• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

UWAYKEY: Can an $18 Amplifier Be Any Good?

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 77 58.8%
  • 2. Not terrible (postman panther)

    Votes: 46 35.1%
  • 3. Fine (happy panther

    Votes: 6 4.6%
  • 4. Great (golfing panther)

    Votes: 2 1.5%

  • Total voters
    131

DanielT

Major Contributor
Joined
Oct 10, 2020
Messages
2,655
Likes
2,063
Location
Sweden - Слава Україні
I mean … it‘s fine if you are listening to cassette …
Talk radio, podcast, via Bluethoote. Along with some small cheap speakers then I can imagine it.:)

OT:
Edit:
Aha! I figured it out. Find an old radio at a flea market. Place that amplifier in it along with some cheap broadband elements.:)..
In that case, no rarity, no valuable old radio, they should not be broken.

By the way, it can be a fun try on DIY project. The big wallet does not need to be opened up and the sound, well it will be what it will be. Not so important the sound, I think, for such a small project.:)

481884579_623fdabb-1fac-4c32-a09f-de2b720b6a3c.jpg
 
Last edited:

tonycollinet

Major Contributor
Forum Donor
Joined
Sep 4, 2021
Messages
2,189
Likes
3,126
Location
UK/Cheshire
Hook it up to a pair of these, and It'll probably sound better than most bluetooth speakers that are priced a fair bit higher.

 

DanielT

Major Contributor
Joined
Oct 10, 2020
Messages
2,655
Likes
2,063
Location
Sweden - Слава Україні
Or maybe some vinyl? :)
Or LP? …:facepalm: Sorry I could not resist .:(
No way. Partly no phono input but vinyl, I think, should be played with vintage turntable and time-typical amplifier, receiver. Something like::)

Harman-Kardon-330C-54771.jpeg

It was my old-fashioned conservative self that spoke out now. But that UWAYKEY with vinyl is like::)

Maybe a bit of a far-fetched parable it is admitted, but still.:)
 
Last edited:

tomtoo

Major Contributor
Joined
Nov 20, 2019
Messages
2,673
Likes
3,140
Location
Germany
For me looks like the 4ohm power is determined by the 3amp powersupply not the amp.
 

TheBatsEar

Major Contributor
Forum Donor
Joined
Jun 16, 2020
Messages
1,751
Likes
2,663
Location
Germany
It was me that asked Amir to waste his time, i apologize. :p

Here is a thread i made back then, it explains some of it's features:

To me it was worth it's cost :cool:
 

tomtoo

Major Contributor
Joined
Nov 20, 2019
Messages
2,673
Likes
3,140
Location
Germany
It was me that asked Amir to waste his time, i apologize. :p

Here is a thread i made back then, it explains some of it's features:

To me it was worth it's cost :cool:

There are many tube amps out there that measuring more worse, have less power, no BT or usb. And the owners think paying 1k is absolutly ok.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
37,954
Likes
162,179
Location
Seattle Area
For me looks like the 4ohm power is determined by the 3amp powersupply not the amp.
3 amps at 24 volts is 72 watts. Allowing for 10% loss, there is still plenty of power available to it. I watched the current meter on my lab supply during the sweep and I don't think it reached 2 amps let alone 3 amps. I think it thermally limited due to poor heatsinking.
 

TheBatsEar

Major Contributor
Forum Donor
Joined
Jun 16, 2020
Messages
1,751
Likes
2,663
Location
Germany

Talisman

Active Member
Forum Donor
Joined
Mar 27, 2022
Messages
128
Likes
244
There are now an impressive amount of small amps from 70 to 150 euros that sound pretty good to very good, that as cute as this little amp is, I would never consider it even for the garage, the cheapest amps I own and use. they are two breeze mini dual tpa 3116, of which I have not found any measurements but I am quite sure that they measure better and I know or absolutely sure that they have much more watts. Paid 38 euros.
I believe that by now the level of decency is so cheap that it is really not necessary to rely on something openly poor because with a few euros more you can get something that sounds really good
 

tonycollinet

Major Contributor
Forum Donor
Joined
Sep 4, 2021
Messages
2,189
Likes
3,126
Location
UK/Cheshire
There are now an impressive amount of small amps from 70 to 150 euros that sound pretty good to very good, that as cute as this little amp is, I would never consider it even for the garage, the cheapest amps I own and use. they are two breeze mini dual tpa 3116, of which I have not found any measurements but I am quite sure that they measure better and I know or absolutely sure that they have much more watts. Paid 38 euros.
I believe that by now the level of decency is so cheap that it is really not necessary to rely on something openly poor because with a few euros more you can get something that sounds really good
I bought a little nobsound amp for my son to go with a a pair of old speakers for TV use.

