Fosi Audio ZA3 Amplifier Review

[Ajax]

Sure. Though couldn’t one use a DAC with variable line out ?

That is how my current system is set up. I have a Benchmark DAC2 with XLR out to a Buckeye Hypex 252 amp and then onto the mains. The RCA out goes to a 12" sub with the cross over set at 65Hz. This works really well and sounds great, however, the mains are playing at full range, as is the Buckeye amp driving them.

With a cross over imbedded in the DAC, or the sub out in the amp, you can alleviate the stress the lower frequencies place on both the amp and the main speakers. If you have a powerful amp and tower speakers it not so important, however, for a 2.1 system incorporating bookshelf mains and a sub it is extremely useful, especially if your measuring with REW software.

 

[Bruce Morgen]

FOSI DISCOUNT CODE IN FEBUARY!!!


VD-G15

15% off.

$127.49 is what I paid this morning, with free delivery.

Less than $1 per watt.

With that code, the amp alone costs under $100 USD with free shipping, still basically double the price of an Aiyima A07. That said, if you need some more power, balanced inputs, and/or the mono mode -- and don't mind that it has the same load-related FR quirks as the 3+-year-old A07 (or any other non-PFFB TPA3255 circuit) -- that price seems reasonable enough AFAICT.

 

[sejarzo]

Is setting up volume knob lower is same as having amplifier set to low again?

No. The volume pot attenuates the input signal to lower the volume.

EDIT: I was wrong.

 

[Guddu]

No. The volume pot attenuates the input signal to lower the volume.

Cool, Then I would think keeping the volume knob to lower position, specially with a low gain amplifier, may not be best thing to do unless there isn’t option to control volume on source.
This would also keep channel imbalance away if there is any because of potentiometer anomalies or otherwise.

 

[sejarzo]

Cool, Then I would think keeping the volume knob to lower position, specially with a low gain amplifier, may not be best thing to do unless there isn’t option to control volume on source.
This would also keep channel imbalance away if there is any because of potentiometer anomalies or otherwise.

That's my take. The chip per the spec sheet applies 21.5 dB gain to whatever input signal is fed to it, and as you note, imbalance tends to get worse with attenuation.

 

[Guddu]

and as you note, imbalance tends to get worse with attenuation.

Please remind me, wherever it is, does it get worse on lower pot position or towards higher pot position?

 

[rj2wells]

Cool, Then I would think keeping the volume knob to lower position, specially with a low gain amplifier, may not be best thing to do unless there isn’t option to control volume on source.
This would also keep channel imbalance away if there is any because of potentiometer anomalies or otherwise.

As mentioned above there's a safety element. In my case that little amp has enough power to damage the little speakers it's driving. I set the volume knob to just below the point where distortion starts to be noticable to my ears

If you're driving huge towers it may not matter but I'm driving ceiling and I'm not sure they can take full bore from that amp.

 

[Guddu]

As mentioned above there's a safety element. In my case that little amp has enough power to damage the little speakers it's driving. I set the volume knob to just below the point where distortion starts to be noticable to my ears

If you're driving huge towers it may not matter but I'm driving ceiling and I'm not sure they can take full bore from that amp.

Cool.

 

[iLoveCats]

can someone smarter than me or a better googler than me tell me the difference between these two sets of op amps? Obviously both 5532's but the number on top is very different. I'm leaning that they are probably manufactured by different TI facilities.

 

[PlasticDoc]

Have you searched the posts following this link in the V3 discussion on this topic?

Fosi Audio V3 Amplifier Review

I have an Fosi Audio V3 on the way. I also have other "ChiFi" products, so my intent is not to engage in political arguments here. What I do know for certain is that tested units have components that appear different than beauty shots by Fosi and that there are those who maintain that fact...

www.audiosciencereview.com

 

[iLoveCats]

Have you searched the posts following this link in the V3 discussion on this topic?

