Op-amp Rolling Using Sparkos on Fosi V3 Mono

[KL....]

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).

Thank you, that raises other questions such as these, doesn't it? and would the measurements show/reveal irregularitys with these....

• IC Socket?.... quality/tarnish/oxidisation, structure, fit/pressure/deformation, etc and can these even be cleaned without issue?
• opamp pins.... quality/tarnish/oxidisation, structure, fit/pressure/deformation, etc and can these even be cleaned without issue?
• Harmonics.... FFT (Fast Fourier Transform) measurement does show harmonic analysis, as it transforms a signal from the time domain to the frequency domain, revealing the presence and magnitude of different frequency components, including harmonics, doesn't it?.... so, this can be ruled out, can't it?
• lousy volume control pots in the signal path?.... as mentioned.
• Anticipation/Expectation Bias?.... must be considered but there are (apparently) thousands of (beneficial) conclusions which are in indication of (beneficial) Repeatable Conclusion, isn't it?
• what else can be considered?

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?

 

[pma]

Sockets may be a stability issue with some parts. EMI either induced or with a signal may be an issue - especially in case of ancient CD players as signal sources. Many things. As already mentioned, I hate simplified answers and generalizing.

 

[Ajax]

Thanks Amir. Excellent objective review.

About 5 years ago I purchased a Nord / Hypex Amp and faced the choice of either a standard, Sonic Imagery or Spakos op-amp. I didn't understand what the difference was then, and still don't today, however, I note that their web site continues to make the same offer.

I guess the lesson from this review is for Colin to stop causing any more confusion and wasting everyone's time.

 

[Tres]

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.

Thank you.

I consider myself normally intelligent (hope my wife doen’t read this) but I’m no engineer and my knowlegde about electricity is just a tad above average. I think measurements are a nice way to show differences if any.

By digging through all your and other posts I learned a lot about what matters. I enjoy my avr and stereo setup more because I learned to trust the measurements and explanations especially from people who know their stuff… Certainly I don’t understand everything. But finally I found answers to a lot of questions I had, especially about hearing differences, who are there subjectively but are absent when measured objectively.

The truth is out there…

 

[Gorgonzola]

I thank Amir for this conclusive result. I do accept that if devices measure the same they will sound the same.

I like the Sparkos SS3602 in my VTV I/O 'buffer' of my VTV Purifi amp, but that was a purely subjective, impressionistic result. I can only add that the context for Amir's test was Fosi V3 whereas the context for my impression was the VTV I/O device. Perhaps context makes a difference; as I discovered, the VTV I/O was designed by a Sparkos designer.

 

[Ismapics]

Another myth debunked. Thanks.

 

[Jimster480]

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

NE5532 isn't a chinese OpAmp. It is originally from the USA. It was designed and released in 1979.... which is quite amazing when you see its performance today and really sheds light on the fact that we have actually solved audio quality a long time ago. It has just taken the industry more than 40 years to start making good products, rather than snake oil nonsense.

 

[Cbdb2]

Headphone amps tho

But even then you can just slap some TO-220 as buffer
View attachment 441397

HP amps are power amps not opamps.

 

[Multicore]

By digging through all your and other posts I learned a lot about what matters. I enjoy my avr and stereo setup more because I learned to trust the measurements and explanations especially from people who know their stuff… Certainly I don’t understand everything. But finally I found answers to a lot of questions I had, especially about hearing differences, who are there subjectively but are absent when measured objectively.

That's good to read. Thanks for piping up. ASR FTW!

 

[pma]

Just to indicate that I know what I am talking about when I speak about op-amps. This is my current workbench:



I always write based on knowledge, design experience and production/testing experience. I do not attend "debates for debates" as a kind of chat, as a mere debater. A kind of respect would be appreciated.

 

[amirm]

A kind of respect would be appreciated.

We are not here to hand out compliments to people who show up demanding that, than furthering the substance of the discussion. Please move on before we hand you sanctions.

 

[yellowshark]

Belief is a powerful thing.

It was Friedrich Nietzsche who observed that the real enemy of the truth is not the lie, but conviction.

 

[solderdude]

HP amps are power amps not opamps.

But they do use them.
https://electronics-diy.com/electronic_schematic.php?id=797

Crystal CMoy Free Form Headphone Amplifier

Crystal CMoy Free Form Headphone Amplifier: This headphone amplifier circuit is different to conventional modern construction techniques in that it is air Wired,P2P (Point to Point) or free form wiring just like in the good old Valve days before the intervention of PCB's and the transistor. …

www.instructables.com

It is exactly these amps where different op-amps do make a difference when driven near and to their limits.

 

[restorer-john]

Thanks Amir. Excellent objective review.

About 5 years ago I purchased a Nord / Hypex Amp and faced the choice of either a standard, Sonic Imagery or Spakos op-amp. I didn't understand what the difference was then, and still don't today, however, I note that their web site continues to make the same offer.

I guess the lesson from this review is for Colin to stop causing any more confusion and wasting everyone's time.

The Sonic Imagery labs opamps were one of the failure points in your actual amplifier. Replaced with NE-5532s.

I've come to think of amplifier manufacturers who offer these unnecessary and expensive add-ons akin to the Ming* Molls at car dealerships or the "extended warranty" upsellers at an appliance store.

Legend of the Ming Moll: How do car dealers get away with this in 2021? — Auto Expert John Cadogan

At the retail coalface, the car industry still gets away with this, in 2021. Here’s the ugly truth about the Ming Moll…

autoexpert.com.au

 

[antcollinet]

I hate simplified answers and generalizing.

You might be happier at ASR's sister site : AEO. (Audio Engineers Only).

 

[Cbdb2]

But they do use them.
https://electronics-diy.com/electronic_schematic.php?id=797

Crystal CMoy Free Form Headphone Amplifier

Crystal CMoy Free Form Headphone Amplifier: This headphone amplifier circuit is different to conventional modern construction techniques in that it is air Wired,P2P (Point to Point) or free form wiring just like in the good old Valve days before the intervention of PCB's and the transistor. …

www.instructables.com

It is exactly these amps where different op-amps do make a difference when driven near and to their limits.

People do all sorts of stupid things. Bet they sound just awful with 30ohm headphones

 

[Gremlins]

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.

Understand, but that doesn't change what is percieved by a huge amount of audiophiles

A couple of objective forums Vs a hundreds of subjective forums and will still read here and there how much a câble change

What Dac are you using currently?

Why this question ? What does it change to his statement?

I had expensive and cheap dacs.. blind listening made me understand the dacs are instiguishable while listening music, period

One just need to have courage to try doing blind testing

But audio is for some, only possessing expensive gear

 

[JSmith]

what is percieved by a huge amount of audiophiles

They need to understand their hearing and perception, like every other human, is fallible.


JSmith

 

[Rednaxela]

I read Sonic Imaginary.

 

[solderdude]

great book ... have it too.