£40 including power supply. It's good enough not to be noticed.
 

KEFCarver

Member
Joined
Mar 29, 2021
Messages
50
Likes
54
Location
Tucson, AZ
This reminds me of an old TDA1554 kit amp I got in the 90’s from an electroncs hobby catalog. Don’t even think the chip was even genuine. It had so much distortion at all volumes that it could easily pump out lots of “power” since the bandwidth was so limited. It just rounded all the edges off when it went into hard clipping. Great for a bass head in high school, but worst SQ ever. I’d say the $18 is too much. Yes it’s cheap, but it will be all over the place sound-wise. Maybe if it was a components and unpopulated PCB project kit I could warm up to it since there would be pedagogical value.

A member asked me a while ago to test the ultra cheap ($18) UWAYKEY Mini Bluetooth Amplifier on Amazon. To make the clickbait title work :), I omitted the cost of the external power supply you need to bring yourself. What you get is a three board assembly:
View attachment 208070
View attachment 208071

It took less than 5 minutes to put the heatsink on the main class D amp chip and sandwich the main board with the top and bottom. The chip used must be for smart speakers as it has voice prompts when you change inputs. Speaking of that, it has Bluetooth (which I did not test), analog and USB in. The little heatsink has no air flow and in testing, it got quite hot to touch at times.

For testing, I used my lab power supply and set the output voltage to 24 volts (max spec). The supply has 3 Amps max current. Amplifier is rated for dual 50 watts at that voltage input.

UWAYKEY Mini Bluetooth Amplifier Measurements
I started testing with analog input with volume adjusted for 29 dB gain:
View attachment 208072

Considering the price, this is not half bad:
View attachment 208073

I kludged up a USB type A to type A cable and ran the dashboard test again:
View attachment 208074

As you see performance is not as good as analog input. Worse yet, just a few seconds later, it lost stability and would no longer work reliably. If I powered it down, it would work for a second or two and then go crazy again. It may be a design issue or my setup. Either way, I could only continue with analog input testing.

Noise floor is high as you can see in the FFT graphs above:
View attachment 208075

Crosstalk managed to be worse than the worst I have tested so far:
View attachment 208076

Multitone shows increased distortion at both ends of the spectrum:
View attachment 208077

The most important test for class D amps shows strong load dependency:
View attachment 208078

So the tonality you get will depend on speaker you hook up to it.

As usual, we fall way short of stated power levels:
View attachment 208079

View attachment 208080

8 Ohm performance was a bit better:

View attachment 208081

Response vs frequency is smooth but that may be due to high noise floor which masks distortion:
View attachment 208082

Amplifier Listening Tests
I hooked up one channel to my Infinity Reference 253 speaker and starting to listen. There was a lot more power than I expectedly, likely due to only having to drive one channel. The sound was surprisingly good until you cranked it to max volume. Speaking of which, if I paused input, the last 25% of the volume range produced tweeter hiss that was audible to about 1 meter/3 feet.

I was very satisfied with subjective performance until I landed on two clips, both of which were busy with both bass and treble notes. On these two tracks, the sound was very distorted at almost all volume levels. High frequencies would get gritty and distorted and bass response was bad as well. I power cycled the unit and let it cool and it seemed to play well for a couple of seconds and then would get distorted. It may be that the crest factor is too low causing the amp to drive hard most of the time with these two tracks. And then it overheats and distorts.

Conclusions
The first amplifier I ever built (with my brother when we were 10 or 11 years old) was this massive board and produced only 10 watts a channel. It also cost us many months of allowance. Compare that to this amplifier which for the price of a fast food meal for two, gives you stereo sound that most of the time is impressively good. If it did not distort on those two channels, I would say you could build an amp with two of them and be in business.

