Fosi Audio ZA3 Amplifier Review

[doug s.]

-> Sparkos Labs SS3602

Fosi ZA3 + Sparkos Op-amp - The real deal - Don't miss out !!!

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mati, you posted this in the other fosi za3 thread; i asking the same question here:

are you running a pair of amps mono, or one in stereo? xlr or no? using its subwoofer out or no? does the sparkos fit inside the case w/o adapters? or are you using adapters or using the amp naked?

thanks!

doug s.

 

[solderdude]

maybe the volume wasn't touched at all, and the sparkos op amps themselves caused this

That is extremely unlikely as gain in any op-amp circuit is always solely determined by the resistors around the op-amp and not the opamp itself.
In order to create an audible difference just adding a few dB works like a charm.

 

[doug s.]

That is extremely unlikely as gain in any op-amp circuit is always solely determined by the resistors around the op-amp and not the opamp itself.
In order to create an audible difference just adding a few dB works like a charm.

i queried greg, stating there were measurements graphed of the recordings, and here's his response:

"I always adjust the volume using pink noise and spl meter. Pink noise averages the volume across very wide spectrum and I'm able to match the volume to around 0.5db

If the recordings are louder - I also have such an impression IMO the sound character difference - more open and pronounced midrange comes from something - louder midrange so yes there will be a difference."

doug s.

 

[DanTheMan]

You can definitely hear the volume difference. That can certainly confuse your hearing making the louder one seem more dynamic and clear (etc...). I'd think pink noise would be a bad way to match volume. Maybe just use a test tone if there needs to be a volume adjustment between opamps. It would be nice if he did the test again so that people could hear a more accurate assessment. He also shouldn't tell you when the opamps are switched out so that you can make the decision with your ears.

It would be nice if he recorded a frequency response of each as well. If there's a difference there.....

 

[solderdude]

i queried greg, stating there were measurements graphed of the recordings, and here's his response:

"I always adjust the volume using pink noise and spl meter. Pink noise averages the volume across very wide spectrum and I'm able to match the volume to around 0.5db

If the recordings are louder - I also have such an impression IMO the sound character difference - more open and pronounced midrange comes from something - louder midrange so yes there will be a difference."

doug s.

So the test is not valid as there is an audible volume difference.

 

[maty]

The reality is what it is, it sounds much better with the sparkos despite the AAC 192 kbps sound quality (the maximum allowed by YouTube, in 4K videos). At least with those speakers, which benefit from the Mundorf AMT dipole tweeter used and which I suppose make differentiation easier.

If you do not appreciate the big difference, you have a bottleneck in your audio system.

 

[PlasticDoc]

The reality is what it is, it sounds much better with the XXX

This appears to be an acute case of "much betterism" (sometimes also called subjectivism).

This condition may arise from biased perception and/or flawed testing methodologies. The affected individuals may need to express their belief in imaginary improvements, using units of measurement such as "much better".

It is unclear why "much betterism" often affects individuals when evaluating "hifi" cables, "hifi" capacitors or "hifi" op-amps.

 

[iLoveCats]

What if the op amps are the reason for the 2dB like Greg says? It's a valid test then because changing the op amps and leaving some out caused that.

 

[nvidia_7]

Just wanted to give an update on my broken RCA connector situation. Fosi sent me a new amp to replace the broken one and all is well now. They have incredible customer service. I wouldnt be able to name one mainstream brand that would do that, in that short of a time frame.

 

[312elements]

Thanks to members' feedback, our R&D team is currently exploring the feasibility of incorporating adjustable HPF and LPF slide/dip switches. Let's see if we can do something.

I hope they can’t figure it out.

 

[BDWoody]

The reality is what it is, it sounds much better with the sparkos despite the AAC 192 kbps sound quality (the maximum allowed by YouTube, in 4K videos). At least with those speakers, which benefit from the Mundorf AMT dipole tweeter used and which I suppose make differentiation easier.

If you do not appreciate the big difference, you have a bottleneck in your audio system.

 

[Guddu]

If you do not appreciate the big difference, you have a bottleneck in your audio system.

Is it okay if I ask you to elaborate this - bottleneck

 

[defstarx]

Completely subjective two-cent perception here, but when I changed my ZA3 opamps to the Sparkos', my first impression was that these play quieter than the TI's.
Also, to me the ZA3 with Sparkos' appear to draw a soundstage with more depth than with the stock opamps. I'm completely open to the possibility of all of that being partly of fully placebo, and hence it'd be super interesting to see what (if any) difference there might be in how the ZA3 measures with the SS3602's.

 

[reference_enthusiast]

possibility of all of that being partly of fully placebo

Unless we're being manipulated by the dude that uploaded the video, there's no placebo, we can all hear the difference. What I want to know is the engineering behind this, what did sparkos do to achieve this and how can we measure it.

 

[PlasticDoc]

I'm completely open to the possibility of all of that being partly of fully placebo

This does not appear to be a placebo effect. A placebo would have cost you nothing and would have been beneficial.

This seems more like a a case of confirmation bias(*), i.e., either a belief perseverance or, more likely, an illusory correlation.

A controlled double-blind test, excluding extraneous factors such as additional gain, would likely demonstrate that you could not distinguish between this amplifier with and without the aforementioned "miracle" op-amps.

(*)"These biases contribute to overconfidence in personal beliefs and can maintain or strengthen beliefs in the face of contrary evidence"

 

[defstarx]

This does not appear to be a placebo effect. A placebo would have cost you nothing and would have been beneficial.

Eh... Placebo as in 'medicine that has no physical effect but produces a mere psychological one'. Might even have a more prominent placebo effect the higher the cost. This way or that - I'm sliding off-topic...

 

[PlasticDoc]

Eh... Placebo as in 'medicine that has no physical effect but produces a mere psychological one'. Might even have a more prominent placebo effect the higher the cost. This way or that - I'm sliding off-topic...

Discussing "confirmation bias" or "placebos" is no more off-topic than talking about the effect of expensive "miracle" op-amps on the sound of low cost chipamp based audio amplifiers (the cost of a TPA3255 chip is aprox. 10€).
There is more to placebos than meets the eye: Six surprising things about placebos everyone should know.
Amazingly, it seems that "placebos work even if people know they are placebos".

 

[312elements]

Unless we're being manipulated by the dude that uploaded the video, there's no placebo, we can all hear the difference. What I want to know is the engineering behind this, what did sparkos do to achieve this and how can we measure it.

I actually didn't hear any difference (in the YouTube video) but full disclosure airplay limited the resolution. I'll be conducting my own tests soon enough. There are a handful of theories shared on this forum that don't sit well with me, but like most others, I haven't taken the time or effort to test. My goal is only to inform my own future purchasing decisions.

 

[Great Sun Jester]

Just wanted to give an update on my broken RCA connector situation. Fosi sent me a new amp to replace the broken one and all is well now. They have incredible customer service. I wouldnt be able to name one mainstream brand that would do that, in that short of a time frame.

Schiit is incredible also.

 

[Bruce Morgen]

Schiit is incredible also.

Topping not so much, at least in my experience with a failed DAC.