Op-amp Rolling Using Sparkos on Fosi V3 Mono

[Old_School_Brad]

Just a thought…but Amir may well be Schrödinger reincarnated as he once again opens the box to find a ‘late cat’

I thought of this..

 

[Gremlins]

With nearly 900 comments on the original youtube video, we made pretty good progress for many people who are not entrenched in such beliefs.

Yes sir

But on the other side of the road, you will have 50 believers that will write down 100 000 comments on all available forums...

Some audiophiles are active on several forums at the same time, daily

Troll farms

 

[Mnyb]

Yes sir

But on the other side of the road, you will have 50 believers that will write down 100 000 comments on all available forums...

Some audiophiles are active on several forums at the same time, daily

Troll farms

Yes but it still helps ASR comes out quite high in the Google search algorithm

 

[Jimster480]

Yes sir

But on the other side of the road, you will have 50 believers that will write down 100 000 comments on all available forums...

Some audiophiles are active on several forums at the same time, daily

Troll farms

Well yes, there are always troll farms around, but this forum doesn't have troll farms. And from what I've seen people on this forum don't even bother to post on most other forums.

 

[antcollinet]

Interesting, measurements are not affected so therefore the sound can't change. So all those people out there who "hear" differences must be wrong.

From memory the Topping E30 measured better than the Chord Dave DAC so it must sound better right? I can absolutely tell you that it does NOT sound better, not even close. I must be hearing things...

Indeed.

From engineering, physics, and psychoacoustics, as well as numerous measurements, we know that DACS (when they perform well, which most do) have no noticeable impact on the sound.

Yet on the other hand we know that our hearing is subject to perceptive bias. What we hear is impacted by what we know, what we believe, how we feel, our life experiences, what we see etc etc. No-one is immune to this if they are human - it is how we are built. In fact we would be unable to function if our senses were not filtered by our subconscious brain. Everyone is subject to this, it happens at the subconscious level, and it is not possible to avoid it - even when we are aware it is happening.

So when we see someone state that they hear differences between DACs where the engineering, science and measurements all tell us that is impossible - do we just take the statement at face value - or do we attribute it to the fact that the listener is being fooled by his (humanities) very fallible auditory system?

(all assuming - as pointed out above, what you are perceiving is not simply down to a level mismatch)

 

[Talisman]

Interesting, measurements are not affected so therefore the sound can't change. So all those people out there who "hear" differences must be wrong.

From memory the Topping E30 measured better than the Chord Dave DAC so it must sound better right? I can absolutely tell you that it does NOT sound better, not even close. I must be hearing things...

Look, we all agree here. Topping definitely doesn't "sound" better than Chord, they will simply be indistinguishable. Just like the two opamps tested.

 

[oleg87]

I must be hearing things...

Yup, almost certainly (even assuming you’ve controlled for obvious confounds like volume). If you understand what the measurements are telling you, then you understand that you are making an *extraordinary claim*. If you claim you can hear 30khz ultrasound or bench press an SUV, don’t expect anyone with a passing familarity with the limits of human physiology to take you seriously without very good evidence.

 

[DavidMcRoy]

When our senses are near the edges of their resolution, our brains are hard-wired to try to make sense of things, and we'll sometimes jump to conclusions that match our expectations...or desires. Paraphrasing Stephen Colbert's definition of "truthiness": It SEEMS like it should be true, I WANT it to be true...so it must be true.

 

[KL....]

For (closed loop) op-amp swaping, the gain is determined by the ratio of output to input voltage, isn’t it? so if only the opamp is swaped and everything else remains unchanged how can the speaker output become Unmatched?

 

[billou5767]

if we believe this graph and mesure : no more evolution need , chinise op is enough for next century

 

[pma]

For (closed loop) op-amp swaping, the gain is determined by the ratio of output to input voltage, isn’t it? so if only the opamp is swaped and everything else remains unchanged how can the speaker output become Unmatched?

This is correct in case you record electrical output and there are no lousy volume control pots in the signal path (their gain position and thus value is unstable). In case of microphone record, the levels must be always additionally matched.

 

[Bel Canto]

Indeed.

From engineering, physics, and psychoacoustics, as well as numerous measurements, we know that DACS (when they perform well, which most do) have no noticeable impact on the sound.

Yet on the other hand we know that our hearing is subject to perceptive bias. What we hear is impacted by what we know, what we believe, how we feel, our life experiences, what we see etc etc. No-one is immune to this if they are human - it is how we are built. In fact we would be unable to function if our senses were not filtered by our subconscious brain. Everyone is subject to this, it happens at the subconscious level, and it is not possible to avoid it - even when we are aware it is happening.

