This is a review and detailed measurements of the WiiM Amp Ultra stereo streaming amplifier. It was sent to me by the company and costs US $529.
I was surprised how heavy and solid feeling the Ultra is for its size. I upgraded its firmware which went smoothly and rather fast. I was pleasantly surprised by the usability of the touchscreen interface.
I tried to use the App but it would not add the unit yet show it as available. It would not however let me try to see or change its settings. Didn't want to spend too much effort here and just tested it using the front panel.
The rear panel shows the familiar interface we have seen in other WiiM products:
Note that this is one of the few amplifiers using TP3255 class D amplifier IC that has an internal power supply. I also like the inclusion of hardwired Ethernet. And support for Roon player streaming.
A thick manual comes with it but alas, it is in many languages so not much covered there. One thing of note was declaration of security fix period. This is welcome.But not the very short duration of December 31, 2026! Just one year from now??? Best to learn how to setup a VLAN to protect yourself.
EDIT: Online notice now says security updates will be available until December 2029 which is nice.
The included remote is another thing that made me happy especially since it is chargeable using USB-C.
WiiM Amp Ultra Measurements
Let's test the amplifier starting with analog RCA input:
This is competitive with other implementations but the real performance is revealing using digital inputs such as Toslink:
Naturally, streaming provides same performance:
This lands the Ultra easily in our "excellent" category of all amplifiers tested:
Using post filter feedback, we get one of the best implementations of PFFB on this platform:
No need to worry about speaker/load dependency.
Noise performance is again, one of the best for this platform and even in general:
Channel separation using digital is excellent as well:
Multitone performance is again, excellent for class and shows the typical rise in high frequencies:
Which is shown in exaggerated manner when we use dual 19 and 20 kHz tones:
There is a lot of power available here (amp rated at 100 watts into 8 ohm and 200 into 4 ohm):
I had to reduce the distortion limit to well below 1% as otherwise, it would simply not distort that much:
Again, we have the typical rise in distortion at higher frequencies:
In use the amp just got warm and handled clipping as if it did not happen. No shut down. Nothing. It simply handled being driven to death! Very nice.
And of course, was stable on power up:
There is no on off button so I did not run my noise test for these conditions.
Conclusions
WiiM delivers very well featured streaming amplifier with every optimization applied to get the best performance out of the TPA3255 class D amp. Measurements leave no room for complaints but a ton of praise. Beautiful and responsive UI completes the picture of one of the best streaming amplifiers I have tested.
The cost is reasonable for so much power in such a small enclosure with internal power supply to boot.
I am happy to recommend the WIiM Amp Ultra. Company is firing on all cylinders to be sure.
------------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
I was surprised how heavy and solid feeling the Ultra is for its size. I upgraded its firmware which went smoothly and rather fast. I was pleasantly surprised by the usability of the touchscreen interface.
I tried to use the App but it would not add the unit yet show it as available. It would not however let me try to see or change its settings. Didn't want to spend too much effort here and just tested it using the front panel.
The rear panel shows the familiar interface we have seen in other WiiM products:
Note that this is one of the few amplifiers using TP3255 class D amplifier IC that has an internal power supply. I also like the inclusion of hardwired Ethernet. And support for Roon player streaming.
A thick manual comes with it but alas, it is in many languages so not much covered there. One thing of note was declaration of security fix period. This is welcome.
EDIT: Online notice now says security updates will be available until December 2029 which is nice.
The included remote is another thing that made me happy especially since it is chargeable using USB-C.
WiiM Amp Ultra Measurements
Let's test the amplifier starting with analog RCA input:
This is competitive with other implementations but the real performance is revealing using digital inputs such as Toslink:
Naturally, streaming provides same performance:
This lands the Ultra easily in our "excellent" category of all amplifiers tested:
Using post filter feedback, we get one of the best implementations of PFFB on this platform:
No need to worry about speaker/load dependency.
Noise performance is again, one of the best for this platform and even in general:
Channel separation using digital is excellent as well:
Multitone performance is again, excellent for class and shows the typical rise in high frequencies:
Which is shown in exaggerated manner when we use dual 19 and 20 kHz tones:
There is a lot of power available here (amp rated at 100 watts into 8 ohm and 200 into 4 ohm):
I had to reduce the distortion limit to well below 1% as otherwise, it would simply not distort that much:
Again, we have the typical rise in distortion at higher frequencies:
In use the amp just got warm and handled clipping as if it did not happen. No shut down. Nothing. It simply handled being driven to death! Very nice.
And of course, was stable on power up:
There is no on off button so I did not run my noise test for these conditions.
Conclusions
WiiM delivers very well featured streaming amplifier with every optimization applied to get the best performance out of the TPA3255 class D amp. Measurements leave no room for complaints but a ton of praise. Beautiful and responsive UI completes the picture of one of the best streaming amplifiers I have tested.
The cost is reasonable for so much power in such a small enclosure with internal power supply to boot.
I am happy to recommend the WIiM Amp Ultra. Company is firing on all cylinders to be sure.
------------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Last edited:
Analog Inputs:
