"Boutique" opamps from chinese vendors. Anyone tested?

[inkster]

While SMD does make a difference due to lower inductance/capacitance at RF frequencies, I have absolutely no clue as to how you think that would make a difference at audio frequencies. Again, can you provide any non-anecdotal evidence of what you are saying? Or are we again back to quoting Goethe like the other posters who claim that ICs have "bad sound"?

I've heard it, as have others including very experienced recording engineers during blind tests...I used to be a skeptic.
That's why I purchased some of the cheap Chinese discrete opamps but the ones I got were a disappointment to say the least.
The ones I'm using are not currently available to buy but are special ordered from a well known US designer...hopefully they will be available soon but they are so busy with other clients and don't really see the need to market them...so the best option for people out there is sparkos.

 

[Ricardus]

Sounds like BS to me.

 

[user 37518]

I've heard it, as have others including very experienced recording engineers during blind tests...I used to be a skeptic.
That's why I purchased some of the cheap Chinese discrete opamps but the ones I got were a disappointment to say the least.
The ones I'm using are not currently available to buy but are special ordered from a well known US designer...hopefully they will be available soon but they are so busy with other clients and don't really see the need to market them...so the best option for people out there is sparkos.

Right... it is the good old quasi scientific argument backed up by BS .

Quasi-scientific:

there's a clarity I can only attribute to reduced stray inductance and capacitance as well as tight tolerances associated with smd components.

BS:

I've heard it

As one studio engineer said to me "it's like you removed the walls and ceiling"

 

[gyraf]

Agree - this is all a reiteration of the old hifi-game "my stuff sounds better than yours because I have esoteric insights into how parts really work", then very-detailed quoting some mundane mechanism that actually could explain some difference, just not one significant for the topic in question. Recent years more and more often backed by anecdotic evidence (.."I've heard about a blind test..")

e.g. skin effect in power cables - yes, but really?

This all feels like trying to apply another modernized layer of smoke screen around audio electronics, setting my teeth on edge

/Jakob E.

 

[Newmarket]

Is it now? Nothing new since 1950 then?

Why take 1950 as a reference point ? In 2023

 

[thor.zmt]

Why take 1950 as a reference point ? In 2023

Because by 1950 it was considered that "Audio is a mature technology". Were they wrong?

Thor

 

[Newmarket]

Because by 1950 it was considered that "Audio is a mature technology". Were they wrong?

Thor

Considered by whom ?

 

[thor.zmt]

e.g. skin effect in power cables - yes, but really?

Now here is the rub, just because the advertising and "scientific reasoning" (or rather lack thereof) for main cables is chemically pure bovine excrement, does not mean that in a system in which multiple mains powered devices are interconnected, mains cables are incapable to make either measurable or audible differences.

Naturally, all we need to be concerned with here is very limited and basic electronic and circuit theory, but it is often overlooked.

I remember discussing this with a gent from Oz at a hifi show, where he was very dismissive about the "special mains cables" the UK distributor had put on his gear and how it was "BS".

Then I asked him how he had handled mains earth, pin 1 and chassis and after his answer I drew him out the respective network and indicated where RLC values of mains cables would make their impact felt.

Thor

 

[thor.zmt]

Considered by whom ?

By the same kind of people who make these pronouncements nowadays, with as much reality.

Thor

 

[Newmarket]

By the same kind of people who make these pronouncements nowadays, with as much reality.

Thor

Easier to just say you don't have a real answer tbh

 

[thor.zmt]

Easier to just say you don't have a real answer tbh

At any point in the last 70 Years or so, there were people who asserted that Audio was a mature technology with nothing more important to discover. Until something was discovered.

I have read statements like this in 1960's books, I heard them in 80's, then came digital. In the 90's we were back to "mature".

Now we are getting mems and other tech like very high speed, digital input class D amplification or fully digital sound producing arrays of micro transducers as well MEMS microphones that are used in arrays, that again have the potential to radically change audio.

I might agree that analogue, linear audio has probably matured to a point where most relevant things are understood and documented, however looking at real world designs we see, few designers seem to have gotten these memos.

Thor

 

[abbey road d enfer]

I remember discussing this with a gent from Oz at a hifi show, where he was very dismissive about the "special mains cables" the UK distributor had put on his gear and how it was "BS".

Then I asked him how he had handled mains earth, pin 1 and chassis and after his answer I drew him out the respective network and indicated where RLC values of mains cables would make their impact felt.

If mains cables make a difference, it means that there is a flaw in the design.
Unfortunately, HiFi is an ecosystem where design is often flawed, starting with unbalanced connections.

