Linkfor/Proster TPA3116D2 Stereo Mini-Amp
I recently picked up two of these...
... one for a friend and one for myself. Notice the return of tone controls... YES!
Per usual I did some testing and a teardown before delivering.
The test results are pretty much right on the TPA3116D2 Spec which should be no surprise. 35 watts per channel on 8 Ohms (50 on 4), 0.1% distortion, 20hz to 20khz within 1 db. But like all of these mini-amps, running them on 4 ohms is not advisable since they are fully enclosed and could overheat.
I find this to be a capable product worth more than it's price.
There is an issue with the bulk capacitors used in this amplifier. Typical of Chinese designs they've made these things with little or no safety margin. Specifically: 25 Volt capacitors on a 24 volt supply. While this isn't a significant risk, on my units I swapped out the 25 volt parts for 35 volt ones just to play it safe.
My full review of the product is on Amazon.ca
The Canadian product page is HERE
The US product page is HERE
Thanks for the review, how did you test the amps?
Pretty much the normal way ... signal generator, oscilloscope, voltmeter, dummy load, Infrared thermometer, and good old visual inspection.
It's pretty simple... run the power up to the edge of clipping, read the output voltage do a little math to get power outputs, run the power up to 50% set up a null test between input and output to see residual distortion, do frequency sweeps with the scope's FFT to see frequency response. Stick the voltmeter on the outputs to check DC offsets and probe around inside to check capacitor tolerances etc. Finally check with the thermometer for hot spots and take a good look at the way it's built.
The first entry in this thread shows a problem with the bulk capacitors in this amplifier. Here is the fix...
I simply removed the 3 x 470uf 25 volt capacitors and put in a single 2200uf 35 volt low ESR part. The provision was already on the board (as it often is) so it was just a simple soldering job. This ups the reserve from 1410uf to 2200uf and provides a much better safety margin for the power supply... 11 volts instead of 1.
One thing I do that most people don't... With double sided boards I will solder both the top and bottom of the board on high current connections. It removes the board's plate-through resistance from the equation and provides a more reliable connection.