There seems to be a certain religious fervour attached to the opinion of whether or not opamps sound ok for audio. I have vaccilated back and forth about whether I should use one or not, and currently in my setup the only one is inside the DVD player right after the D/A converter; some 8 pin thing made by JRC.
Anyway, what I decided to do was make an opamp buffer cct and have a changeover relay so I could listen through it or bypass it completely, and have a long wire so I could switch it from my normal listening position. I chose a Texas Instruments TLC2274 quad fet opamp simply because I had a few. Also, the distortion as a buffer is only 0.0008%. Naturally as with all stuff diy, things got out of control and before I knew it I had no less than 12 opamps wired in series as unity gain buffers in each channel.
I wired it between the DVD player and the power amp.
Well, what did it sound like??? I was expecting the worst, BTW.
Hiss - Only the tiniest, tiniest, weeniest increase in hiss.
Distortion - no obvious change.
Frequency response - no obvious change.
Overall clarity - no obvious change.
Left to right soundstage - again, no obvious change.
Front to back soundstage - aha! Instead of extending off into the distance somewhat, it only sounded as if it was about a foot deep. Not objectionable, just different.
It took me about 10 minutes of listening to actually pick this difference - it was simply not a black and white thing like some people have claimed. Also, if someone else was operating the switch I have some doubts that I would have picked the difference.
Now I know that all kinds of people may jump in and tell me this and that, and how some wonderful opamp magically improved their system, or how completely junky my system must be, but that's not what I am talking about for indeed there are good, bad and ugly opamps for sure. What I am saying to the *anti opamp brigade* is that I don't think opamps are all that bad per se. Some people just say 'all opamps are no good' and don't investigate the matter any further. The result of my experiment is - I for one can't hear what all the fuss is about. 
Anyway, what I decided to do was make an opamp buffer cct and have a changeover relay so I could listen through it or bypass it completely, and have a long wire so I could switch it from my normal listening position. I chose a Texas Instruments TLC2274 quad fet opamp simply because I had a few. Also, the distortion as a buffer is only 0.0008%. Naturally as with all stuff diy, things got out of control and before I knew it I had no less than 12 opamps wired in series as unity gain buffers in each channel.
I wired it between the DVD player and the power amp.Well, what did it sound like??? I was expecting the worst, BTW.
Hiss - Only the tiniest, tiniest, weeniest increase in hiss.
Distortion - no obvious change.
Frequency response - no obvious change.
Overall clarity - no obvious change.
Left to right soundstage - again, no obvious change.
Front to back soundstage - aha! Instead of extending off into the distance somewhat, it only sounded as if it was about a foot deep. Not objectionable, just different.
It took me about 10 minutes of listening to actually pick this difference - it was simply not a black and white thing like some people have claimed. Also, if someone else was operating the switch I have some doubts that I would have picked the difference.
Now I know that all kinds of people may jump in and tell me this and that, and how some wonderful opamp magically improved their system, or how completely junky my system must be, but that's not what I am talking about for indeed there are good, bad and ugly opamps for sure. What I am saying to the *anti opamp brigade*
is that I don't think opamps are all that bad per se. Some people just say 'all opamps are no good' and don't investigate the matter any further. The result of my experiment is - I for one can't hear what all the fuss is about. Attachments
That is an interesting experiment. I haven't done something like that, but am aware that mixing and other consoles used in producing some of those fine sounding LPs and CDs must contain also many, sometimes 100's of opamps. Of course, it's not the same, but makes one wonder why a single opamp on replay would have much more influence than say 10 or 20 on the recording side.
Jan Didden
PS Like your choice of words - like to concatenate or not is the vacillating question. (Yes, it's one c and two l's ).
Jan Didden
PS Like your choice of words - like to concatenate or not is the vacillating question. (Yes, it's one c and two l's
).
Great experiment !
Not many people realize that their beloved recorded music went through a long chain of op-amps already, in the mixing console for instance.
But it is not the op-amp by itself that makes sense but the right op-amp in the right place. The so much discussed I/V converter here on the board is one of the trickiest applications for an op-amp.
Cheers
Not many people realize that their beloved recorded music went through a long chain of op-amps already, in the mixing console for instance.
But it is not the op-amp by itself that makes sense but the right op-amp in the right place. The so much discussed I/V converter here on the board is one of the trickiest applications for an op-amp.
Cheers
Do it!!...see post in post #8 in :Circlotron said:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=13415
That's why I love double blind tests
It's a pity you hadn't placed sockets on the test boards, It would be funny idea to test more crappy things like LM324 or TL074
Tube_Dude :
The funniest thing about nulling is that you can connect the resulting signal from the substraction to an amplifier and a speaker to be actually able to *hear* the *difference*
It's a pity you hadn't placed sockets on the test boards, It would be funny idea to test more crappy things like LM324 or TL074
Tube_Dude :
The funniest thing about nulling is that you can connect the resulting signal from the substraction to an amplifier and a speaker to be actually able to *hear* the *difference*
the sound of concatenated (low-quality cheap) opamps is in every (modern at least) recording we listen every single day.
The sound of concatenated high-quality expensive opamps does not exist unless you do the recording yourself,
I have said this many times: if you take a look inside a studio mixer, you wouldn't care if you had used a 324 in your preamp.
The sound of concatenated high-quality expensive opamps does not exist unless you do the recording yourself,
I have said this many times: if you take a look inside a studio mixer, you wouldn't care if you had used a 324 in your preamp.
I had mixed feelings about Circlotron 's test...and I do not think it gives more than a single opinion on a single test.
The same op-amps in another config. would probably sound/measure different.
Try them with different gain, in a filter, with capasitive or inductive load, among muting transistors and other "artifacts", and they for certain will sound different.
Arne K
The same op-amps in another config. would probably sound/measure different.
Try them with different gain, in a filter, with capasitive or inductive load, among muting transistors and other "artifacts", and they for certain will sound different.
Arne K
SY said:
The added noise and the added distortion of each op amp...because in audio "Less is more".
A op amp can have low distortion...but in a string of of amps ,that in normal conditions, are not needed the distortions will add.
If Ciclotron do de some experience ,with a string of no feedback amps...the output wil be very diferent from the input...
Anyone want to try that experience??
PS :Because a string of amps without feedback was used as repeters in transatlantic telephone lines...at the the end the voices become unrecognizable.
For put a end to this Arnold Black that work at this time in the telephone conmpany...invent negatif feedback!!!
This is much the same argument as that of interconnects.
The recording and broadcast industries pass the signals we listen to through vast lengths, with no apparent loss.
However, I'm not going to say that interconnect and opamp quality is irrelivant. I believe many percieved differences depend on local conditions.
I have used TLO74's for over a decade as unity gain buffers. I cannot hear the difference between those and NE5532's in this application IE a well laid out PCB with quiet linear PSU, balanced audio inputs and outputs, and metal case.
Now, whether there would be a difference in a CD player, where some gain was used to use it as a Sallen-Key or Butterworth filter, and loads of digital and RF mush around, is too complex to analyse.
The recording and broadcast industries pass the signals we listen to through vast lengths, with no apparent loss.
However, I'm not going to say that interconnect and opamp quality is irrelivant. I believe many percieved differences depend on local conditions.
I have used TLO74's for over a decade as unity gain buffers. I cannot hear the difference between those and NE5532's in this application IE a well laid out PCB with quiet linear PSU, balanced audio inputs and outputs, and metal case.
Now, whether there would be a difference in a CD player, where some gain was used to use it as a Sallen-Key or Butterworth filter, and loads of digital and RF mush around, is too complex to analyse.
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