Above 10V/uSec there is no guarantee that the faster opamp sounds better! It is meaningless to chose the faster opamp above 10V/uSec.
I would choose all opamps above 10V/uSec with compatible specs for my project. After that measuring and finally listening test with several people on different equipment will provide best results.
I hold my hand up Sin Gun --yes I am a "bit biased " as a follower of JLH and I didn't hide it ,I wrote to EW and defended him when JLH was utterly "torn apart " by you know who --.
Of course I was "set upon " by the same person -- denigrated for even believing in JLH but that didn't change my mind one iota.
Ever the gentleman he did NOT reply in kind but posted articles backing up his stance after a whole lifetime of service to the industry.
Starting in the 80,s I built most of JLH,s designs including test gear and they performed to spec.
Of course I was "set upon " by the same person -- denigrated for even believing in JLH but that didn't change my mind one iota.
Ever the gentleman he did NOT reply in kind but posted articles backing up his stance after a whole lifetime of service to the industry.
Starting in the 80,s I built most of JLH,s designs including test gear and they performed to spec.
Yes, for music production.
When it comes to music reproduction, of course, within audible range.
Anything on the judging criteria for reproduced sound?
I had observe often the same.
If the associated test reviews show the diagrams from my post #2 one would have clearly seen why that was so.
To get such diagrams for op-amps was the actually reason to start this thread.
BTW - an excellent sounded amp from Japan was this YAMAHA model:
Yamaha's Hyperbolic Conversion Amplification (HCA) Circuit
Last edited:
The specific circuit used surrounding the Op Amp matters. Some op amps are more tolerant of low impedance and heavily capacitive loads. Some (FET input) are better in high input impedance circuits. Some are better as high impedance followers (DI FET input). Some have lower distortion, some have lower (BJT) input voltage noise. Some (FET) have lower input current noise. Some have larger GBWP or higher slew rate.
Self can be rather conceited. He seems to think he has every right to attack others but finds it hard to accept valid criticism of his own work with good grace. That is conceit I am afraid.
I designed discrete op-amp with output class A single-ended and I share it. A friend made layout pcb with smd part and he sell it. People like it very much. He sent me some for free but I have no time to tested until now.
I also design several discrete pre-amplifier. Some of them I share it.
Of course, higher slew rate not always sound good, because it is not only slew rate that matter. Monotonic harmonic profile or low order harmonic distortion dominant is preferred. And low THD at 20kHz as Bob Cordell said is good. If you never tried it you never know the sound.
But it depend of how good your other equipment, how good your listening skill and how your taste.
"low THD at 20kHz as Bob Cordell said is good."
I have always wondered---how the hell can you hear distortion at 20 KHz? Both the even and odd harmonics are well out of audibility; and even the fundamental is on the very edge of detectability for even the best ears.
I have always wondered---how the hell can you hear distortion at 20 KHz? Both the even and odd harmonics are well out of audibility; and even the fundamental is on the very edge of detectability for even the best ears.
I am only vaguely aware of some of this discussion, but could you elaborate? What exactly was the bone of contention and what were the positions of the two "camps"?
He can't hear distortion at 20KHz, in most amps the distortion is going up beyond 2-5KHz, so it's that kind of logic, I think.if you make it low distortion at 20KHz, then at 1KHz will be even lower...
True!
However, a CCIF twin-tone IMD test uses summed 19 kHz and 20 kHz tones, and we look for the F2-F1 difference at 1 kHz. (F2-F1) and (F1+F2) IM products are made by the same non-linearity as 2nd harmonics. So, 2nd harmonic at 20 kHz does matter.
What I am leaving out is that the 1 kHz IM product will also be corrected by the amplifier's feedback margin at 1 kHz. If the 2nd harmonic of a 19 kHz or 20 kHz signal is at -40 dB, and there is 40 dB of feedback margin at 1 kHz, then the IM product will be at -80 dB.
Of course there are other IM products in the audio band corresponding to the other harmonics.
- 2nd: F2-F1 -- 1kHz
- 3rd: (2xF1)-F2 -- 18kHz
- 4th: (2xF2)-(2xF1) -- 2kHz
- etc.
