Fosi Audio's First Dual-Mode Balanced Amplifier ZA3

[K.Kevin]

Yup you are completely correct my mistake. You have now convinced me that the toggle switch is a modern miracle and a sight to behold! The world needs more toggle switches! Toggle switches everywhere for me and Gygess! If a device doesn’t have at least 3 toggle switch’s it should not even be considered on ASR!!
I hope every company is listening that we want toggle switches!!

You don't feel it's slightly pathetic to react this way when somebody challenges your views?

Please take care

 

[CamRector]

OCD is being bothered by a switch that you will set once and leave there for the rest of your use. OCD is being bothered by it both because of how it looks and being bothered that it is a useless feature for a minority of people using it.

When you can't look past yourself, and be at peace at a feature going unused on your device, or you think that a little switch like the ZA3 ruins its aesthetic, that is textbook OCD.

You say Fosi has 5/7 amps, you want them to have more? How many do you want them to have? 100? One amp for every percentile of user, to satisfy their eccentricities?

It's okay, I treat OCD very seriously. I have it in some other aspects of my life too. But too many times on ASR people have no self-awareness of their OCD. When it starts to manifest itself in what I consider to be incredibly unsatiable and nitpicky "suggestions", ones that muddy waters with "noise" amongst genuinely significant audible improvements suggestions, that's when I counter back on here.

Regarding your second post

You say Purifi and Hypex as examples have mono and stereo versions. Afaik they sell modules, not fully furnished finished retail amplifiers. Companies can create mono and stereo versions, sure, but who has to be beholden to who here? Your point here is very weak overall. Maybe those companies ought to unify their product to be able to have a mono and stereo switch so that they could satisfy the needs of both sets of customers...

A company like Fosi could still compete with those sub 1k "legends" with such a switch. It won't be the presence of a switch that will exclude them from doing so.

In all seriousness your hyper focus here on one little aspect of my statement, is a very big indicator of Autism Spectrum Disorder.
I mentioned about 5-6 changes myself and many other would like to see any you just can’t seem to take your mind off toogle switches.

All those unused inputs you seem to love covering your devices well they cost money. Frankly I don’t like paying for something that goes unused and I’d rather it not even be there. As a audio device those inputs could potentially introduce noise into the device. Better they aren’t there.

I would like Fosi to have as many amps as they wish to have. They seem very responsive to us customers. I would like them to spend less time with those amps that measure poorly and focus on innovative and growing into the future. With the v3 and this Za3 they seem able to accomplish that.
I believe that they can and they can do it without your precious toggle switch!

 

[CamRector]

You say Purifi and Hypex as examples have mono and stereo versions. Afaik they sell modules, not fully furnished finished retail amplifiers. Companies can create mono and stereo versions, sure, but who has to be beholden to who here? Your point here is very weak overall. Maybe those companies ought to unify their product to be able to have a mono and stereo switch so that they could satisfy the needs of both sets of customers...

Yes they create modules and every company that uses these modules does so to meet the customers needs.
Mono, stereo, 8channel you name it!
Anything and everything in between. All without a toogle switch mind you!!
The free market is amazing!
Yet I don’t see a company doing anything similar below $1000. I don’t see anything listed in the top measuring amps on this site.
If you look at the were the V3 lands on this graph is there any mono amp or balanced stereo amp that measures better and beats the Fosi price wise?
I see a lot of mono and stereo amps I don’t see any at $150.
Fosi could have that entire market.

 

[jackdanyal]

is it only me who has an issue with the ON/OFF functionality of the amp? I know that I need to hold it for 3-5 secs to turn on/off, but often the knob just ignores the action and I need to try 3-4 times every time. it may sound like a minor issue, but makes me nervous from time to time.

 

[vicenzo_del_paris]

is it only me who has an issue with the ON/OFF functionality of the amp? I know that I need to hold it for 3-5 secs to turn on/off, but often the knob just ignores the action and I need to try 3-4 times every time. it may sound like a minor issue, but makes me nervous from time to time.

I did not have this issue.
Both manual on/off using the knob and trigger work as expected.

 

[Guddu]

is it only me who has an issue with the ON/OFF functionality of the amp? I know that I need to hold it for 3-5 secs to turn on/off, but often the knob just ignores the action and I need to try 3-4 times every time. it may sound like a minor issue, but makes me nervous from time to time.

Others have reported it too.
However Mine is fine, just needs a but longer push + hold.

 

[Hertel]

According to Fosi, they sold more than 2 thousand units of the ZA3, which is sold out. They are only accepting orders.

I bought two units a few days ago to use as monoblocks. I hope its measurements are as good as those of the V3, but delivering more power and dynamics when used in bridge mode. I also have a bt20a pro but it definitely doesn't suit the tropical climate in my country (Brazil) and it gets really hot. The V3 has improved the cooling system and it no longer heats up as much. The ZA3, with the same cooling system as the V3, has a larger area for heat dissipation, so you won't have any problems with heating, I think.

Until my ZA3 arrives, I'm still waiting for any subjective review about the device. Especially when used in bridge mode

 

[nastynick]

No offensive but this thread sucks. Ruined by pissing matches over mediocre takes.

