Op-amp Rolling Using Sparkos on Fosi V3 Mono

[Geert]

What other factors do the comments suggest contribute to the perceived difference? What's left on the list?

That we can’t measure imaging and soundstage

 

[restorer-john]

The plot below is interesting for the technical minded as it shows the switching frequency of the class-D output (600kHz) with a good suppression (112dB or so) of the switching frequency.

112dB? Nah. And that's after the AES filter...

 

[solderdude]

What is the AES filter response ?
Why would one measure the frequency response up to 1MHz and then add a filter that affects the shown frequency response in the shown plot and not show its effect on that response ?
Is every reader expected to know what the AES filter does over the 1MHz range ?
Is the 600kHz frequency level dependent ?

 

[amirm]

What is the AES filter response ?
Why would one measure the frequency response up to 1MHz and then add a filter that affects the shown frequency response and not show its effect on that response ?
Is the 600kHz frequency level dependent ?

The filter is always inline when I make class D amplifier measurements (most other times as well). I need to remember to take it out of the loop but forgot in this instance. Without it, AP's front end gets confused with the switching frequency's slew rate.

 

[solderdude]

How much attenuation does the AES filter have at 600kHz (probably around 60dB) ?
The plot is kind of useless as it is now (above 20kHz or so).
It would be interesting to know how much the 600kHz switching frequency is actually attenuated and might be a good idea to test this with all class-D amps.
The output filter of the amp is probably 40 dB/decade so the 600kHz frequency will probably be attenuated by around 55dB so somewhere around 60mV amplitude.

 

[welwynnick]

Thanks as always, Amir.

I think people don't realise how good IC opamps are.

If one was really determined to see the difference it made, you'd need to start with better gear, like a Purify amp or a good DAC.

 

[JSmith]

If one was really determined to see the difference it made, you'd need to start with better gear, like a Purify amp or a good DAC.

Discrete OpAmp Review: Sonic Imagery vs Sparkos

Recently I reviewed the Nord Three SE 1ET400A Dual Mono Stereo Amplifier. That unit came with the Sonic Imagery's 990ENH discrete operational amplifier ("opamp") in the buffer stage (pre-amplifier). The owner then ordered a set of Sparkos Pro SS2590 discrete opamps. This gave me a chance to...

www.audiosciencereview.com

JSmith

 

[tomtoo]

If you paid some $ and did some work you will hear the difference thats how it is ask your brain.

 

[JeremyFife]

Thank you for what should be a completely unnecessary piece of work! I found this one particularly clear though, so much appreciated.

We have, again, been led to the water - how many will refuse to drink?

(That came across as a bit preachy, I didn't mean that but I still like the phrase)

 

[welwynnick]

Discrete OpAmp Review: Sonic Imagery vs Sparkos

Recently I reviewed the Nord Three SE 1ET400A Dual Mono Stereo Amplifier. That unit came with the Sonic Imagery's 990ENH discrete operational amplifier ("opamp") in the buffer stage (pre-amplifier). The owner then ordered a set of Sparkos Pro SS2590 discrete opamps. This gave me a chance to...

www.audiosciencereview.com

JSmith

That was what I had in mind when I commented.
It made me go looking for the specs and measurements of discrete opamps. On the face of it, they sound great, but they're actually slightly worse than the better ICs.
I sincerely wish Marantz would give up on their obsession with using HDAMs instead of opamps.

 

[esl 63]

1. There is two positions for the OP amp. Did you try both?
2. The blue trace is above the red trace can you please reverse the order so we can se the distribution of the harmonics better?
3. 5532 do have distortion levels that is clearly measurable, and audible, I can not disregard thousands of people who have swapped their 5532 and heard an improvement.

 

[johny_2000]

@amirm Can you do the same test with a high performance DAC with swappable op amps?

I put some examples in this thread.

 

[Talisman]

3. 5532 do have distortion levels that is clearly measurable, and audible, I can not disregard thousands of people who have swapped their 5532 and heard an improvement.

If thousands of people say the earth is flat can you ignore them or are they definitely right despite scientific evidence to the contrary?

 

[antcollinet]

5532 do have distortion levels that is clearly measurable, and audible,

What scientifically valid tests (level matched, controlled, blind) have been done to demonstrate that audibility?

 

[amirm]

How much attenuation does the AES filter have at 600kHz (probably around 60dB) ?

 

[amirm]

@amirm Can you do the same test with a high performance DAC with swappable op amps?

I did the Topping D10 many years ago:

Rolling (replacing) Op-amps in Topping D10 DAC

This is a study of whether changing op-amps in a DAC makes a measurable difference. Taking a lead form "rolling" tubes in tube products, a trend has started in replacing op-amps -- sometimes with much difficulty -- to improve performance of solid state products like DACs. A few months ago I...

www.audiosciencereview.com

Same results.

 

[antcollinet]

@amirm Can you do the same test with a high performance DAC with swappable op amps?

I put some examples in this thread.

By high performance, you mean a DAC that already has inaudible noise and distortion, and audibly perfectly flat frequency response.

What would be the point of changing anything here? You can't get "more inaudible"

 

[NADKEF listener]

Good to know what not to waste your money on…

 

[Scrivs]

1. There is two positions for the OP amp. Did you try both?
2. The blue trace is above the red trace can you please reverse the order so we can se the distribution of the harmonics better?
3. 5532 do have distortion levels that is clearly measurable, and audible, I can not disregard thousands of people who have swapped their 5532 and heard an improvement.

True believers without any concept of how electronics actually work. At least you retar... Dunces are consistent in your refusal to actually learn anything.

Even when the EViDENCE is staring you in the face.

Donkies.

 

[Mnyb]

Even if could get it inaudibly better to do that cost and serviceability must be considered , you can at anytime buy a whole box of generic op amps for peanuts .
But these specialty companies would they be there for you , and how do they hold their performance over time let say 10 years from now ?

IF it where between two normal op amps i would pick the one with slightly better performance (even inaudibly better ) as the price differences are typically benign and typical op amps can be had as spares forever.