[beyerdude]

As much as i want to roll my opamps, i'm not going to anymore, for 2 reasons: getting real opamps, instead of their fake counterparts is too much of a hassle, and then getting real ones for a proper price within proper time, is almost impossible.
And my MUSE 02 has very bendy legs. Don't want to break them.
Depending on your location. If you live in europe you're in luck!

http://www.playstereo.com/product_info.php?cPath=6_55&products_id=2422

I bought mine from there. Last place not to have a ridiculous pricetag.

I would be nervous with a Muses opamp - I know the opa627 dip8 pins were pretty easy to bend and it was also a pig to remove on my old amp - was always nervous with them

 

[CH23]

To all, as promised, I have opened an build thread for opamp with adapter for E12DIY. Please refer to the thread below for detail:

http://www.head-fi.org/t/728607/opamp-adapter-for-fiio-e12diy

Right as i'm in the middle of buying a complete furniture ( ;A; )

I would be nervous with a Muses opamp - I know the opa627 dip8 pins were pretty easy to bend and it was also a pig to remove on my old amp - was always nervous with them

I'm glad it fit without having to modify my case, albeit snug.

Just going to leave it in there and not worry about it

 

[ClassicalViola]

  I just notice:
OPA627 slew rate: 55V/µs
OPA827 slew rate: 28V/µs
 
OPA827 slew rate is about half the slew rate speed of OPA627.
Still much higher than what required for audio, but there is certainly some differences there.

Just curious about this term 'slew rate' since you mentioned it.
 
So in the case of these two op amps, does the slew rate indicate that one will have an advantage/disadvantage over the other under certain circumstances (if any)? Tried searching and reading about 'slew rate' but still couldn't really find what I wanted to know. Would appreciate it if you (or anyone else who knows about this kind of stuff) could elaborate more on what you have posted as quoted above. Thanks!

 

[Loquah]

  Just curious about this term 'slew rate' since you mentioned it.
 
So in the case of these two op amps, does the slew rate indicate that one will have an advantage/disadvantage over the other under certain circumstances (if any)? Tried searching and reading about 'slew rate' but still couldn't really find what I wanted to know. Would appreciate it if you (or anyone else who knows about this kind of stuff) could elaborate more on what you have posted as quoted above. Thanks!

 
Agree!! It's really hard to find easy to understand explanations of how to read op amp data sheets.

 

[ampair]

  Just curious about this term 'slew rate' since you mentioned it.
 
So in the case of these two op amps, does the slew rate indicate that one will have an advantage/disadvantage over the other under certain circumstances (if any)? Tried searching and reading about 'slew rate' but still couldn't really find what I wanted to know. Would appreciate it if you (or anyone else who knows about this kind of stuff) could elaborate more on what you have posted as quoted above. Thanks!

 
slew rate describes the maximum steepness of the voltage ramp at the output of the opamp, means: if you perform a sudden jump in input voltage, the output cannot immediately follow this jump but ramps the voltage up until it reaches the end value.
 
in the case of opa827 in the e12diy (max output voltage is just short of 20Vpp iirc) this means that it can perform a full-range sine wave of (roughly estimated) 500khz without distortion. that is about 25 times faster than required for audio applications, so you should be on the safe side

 

[earfonia]

  Just curious about this term 'slew rate' since you mentioned it.
 
So in the case of these two op amps, does the slew rate indicate that one will have an advantage/disadvantage over the other under certain circumstances (if any)? Tried searching and reading about 'slew rate' but still couldn't really find what I wanted to know. Would appreciate it if you (or anyone else who knows about this kind of stuff) could elaborate more on what you have posted as quoted above. Thanks!

 
In simplistic analogy, slew rate can be understood as speed. How fast an amplifier output can follow voltage variation on its input. The faster the slew rate, theoretically the amp output can imitate the waveform at its input, more precise. Translate to audio quality, we can expect less waveform distortion with high slew rate amp, for more accurate tonality and dynamic.  But slew rate is not everything, there are many other factor that make up the audio quality. And for audio, theoretically we don't really need a very high slew rate.
 
Minimum theoretically required slew rate:
 
Slew Rate = 2 x π x Frequency x Peak Voltage
 
Let's assume maximum requirement for headphone amplifier, for example my Mytek 192-DSD DAC headphone output, it has a maximum of 10 volt rms output. The minimum required slew rate for that amplifier would be 1.78 V/µs to cover 20kHz frequency.
 
Let say with the high definition formats these days, we want amplifier that is linear up to 100 kHz, than we can see that 8.9 V/µs slew rate would be sufficient for most headphone amp.

 

[ClieOS]

The key is mostly not to be slew rate limited (*too slow for the job), as opposed to which one is faster, since most opamp these days are much faster than what audio required. Opamp for video, which tends to be very wide band and super fast, can be problematic too, as they are less stable on audio circuit without some kind of compensation. Basically you want something there is neither too slow or too fast, so to speak.

 

[earfonia]

  The key is mostly not to be slew rate limited (*too slow for the job), as opposed to which one is faster, since most opamp these days are much faster than what audio required. Opamp for video, which tends to be very wide band and super fast, can be problematic too, as they are less stable on audio circuit without some kind of compensation. Basically you want something there is neither too slow or too fast, so to speak.

 
That's correct!  
Ultra fast slew rate usually needs compensation that might not do good to audio quality.

 

[ClieOS]

Just a reminder to those who are interested in the E12DIY opamp build that the thread will be closed soon at 6th August (around 12am EST US). There won't be a 2nd run so please decide soon.

 

[nmatheis]

Just a reminder to those who are interested in the E12DIY opamp build that the thread will be closed soon at 6th August (around 12am EST US). There won't be a 2nd run so please decide soon.

Thanks again for offering this service to the community!

 

[hoekeat]

I am curious how you guys store your extra opamp/buffer that is not in use? I am still keeping them in the static bag that comes with it, and then placing all of them in a bigger box. But it is getting kind of unorganized now.

 

[Loquah]

  I am curious how you guys store your extra opamp/buffer that is not in use? I am still keeping them in the static bag that comes with it, and then placing all of them in a bigger box. But it is getting kind of unorganized now.

 
My op amps for the DIY (SOIC on adapters) are all stuck into the foam in the tin that came with the DIY. My full size ones are in a little snap-lock container that came with the OPA627BPs and A-Class browndogs I ordered ages ago.

 

[nmatheis]

Stuck in the foam that came with E12 DIY or in a storage "tube" some opamps I ordered case in.

 

[Chefano]

Well, Ive decided to buy another unit, meanwhile mine gets back from China.  One unit will run on OPA627 and onther one almost sure on Muses01.
 
Lets wait! 

 

[CH23]

ClieOS just got the buffers. The air instrument separation made my head spin. I am flabbergasted. Wow.

I thank you so very much. Well worth the wait/money.