Be careful about drilling or enlarging holes in two-sided boards . not only because you might accidentally cut or short another via but because there can be metallized though hole connections which you break when enlarging holes. Personally I think it much better to raise the board and ADD or Mount the caps below it. Plus some apparently two layer boards might be 4 layer ones , not easily seen even looking at the edges
The size of the Shui Yuan boards is length 110 mm by width 70mm so that :
Provided your enclosure has an interior height of 75mm or more my advice is :
Mount the boards vertically with the long edges at the bottom and near the top of your enclosure . This way you gain two advantages :
The first one is the heatsink and its fins are oriented vertically which greatly improves its efficiency and the chip runs cooler. The board are 70 wide and the heat sinks are 60 so even with an enclosure of only 72mm interior height there is enough space below and above the heat-sink for air circulation , when mounted yiertically ,.
The second is that you can add filtering caps on the now vertical underside of the board , even without taking the originals out and without constraints regarding their size .For instance it is no problem to add two 4700uf/63volt caps and two ceramic 1uf/100 volt caps parallel to the electrolytics , by simply laying the electrolytics flat against the underside of the board and soldering them to the existing solder-points with short pieces of flexible wire and holding them in place with a suitable silicone or glue .
Or , if you do not mind somewhat longer conections , you can stand the caps in silicone on the bottom of your enclosure , in which case it is important that the ceramic 1uf caps be soldered on the underside of the board , not on the added caps. Be very careful when soldering the positive connections as they are tightly surounded by the ground-plane on the underside of the board
Provided your enclosure has an interior height of 75mm or more my advice is :
Mount the boards vertically with the long edges at the bottom and near the top of your enclosure . This way you gain two advantages :
The first one is the heatsink and its fins are oriented vertically which greatly improves its efficiency and the chip runs cooler. The board are 70 wide and the heat sinks are 60 so even with an enclosure of only 72mm interior height there is enough space below and above the heat-sink for air circulation , when mounted yiertically ,.
The second is that you can add filtering caps on the now vertical underside of the board , even without taking the originals out and without constraints regarding their size .For instance it is no problem to add two 4700uf/63volt caps and two ceramic 1uf/100 volt caps parallel to the electrolytics , by simply laying the electrolytics flat against the underside of the board and soldering them to the existing solder-points with short pieces of flexible wire and holding them in place with a suitable silicone or glue .
Or , if you do not mind somewhat longer conections , you can stand the caps in silicone on the bottom of your enclosure , in which case it is important that the ceramic 1uf caps be soldered on the underside of the board , not on the added caps. Be very careful when soldering the positive connections as they are tightly surounded by the ground-plane on the underside of the board
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I wanted to avoid drilling out the PCB, if you look at the pic in my post #355, I had some fat little Super Through snap in caps - theres no way they will fit thru the existing very small PCB holes. I flipped the caps, double side taped them to the PCB, and soldered the tags at the tops of the caps to hook-up wire soldered into the PCB holes. Not a perfectly elegant solution but functional. I've since bypassed those big caps also with smaller poly caps, and its easy to do that with inverted caps.
I ended up dremelling short gaps in the first fin of the heatsink to allow the width and mounting the caps on silicone blobs a bit higher with thinner legs/leads soldered to the original. Not especially tidy I will confess but it works and I didn't have to build new mounts for sideways mounting.
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No it is not possible with this chips. To increase or double the power (with low impedance) it takes a version with double chips in PBTL mode. This model is not available in double PBTL
The TPA3255 Chip can be used in three modes.
4 x SE Channels
2x BTL Channels
1 x PBTL Channels.
It does not require two chips for PBTL. It does however require a PCB with the necessary circuits to configure in the different modes. See TI Data Sheet
https://www.ti.com/lit/ds/symlink/t...=https%3A%2F%2Fwww.ti.com%2Fproduct%2FTPA3255
Yes I know the specifications well (SE, BTL, PBTL),
I forgot to mention that it is for a PBTL stereo.
2 chips PBTL for stereo mode at maximum power.
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I just received the "deluxe" version of this amp with the LME49720NA op-amps, Nichicon FW 2200uF/63v caps and Wima caps. I measured the height of the Nichicon caps and they are 35 mm. My "basic" version amp has 30 mm high caps.
I first plan on doing distortion tests on both boards at various power levels. I honestly don't expect to see any significant differences, but we'll see. Then I plan on doing a double-blind listening comparison of the boards. Will probably be a couple of weeks before I'm ready to post results.
double blinded no less! Impressive commitment to an evidence based approach. Await the results with interest!
To rrobot....
To get the boards mounted vertically sideways what I do is get an aluminum cut-off from some place making aluminum windows/doors then cut that to size with an angle-cutter /stainless steel disc which is only 1mm in thickness , then machine it with file and drill to the exact size and lenght I need , base 40 mm , vertical plane 75 mm and lenght 120 is what I do. Then mount the board with spacers to allow for the electrolytic caps which go between the board and the aluminium-angle .
But of course one could simply use two angles only . The advantage of my solution is sturdyness and easy mounting of the caps which can be glued onto the aluminium so be totally inmobilized with respect to the PCB but without touching that.
To get the boards mounted vertically sideways what I do is get an aluminum cut-off from some place making aluminum windows/doors then cut that to size with an angle-cutter /stainless steel disc which is only 1mm in thickness , then machine it with file and drill to the exact size and lenght I need , base 40 mm , vertical plane 75 mm and lenght 120 is what I do. Then mount the board with spacers to allow for the electrolytic caps which go between the board and the aluminium-angle .
But of course one could simply use two angles only . The advantage of my solution is sturdyness and easy mounting of the caps which can be glued onto the aluminium so be totally inmobilized with respect to the PCB but without touching that.
Hello everyone,
It's been more than me that I did not come to see what is happening on the side of the suiyuan audio 3255, I remained a modification of change of the op with a OPA 1656 and condos by nichicon 4700uf-63v ...
what about the different PO possibilities?
you therefore advise to change the wima ...
what type of food is ultimately best suited?
I had selected a DC48V@6.5A
Alimentation de commutateur HIFI 250W, DC300V0.6A + 12.6V4A + 6.3V4A pour amplificateur a Tube Audio | AliExpress
Is there anything else?
It's been more than me that I did not come to see what is happening on the side of the suiyuan audio 3255, I remained a modification of change of the op with a OPA 1656 and condos by nichicon 4700uf-63v ...
what about the different PO possibilities?
you therefore advise to change the wima ...
what type of food is ultimately best suited?
I had selected a DC48V@6.5A
Alimentation de commutateur HIFI 250W, DC300V0.6A + 12.6V4A + 6.3V4A pour amplificateur a Tube Audio | AliExpress
Is there anything else?