Op Amp selection for audio......
Sept 18, 2006 19:29:35 GMT
Post by rickcr42 on Sept 18, 2006 19:29:35 GMT
Not about which sounds better with what but what to choose deoending on end use so without any more blathering............
1-Performing musician : Texas Instruments TL072CP,National Semiconductor LF357 and the generics of.
This is not only all the Op Amp you will ever need but in fact using a so called better Op Amp can actually be detrimental by the very nature of how and why it is superior.We are not talking about "reproducing" music but CREATING music here so any harmonics are part of the actual performance and in this case the harmonics of the part suit guitar work disturbingly well even though the part is totally lacking for hi-res hi-fidelity home playback system use.Wed on't need or want 20hz to 20,khz response and lightening fast but medium slow and good sonics in the relevant frequencies while being stable enough that even a piss poor layout will usually get you a working device unlike the new chips that require careful consideration or the will oscillate and even when they don't will sound far too clean for guitar work
Live perfrmance/studio recording : Burr-Brown OPA604/OPA624
The workhorse Op-Amp of the pro.Stable,fairly tame in use,easy to implement,can drive a 600 ohm output tranformer with good power,hard to beat unless you step up in class to a fully discrete Op Amp module like the JT-990 (or the forsell FET version )
again we are not even thinking about music playback but music creation so the "sound" is no more than part of the performance.what we need is a well behaved opamp that can handle high levels and drive the shit out of any rational load-the 604 does this well as would the next Op Amp (though would break the bank in the quanities used for studio gear)
Home Audio : Burr-Brown OPA627 for unity gain up to X10/OPA637 X10 gain and up
Yes there are a bazillion options and yes taste has a lot to do with selection but this part will never sound BAD so if there is a single Op Amp that can be considered "universal for home audio use" this is the ticket.
again we have not so fast it is jittery in use though slow it is not but one thing this chip does have over the above choices is great performance in a PLAYBACK system and that is the major difference between this category and the above two.
The job of the home system meant for musical enjoyment is the electronics need to get out of the way and let through the performance with minimal damge to the signal whereas in the other two categories the parts are PART of the performance so any veering away from dead nuetral meaningless since there is no nuetral until there is a recording !
ANY sounds become part of the whole in both studio and PA work and will be EQeed anyway so parts "sonics" have less import than reliable parts with no "gotchas" in the use of.The end user is trying to REPRODUCE and not PRODUCE so requirements for both parts and design not even in the same part of the audio booklet
Public Service announcement #2 for September 18,2006
more than enough for mere mortals to take in on a single day
1-Performing musician : Texas Instruments TL072CP,National Semiconductor LF357 and the generics of.
This is not only all the Op Amp you will ever need but in fact using a so called better Op Amp can actually be detrimental by the very nature of how and why it is superior.We are not talking about "reproducing" music but CREATING music here so any harmonics are part of the actual performance and in this case the harmonics of the part suit guitar work disturbingly well even though the part is totally lacking for hi-res hi-fidelity home playback system use.Wed on't need or want 20hz to 20,khz response and lightening fast but medium slow and good sonics in the relevant frequencies while being stable enough that even a piss poor layout will usually get you a working device unlike the new chips that require careful consideration or the will oscillate and even when they don't will sound far too clean for guitar work
Live perfrmance/studio recording : Burr-Brown OPA604/OPA624
The workhorse Op-Amp of the pro.Stable,fairly tame in use,easy to implement,can drive a 600 ohm output tranformer with good power,hard to beat unless you step up in class to a fully discrete Op Amp module like the JT-990 (or the forsell FET version )
again we are not even thinking about music playback but music creation so the "sound" is no more than part of the performance.what we need is a well behaved opamp that can handle high levels and drive the shit out of any rational load-the 604 does this well as would the next Op Amp (though would break the bank in the quanities used for studio gear)
Home Audio : Burr-Brown OPA627 for unity gain up to X10/OPA637 X10 gain and up
Yes there are a bazillion options and yes taste has a lot to do with selection but this part will never sound BAD so if there is a single Op Amp that can be considered "universal for home audio use" this is the ticket.
again we have not so fast it is jittery in use though slow it is not but one thing this chip does have over the above choices is great performance in a PLAYBACK system and that is the major difference between this category and the above two.
The job of the home system meant for musical enjoyment is the electronics need to get out of the way and let through the performance with minimal damge to the signal whereas in the other two categories the parts are PART of the performance so any veering away from dead nuetral meaningless since there is no nuetral until there is a recording !
ANY sounds become part of the whole in both studio and PA work and will be EQeed anyway so parts "sonics" have less import than reliable parts with no "gotchas" in the use of.The end user is trying to REPRODUCE and not PRODUCE so requirements for both parts and design not even in the same part of the audio booklet
Public Service announcement #2 for September 18,2006
more than enough for mere mortals to take in on a single day