Fosi Audio V3 Amplifier Review

I have an Fosi Audio V3 on the way. I also have other "ChiFi" products, so my intent is not to engage in political arguments here. What I do know for certain is that tested units have components that appear different than beauty shots by Fosi and that there are those who maintain that fact...

www.audiosciencereview.com

Ok different factory. Still sounds the same FYI.

 

[2muchstuff]

I just happen to have a Rolls DI box laying around. https://www.sweetwater.com/store/detail/DB24--rolls-db24-passive-stereo-direct-interface

Would there be any advantage at all to putting this in the chain from my RCA outs on the pre-amp to the RCA ins on the Rolls box and using the balanced out of the Rolls Box to the Za3s (2 used in mono). Is this just a useless addition since it is not fully balanced from the source and to the speakers? Thanks in advance. I feel like this is a dumb question that is below the brainpower on here.

 

[Toni Mas]

I just happen to have a Rolls DI box laying around. https://www.sweetwater.com/store/detail/DB24--rolls-db24-passive-stereo-direct-interface

Would there be any advantage at all to putting this in the chain from my RCA outs on the pre-amp to the RCA ins on the Rolls box and using the balanced out of the Rolls Box to the Za3s (2 used in mono). Is this just a useless addition since it is not fully balanced from the source and to the speakers? Thanks in advance. I feel like this is a dumb question that is below the brainpower on here.

Balanced mode does not bring any audible benefit, unless you use meters and meters of interconnects in your set up... You just gain marginal sinad improvement if any... Note that cheaper Fosi V3 brings better measurements with rca only and a simpler circuit inside...
Balanced mode for home audio IS mainly marketing hype: sinad for sinad sake...

 

[dixter]

Balanced mode does not bring any audible benefit, unless you use meters and meters of interconnects in your set up... You just gain marginal sinad improvement if any... Note that cheaper Fosi V3 brings better measurements with rca only and a simpler circuit inside...
Balanced mode for home audio IS mainly marketing hype: sinad for sinad sake...

balanced is nice if your source is balanced... otherwise you have to get a strange cable... like XLR balanced out to RCA input.... why not get the balanced version of the amp if your source has balance output... XLR balanced to XLR balanced input.... see how that works

 

[Toni Mas]

balanced is nice if your source is balanced... otherwise you have to get a strange cable... like XLR balanced out to RCA input.... why not get the balanced version of the amp if your source has balance output... XLR balanced to XLR balanced input.... see how that works

It s overkill for me but It is part of what this hobby is all about...

 

[dixter]

It s overkill for me but It is part of what this hobby is all about...

the real problem is that " balanced " is an overused definition.... a true balanced circuit is where the signals are inverted and summed together where the mathematical relationship of sign/cosign is used to subtract noise from the signal.... but another definition is used when a long run of a cable is used at a concert.. and they use " balanced" cables.... and then in this hobby where a balanced source/amp is where the left/right are separated from each other in a " balanced " input/output.... thats 3 different kinds of " " balanced " most of the time in this hobby a " balanced " circuit design is better designed than a non balanced design and is measured as such the benefits...

 

[Toni Mas]

the real problem is that " balanced " is an overused definition.... a true balanced circuit is where the signals are inverted and summed together where the mathematical relationship of sign/cosign is used to subtract noise from the signal.... but another definition is used when a long run of a cable is used at a concert.. and they use " balanced" cables.... and then in this hobby where a balanced source/amp is where the left/right are separated from each other in a " balanced " input/output.... thats 3 different kinds of " " balanced " most of the time in this hobby a " balanced " circuit design is better designed than a non balanced design and is measured as such the benefits...

We like theoretical benefits... Part of this hobby too...

 

[dixter]

the theory in this case is factual... you eliminate cross talk with xlr to xlr cables...

 

[Toni Mas]

the theory in this case is factual... you eliminate cross talk with xlr to xlr cables...

Cross what?

 

[howard416]

Man, where is the “dislike” button…