My WiiM Amp tests, chapter 2

[Yoku-San]

A new unit is with me. Because new device is too cold to be powered, I can focus on external differences. Both units are almost undistinguishable.
One difference is reversed channels on RCA inputs. Second one is a class II power supply mark printed on the bottom.

I've seen units with reversed RCA plugs in some recent YouTube movies, so this change was probably applied in the meantime.

There are also subtle differences between outside boxes, like the mentioned class II mark. Another one are black and white icons of the music services vs colorful ones for the box of old unit.




First things first, as the full set of measurements and tests takes a lot of time, I will verify known issues at the very beginning.

PSU noise - absent, it's (almost) deadly silent. I can hear something only when my ear touches the chassis directly. Well, I know it could be pretty risky idea...

PCB_version - 5.

HF switching signal on sub out - absent.

Low frequencies / multitone bad performance - seems to be greatly improved in my quick and dirty measurements. I will provide more details tomorrow.

SMPTE, 5W:

View attachment 4658

Multitone, 5W:

View attachment 4659

Differences are huge.



Stay tuned.

Could you also post your results in the Wiim Amp Thread on ASR? I guess a lot of people there might be interested in the new measurements.

 

[Matt_Holland]

No need for that. Just look what your Amp reports when you call

https://xxx.xxx.xxx.xxx/httpapi.asp?command=getStatusEx

in the web browser (replace xxx.xxx.xxx.xxx with IP of your device).

Report:

{ "language": "en-GB", "ssid": "WiiM Amp-B0C4", "hideSSID": "0", "firmware": "Linkplay.5.0.604458", "build": "release", "project": "WiiM_AMP", "priv_prj": "WiiM_AMP", "project_build_name": "WiiM_AMP", "Release": "20240113", "FW_Release_version": "", "PCB_version": "4", "cast_enable": 0, "cast_usage_report": 1, "group": "0", "wmrm_version": "4.2", "expired": "0", "internet": "1", "uuid": "FF98F359E491E8054FCA10BB", "MAC": "C0:F5:35:2F:B0:C4", "BTMAC": "c0:f5:35:2f:b0:c5", "InitialConfiguration": "1", "temperature_power_control": "1000", "temperature_cpu": "34", "temperature_tmp102": "38", "AP_MAC": "C2:F5:35:2F:F0:C4", "date": "2024:01:19", "time": "16:21:34", "netstat": "0", "essid": "", "apcli0": "0.0.0.0", "eth0": "192.168.0.115", "eth2": "0.0.0.0", "ETH_MAC": "00:22:6C:2C:B3:4E", "hardware": "AmlogicA113", "VersionUpdate": "0", "NewVer": "0", "mcu_ver": "0", "mcu_ver_new": "0", "hdmi_ver": "15", "hdmi_ver_new": "", "update_check_count": "52", "BleRemote_update_checked_counter": "49", "ra0": "10.10.10.254", "temp_uuid": "5E4FF2C4E5641259", "cap1": "0x40000400", "capability": "0x20084808", "languages": "0x1ec", "prompt_status": "1", "alexa_ver": "20180604", "alexa_beta_enable": "0", "alexa_force_beta_cfg": "0", "dsp_ver": "", "ModuleColorNumber": "3", "ModuleColorString": "", "dsp_ver_new": "", "uboot_verinfo": "231201.154735", "kernel_verinfo": "#2 SMP PREEMPT Sat Jan 13 19:30:35 CST 2024", "silence_ota_flag": "0", "ota_interface_ver": "2.0", "streams_all": "0xeff33fd", "streams": "0xeff33fd", "region": "unknown", "volume_control": "0", "external": "0x0", "preset_key": "12", "plm_support": "0xb00416", "lbc_support": "0", "WifiChannel": "0", "RSSI": "0", "BSSID": "", "wlanSnr": "0", "wlanNoise": "0", "wlanFreq": "0", "wlanDataRate": "0", "battery": "0", "battery_percent": "0", "securemode": "1", "upnp_version": "1005", "upnp_uuid": "uuid:FF98F359-E491-E805-4FCA-10BBFF98F359", "uart_pass_port": "0", "communication_port": "8819", "web_firmware_update_hide": "0", "new_tunein_preset_and_alarm": "1", "new_iheart_podcast": "1", "tidal_version": "2.0", "service_version": "1.0", "HiFiSRC_version": "1.0", "EQ_support": "Eq4p_ver_2.0", "audio_channel_config": "1.0", "tz_info_ver": "1.0", "tz": "0.0", "max_volume": "75", "power_mode": "-1", "security": "https\/2.0", "security_version": "3.0", "security_capabilities": { "ver": "1.0", "aes_ver": "1.0" }, "public_https_version": "1.0", "BleRemoteControl": "1", "BleRemoteConnected": "1", "BleRemoteVersion": "0041", "BleRemoteBatterylevel": "100", "BleRemote_has_new": "0", "BleRemoteNewVersion": "", "BleRemoteRSSI": "-62", "BleRemote_dev_state": "normal", "autoSenseVersion": "1.0", "privacy_mode": "0", "DeviceName": "Living Room", "GroupName": "Living Room" }

