Does Op-amp Rolling Work?

[evanft]

Ron is Danny Richie's former video producer and the audiophool sidekick who got him into the utter foolishness of op-amp rolling -- IMO that alone should make one take anything he presents with a boulder size chunk of good old NaCl. The fact that he's also buddied up with Randy, the "cheapaudioman" and a literal comedian, simply confirms his subterranean level of credibility.

You mean the dude that sells his crossover kits that supposedly make massive differences in sound? Lmao well I'm definitely trusting everything this guy says.

 

[amirm]

You mean the dude that sells his crossover kits that supposedly make massive differences in sound?

Same. He measures the pre/post crossover measurements which make a large audible difference. But he never listens to the speaker (pre or post mod). But somehow, when it comes to inaudible differences like cables, cable lifters, op amp changes, he thinks measurements are useless and both eyes and ears need to be used to judge the fidelity....

 

[solderdude]

This might prove to be helpful as there is a sound comparison for the OP-amps He picked.

Waiting for the usual suspects to analyze the short clips (too short for Deltawave ?)

 

[pma]

Waiting for the usual suspects to analyze the short clips (too short for Deltawave ?)

No, but the whole video is so much utterly stupid and the time is precious. I hate that video culture that wants for you to spend your 15 - 60 minutes in something where you need 5 seconds to make it clear! I hate it and I do not watch any kind of these videos, including ASR videos.

But OK. Here you go. From the first music sample in that video, part #1 x #3. I did not bother to listen to that guy, I do not know what he tested, I just recorded it and then cut all his stupid comments. The files are manipulated or he is as incompetent as being unable to create a proper ADC recording. Below your DW.

Edit: I did the test with music samples when swapping op-amps in the preamp, several times, properly level matched and time aligned. The differences are far below -100dBr and linearity is 20bit or better. I do not know why to spend time with charlatans.

 

[RickS]

He is producing all of his videos. He was hosting him on his channel for a while but then spun off. But Ron remained as the video producer.

Not too surprisingly NRD exceeds GR's YouTube subscribers. May explain why Danny has hinted that he wants to do more reviews too. 

Appears Ron produces the videos and so no coincidence they both released op amp rolling and speaker placement content at about the same time.

 

[solderdude]

the whole video is so much utterly stupid and the time is precious. I hate that video culture that wants for you to spend your 15 - 60 minutes in something where you need 5 seconds to make it clear! I hate it and I do not watch any kind of these videos

Exactly the reason I did not go through any trouble. (watching the nonsense videos)

Fortunately the time can be cut in half by doubling the speed but music samples will sound utterly crap.

It seems as though there were no level differences/manipulations as opposed to our friend Danny who clearly rigged his video.
I got the impression the recordings were all done using a microphone in front of a speaker (which could easily be a fixed position) with only the op-amps changed.
Of course... placebo will do its job here too as one is told which op-amp is in the amp.

 

[andymok]

Wish we could see the step response

 

[Earwax]

When I post my last video on review of Douk A5 amplifier, I mentioned that rolling (changing) op-amp ICs in there is fruitless. I got have a dozen comments under that video in youtube asking why so I thought I experiment again with the A5. Note that I have done the same testing with both DACs and Power Amplifiers and found the change to not make a difference. But let's see if the results are different this time.

View attachment 436787
The Douk A5 makes this job both easy and hard. It is easy because you can just lift the plexiglass and replace the op-amps. The difficulty was replacing the standard TI NE5532P opamp with the discrete Sonic Imagery Labs as it was too larger to fit in there. I pushed the adjacent caps more than I was comfortable with to get it to fit. Fortunately it worked.

