Op-amp Rolling Using Sparkos on Fosi V3 Mono

[Beave]

Listen, perhaps measurements doesn't notice the change but obviously when a audio circuit is full discrete, the internal conductors , capacitors, transistors, inductors, etc has more conductivity because larger gauge and less resistance which obviously translate into better current delivery and lower output impedance even in class-D Output like in discretes Purifi or Hypex has way more power, lower output impedance than other also class-D amp but chip-based like the other way great TI TPA3255 PFFB which also sounds great but obviously has a limitation in terms of absolutely lowest output impedance (conductivity current), which translates in better dynamics with normal low sensitivity low impedance speakers. With Op-amp happens the same, discrete means more conductivity way more which translates into better dynamics with low impedance low sensitivity internal circuits around. And if that Op-amp is also real class-A like the one Australian or American brand mentioned in this page, you also have that transistors higher temperature which translates into a subjectively warmer sound like happens in absurdly big absurdly heavy absurdly high current consumption all pure class A amplifiers/tube amplifier but with just , according chatgpt, only one watt of power consumption and only 10grams more of weight.
You get the "passlabs class-A warm sound" in your efficient, small, cheap, cool at touch, low output impedance, big output power, high SINAD class-D rig which is amazing and one of best things happened to budget hi-fi and budget studio audio since transformer-volume-control line-preamps.

Surely you can't be serious.

 

[VientoB]

Listen, perhaps measurements -which are really helpful and make us to understand what's happening - doesn't draw what's happening with current and impedance, but obviously when a audio circuit is full discrete, the internal conductors , capacitors, transistors, inductors, etc has more conductivity because larger gauge and less resistance which obviously translate into better current delivery and lower output impedance even in class-D Output like in discretes Purifi or Hypex has way more power, lower output impedance than other also class-D amp but chip-based like the other way great TI TPA3255 PFFB which also sounds great but obviously has a limitation in terms of absolutely lowest output impedance (conductivity current), which translates in better dynamics with normal low sensitivity low impedance speakers. With Op-amp happens the same, discrete means more conductivity way more which translates into better dynamics with low impedance low sensitivity internal circuits around. And if that Op-amp is also real class-A like the one Australian or American brand mentioned in this page, you also have that transistors higher temperature which translates into a subjectively warmer sound like happens in absurdly big absurdly heavy absurdly high current consumption all pure class A amplifiers/tube amplifier but with just , according chatgpt, only one watt of power consumption and only 10grams more of weight.
You get the "passlabs class-A warm sound" in your efficient, small, cheap, cool at touch, low output impedance, big output power, high SINAD class-D rig which is amazing and one of best things happened to budget hi-fi and budget studio audio since transformer-volume-control line-preamps.

The measurements do not show a "warm" sound.

 

[transformer-coupled]

Surely you can't be serious.

Yes I'm serious

 

[Beave]

Yikes. You do realize that there are several electrical engineers on this forum, right? The terminology and claims you made in that post are nonsensical.

 

[transformer-coupled]

The measurements do not show a "warm" so

The measurements do not show a "warm" sound.

Warm does mean almost never a roll off in high frequency. Example: Pass ACA greatly measured here , yes with lots of distortion, has a frequency response absolutely flat till hundreds khz

 

[transformer-coupled]

Yikes. You do realize that there are several electrical engineers on this forum, right? The terminology and claims you made in that post are nonsensical.

Tell exactly which one are "nonsensical" doctor in engineering sir

 

[Beave]

Listen, perhaps measurements -which are really helpful and make us to understand what's happening - doesn't draw what's happening with current and impedance, but obviously when a audio circuit is full discrete, the internal conductors , capacitors, transistors, inductors, etc has more conductivity because larger gauge and less resistance which obviously translate into better current delivery and lower output impedance even in class-D Output like in discretes Purifi or Hypex has way more power, lower output impedance than other also class-D amp but chip-based like the other way great TI TPA3255 PFFB which also sounds great but obviously has a limitation in terms of absolutely lowest output impedance (conductivity current), which translates in better dynamics with normal low sensitivity low impedance speakers. With Op-amp happens the same, discrete means more conductivity way more which translates into better dynamics with low impedance low sensitivity internal circuits around. And if that Op-amp is also real class-A like the one Australian or American brand mentioned in this page, you also have that transistors higher temperature which translates into a subjectively warmer sound like happens in absurdly big absurdly heavy absurdly high current consumption all pure class A amplifiers/tube amplifier but with just , according chatgpt, only one watt of power consumption and only 10grams more of weight.
You get the "passlabs class-A warm sound" in your efficient, small, cheap, cool at touch, low output impedance, big output power, high SINAD class-D rig which is amazing and one of best things happened to budget hi-fi and budget studio audio since transformer-volume-control line-preamps.

This part. Yeah, the whole thing. It's practically all wrong.

 

[wwenze]

The fact that they understand that "measuring the end result" is more accurate than "measuring the components used to build the end result and predicting how the end result will perform" already shows that they are pretty competent.

also btw

lowest output impedance (conductivity current),

This itself is already wrong, so good luck with your quest in finding "nonsensical doctors". Bring a mirror.