 

[thor.zmt]

If mains cables make a difference, it means that there is a flaw in the design.

Then almost every mains powered product is flawed by design. Not just hifi, but also Pro-Audio. Inclusing AP2 incidentally.

Or we can acknowledge the problem and deal with parasitics and electrical safety regulations and adjust the we make our designs.

And it is exactly that dismissive attitude "If mains cables make a difference, it means that there is a flaw in the design." together with "naturally my designs are not flawed so mains cables make no difference and I already know this, so there is no need to test" that perpetuates this bad design all across the industry.

Thor

 

[abbey road d enfer]

Then almost every mains powered product is flawed by design. Not just hifi, but also Pro-Audio. Inclusing AP2 incidentally.

Well, everything in the world is flawed. Our job is to make these flaws as imperceptible as can be.

Or we can acknowledge the problem and deal with parasitics and electrical safety regulations and adjust the we make our designs.

I fully agree that safety regulations are often contradictory with good performance.

And it is exactly that dismissive attitude "If mains cables make a difference, it means that there is a flaw in the design." together with "naturally my designs are not flawed so mains cables make no difference and I already know this, so there is no need to test" that perpetuates this bad design all across the industry.

It probably makes a difference if one lives near the district xfmr or at the end of the distro line. I don't think the influence of a 6 ft mains cable makes so much difference.
Except for big power amps, where the cable resistance has a measurable effect, I never observed a significant difference between mains cables.
Some claim there is a difference if the cable goes down from the wall socket to the amp or up. Same for speaker cables.

 

[Newmarket]

At any point in the last 70 Years or so, there were people who asserted that Audio was a mature technology with nothing more important to discover. Until something was discovered.

I have read statements like this in 1960's books, I heard them in 80's, then came digital. In the 90's we were back to "mature".

Now we are getting mems and other tech like very high speed, digital input class D amplification or fully digital sound producing arrays of micro transducers as well MEMS microphones that are used in arrays, that again have the potential to radically change audio.

I might agree that analogue, linear audio has probably matured to a point where most relevant things are understood and documented, however looking at real world designs we see, few designers seem to have gotten these memos.

Thor

afaik no one is saying that there is no further work to do or being done. It's a matter of scale.
And how the industry turns out is hard to predict. eg If I think about the late 80s/early 90s from a domestic hi fi viewpoint - there was a trend of thinking where by now we'd all be listening to planar speakers powered by class D amplification. There is some of that of course. But the dominant trend is listening on 'phones/buds to streaming services on mobile devices.

Going back to who said what. Well I'd say that those saying / writing those things in eg 60s / 70s or actually believing the "Perfect Sound" hype of early 14 Bit CDs and players were often not knowledgeable about audio or just plain wrong.

The transducer thing - both mics and speakers - is interesting. And leads us into the 'real' aspect of sound propagation in air. And so to acoustics.
Worth considering the emphasis on environmental acoustics in studio environments in contrast to typical domestic settings.

 

[thor.zmt]

It probably makes a difference if one lives near the district xfmr or at the end of the distro line. I don't think the influence of a 6 ft mains cable makes so much difference.

Why not?

What is the impedance of a 6' mains cable, specifically the earth?

What are the fault currents (level, frequency etc) flowing in the network of multiple mains powered devices plugged into mains via multiple 6' mains cables and via line level audio interconnects?

What are the resultant error voltages appearing to the common mode (balanced connections) or differential mode inputs of the various devices in the system as a result?

Except for big power amps, where the cable resistance has a measurable effect, I never observed a significant difference between mains cables.

Did you ever look at a whole complex system? Not cable and one powered device and assuming that actual power delivery is at issue?

Some claim there is a difference if the cable goes down from the wall socket to the amp or up. Same for speaker cables.

Some claim 6' cables cannot make a difference - same thing really, claims devoid of rigorous analysis and lacking any proof of the claim.

Thor

 

[Newmarket]

If you're reacting to my post, it is my belief and experience as a professional studio tech that through hole circuits when compared directly to identical discrete smd circuits often lack detail and imaging among other desirable traits...that said I'm still a big fan of Neve, API and other classic circuits, but even those can benefit from nice smd equivalents.
In those consoles I typically only use smd versions in the center section(control monitoring) depending on the client's needs.
As one studio engineer said to me "it's like you removed the walls and ceiling", I took that as a compliment.