Given the distortion/heat issue, I can't recommend the UWAYKEY amplifier.

------------
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 looking at that same amp and decided to go with the Douk Nobosound NS-01G Pro, which was about $33 (Amazon), which actually worked for what I needed though, it does not put out the power they say. Like your anecdotal amp building story.
 

tomtoo

Major Contributor
Joined
Nov 20, 2019
Messages
2,673
Likes
3,140
Location
Germany
3 amps at 24 volts is 72 watts. Allowing for 10% loss, there is still plenty of power available to it. I watched the current meter on my lab supply during the sweep and I don't think it reached 2 amps let alone 3 amps. I think it thermally limited due to poor heatsinking.

Its interesting. The only thing i could read
"...7.3.11 Thermal Protection Thermal protection on the TPA31xxD2 family prevents damage to the device when the internal die temperature exceeds 150°C. There is a ±15°C tolerance on this trip point from device to device. Once the die temperature exceeds the thermal trip point, the device enters into the shutdown state and the outputs are disabled...."

There is no talk about power limiting due thermal problems. That i could find.
 

TheBatsEar

Major Contributor
Forum Donor
Joined
Jun 16, 2020
Messages
1,751
Likes
2,663
Location
Germany
Its interesting. The only thing i could read
"...7.3.11 Thermal Protection Thermal protection on the TPA31xxD2 family prevents damage to the device when the internal die temperature exceeds 150°C. There is a ±15°C tolerance on this trip point from device to device. Once the die temperature exceeds the thermal trip point, the device enters into the shutdown state and the outputs are disabled...."

There is no talk about power limiting due thermal problems. That i could find.

There are two things that would limit the output voltage, first is a voltage at the PLIMIT pin:
1653284707203.png
1653284780008.png


Second would be thermal protection with automatic recovery pin active, depends on how fast it recovers i guess:
1653284831189.png


Sadly, it's very hard to see how the pins are connected.

I only used a 12v PSU from an old external hard drive, which limits max voltage and thus heat, i guess. Never had it go into any sort of protection nor produce any amount of heat.
 

tomtoo

Major Contributor
Joined
Nov 20, 2019
Messages
2,673
Likes
3,140
Location
Germany
There are two things that would limit the output voltage, first is a voltage at the PLIMIT pin:
View attachment 208365View attachment 208366

Second would be thermal protection with automatic recovery pin active, depends on how fast it recovers i guess:
View attachment 208368

Sadly, it's very hard to see how the pins are connected.

I only used a 12v PSU from an old external hard drive, which limits max voltage and thus heat, i guess. Never had it go into any sort of protection nor produce any amount of heat.

The second way it cant be, couse the result would be on,off,on.
And the first way looks complicated. How to decide plimit voltage to not get thermal protect that would switch off the chip?
 

TheBatsEar

Major Contributor
Forum Donor
Joined
Jun 16, 2020
Messages
1,751
Likes
2,663
Location
Germany
The second way it cant be, couse the result would be on,off,on.
Unless it's really, really fast, but then you'd always be limited by the speed with which you ask the internal sensor.

And the first way looks complicated. How to decide plimit voltage to not get thermal protect that would switch off the chip?
Don't know, it's just another way to limit voltage i found. I doubt it's activated right now.
 

tomtoo

Major Contributor
Joined
Nov 20, 2019
Messages
2,673
Likes
3,140
Location
Germany
Unless it's really, really fast, but then you'd always be limited by the speed with which you ask the internal sensor.


Don't know, it's just another way to limit voltage i found. I doubt it's activated right now.

Overall iam not realy happy with that power limiting out of thermal reasons. I not get a good explanaiton for it.
 

TheBatsEar

Major Contributor
Forum Donor
Joined
Jun 16, 2020
Messages
1,751
Likes
2,663
Location
Germany
Overall iam not realy happy with that power limiting out of thermal reasons. I not get a good explanaiton for it.
Thinking about it again, yeah, you are right, it's on/off, not really voltage limiting.
 
Top Bottom