I just got my second TPA3156D2 kit from Jerry's Electronics. I am very, very pleased. Name brand parts - Panasonic capacitors, what look to be carbon film resistors, Bourns volume pot, not sure of the inductor brand, but they are heavy and nicely made. The board is solid and flawless. It's well laid out, with the bootstrap and snubber caps close to the chip. Some thoughts after building the first one: I have set the gain at 26db as recommended above, and used four 3.3uf WIMA MKS2 film caps on the inputs. The TPA3156 datasheet recommends this value if the gain is set at 26db. Not knowing anything about class D amps going in (I'm a '70s audio dinosaur), I thought the .22uf bootstrap caps were actually serial coupling caps to the speakers (don't laugh), so I used .22uf WIMA films instead. The datasheet recommends .22uf X7R ceramics, and I will be using them on the second build. In fact, X7Rs may be included in the kit, but I can't tell from looking at them, and I had some laying around. You can build in a turn-on speaker delay by increasing the value of C6 from 10uf to 22uf or larger. I'm going to add some sort of reverse polarity protection. I haven't put it on a scope yet, so I'm not sure how many watts output I'm getting into 8 ohms. But it drives my 91dB @ 1 watt / 1 meter 8 ohm speakers to clean, room-filling volume. The heatsink barely gets warm after and hour or so. Idling with no input, this thing is dead quiet when "dimed" with my ear against the speakers! That may have something to do with the quality power supply I'm using,see below. I'm powering it with an 18 volt 200ma toroid transformer into a full wave rectifier / filter board, 18,800uf of filtering, which pumps a very clean 25.4 VDC unregulated into the amp, and doesn't sag at high volume. I also hooked it up with an 18V 3A wall wart into the same rectifier board, and it sounded fine. This thing sounds great. Plenty of gain for a 1970s tuner, plenty of gain for a laptop via an outboard DAC. Haven't tried a phone or mp3 player yet. I have a hard time hearing any difference between this amp and my 1970 Sansui AU555A amp, which is my everyday favorite.
A bit late to the show, but you can get a much lower THD+noise value if you run it in the right bridged mode. Only one channel output but the datasheet says .1% THD+noise at 100 watts.
Excellent video. My TPA3156D2 kit from Jerry's should be here any day now. I plan on replacing the ceramic caps at C1-C4 and C12, 14, 16, and 18 with film caps, since they are in the signal chain. Based on my reading of the TPA3156 data sheet, I may replace C1-C4 input caps with 3.3uf instead of the original 10uf. This supposedly gives better bass response if you select the 26db gain resistor combo. The TPA3156 is claimed to give 70 watts per channel into 4 ohms, so I'm expecting 30 watts per into 8 ohm speakers. I will use a heavy duty 25 volt unregulated linear power supply.
@@ccoyle I just recently got the lower power TPA3116D2 kit and am interested in implementing bootstrap snubbers [330pF radial ceramics to 10 Ohm 1/4W axial resistor] on C11, 13, 15, 17 (prior to which which will be changed to TDK .22 uf X7R caps). Could you provide a recommendation for realizing this? Especially for accessing ground for the resistors? Jerry when asked only said: "no easy solution". It would likely be done on the underside of the PCB. Thanks in advance for any help.