 

[Yorkshire Mouth]

We're going to add the adjustable high pass filter in another model. It won't introduce distortion.

Any idea when this model will be up for sale?

Many thanks.

 

[alarum_78]

I was lucky and managed to grab one of these to add on to my AVR-X3800. I decided to run my FRONT speakers off it (I am running an 11.1 Setup). Does that seem like a bad idea?, instead of running a less important height channel for example??... I also cant seem to get the trigger to work. Tested my trigger cable and its delivering voltage. When I turn on the FOSI now manually with the 12v cable it just gives me a humming noise. I have set everything to trigger the amp on in the Denons settings. Trigger removed for now and all is working well otherwise. Volume set @ max the Denon set it to -2.0db for those who are looking to use this as a "power amp".

 

[JCarp]

Williston Audio reviewed the amp and ran it on his SMD amp dyno AD-1 with the 48v 5 amp power block. It made
94w & 97w @ 1% distortion @ 8ohms
177w & 174w @ 1% distortion @ 4ohms
Mono it got interesting.
106w 1% @ 8ohms
193w 1% @ 4ohms.
So it appears the mono isn't bridged.

 

[charlielaub]

Williston Audio reviewed the amp and ran it on his SMD amp dyno AD-1 with the 48v 5 amp power block. It made
94w & 97w @ 1% distortion @ 8ohms
177w & 174w @ 1% distortion @ 4ohms
Mono it got interesting.
106w 1% @ 8ohms
193w 1% @ 4ohms.
So it appears the mono isn't bridged.

The TPA3255 contains 4 single ended channels. The stock ZA3 operates two pairs of these in bridged mode, so you cannot yet again bridge those for mono mode. Instead the mono mode puts the two bridged pairs in parallel so that both can deliver current into the load at the same time.

Mono mode allows the amp to deliver more power into a 2 Ohm load, which Williston did not test. It's strange because he did test the amp in 2 Ohms stereo load. Power should almost double into 2 Ohms in mono mode versus the stereo 4 Ohm power levels.

 

[Penelinfi]

If I had one of these I'd probably 3d print a switch cover so that it can't accidentally be mono/stereo switched

 

[surroundman]

It seems intriguing just how many reviewers posted their videos online on the day of the ZA3 release (or very shortly after). It probably does indeed sell well; after all, to me it seems like dozens of free samples were sent for marketing's sake. I just don't know if this is a good or a bad thing when it is so obvious.

 

[MCH]

Mono it got interesting.
106w 1% @ 8ohms
193w 1% @ 4ohms.
So it appears the mono isn't bridged.

Ballpark or a little bit less than Aiyima A07 max. Maybe they are "bridged" similarly after all?
(Amir result A07 max 48V/5A bridged 1% 4Ohm: 226W)

 

[somebodyelse]

Mono mode allows the amp to deliver more power into a 2 Ohm load, which Williston did not test. It's strange because he did test the amp in 2 Ohms stereo load. Power should almost double into 2 Ohms in mono mode versus the stereo 4 Ohm power levels.

It should with a sufficiently capable PSU, but with the 48V 5A PSU that Williston tested it wouldn't manage it for long.

 

[Toku]

If the ZA3 is actually operating in PBTL mode, it should of course display the output under a 2Ω load, but the ZA3 specs do not.
Fosi's response is very strange since Chinese products always show the output value of 2Ω load to show off the large output in PBTL operation.

 

[Lux_ury]

I'm disappointed for the output ratings monoblocks used to give me more output, otherwise Fosi can I please pay half for the second Amp Yes I do understand its only one balanced channel per side
The math just doesn't add up even if I use the 48v brick I already own.
Still as a upgrade from my v3 well done, and congratulations for moving into the right direction

 

[G-Can]

I was lucky and managed to grab one of these to add on to my AVR-X3800. I decided to run my FRONT speakers off it (I am running an 11.1 Setup). Does that seem like a bad idea?, instead of running a less important height channel for example??... I also cant seem to get the trigger to work. Tested my trigger cable and its delivering voltage. When I turn on the FOSI now manually with the 12v cable it just gives me a humming noise. I have set everything to trigger the amp on in the Denons settings. Trigger removed for now and all is working well otherwise. Volume set @ max the Denon set it to -2.0db for those who are looking to use this as a "power amp".

I am literally planing to do the same, and know Im worried about that 12V trigger, did you figure it out?
DId you try contacting Fosi about it?

when you say Denon set it to -2Db, does that mean Denon reduced output to Fosi, or increased? Is it better when receiver add db, or reduces?

 

[alarum_78]

I am literally planing to do the same, and know Im worried about that 12V trigger, did you figure it out?
DId you try contacting Fosi about it?

when you say Denon set it to -2Db, does that mean Denon reduced output to Fosi, or increased? Is it better when receiver add db, or reduces?

After I ran the audyssey setup my L/R Front were showing -2db. So setting the volume to max on the Fosi looks to be ideal. Have not had a chance to mess around with the trigger yet.