for a lot less.

 

[Chodi]

   
I believe a bit back someone state the LME49720 is the same as the LME49710. They can be had for a lot less.

 
I believe in this case you are paying for the implementation on a custom pcb. If you have the soldering skills and the passion for DIY I guess it is possible to duplicate the results for some savings. Wasn't worth it to me to save $15.

 

[elwappo99]

 

   
I believe a bit back someone state the LME49720 is the same as the LME49710. They can be had for a lot less.

 
I believe in this case you are paying for the implementation on a custom pcb. If you have the soldering skills and the passion for DIY I guess it is possible to duplicate the results for some savings. Wasn't worth it to me to save $15.

 
Someone check my work here, but I got mine for free, and digikey has them at a pretty low price:
 
http://www.digikey.com/product-search/en?pv1291=862&FV=fff40027%2Cfff800dd&k=LME49720&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25

 

[Chris J]

I believe a bit back someone state the LME49720 is the same as the LME49710. They can be had for a lot less.

The LM49710 is a single Op Amp.

The LM49720 is a dual Op Amp.

The LM49720 is the same Op Amp as the LM4562.

 

[Redshift Rider]

To clarify further:
 
----LM4562, LME49720NA,LME49860NA are duals, "plastic" opamps. 
http://www.head-fi.org/t/521972/lm4562-lme49720-lme49860-do-they-sound-different-to-you
LM4562 and LME49720NA sound the same to me. Haven't heard LME49860NA.
----Single version of these is LME49710NA, also "plastic" opamp. Haven't heard them. No idea if they sound different than the plastic dual versions.
 
----LME49720HA is a dual "metal can" opamp and it sounds different than the plastic dual versions. 
----Single version of LME49720HA is LME49710HA. They sound different according to other people when used in various different applications. I will know for myself as i ordered another 2xLME49710HA+Adaptor to use and compare in the soundcard and also compare them in m-stage.

 

[Shini44]

so LT1364 vs  LM4562, what do you guys think?

so far i heard only one person saying that LT is almost the same yet slightly better Treble & Bass

 

[elwappo99]

 

I believe a bit back someone state the LME49720 is the same as the LME49710. They can be had for a lot less.

The LM49710 is a single Op Amp.

The LM49720 is a dual Op Amp.

The LM49720 is the same Op Amp as the LM4562.

 
Oops! Yeah, I was in a rush when I wrote that and didn't explain it well. The ebay listing was for two SOIC type onto a single DIP adapter. It seems easier to just grab one dual channel LM49720 and toss that in. Plus, if you're a student you can get free ones 

 
I'm not super well versed in opamp theory, but I don't think there should be any difference between getting a single LM49720  vs having two LM49710  on an adapter.