There is a massive cost difference with the stock NE5532P costing US 57 cents in single quantity compared to minimum of $49 I found for the Sonic Imagery 994Enh-Ticha dual opamp. You would need two of them for stereo operation which would represent a premium that matches that of the amplifier itself! Here is a close up shot the 994Enh-Ticha:

As you see in the above picture, i decided to replace the right channel (Ch 2 below) and left left channel (Ch 1) the same. That way we can compare the two channels simultaneously under the same environmental situation. Amplifiers are temperature sensitive and shutting down to replace the opamp and powering back up would have created another variable. Alas, there is also channel to channel variations so the testing is not 100% exact but very close as you see below.

Opamp Rolling Measurements
Here is our usual dashboard:

View attachment 436792
As we see the performance is the same with SINAD which sums noise and distortion. This is of course at one power level so let's sweep the input voltage and measure at all power levels up to clipping:
View attachment 436793
There is the tiniest gap between the two but that may just be variations between channels. Even if it weren't so, it is a miniscule difference.

Maybe the differences becomes more visible if we use other frequencies than 1 kHz represented above:
View attachment 436795

I have zoomed into this graph to make differences larger. Dashed line is the Sonic Imagery discrete op-amp. We see that both at 15 kHz and at less than 500 Hz, the discrete amplifier is actually worse! But again, that could be variations between channels.

I wanted to investigate that a bit more so ran a couple of FFTs at both 100 Hz and 1 kHz:
View attachment 436797




View attachment 436798
The profile of distortion changes but not the high-order message that any difference is relegated to high order harmonics that are at or below threshold of hearing.

Discussion And Conclusions
It is natural to assume that the much more expensive, larger and fancier hand-made opamp IC would do better. All is not as it seems. An integrated circuit (IC) benefits from high precision components and even components that cannot be instantiated using discrete parts. Path lengths are also shorter allowing for better optimization of the design. Mass production using automated systems follows up by sharply reducing its cost.

On the other hand ICs can be subject to thermal coupling where rise in temperature in one part of the IC can negatively impact the performance of the rest of the IC. This doesn't apply here because the opamp is used at the front-end of the amplifier that is not attempting to produce power (only acts as a buffer and/or gain stage). Importantly, there is feedback that is used to correct the non-linearities in the op-amp. This correction highly linearizes both discrete and integrated op-amps as to almost erase any signature of the original part. This is why we don't see much difference in measurements.

People report improvements in sound and with it justify the upgrade. As members of this forum well know, such listening tests are improper. Testing must be controlled to exclude all extraneous (non audible) factors. When done, the measurements powerfully predict no audible difference. Indeed, I only know of one research paper that dug into sonic differences in op-amps and that only happened when the opamp was vastly overdriven.

Finally, I am not saying that all opamps are the same. There are countless ones for a reason. But unless you have instrumentation such as I am using, you have no prayer of knowing if a change improves anything. Or worse yet, made things worse. Here are the results form the DAC test:

There we do see a bit of differentiation but not enough to bother with any of this.

Net, net, leave the engineering to well, engineers! But a performant audio product and use it as is. Don't risk damaging and spend money on something that has essentially no chance of doing you any good.

Video version available as well:

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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Stellar insight knowing facts is crucial these days before spending hard earned money.

This review is also insightful with audible comparison but no factual data like Amirm's pointing out not all op amps are created with same design specs.
Probably good idea to research exactly what op amps do to the frequency passing through them then investigate your op amp comparisons.

 

[Scrivs]

I'm definitely not watching any of the above garbage. I'd rather spend the time doing almost anything else.

That cringe takes a while to rinse away.

 

[DACsNoMore]

Almost all documented tests are done with single frequency or frequency sweep. But it is the easiest for circuit and opamp to handle.

I think things go different when you play real music that contains a lot of frequencies at once.

For example: MUSES opamps - the manufacturer claims - do not look at the specs (nothing to write home about), but you need to listen to real music to make a conclusion.

So how one can quantify a test for opamp with real music? Possibly test that compares rendered output samples with the original, spectral analysis? If you have an answer - you could potentially put an end to all of these endless discussions.

