Review and Measurements of Yamaha WXA-50 Streaming Amp

[maty]

Spanish Qobuz review

https://www.qobuz.com/es-es/info/hi-fi/bancs-d-essai/yamaha-wxa-50-un-amplificador-con179675

Picture optimized and rotated

to English:

It is important to note that the amplification stages benefit from heat sinks equipped with thermoconductive pads that transfer excess calories to the upper closure plate, while at a given time a small fan can contribute to accelerate cooling.

IcePower 125ASX2

 

[gvl]

^^^ ICEPOWER 125ASX2

 

[maty]

[Polish] https://audio.com.pl/testy/stereo/wzmacniacze-sieciowo-strefowe/2757-musiccast-wxa-50

to English:

* https://translate.google.com/translate?hl=&sl=pl&tl=en&u=https://audio.com.pl/testy/stereo/wzmacniacze-sieciowo-strefowe/2757-musiccast-wxa-50&sandbox=1

* https://www.translatetheweb.com/?fr...acze-sieciowo-strefowe/2757-musiccast-wxa-50#

Rated power (1% THD + N, 1 kHz) [W] 8 Ω, 2x 66
Rated power (1% THD + N, 1 kHz) [W] 4 Ω, 2x 109
Sensitivity (for maximum power) [V] 1.4
Signal / noise ratio (A-weighted filter, with reference to 1W) [dB] 78
Dynamics [dB] 96
Damping factor (relative to 4 Ω) 62

 

[maty]

Again, some measurements differs.

 

[maty]

Polish site:

Rated power (1% THD + N, 1 kHz) [W] 8 Ω, 2x 66
Signal / noise ratio (A-weighted filter, with reference to 1W) [dB] 78

Amirm measurement:

Measurements at 1 watt vs 66 watts (max power).

We need substract about 12 dB -> 84 dB


Polish site, SNR-A

Amirm: SNR

SNR-A is alway better than SNR -> SNR-A by Amirm must be about 86 dB.


8 dB is too much difference. Since Amirm has a spectacular measuring device (APx555), everything indicates that something is wrong with some of the Polish website measurements.

APx555

https://www.ap.com/analyzers-accessories/apx555/

It is best to write an email (Polish site) notifying of the divergence of measurements in this and other devices.

Message sent (with link) from its contact page: https://audio.com.pl/kontakt

 

[amirm]

Amirm measurement:

He is using 1 watt which will have worse SNR than my 5 watt or full power. He is also using a-weighting and I don't. So the measurements are not comparable. Mine though, is closer to how the manufacturer specs it.

 

[maty]

5 watts and not 66.

New numbers.

We need to substract about 7 dB. 96 -7 = 89 dB

The difference is greater than before, so something is not doing well or there is a problem in some device.

 

[Willem]

Anyway, it shows what a major manufacturer with serious engineering capacity can achieve. Excellent usability and properly implemented bugfree modern facilities combined with a sensible mix of amplification compromises for real world quality. Its only limitation is somewhat low power output. In the Netherlands it now sells for 400 euros (incl tax), or some 450 US dollar.

 

[maty]

Yamaha only says:

* Signal-to-Noise Ratio: 110 dB (Opt / Net / USB / Bluetooth in) / 98 dB (AUX in)


Must be at max power, which is the usual, to dazzle the potential client.

* Maximum Output Power: 90 W + 90 W (6 ohms, 1 kHz, 0.9 % THD, 1-ch driven)

 

[pjug]

Maybe it is just me, but it seems like this Yamaha amplifier is receiving more praise than it deserves. The Amazon amplifier has pretty much identical THD+N below 10W and provides a little more power. And costs less. Am I missing something?

 

[SimpleTheater]

Maybe it is just me, but it seems like this Yamaha amplifier is receiving more praise than it deserves. The Amazon amplifier has pretty much identical THD+N below 10W and provides a little more power. And costs less. Am I missing something?

I don't think you're missing much. The key item, as far as the amp is concerned, is what Amirm wrote "We have cleaner power than either Sonos or Amazon amps"

Coupled with bluetooth support, some trigger controls, which the Amazon* and Sonos do not have, it seems a good value.

* Casting to multi-room music from a line-in or Bluetooth input is not currently supported

 

[pjug]

I don't think you're missing much. The key item, as far as the amp is concerned, is what Amirm wrote "We have cleaner power than either Sonos or Amazon amps"

Coupled with bluetooth support, some trigger controls, which the Amazon* and Sonos do not have, it seems a good value.

* Casting to multi-room music from a line-in or Bluetooth input is not currently supported

Yes, but is it really cleaner, at least for practical purposes? The Amazon is just as clean below 10W, and the Sonos is cleaner with digital input.

 

[invaderzim]

@amirm....This unit uses an ICEpower125ASX2 module hence some good results

Does anyone sell buffers to use with the ICEpower modules? Their performance seems to be linked to the impedance and design of the input stage but I haven't seen anyone offer inputs for sale for the DIY crowd.

 

[folzag]

@amirm the amplifier 5W SINAD graph is starting to get pleasantly crowded.

Rather than grouping colors by 10db, how about by dynamic range of common playback media?

• Red for FM radio
• Yellow for analog cassette tape/vinyl
• Green for Redbook CD
• Blue for "Hi-Res" digital

PS. This might be more effort than you want to make, but going back and color-coding DAC SINAD graph in the same manner might be cool too.

 

[HammerSandwich]

5 watts and not 66.

New numbers.

We need to substract about 7 dB. 96 -7 = 89 dB

Quick sanity check: 10x power change = +/-10dB. How did you calculate 7dB?

 

[maty]

From the easy way, without logarithms

Double power: + 3dB

Half power: - 3 dB

5 watt -> 2.5 watts (-3 dB) -> 1.25 watts (-3 dB) -> 1 watt (almost -1 dB) => -7 dB.

 

[amirm]

@amirm the amplifier 5W SINAD graph is starting to get pleasantly crowded.

Rather than grouping colors by 10db, how about by dynamic range of common playback media?

Yeh, we are finally getting critical mass. I added the Median to the graph to separate it into two buckets. Once we have more, I will look at color coding.

 

[HammerSandwich]

From the easy way, without logarithms

Sorry! I thought you were looking at the dB difference between 5 & 66W. Carry on.

 

[pjug]

I don't think you're missing much. The key item, as far as the amp is concerned, is what Amirm wrote "We have cleaner power than either Sonos or Amazon amps"

Coupled with bluetooth support, some trigger controls, which the Amazon* and Sonos do not have, it seems a good value.

* Casting to multi-room music from a line-in or Bluetooth input is not currently supported

I just noticed that the THD+N curve is with analog input for both the Amazon and Yamaha. Now I see that the Yamaha is good deal better than the Amazon with digital input. So i take back what I said!

 

[Damian]

Where is the recommended list? I’ve only seen the review index.