Fosi Audio's First Dual-Mode Balanced Amplifier ZA3

[Volendrung]

Does anyone or @Fosi Audio know what the single ended RCA input impedance is on the ZA3? Thanks!

 

[Guddu]

Does anyone or @Fosi Audio know what the single ended RCA input impedance is on the ZA3? Thanks!

If you mean input sensitivity then 0.775v.

 

[maty]

-> Sparkos Labs SS3602

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

 

[doug s.]

-> Sparkos Labs SS3602

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

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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.

 

[maty]

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? ..

maty != Greg

 

[doug s.]

maty != Greg

sorry, maty, i don't understand your answer.

or, are you just saying it's what you heard on your speakers, listening to the recording? it seemed to me initially, that you were comparing your own fosi amps w/the different op amps. i don't think i could even begin to try to compare something i heard from a recording of another system over a youtube video...

doug s.

 

[maty]

That maty is me and, as the great Spanish philosopher Ortega y Gasset would say, my circumstances.

In my second audio system, the cheap one, connected to a PC with W10 optimized for multimedia (minimization of the jitter created in the CPU), I listen to the music with my modified KEF Q100 5.25 coaxial via the Magnat MA 900 hybrid integrated (modified three weeks ago, like almost all the audio hardware I have at home). Near-field usually.

On my X / Twitter account I have long threads about audio and music as well as other topics. In one of them I focus on FOSI amplifiers and different op-amps.

 

[Zek]

maty != Greg

The rest of us still don't understand what this means.

 

[maty]

The rest of us still don't understand what this means.

Without acrimony, it is supposed to be taught in math classes (Algebra) in compulsory education < 16 years old to everyone, at least years ago. Then in programming. But the educational system in most Western countries has been in free fall for too many years, as evidenced by the PISA reports.

 

[MCH]

Without acrimony, it is supposed to be taught in math classes (Algebra) in compulsory education < 16 years old to everyone, at least years ago. Then in programming. But the educational system in most Western countries has been in free fall for too many years, as evidenced by the PISA reports.

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this is not my field, so i could be wrong, but i think what you are saying is not correct.
The maths symbol for not equal is ≠, and this is what people do and should learn in the school. The symbol you use is used in some computer languages, probably because in the old times they didn't have the actual symbol.

 

[maty]

It is the same, but look for the ≠ symbol on the keyboard... Hence !=, they are there, more easy to type.

 

[Zek]

The maths symbol for not equal is ≠

That's what I know too...

 

[mike70]

Not Equal Sign ≠

 

[maty]

[ ..when I've removed all unused opamps, that made a big difference in sound too! ]

 

[Talisman]

How heartbreaking are all these useless posts on operational amplifiers, but am I the only one who finds this useless and boring as hell?

 

[Zimmerframe]

How heartbreaking are all these useless posts on operational amplifiers, but am I the only one who finds this useless and boring as hell?

I think we can all agree that they'd sound better if they were available in Orange to match the volume knob.

 

[iLoveCats]

[ ..when I've removed all unused opamps, that made a big difference in sound too! ]

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I removed the unused op amps yesterday and watched Netflix all day with the wife. For sure better vocals. Previously I already thought the vocals improved when I swapped to burr brown opa2604 op amps, I described it in the other thread as 'voicey'. This is good for me because the amp is primarily used for TV sound even though it's my main music system too.

 

[maty]

OPA234. 8 months ago, Which Rocks? Fosi Audio V3 with Various Op-Amps Demonstration

 

[maty]

A note

We know that the Fosi and other cheap class D do not have the PFFB implemented for now, so the impedance graph of the speakers must be taken into account > 10 kHz in case it triggers at >> 4 Ohms.

Qualio IQ speakers (YT video) use the Mundorf AMT17D2.2 Dipole AMT Tweeter. I investigate and it complies with the above, so the Fosi ZA3 and others must work well with them.

Impressive measurements (and price).

Mundorf AMT17D2.2 Dipole Air Motion Tweeter

Mundorf AMT17D2.2 Dipole Air Motion Tweeter

www.madisoundspeakerstore.com

 

[doug s.]

Hello friend, you can refer to this video we've uploaded. Timestamp at 12:26 Rolling the Op-Amps

hi!

there seems to be some confusion regarding replacing op amps when the za3 is to be used in mono mode. or even using the stock op-amps. i've read that you only need to use the op amp for the right channel when in mono mode, and you can remove the left channel op amp altogether. as shown here:

but another thought is that you actually do need the left channel op amp in the circuit when in mono mode, to get the full effect of the amp's capabilities. please explain/advise.

thanks!

doug s.