 

[transformer-coupled]

This part. Yeah, the whole thing. It's practically all wrong.

Tell me exactly which argument is wrong and why Mr doctor in engineering

 

[transformer-coupled]

The fact that they understand that "measuring the end result" is more accurate than "measuring the components used to build the end result and predicting how the end result will perform" already shows that they are pretty competent.

also btw



This itself is already wrong, so good luck with your quest in finding "nonsensical doctors". Bring a mirror.

So are you telling me that a circuit that has a lower output impedance won't have the capability of draw more current and won't have the capability of output more current?

 

[transformer-coupled]

The fact that they understand that "measuring the end result" is more accurate than "measuring the components used to build the end result and predicting how the end result will perform" already shows that they are pretty competent.

also btw



This itself is already wrong, so good luck with your quest in finding "nonsensical doctors". Bring a mirror.

Stay with IC based opamps and be happy with the sound ;-)

 

[wwenze]

So are you telling me that a circuit that has a lower output impedance won't have the capability of draw more current and won't have the capability of output more current?

That is correct. Output impedance is a number that measures the amp's behavior, specifically the change in voltage following a change in load.

Notice that the definition does not involve max current.

And we see this in real life examples. A good headphone amp would have an output impedance of around 1ohm or less

While a tube speaker amp can have an output impedance of 2ohm to 4ohm depending on frequency.

Amplifier Output Impedance (Damping Factor) and Speakers

This is a reprint of an article written ca. 2011-2012. I've been meaning to rewrite and update it, but Life and Work keeps getting in the way, so I am reposting the original as-is. Take it for what it's worth, an introductory take on one of the potential causes for differences in sound among...

www.audiosciencereview.com

However clearly the amp with the higher output impedance is outputting way more current than the headphone amp.

 

[RandomEar]

Despite you being dismissve of other members further down the thread, I'll try to explain where you are mistaken. You seem to have a basic understanding of concepts in electric circuits, but in this post, you're randomly mixing things up and combining concepts which are just not compatible. Let's start:

Listen, perhaps measurements -which are really helpful and make us to understand what's happening - doesn't draw what's happening with current and impedance, but obviously when a audio circuit is full discrete, the internal conductors , capacitors, transistors, inductors, etc has more conductivity because larger gauge and less resistance which obviously translate into better current delivery and lower output impedance even in class-D Output like in discretes Purifi or Hypex has way more power, lower output impedance than other also class-D amp but chip-based like the other way great TI TPA3255 PFFB which also sounds great but obviously has a limitation in terms of absolutely lowest output impedance (conductivity current),

Current driving capability in modern high power semiconductor devices is almost never limited by "gauge" anymore. The devices operate at the limit of their cooling capability due to their power density. You literally cannot get the heat away from the chip fast enough anymore. The main driver of heat in semiconductor components is switching losses in transistors - something extremely relevant for class D amps.

Output impedance is a measured value which is mostly relevant because a high and/or frequency dependant output impedance would alter the frequency rersponse of your speaker drivers. Amplifier output impedance does not limit the current flow in the classic "analog" way you think. The output impedance of a 1ET6525SA module is 30 µΩ, which would allow it to provide 140 MW at 65 V - clearly, not something that is possible. Your speaker has 4 Ω, maybe 2 Ω at the lowest impedance dip. That is the limiting factor for current flow in an audio system.

which translates in better dynamics with normal low sensitivity low impedance speakers.

It does not. If the amplifier is able to provide enough power not to clip and can reproduce the audible range (typically assumed to be 20 Hz - 20 kHz, but a couple of Hz more or less are not relevant here) without a drop in its frequency response, it has all the "dynamics" it can have. The upper frequency of that range at 20 kHz contains the steepest slope the amplifier will ever have to reproduce.

With Op-amp happens the same, discrete means more conductivity way more which translates into better dynamics with low impedance low sensitivity internal circuits around.

As explained above, the output impedance of the amp itself is already not the critical value. For op amps, however, impedance is even more irrelevant. The op amp is not driving the speaker directly. It has to deliver the tiny mA-level current it is designed for in its specific circuit and that's it. Unless the amp designer majorly fucked up, the current driving ability of the op amp is never a limit for the amplifier power in its specced power and frequency range.

And if that Op-amp is also real class-A like the one Australian or American brand mentioned in this page, you also have that transistors higher temperature which translates into a subjectively warmer sound like happens in absurdly big absurdly heavy absurdly high current consumption all pure class A amplifiers/tube amplifier but with just , according chatgpt, only one watt of power consumption and only 10grams more of weight.

Things don't sound warmer because they are hotter. Do you sound orange if you eat an orange?

Semiconductor devices like transistors or op amps have fixed spec ranges, including an operating temperature range. Within that temperature range, they operate 100% within spec unless the individual device is defective. The ciruit designer of the amp used those spec ranges to select the right op amp for the application, meaning everything works as designed in the expected temperature range of the amplifier.

