Fosi Audio ZA3 Amplifier Review

[LeonidKogan]

They were an improvement over the class A and class AB amps they replaced.

What were you using previously and what are your speakers?

 

[olds1959special]

I started using my 32V psu instead of the 48V one after finding the volume control was too sensitive for low level listening, and also I read reports that the 32V sounded better.

 

[EddNog]

I started using my 32V psu instead of the 48V one after finding the volume control was too sensitive for low level listening, and also I read reports that the 32V sounded better.

Where did you read that 32V sounded better?

-Ed

 

[olds1959special]

Where did you read that 32V sounded better?

-Ed

in the comments of these two videos

 

[Talisman]

in the comments of these two videos

Ah well in the comments of a video, I would say that we can absolutely take them as a certain source of truth

 

[Jon L]

Interesting video. I wouldn't say 32V sounds "better" than 48V, but at least in that video, 32V has less-detailed and less bright sound, which has the effect of making the midrange rounder/smoother but less detailed. 48V also does seem more energetic and snappy. If one has speaker/system that already sounds bright or forward, 32V may fit better. I do wonder how a 24V battery would compare to these smps.

 

[Talisman]

Interesting video. I wouldn't say 32V sounds "better" than 48V, but at least in that video, 32V has less-detailed and less bright sound, which has the effect of making the midrange rounder/smoother but less detailed. 48V also does seem more energetic and snappy. If one has speaker/system that already sounds bright or forward, 32V may fit better. I do wonder how a 24V battery would compare to these smps.

All these sentences make no sense. The amplifier takes the energy necessary to carry out its task, if it falls within the parameters of use and the power, current and voltage necessary to carry out the work you will not hear any difference, a power supply does not have the magical ability to make the mid range more soft or "snacker" sound.

 

[olds1959special]

All these sentences make no sense. The amplifier takes the energy necessary to carry out its task, if it falls within the parameters of use and the power, current and voltage necessary to carry out the work you will not hear any difference, a power supply does not have the magical ability to make the mid range more soft or "snacker" sound.

I did notice a change when using the 32V psu. First of all, I gained a little more room to adjust the knob when playing at low volumes, which was my main reason for switching from the 48V psu. Also, I felt the sound became more controlled and not as boomy, but it was subtle change so I'm not sure if it was just in my mind. I could always switch back and forth and check again, but I felt the sound quality was excellent with the 32V psu and the power levels were still plenty for my needs, so my 48V psu is now in storage and I'm using the 32V.

Edit: I switched back to the 48V. It's a little fuller sounding.

 

[dedede223]

i bought this amp 3 days ago, and during the first two days i had no issue with it at all. But from this morning i keep having channel drop, mostly the right one. Does anyone had the same issue with it so far? (it's used to power B&W Matrix 2 S1 at pretty low power and is feeded by a topping DX3PRO+)

 

[RCL162]

any cheaper amp op for make it sound good?

I like these opamps (AD712)..oh i like OPA1612 too.

 

[RCL162]

any cheaper amp op for make it sound good?

OPA1612

 

[gigantic]

What were you using previously and what are your speakers?

I was previously using an Emotiva Mini-X A100 and a pair of Alesis RA150 bridged mono blocks, along with a modded Glow Audio Amp Two that was driving the mids of a pair of LaScala inspired, 3-way horns. I now use the ZA3 mono blocks on the woofer and tweeter horns, with the valve amp on the mids, a Thomann T.Racks FIR DSP408 active crossover and a Schiit Freya preamp.

 

[Shadow Michael]

What preamplifier can be used with 12 trigger? Can you recommend something?

 

[Power Pop 23]

What preamplifier can be used with 12 trigger? Can you recommend something?

The WiiM Pro Plus streamer and upcoming WiiM Ultra streamer have 12 volt trigger outputs to signal a ZA3

https://www.audiosciencereview.com/forum/index.php?threads/wiim-pro-plus-streamer-review.50254/

 

[Jon L]

Thomann T.Racks FIR DSP408

Thomann DSP does not have a way to record room response and generate room correction then?
Have you tried feeding it the AES digital input and the sound quality?

 

[Richard G]

+1
Nice exterior design and power. Otherwise not superbly interesting

The superbly low price evidently isn’t an attraction for you

 

[Bleib]

The superbly low price evidently isn’t an attraction for you

PA5 II (plus) is not a lot more expensive

 

[viper414]

I've bought two ZA3 intending to use them as Monoblocks. However I do see that mono mode drops the SINAD from 87 to 74 which is considerable. If I don't actually need the extra power it provides but instead want the headroom and isolation that monoblocks provides. Wouldn't it be better to just use them in stereo mode but just 1 channel connected I haven't seen the test of max power vs distortion in stereo mode but only 1 channel driven. I will do the test when I have time and hope that it's audible. And I am using these with the Magnepan LRS which are power hungry. I can easily tell the amp is quite powerful in mono mode since they can push the LRS to a considerable volume without hearing any stress. I do feel they aren't that transparent and on stock op amps(this seems to be the craze nowadays). I am saying this from the following experience where I have tested the following amps extensively with the LRS - Cambridge audio 651W, Canto M300 Monoblocks, NAD T975 (using only two channels out of the 7), DIY Hypex NC500 OEM Monoblocks, and the best amp I've ever heard the Benchmark AHB2 which is absolute bliss but I can't afford it.
The V3 mono is my goal for the LRS with the ZA3 used with the Marantz 8805 processor via XLR to power the LCR

 

[EddNog]

I've bought two ZA3 intending to use them as Monoblocks. However I do see that mono mode drops the SINAD from 87 to 74 which is considerable. If I don't actually need the extra power it provides but instead want the headroom and isolation that monoblocks provides. Wouldn't it be better to just use them in stereo mode but just 1 channel connected I haven't seen the test of max power vs distortion in stereo mode but only 1 channel driven. I will do the test when I have time and hope that it's audible. And I am using these with the Magnepan LRS which are power hungry. I can easily tell the amp is quite powerful in mono mode since they can push the LRS to a considerable volume without hearing any stress. I do feel they aren't that transparent and on stock op amps(this seems to be the craze nowadays). I am saying this from the following experience where I have tested the following amps extensively with the LRS - Cambridge audio 651W, Canto M300 Monoblocks, NAD T975 (using only two channels out of the 7), DIY Hypex NC500 OEM Monoblocks, and the best amp I've ever heard the Benchmark AHB2 which is absolute bliss but I can't afford it.
The V3 mono is my goal for the LRS with the ZA3 used with the Marantz 8805 processor via XLR to power the LCR

Do note with ZA3 that the frequency response is load-dependent so switching between stereo and mono modes may yield a different frequency response (whether you can hear the difference at such high frequencies is debatable). Mono may sound darker/less airy. Or it might not (to you).

-Ed

 

[MCH]

switching between stereo and mono modes may yield a different frequency response

Are you sure about that? The LC filter is still the same.
It is a question.