Harmonic distortion is simply the fundamental modulating itself. F1+F1=2nd harmonic. F1-F1=DC. Consider that 2nd harmonic distortion also produces a DC offset, and this will make sense.
Exactly the same position that exists on most audio forums and magazines ---
Subjective comment on scientific data as regards whether a human being who is composed of up to 60 % water -has feelings -emotions -moods- effected by their brain function and connectivity via their auditory nervous system as to their personal mental judgement on -----Music .
On the other hand this is mostly discounted by those who put facts -- figures and science before a thought of "what/who " is listening to it.
In other words if science confirms its of a high technical standard then it should be accepted without argument .
Every person on this earth is unique with their own individual personality and will react in their own individual way to external actions directed towards them be it a punch on the jaw or music they don't like .
There are people with acute hearing and can easily spot music that "doesn't sound right " in their minds just as a guitarist can spot a string slightly wrongly adjusted its built in they don't need any electronic standard tone to make adjustments.
Who is right ?---- you take a side and stick to it because it gives you mental satisfaction to know that----YOU -- are right but in the end its only "right " for you not your next door neighbor.
Judging musical performance is one thing, judging the reproduction of that musical performance is another.
Listening to which version, live or reproduced one?
Oh--THAT discussion! The old "my ears are better than your test instruments" argument! Well, I'm a firm believer of both camps---my ears can detect things that my test gear can't measure, and my instruments can detect things my ears don't give a damn about.
Even Harmonics--- by "listening to it " I mean listening to the reproduced music through an audio chip which D.Self had much to say at the time about it including his "disbelief " in sound difference through a film capacitor in comparison to a normal electrolytic-- and he was quite "audible " in disclaiming any difference between the two .
Whether that dogma has changed in 2021 I know not but at the time it caused a big ( one -sided fight) between him and JLH .
I still have an audio magazine somewhere where JLH lists his subjective view on a whole range of capacitors.
Whether that dogma has changed in 2021 I know not but at the time it caused a big ( one -sided fight) between him and JLH .
I still have an audio magazine somewhere where JLH lists his subjective view on a whole range of capacitors.
Coming from the music production side of things I can offer several things that might be of interest.
First, the highest discernable musical note most humans can identify (meaning "that's an A8", or whatever) is generally understood to be somewhere in the 7-8K range. Above that, frequency is discerned as timbre.
Second, most young adults can only hear up to about 16K or so and it just gets lower as we age. Of course this limit is usually not a hard cutoff, but rather a situation where if enough power is applied the person can still hear higher frequencies. LOL, in the practical realm its often easy for fresh ears to detect music produced and mixed by someone with aged ears. It can tend to sound very bright to young ears while in fact sounding "right" thru aged ears...(U2's "Songs of Innocence" comes to mind, though I have no proof this is why that album is so bright...)
Third, selectively adding distortion in the 9-15K range is an age old tool in music production/restoration to "restore clarity and add brightness" to the original source. It can be quite effective when used judiciously, and plenty of free examples of such software in VST format (so call harmonic exciters) are available for those wanting to experiment in a free DAW like Audacity. But that said, those who use professional versions of such tools for musical projects can often detect its use with relative ease...particularly when used to excess.
So, detecting distortion at 20K by ear? I don't think so. But detecting by ear in the 10-15K range? Absolutely. In fact chances are you've listened to a piece of source material that has it added in as part of the mix.
With respect to caps and sound differences, much of the phenomenon is easily explained by the cap's impedance vs frequency plot. Electrolytics are usually non-linear while polys tends to be very flat. That said, its not the only factor imo, but it is one that is easily quantifiable on parts that publish a curve, and it makes sense imo.
As for subjective differences, just sub a ceramic in for a low value poly and take a listen...you'll likely become a believer real fast...jmo of course. And if I were to hazard a guess as to why? Without doing the analysis and/or research, I'd guess the ceramic has slight microphonics and a faint piezo effect where the poly does not. In fact its a very common trick for guitarists to cap their guitar and/or amp tone stack with ceramic or poly to achieve a certain sound.
So the idea that caps are relevant for music reproduction is 100% valid imo.