 

[BDWoody]

For example: MUSES opamps - the manufacturer claims - do not look at the specs (nothing to write home about), but you need to listen to real music to make a conclusion.

Huh...Imagine that. They want you to just go buy it, not try to understand when it might be useful. Sounds pretty much like standard fare in the high end audio community.

Do you have a background in electronics or electrical engineering?

 

[Geert]

So how one can quantify a test for opamp with real music? Possibly test that compares rendered output samples with the original, spectral analysis? If you have an answer - you could potentially put an end to all of these endless discussions.

That has been discussed in this thread and the related master thread https://audiosciencereview.com/foru...any-confused-master-thread.61010/post-2256982:

• Do a controlled listening test (level matched and so on, see Audio Blind Testing - You Are Doing It Wrong!).
• Do a null test, which includes the spectral analysis you suggested. (Examples using DeltaWave in the master thread)

 

[T&T]

Almost all documented tests are done with single frequency or frequency sweep. But it is the easiest for circuit and opamp to handle.

I think things go different when you play real music that contains a lot of frequencies at once.

For example: MUSES opamps - the manufacturer claims - do not look at the specs (nothing to write home about), but you need to listen to real music to make a conclusion.

So how one can quantify a test for opamp with real music? Possibly test that compares rendered output samples with the original, spectral analysis? If you have an answer - you could potentially put an end to all of these endless discussions.

The only way to do it playing music is using analyzer spectrum app and recording the peak in all the frequencies, using different opamps and the same music...and believe is different

 

[oleg87]

Almost all documented tests are done with single frequency or frequency sweep. But it is the easiest for circuit and opamp to handle.

I think things go different when you play real music that contains a lot of frequencies at once.

For example: MUSES opamps - the manufacturer claims - do not look at the specs (nothing to write home about), but you need to listen to real music to make a conclusion.

So how one can quantify a test for opamp with real music? Possibly test that compares rendered output samples with the original, spectral analysis? If you have an answer - you could potentially put an end to all of these endless discussions.

This nonsense again…

 

[MAB]

Almost all documented tests are done with single frequency or frequency sweep. But it is the easiest for circuit and opamp to handle.

You seemed to miss the multi-tone and IMD tests in the reviews here, which use multiple tones, which is why they are called multitone tests. You may want to upgrade your reading comprehension.

Also, single-frequency and sweeps are more difficult on a circuit, and results are more audible since not masked. So might have other work to do on your comprehension.

Also, AP platform allows any test signal to be used, including music. The problem is using music makes quantification of things like distortion difficult. But you can for comparison purposes. And of course there is DeltaWave, written by a member here, that allows you to do what you just claimed isn't done at ASR, by yourself, all on your own, for free!

You are 0 for 3 on your attempted gotchas.

So actually, this is one of the few forums where the tools to do just what you claim isn't done are used. Exactly the opposite of every claim packed into your two short sentences. You are exemplar of irony.

 

[oleg87]

You seemed to miss the multi-tone and IMD tests in the reviews here, which use multiple tones, which is why they are called multitone tests. You may want to upgrade your reading comprehension.

Also, single-frequency and sweeps are more difficult on a circuit, and results are more audible since not masked. So might have other work to do on your comprehension.

Also, AP platform allows any test signal to be used, including music. The problem is using music makes quantification of things like distortion difficult. But you can for comparison purposes. And of course there is DeltaWave, written by a member here, that allows you to do what you just claimed isn't done at ASR, by yourself, all on your own, for free!

Worth noting that some kind people here have put together comparisons by recording the output of various devices playing music.
Needless to say, it's not going to put these discussions to bed, because if you are intent on believing in magic, you'll just move the goalposts.

This mental image of an amp struggling to juggle the complexity of music just bears no relationship to reality. An amp or an opamp, at any given point, has exactly one voltage and current value at its output. If there is non-linearity in its transfer function, multiple frequencies will intermodulate, but the cause is the same as THD measurements - nonlinearity.

