Finally got my 3e-audio board today! 
I hooked it up to a 48V 7.5A switching psu and fired it up! Dead silent and no pops what so ever! I only have reguluar RCA from my dac/cd player so I had to run it in SE mode. Gain seems to a little lower than I'm used to, and I managed to activate the clipping led when maxing out the cd player. I guess the player started to clip(is has volume control). At this point I also maxed out the Xtz speakers@6ohm/87db so it was very loud! It's officially a beast! It plays super clean at higher volume, and in my system the bass improved a lot over tpa3116 (probably more room gain helps also). This amp really outshines its smaller brothers at max voltage and higher volume. I've not tested it with my normal setup yet, but I couldn't detect any sibiliance or ringing that the early tpa3116 cards suffered from. The aluminium fin do get warm and the chokes goes over 40C with no fan. I have to test it at max for longer to see if it needs any active cooling. The chokes looks to be of good quality@this price point.
Overall I'm very impressed with how polished the 3e card is.
Do anyone know what the gain is in SE mode?
I hooked it up to a 48V 7.5A switching psu and fired it up! Dead silent and no pops what so ever! I only have reguluar RCA from my dac/cd player so I had to run it in SE mode. Gain seems to a little lower than I'm used to, and I managed to activate the clipping led when maxing out the cd player. I guess the player started to clip(is has volume control). At this point I also maxed out the Xtz speakers@6ohm/87db so it was very loud! It's officially a beast! It plays super clean at higher volume, and in my system the bass improved a lot over tpa3116 (probably more room gain helps also). This amp really outshines its smaller brothers at max voltage and higher volume. I've not tested it with my normal setup yet, but I couldn't detect any sibiliance or ringing that the early tpa3116 cards suffered from. The aluminium fin do get warm and the chokes goes over 40C with no fan. I have to test it at max for longer to see if it needs any active cooling. The chokes looks to be of good quality@this price point. Overall I'm very impressed with how polished the 3e card is
. Do anyone know what the gain is in SE mode?
The TI board has a reset switch on it. Do you have to press it every time you start the board?
Once you put the board inside a cabinet, the reset switch will not be accessible. Is there a header which we can connect to a switch outside?
The 3e board only have a 4 pins header, no reset switch! So no thump without the use of the reset function! . In the ebay auction 3d-audio states that he integrated a anti-pop noise circuit and it seems to work good! The shipping was 11 days (which is quick to Norway) and it was well packaged. To me this board feels complete and finished, but remember I'v only tested it for about 4 hours at this point.
. In the ebay auction 3d-audio states that he integrated a anti-pop noise circuit and it seems to work good! The shipping was 11 days (which is quick to Norway) and it was well packaged. To me this board feels complete and finished, but remember I'v only tested it for about 4 hours at this point.My experience with the 3eaudio 3251 board is the same. Theyre excellent boards. There is a 4 pin header, which has Common, clipping, Fault and reset pins. So if you *do* want a reset switch, you can wire it.
My comment above is about the TI Eval module, which has a separate switch for reset. How to bring it to the front plate is the question.
My comment above is about the TI Eval module, which has a separate switch for reset. How to bring it to the front plate is the question.
According to TI, the spike in distortion around 5-6 kHz can be reduced if more linear filter inductors are used. Based on the LC filter tech notes available on their product page for the TPA3255, the Wurth 7uH inductors have the best performance.
Has anyone tried this and been able to perceive any difference in sound quality?
Has anyone tried this and been able to perceive any difference in sound quality?
Delay muting board
Knowing this, I believe we can use this Muring Relay PCB delay/muting circuit upon start up.
By reading the EVM manual?
/RESET is available at J28.10 together with GND at J28.22
Knowing this, I believe we can use this Muring Relay PCB delay/muting circuit upon start up.
With the tight space between components on the TPA3255EVM, it looks very challenging to fit the Wurth 7443631000 (10uH) or the 7443630700 (7uH) inductors on the board, unless they fitted them on the bottom-side of the PCB or somehow stood them up on the top-side of the PCB. The lead spacing is about 9mm and the body is approximately 21.8mm wide. The stock Coilcraft MA5172-AE 10uH inductors have a lead spacing of 10mm and the toroid is approimately 12mm wide. It would be interesting to know how TI rigged this up in their inductor evaluations.
I forgot to mention that doctormord's TPA3255 boards accommodate the Wurth inductors. I wish I had my equipment with me, but it's buried with a lot of my stuff in a storage unit. Otherwise, I'd build these amps up. I have to admit that I thought the Wiener 2.0 TPA3118 PBTL amps were the pinnacle of TI's Class D amplification, but I think the TPA3255 amps are at a new level.
It depends on the voltage you are using. If you run the tpa3255 at its full rated 53.5V, it will get somewhat hot at idle. It is pulling about 200mA at that voltage and therefore using more watts from the wall that dissipates as heat.
At 48V it only gets barely warm, not hot, pulls about 100mA, and uses about 5-10W less power. (sorry i didn't write down measurements when i was testing)
I had been running at 48V for over a week, was really really happy with the sound, but I talked myself into thinking it sounded slightly better at the higher voltage, so I settled on 50V as a good compromise between idle dissipation and sound quality.
So...to reduce waste heat, reduce voltage and save a little money on your electric bill. Determine for yourself if higher voltages actually sound different/better in your system.