You get the "passlabs class-A warm sound" in your efficient, small, cheap, cool at touch, low output impedance, big output power, high SINAD class-D rig which is amazing and one of best things happened to budget hi-fi and budget studio audio since transformer-volume-control line-preamps.

There's no "class-A sound". The job of an amplifier is to amplify and do nothing else - especially not colour the sound in any way. Unless the amp is badly designed or broken, it should have no sound at all. Otherwise, it would be doing a bad job.

There's definitely tube amps which have so much distortion that they sound different. If you are looking for that, get one of those. They are fun to look at and cozy in the winter.

 

[solderdude]

Well ... that saved me a lot of typing

Burson V7 Classic, this thing converts any sterile sounding class D amplifier into a "warm tube-like sounding class D" it's amazing sound warmer actually than pass ACA real class A power amp

At ASR we just don't accept 'subjective opinions' as facts.
Please tell me what you wrote was determined in a level matched, blind and statistically relevant test and repeated by independent listening tests and accompanied with relevant measurements ... if not ... its just anecdotal.

(I know is just subjectively though, not proof)

Awwwh... right.

 

[antcollinet]

Listen, perhaps measurements -which are really helpful and make us to understand what's happening - doesn't draw what's happening with current and impedance, but obviously when a audio circuit is full discrete, the internal conductors , capacitors, transistors, inductors, etc has more conductivity because larger gauge and less resistance which obviously translate into better current delivery and lower output impedance even in class-D Output like in discretes Purifi or Hypex has way more power, lower output impedance than other also class-D amp but chip-based like the other way great TI TPA3255 PFFB which also sounds great but obviously has a limitation in terms of absolutely lowest output impedance (conductivity current), which translates in better dynamics with normal low sensitivity low impedance speakers. With Op-amp happens the same, discrete means more conductivity way more which translates into better dynamics with low impedance low sensitivity internal circuits around. And if that Op-amp is also real class-A like the one Australian or American brand mentioned in this page, you also have that transistors higher temperature which translates into a subjectively warmer sound like happens in absurdly big absurdly heavy absurdly high current consumption all pure class A amplifiers/tube amplifier but with just , according chatgpt, only one watt of power consumption and only 10grams more of weight.
You get the "passlabs class-A warm sound" in your efficient, small, cheap, cool at touch, low output impedance, big output power, high SINAD class-D rig which is amazing and one of best things happened to budget hi-fi and budget studio audio since transformer-volume-control line-preamps.

That is not how it works - not even a little bit.

Warm does mean almost never a roll off in high frequency. Example: Pass ACA greatly measured here , yes with lots of distortion, has a frequency response absolutely flat till hundreds khz

There is only noise, distortion, frequency response which can change the sound of an audio device, and we can measure them all well below the levels the human ear can detect. Tell me which of those changed.

Did the amp become noisy? Did it start horribly distorting, or did its frequency response go off the rails?

And how did you measure this?

 

[VientoB]

Warm does mean almost never a roll off in high frequency. Example: Pass ACA greatly measured here , yes with lots of distortion, has a frequency response absolutely flat till hundreds khz

Eh, what on earth...

 

[Pausi]

I just had a Sparkos SS3602 opamp go bad in my Fosi ZA3. I had put in three, one for each channel and one for the XLR input circuit. Go ahead, make fun of me! I bought them before the ASR review. After a year or so of being turned on a few hours a day and playing at low desktop volumes, the left channel started randomly popping and crackling with enough volume that I was worried about it damaging the speaker, plus that channel was producing audible hissing and humming. It was doing it even without a signal, and regardless of volume position, and I confirmed it wasn't my source by swapping in a different amp. I swapped around the opamps, removing the suspect left Sparkos, moving the XLR Sparkos to the left channel and replacing the XLR with the stock opamp. All problems gone. So in additon to any sonic benefits being dubious, they aren't built for the ages, either. I now see they do not have any kind of warranty for the opamps (which is understandable, given the chances of user error in installation). So another reason to buyer beware, I suppose, even if you still believe they make a sonic difference. And obviously any product is going to have a bad apple, but since I haven't seen anyone else run into this issue, I thought I'd add my experience to the hivemind.

I've had the same experience with Sparkos SS3602s. One died after 4 months. Now I only go for TIs high quality ones that are mass produced with high accuracy, like the NE5532, OPA1612 or OPA1656. All work perfectly over time and have never let me down.

 

[transformer-coupled]

I've had the same experience with Sparkos SS3602s. One died after 4 months. Now I only go for TIs high quality ones that are mass produced with high accuracy, like the NE5532, OPA1612 or OPA1656. All work perfectly over time and have never let me down.

oh yeah IC's are more reliable than discrete circuits in case of voltage rise and even thunder stroke , right?

 

[NTK]

oh yeah IC's are more reliable than discrete circuits in case of voltage rise and even thunder stroke , right?

Do you know there are tens of billions of transitors in a cell phone chip? Try make one in discrete and get it to work.

 

[transformer-coupled]

Do you know there are tens of billions of transitors in a cell phone chip? Try make one in discrete and get it to work.

We are talking speakers amplifiers here not about cell phones
I advise to IC industry lobby to sell products in a computing forum, not in audio forum