 

[Earwax]

None technical question :/

Is it not possible to have the same affect using an EQ or Parametric EQ ?

Considering the amp was designed perfectly neutral.

 

[NTK]

Almost all documented tests are done with single frequency or frequency sweep. But it is the easiest for circuit and opamp to handle.

I will quote Doug Self once again.

The Dan Rather Approved Douglas Self Site

"Sinewaves are steady-state signals that represent too easy a test for amplifiers, compared with the complexities of music."​

This is presumably meant to imply that sinewaves are in some way particularly easy for an amplifier to deal with, the implication being that anyone using a THD analyser must be hopelessly naive. Since sines and cosines have an unending series of non-zero differentials, "steady" hardly comes into it. I know of no evidence that sinewaves of randomly varying amplitude (for example) would provide a more searching test of amplifier competence.​

I believe this outlook is the result of anthropomorphic thinking about amplifiers; treating them as though they think about what they amplify. Twenty sinewaves of different frequencies may be conceptually complex to us, and the output of a symphony orchestra much more so, but to an amplifier both composite signals resolve to a single instantaneous voltage that must be increased in amplitude and presented at low impedance. The rate of change of this voltage has a maximum set by the frequency response and amplitude capability of the channel and is not generally greater for more complex signals; you do not get higher slew rate with bigger orchestras. You must remember that an amplifier has no perspective on the signal arriving at its input, but literally takes it as it comes.​

​

 

[Mnyb]

None technical question :/

Is it not possible to have the same affect using an EQ or Parametric EQ ?

Considering the amp was designed perfectly neutral.

Yes and no , in case of a ”working” op swap you leave the eq as a flat line as usually is the same and there is no actual audible difference . If you happen to swap in some op not fit for the circuit it’s mostly other effects that make it audible not always fr response alone , horrid amounts of THD and noise demands some other sfx plugin I think pkane has an app called distort one could experiment and experience with ?
Maybe a badly designed circuit could show complex non linear behavior not entirely replicable ?

 

[Mnyb]

Worth noting that some kind people here have put together comparisons by recording the output of various devices playing music.
Needless to say, it's not going to put these discussions to bed, because if you are intent on believing in magic, you'll just move the goalposts.

This mental image of an amp struggling to juggle the complexity of music just bears no relationship to reality. An amp or an opamp, at any given point, has exactly one voltage and current value at its output. If there is non-linearity in its transfer function, multiple frequencies will intermodulate, but the cause is the same as THD measurements - nonlinearity.

I will quote Doug Self once again.

The Dan Rather Approved Douglas Self Site

"Sinewaves are steady-state signals that represent too easy a test for amplifiers, compared with the complexities of music."​

This is presumably meant to imply that sinewaves are in some way particularly easy for an amplifier to deal with, the implication being that anyone using a THD analyser must be hopelessly naive. Since sines and cosines have an unending series of non-zero differentials, "steady" hardly comes into it. I know of no evidence that sinewaves of randomly varying amplitude (for example) would provide a more searching test of amplifier competence.​

I believe this outlook is the result of anthropomorphic thinking about amplifiers; treating them as though they think about what they amplify. Twenty sinewaves of different frequencies may be conceptually complex to us, and the output of a symphony orchestra much more so, but to an amplifier both composite signals resolve to a single instantaneous voltage that must be increased in amplitude and presented at low impedance. The rate of change of this voltage has a maximum set by the frequency response and amplitude capability of the channel and is not generally greater for more complex signals; you do not get higher slew rate with bigger orchestras. You must remember that an amplifier has no perspective on the signal arriving at its input, but literally takes it as it comes.​

​

You seems to basically saying the same thing the amp does not know the past or the future of the signal* it’s right now a voltage to amplify a point .

*The future could be rate of change ? But this is basically right now compared ta a piece of music