tpa3116d2 XY-502 modify for PBTL operation

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I have a few of these boards as they are on ebay for under $5 USD all the time. I wanted to use one to power a 5" sub I just built so I referenced some other threads, the data sheet, and my cellphone camera in order to see the traces lol. It turns out you need to just short out C4 and C5. You can see in my pic C3 was missing, ignore that, it is from the way they ship these with the heatsink bouncing around, it scraped it right off.. You can see the scrape along the side of the power LED. For mine I had to move once of the caps I pulled off the L channel to fix that on the R channel. I have a big tip soldering iron, no needle tip, and I hope it is just caffeine but I cannot keep my hands still today :( So ignore the melt marks on the terminals too please :)

The other piece is to tie the L in put to ground, which I did under the input terminal, and then to tie the L output pins and R output pins together. I tied those together under the output terminal as pictured. This actually surprised me by working first try. I do NOT recommend soldering below the board like I did though as after about 3 minutes some magic smoke came out where the terminal shorted to the ground plane. It is easier to just stick a piece of wire in the R+ to R- and the L+ to L- outputs in order to tie the outputs together anyways. Same for the input. This makes it so all you need to do solder wise is short the two input caps C4 and C5.

TLDR: Short out C4 and C5, add a jumper from L in to gnd, a jumper from R+ to R-, and a jumper from L+ to L- and you will have a mono board.
XY-502
XY502
 

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Hi!! I did your mod, but, shorting out the C4 and C5 it not work anymore. I tried then to putt a jumper of the terminals of the C4 and then again of the C5 and then worked.

But then I plugged one XY-502 without mod and other XY-502 with the mod, to compare, and there isn't any audible differnce of power or increase of the volume... Can you verify that mod is the correct PTBL mod? Thanks ;)
 
2x BTL -> PBTL
2x50W@4Ohm -> 1x100W@2Ohm
Voltage and gain remain the same, so only if you lower the impedance of the load you will get more power out of it.

I read in the specs of Texas Instruments that should be BTL (2x50W@4Ohm) or PTBL (1x100W@4Ohm).

Maybe I'm wrong, but for me, it makes sense because in BTL there the two channels that will go 50W each channel, meanwhile in PTBL it's the "fusion" of both channels, and for this will go to 100W at the same Ohms.

That is what I understood
 
Not "maybe", but sure you are wrong. Single ended to BTL= 4x power on same resistor,
PBTL = same watt and volt, but it is able to deliver more ampere in lower resistor.
So: 2x power on half ohm´s.

Easy. No opinion, but physical fakt. Sorry.

Okay, got it! Thanks! So now I know that I need another chip amp with more output Watts than the TPA3116 :rofl: That also means a new Power Supply...

I need enough power to create a portable guitar amp and I thought with 50W was pretty enough, but not... I have a Valve Fender 40W and it sounds like the double or triple loud than the 50W of the TPA3116...

Any suggestion?

Thanks!
 
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Okay, got it! Thanks! So now I know that I need another chip amp with more output Watts than the TPA3116 :rofl: That also means a new Power Supply...

I need enough power to create a portable guitar amp and I thought with 50W was pretty enough, but not... I have a Valve Fender 40W and it sounds like the double or triple loud than the 50W of the TPA3116...

Any suggestion?

Thanks!


The fender speaker has an impedance of 8 Ohms, hence the TPA3118 may deliver 30W into it. A TPA3118 powered by 24V laptop brick drives a 12" celestion speaker in my guitar combo. Enough power to jam with a loud drummer imho;)
 
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