Do we know which PCB version received the improvements?

 

[canard]

Could you also post your results in the Wiim Amp Thread on ASR? I guess a lot of people there might be interested in the new measurements.

I slipped the links again a few days ago on asr to the onlyoneme threads.... so it's ok..

Post in thread 'WiiM Amp discussion' https://audiosciencereview.com/forum/index.php?threads/wiim-amp-discussion.47096/post-1853003

(onlyone knows me well asr...if he didn't do it..he has his reasons..
but it doesn't seem abnormal to present your Wiim device measurements... on the "wiim" forum... no? ;-)
)

 

[Yoku-San]

Do we know which PCB version received the improvements?

First things first, as the full set of measurements and tests takes a lot of time, I will verify known issues at the very beginning.

PSU noise - absent, it's (almost) deadly silent. I can hear something only when my ear touches the chassis directly. Well, I know it could be pretty risky idea...

PCB_version - 5.

HF switching signal on sub out - absent.

Low frequencies / multitone bad performance - seems to be greatly improved in my quick and dirty measurements. I will provide more details tomorrow.

PCB 5

 

[onlyoneme]

Could you also post your results in the Wiim Amp Thread on ASR? I guess a lot of people there might be interested in the new measurements.

I post some single results on ASR too, but I've decided that this forum will remain the main place where I share my experiences around WiiMs. That's why I have so many fans here who love measurements in audio just like me

 

[Smartplug]

I post some single results on ASR too, but I've decided that this forum will remain the main place where I share my experiences around WiiMs. That's why I have so many fans here who love measurements in audio just like me

We appreciate your effort as I also learn a lot from your experience. Thanks!

 

[onlyoneme]

I got the confirmation that my unit is a standard unit available since early December. So every pcb 5 ver device should behave like mine.

 

[Yoku-San]

I got the confirmation that my unit is a standard unit available since early December. So every pcb 5 ver device should behave like mine.

I think that's not the really true. I received a humming unit with production date week 50 of 2023. I think others with the same production week also had similar issues. And I think I remember they were not PCB5 but PCB 2. I did not check my PCB version unfortunately since I directly sent it back after hearing the hum.

 

[onlyoneme]

Maybe different revisions were sold the same time and the newest one was replacing older ones gradually.

Also

WiiM Amp discussion

Well, good news! I just got my replacement WiiM Amp from Amazon and it has absolutely no audible hum issue! I received my first WiiM Amp from Amazon on 12/27 with PCB version 2 and my replacement was received today on 1/12 with PCB version 5. As a separate tangent, WiiM should reconsider...

audiosciencereview.com

 

[steadyshot]

I think Wiim should pay you to test the units before release.

 

[canard]

I think Wiim should pay you to test the units before release.

That's just an enormity...and very much the subject...