Yes. It was intended as a reply to your post.
Interesting observations and comment. I see others have commented on various points so I won't go over those.
What I was thinking is about pcb fabrication / layout / layer stack etc.
ime pro level 'big board' mixers typically had Double Sided PTH pcbs.
Now it's more usual to have (at least) a four layer pcb with inner 0V / Power Copper layers or pours. Coupled with SMT packages this can result in a pcb assembly that has much more integral 0V / Power routing with the technical advantages that can bring with proper implementation.
eg screening / guarding (reducing crosstalk) and reduced loop area (stability / decoupling / rf susceptibility) and such like.

 

[thor.zmt]

Going back to who said what. Well I'd say that those saying / writing those things in eg 60s / 70s or actually believing the "Perfect Sound" hype of early 14 Bit CDs and players were often not knowledgeable about audio or just plain wrong.

Nope, they just looked at numbers and considered that the numbers were much better than those for "analog" systems.

What they missed (and many mss even miss today) that whole lot of terminology was changed and redefined.

We went from "0dBVU" which for LP is 14dB below agreed limits (5cm/S vs 25cm/S) with both cutters and pickups having headroom past this to "0dBFS".

Now some people missed that "96dB dynamic range" is actually a bit misleading.

With 65k values, we can only use 32k values per polarity, so a "16 Bit Audio System" is actually a signed 15 Bit Audio system. So it actually cannot do 96dB, only 90dB.

By no longer referring to an arbitrary reference level significantly below the allowable maximum, the SNR was inflated.

Once we actually normalise all of this we find that if we define SNR like LP, CD only manages 76dB. This is still greater than any analog system, but by a lot less than it appeared or rather was made to appear.

Worth considering the emphasis on environmental acoustics in studio environments in contrast to typical domestic settings.

Turning a living space into an acoustically treated room is expensive and is usually not conductive to a comfortable living environment.

Logic (which seems mostly absent in audio) would suggest that one should design speakers such that can be easily placed in normal living environments, preferably visually blending in and having a directivity, frequency response etc. conductive to offering high quality audio without the requirement for acoustic treatment etc.
It is not even that hard to do.

Siegfried Linkwitz did a fair bit of work in this area - something for which I'm even willing to forgive him for his part in foisting this absurd and unnecessary even order crossover onto the world, where a 3rd order butterworth would have been a MUCH better choice for MOST applications and an "infinite slope" (elliptic) type where a 3rd order Butterworth is not.

Still, most speakers are made literally "CONTRA LEX NATUREM", so we fight to make an inappropriately designed speaker by taking a perfectly appropriate living and listening environment and turning it into a much less appropriate one.

Thor

 

[JohnRoberts]

I covered some of these exact same topics in my old "Audio Mythology" magazine column back in the 1980s. The science has not changed since then, but the technology has, mainly making SKUs cheaper and better.

Consumers are driving this bus, and they don't care that much about audio beyond an acceptable level of performance.

JR

PS: +1 Abbey about line cords. If a different one makes an audible difference that suggests a design flaw in the SKU. I don't remember writing about funny line cords in my old magazine column because the snake oil crowd hadn't gotten that creative yet. That crowd is still with us. Next they will try to sell some new gadget to deliver higher EV mileage.

PPS: I did talk about skin effect in my old column.

 

[abbey road d enfer]

Why not?

What is the impedance of a 6' mains cable, specifically the earth?

6uH

What are the fault currents (level, frequency etc) flowing in the network of multiple mains powered devices plugged into mains via multiple 6' mains cables and via line level audio interconnects?

As you know, it depends on the conducted emission levels.

What are the resultant error voltages appearing to the common mode (balanced connections) or differential mode inputs of the various devices in the system as a result?

Same as before.

Did you ever look at a whole complex system?

Do you think a complete arena sound system is not complex enough?
That is my domain of expertise.

Some claim 6' cables cannot make a difference - same thing really, claims devoid of rigorous analysis and lacking any proof of the claim.

I maintain that a cable that shows a significant difference has a flaw. What else is there than resistance, inductance at contact quality? Maybe shielding...

 

[abbey road d enfer]

What I was thinking is about pcb fabrication / layout / layer stack etc.
ime pro level 'big board' mixers typically had Double Sided PTH pcbs.
Now it's more usual to have (at least) a four layer pcb with inner 0V / Power Copper layers or pours. Coupled with SMT packages this can result in a pcb assembly that has much more integral 0V / Power routing with the technical advantages that can bring with proper implementation.
eg screening / guarding (reducing crosstalk) and reduced loop area (stability / decoupling / rf susceptibility) and such like.

Indeed, access to cheaper fab allows the use of multipe layer PCB's. When used wisely, it has a potential for improved performance. When used without proper understanding, it can result in degraded performance. Unwise copper pours have a tendency to mix "grounds" that shouldn't be.