So when we see someone state that they hear differences between DACs where the engineering, science and measurements all tell us that is impossible - do we just take the statement at face value - or do we attribute it to the fact that the listener is being fooled by his (humanities) very fallible auditory system?

(all assuming - as pointed out above, what you are perceiving is not simply down to a level mismatch)

What Dac are you using currently?

 

[solderdude]

the gain is determined by the ratio of output to input voltage, isn’t it?

The gain of an op-amp circuit is determined by the ratio of the resistors around it (except in unity gain where there is no gain and the output is connected directly to the negative input for full signal feedback.

Swapping out (suitable for the job) op-amps the gain is determined by the resistors. The noise can be determined by the resistors around it, the bandwidth is determined by op-amp properties and gain and often also by compensation or frequency limiting components around the op-amp (low/high/band pass).
Also distortion, max. output voltage swing, load capabilities are all determined by the used op-amp.

Whether or not this reaches audible levels (it will certainly be measurable) thus largely depends on the components around the opamp (the circuit it is in) and how it is applied.

Other factors can be power supply and power supply decoupling (capacitors close to the power pins) as well as PCB layout (how the 'wires' on the PCB are routed)

 

[pma]

In case of usually used gain 1x - 20x for op-amps within audio circuits, OLG gain of normally used opamps (DC 100-130dB, 60-80dB at 1kHz), closed loop gain of the amp makes no difference after op-amp swapping.

I find all this and similar discussions with laymen audience to be pointless. Those who know they do know and those who do not will get almost nothing from short explanations. They need to learn and the forum is not a source.

The posts like that of Frans are rather a discussion between knowledgeable members. And they do not need to persuade each other that they do know.

 

[DanielT]

This opamp theme is boring.

View attachment 441385

Maybe, in a way for us who know with a fairly high probability what the results will be, it can be seen that way. Even though I think it's good that Amir occasionally verifies it with objective tests. Not every week but like, a few times a year. That's to keep the discussion going. This is where I think Amir's intention lies. Amir's target group for these tests are "much better sound with op amp swapping" believers. Get them started on discussions and get them to think and, in the best case, question nonsense imaginary ideas as they take part in Amir's results and conclusions. Plus, the "believers" can take advantage of what everyone else writes and explains when they argue for the rather pointless nature of op amp swapping in this and similar threads.

I'm speculating about Amir's motives. He can of course answer that himself if he feels like it.

 

[SIY]

I find all this and similar discussions with laymen audience to be pointless.

I'll continue staring at the ground and drooling.

 

[solderdude]

I find all this and similar discussions with laymen audience to be pointless.

Isn't the idea of forums like this to educate laymen so they can learn from experienced (technical) people ?
If so ... what is pointless about the discussion ?
The forum and most of the discussions here are not for 'technical guys with deep knowledge' (like you amongst a few) but for others to learn and be educated by the more knowledgeable people.
And even knowledgeable people sometimes can't even fully agree on certain things, especially when perception is involved.

ASR visitors that want to learn about certain aspects can find more valuable info here from 'experienced techy guys' on ASR than on 'more subjective' sites.

 

[Sokel]

In case of usually used gain 1x - 20x for op-amps within audio circuits, OLG gain of normally used opamps (DC 100-130dB, 60-80dB at 1kHz), closed loop gain of the amp makes no difference after op-amp swapping.

I find all this and similar discussions with laymen audience to be pointless. Those who know they do know and those who do not will get almost nothing from short explanations. They need to learn and the forum is not a source.

The posts like that of Frans are rather a discussion between knowledgeable members. And they do not need to persuade each other that they do know.

Explanations may be pointless to the ones who don't know, agreed.
Conclusions though are very, VERY useful for the ones who will bite from the marketing all over and decide to try their luck.

That's where the members like you who know stuff are valuable. Just tell them not to do it and to trust the engineers who already chose the suitable one for the circuit.

 

[Multicore]

In this second assessment of opamp rolling, I tried to address some of the criticism of the last test as you see below. Hopefully it completes a picture as this is the forth or fifth such testing.

It does so admirably and I expect this controversy will soon be settled.

 

[pma]

Isn't the idea of forums like this to educate laymen so they can learn from experienced (technical) people ?

In case of feedback theory and op-amps, I strongly doubt it. For those interested in more than two sentences of simple explanations:

https://web.mit.edu/6.101/www/reference/op_amps_everyone.pdf

(From MIT web library)