 

[Achim1811]

The history of f.e. given selected devices to "testers" is long and infamous

 

[onlyoneme]

I think Wiim should pay you to test the units before release.

Bad idea and I would disagree. However, I think they should definitely pay more attention to such tests made internally before the release.

 

[Achim1811]

I would recommend them spending more money in quality control!
But my fear is that this would be a high obstacle in such cheap mass market devices like the Amp, making it much more expensive. The quality dispersion of this device is quite high.

 

[dimangiful]

I think that's not the really true. I received a humming unit with production date week 50 of 2023. I think others with the same production week also had similar issues. And I think I remember they were not PCB5 but PCB 2. I did not check my PCB version unfortunately since I directly sent it back after hearing the hum.

My humming Wiim is PCB 4, production week 50. Ordered from Amazon on Jan 13th. The order date is well after the issues were widely recognised. Also some folks have reported later production batch with earlier delivery. Assuming here that the time of production directly relates to product quality (later = better). The humm on my unit is not as bad as others have it, but still a concern.

I really don't know how Amazon works with their logistics and supply, especially when there are different types of scenarios (amazon is in control vs supplier is in control). But it does seem that with Wiim, the supply chain does not have the capability to recognise production batches and tag the faulty ones. Or they simply decided not to do it for some reason.

 

[Vladetz]

My humming Wiim is PCB 4, production week 50. Ordered from Amazon on Jan 13th. The order date is well after the issues were widely recognised. Also some folks have reported later production batch with earlier delivery. Assuming here that the time of production directly relates to product quality (later = better). The humm on my unit is not as bad as others have it, but still a concern.

I really don't know how Amazon works with their logistics and supply, especially when there are different types of scenarios (amazon is in control vs supplier is in control). But it does seem that with Wiim, the supply chain does not have the capability to recognise production batches and tag the faulty ones. Or they simply decided not to do it for some reason.

Maybe it is not bad batches, but some bad samples in first batches

Anyway almost everyone who received humming unit has an opportunity to exchange it

 

[Smartplug]

Report:

Do we know which PCB version received the improvements?

Darn, I run the link and mine shows pcb version 2. I have till end of the month for exchange. There was hum and tick on sub even with the latest firmware. So if I would exchange this will I get ver 5?

 

[Smartplug]

Bad idea and I would disagree. However, I think they should definitely pay more attention to such tests made internally before the release.

I agree they should released this product after all test good. Now, many users seeing these and hearing hum and then return or exchanged.

 

[dimangiful]

Maybe it is not bad batches, but some bad samples in first batches

Anyway almost everyone who received humming unit has an opportunity to exchange it

The consensus on this forum is that the problems are related to production batches. That is partly confirmed by Wiim. They haven't acknowledged if all early units have issues, but they state the issue is fixed for later batches. At this point as there's so much speculation going, a lot of people will be unhappy just to know their unit is from early batch.

I have no complaints with the company so far, I can replace the unit, assuming that the replacement will not have these issues. With Amazon it could be challenging, as they don't seem to have control over the supply chain. And that was my second point. Not complaining I can't replace it, just a bit awed about the lack of quality and control with supply chain.

 

[onlyoneme]

The consensus on this forum is that the problems are related to production batches. That is partly confirmed by Wiim. They haven't acknowledged if all early units have issues, but they state the issue is fixed for later batches. At this point as there's so much speculation going, a lot of people will be unhappy just to know their unit is from early batch.

I have no complaints with the company so far, I can replace the unit, assuming that the replacement will not have these issues. With Amazon it could be challenging, as they don't seem to have control over the supply chain. And that was my second point. Not complaining I can't replace it, just a bit awed about the lack of quality and control with supply chain.

We should distinguish possible problems. Every pcb 2 unit will be affected by HF switching noise on sub out and will have worse performance at low frequencies, and it's due to design changes made in HW for newer units.
And it's probably more complex for humming issue. I think that some improvements were made in the design, manufacturing process or QA, and these result in lower probability of getting the affected unit in case of higher HW revisions.