TPA3255 Reference Design Class D Amp GB

[xrk971]

The LM5010 is a known problem and only workaround is to provide an external 15v supply. Many SMPS have auxilary 15v so it’s an easy fix. Just connect it to where the +15v solder bridge is. Add a 2200uF cap to make sure the 15v rail stays up longer than main amp shutdown to prevent turn off thump.

You can see my workaround was to make a connector where the inductor for the LM5010 is. You could use the pads of the inductor and wire jumper from there to 15v solder bridge. Find a suitable ground point.
Basic SOT-223 12v LDO with 1A capability. Really only maybe 100mA is needed.

Look for Input / GND / Output pinout.

 

[borisbergman]

Thanks, LM2940IMP-12/NOPB -> MIC2920A-12WS.

 

[xrk971]

Thanks for finding that part. I had a hard time actually. Kept getting wrong pinout.

 

[borisbergman]

LM5010 has LMR38010 when you draw a new board
One more thing, line 56 of BOM says 220R/1%/TF/0805, but product number 603-RT0805FRE072K2L refers to 2k2. Which one is it?
Oh, I believe I cannot PM, but I would like a schematic if possible.

 

[xrk971]

Please pm me with your email. I only provide schematics to people who buy the board. You can also message me on Etsy.
What is part designator of that resistor?

 

[borisbergman]

The resistors are R1021-R1024.

 

[xrk971]

You must be looking at an old BOM and schematic. There is nothing higher than 2xx on part labels.

 

[RAAM]

I think I am going to build one of these amps to power the XDS8's I am gathering parts for so will start selling off parts and gear I no longer need.

 

[rhing]

I'm beginning my build and I am using a HiFi 2000 ModuShop Pesante 2U chassis with a baseplate. Is there a mounting hole pattern for the amp module PCB? It doesn't exactly line up with the Pesante baseplate mounting holes which are 10mm apart.

 

[Vunce]

I’m not sure using the modushop baseplate is a good idea. The TDA chip uses an aluminum spacer sandwiched between the aluminum chassis floor and chip to conduct heat. The modushop baseplate is steel which is not good for heatsinking purposes.

 

[xrk971]

You could just mount the amp onto a smaller aluminum plate and put that onto your Modushop case with steel bottom.

 

[xrk971]

Super build by Mikebarney with detailed write up and build instructions on how to make a complete amp with buffer, PSU and chassis.

https://sites.google.com/site/mpbarney/xrk-tpa3255-amplifier

 

[xrk971]

Congrats to Plott for a superb build of this amp!


Pro level uber-DIY execution!

 

[zman01]

Istvan,

That's a very nice build - congratulations!

 

[Plott]

Many thanks Zia, glad you like it! I like it very much

And many thanks X for the kind words

 

[redjr]

@Plott A very, very nice build. Beautifully executed!

 

[rhing]

Very nice indeed. It makes my black box look rather pedestrian.

 

[Plott]

@redjr @rhing many thanks

 

[xrk971]

Hi Folks,
I am re-releasing the non-PFFB version of this amp (Rev001) as a bare PCB. Note that the commercial Warp-1 amp does not employ PFFB either. The sound of no-PFFB amp is superb and distortion is already low enough that I don’t really think it sounds better with PFFB. The DCDC buck converter that was out of stock for a long time is now back in stock, so that makes building this version much more attractive. There are some tricks that this PCB has compared to other TPA3255 implementations out there that still won’t sound as nice. Thick 2oz copper double stitched ultra-low impedance current paths where it matters, unique extra filtering on outputs, a layout that emphasizes low ground loop area, low impedance, and great symmetry.

Blue solder mask, 2mm thick PCB, 2oz copper, ENIG finish. $23ea.

https://xrkaudio.etsy.com/listing/740773357

This is what it looks like fully assembled: