My WiiM Amp tests, chapter 2

Looks like date/time stamp indeed, but I'm not convinced that this a production date. For example it doesn't follow the week number in the serial number.
My serial # starts P1TF235005xxx.
And the 50th work week would match my "uboot_verinfo": "231211.095208"

But I agree it is still probably not a production timestamp. The binary build date seems more likely. It could just be coincidence that my dates aligns or maybe they need to build a new binary when the line switches over for each production run.
 
My serial # starts P1TF235005xxx.
And the 50th work week would match my "uboot_verinfo": "231211.095208"

But I agree it is still probably not a production timestamp. The binary build date seems more likely. It could just be coincidence that my dates aligns or maybe they need to build a new binary when the line switches over for each production run.
"uboot_verinfo" for my 2 units is week before the week from the serial number.
 
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.
My unit has no class II power supply mark, the packaging has colourful music service icons, but the RCA inputs are as your new unit.

EDIT: my unit makes only the faintest of pulsing noises when my ear is within a couple of inches from it.
 
My unit has no class II power supply mark, the packaging has colourful music service icons, but the RCA inputs are as your new unit.

EDIT: my unit makes only the faintest of pulsing noises when my ear is within a couple of inches from it.
Different combinations are possible obviously. What about PCB_version of your Amp?
 
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.



Stay tuned.
measuring and creating a thread of an "all in one" amplifier, its inputs, its outputs etc. is much heavier (especially since this is a repeat) and technic than simple DAC sources etc. so good luck... ;-)
 
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Ver 5 is near perfect in term of measurement? I hear tick sound on sub when going to the next track. I’m not sure if it’s related to earlier pcb version or firmware. It’s hard to get replacement even on Amazon since they don’t have it in stock. I have not seen used wiim amp being sold.
 
Of course it's not near perfect, it's not a Purifi class amp. But so far it measures in accordance with my expectations without flaws I've seen previously.
And notice that I've no idea if my unit is like every ver 5 unit, or maybe it's different.
 
as far as possible...

now...
comparisons with the small fosi v3, ayima etc , necessarily comparable in terms of amplification, will be interesting ;-)
(tests at 4 or 8ohm?)
 
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Of course it's not near perfect, it's not a Purifi class amp. But so far it measures in accordance with my expectations without flaws I've seen previously.
And notice that I've no idea if my unit is like every ver 5 unit, or maybe it's different.
You may have mentioned this in previous posts, so forgive me if I missed this, but are these comparisons with original and new units running same updated firmware i.e just comparing hardware difference?
 
No, quick tests I've published so far were compared to the results I got when I was testing the old unit. I will repeat some tests also with the old device but I do not expect that the FW version will affect results in the areas where the device had HW related issues.
 
Cheers, that makes some sense - although the graphs are just blibs and blobs to me (niche Uncle Albert-related reference)
 
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.
 
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