Dear FMs,
Enthused by the performance of the TPA3116D2 Class-D chip, I ventured into the TPA3251 territory, and replaced the 3116 board in my player with the 3251D2 based board from 3eAudio.
The 3251 is a high performance amplifier chip which gives 140W stereo into 4ohm at 1% distortion. S/N ratio is 111dB, Distortion at 1W is 0.005%. I have connected it to my 6 ohm bookshelves, so I guess I am getting around 100W stereo.
I have bought a 24V 10A toroidal transformer, an Audio Grade 4700uF 63V X 8nos Dual Rail Power Supply board from Eight Audio and set the whole thing up. My RPi and Allo Boss DAC are the same, connected to them is the 7 inch LCD screen as before. The TPA3251 board now gets 36.6 volts DC. The recommended range is 24 to 38 VDC.
As the transformer is pretty big in size, I had to build a new cabinet. That took time.
I am currently running the RPi + DAC from a 10000 mAh mobile battery bank, just to give the RPi a very clean linear supply. The battery bank voltage sags a bit, at no load it gives 5.1V, but on load it falls to 4.6 volts and a low-voltage sign shows up on the display. The RPi still plays, though the screen becomes a tad unresponsive.
I have also built an adjustable regulated 5V 5A PS using LM338, but somehow the 338 is heating up considerably, going into thermal shutdown even at 1.5A current drawn by the RPi+DAC+LCD combo, so I am not using it right now. Perhaps the voltage drop is quite a lot from 9V to 5V at 1.5A.
The sound quality of this board is much better than what I got out of the 3116. Highs and lows are both clearer and resolved. The amp sings with an 'open throat'. Since the distortion and noise figures for this chip are markedly lower, the instruments sound more authentic and the background is black. You can hear even the faint sounds which got drowned out by noise in 3116.
I am very appreciative of the sound quality of this 3251 board. Perhaps it will outshine quite a few boxes and heaters
I will strongly recommend it to all FMs.
Enthused by the performance of the TPA3116D2 Class-D chip, I ventured into the TPA3251 territory, and replaced the 3116 board in my player with the 3251D2 based board from 3eAudio.
The 3251 is a high performance amplifier chip which gives 140W stereo into 4ohm at 1% distortion. S/N ratio is 111dB, Distortion at 1W is 0.005%. I have connected it to my 6 ohm bookshelves, so I guess I am getting around 100W stereo.
I have bought a 24V 10A toroidal transformer, an Audio Grade 4700uF 63V X 8nos Dual Rail Power Supply board from Eight Audio and set the whole thing up. My RPi and Allo Boss DAC are the same, connected to them is the 7 inch LCD screen as before. The TPA3251 board now gets 36.6 volts DC. The recommended range is 24 to 38 VDC.
As the transformer is pretty big in size, I had to build a new cabinet. That took time.
I am currently running the RPi + DAC from a 10000 mAh mobile battery bank, just to give the RPi a very clean linear supply. The battery bank voltage sags a bit, at no load it gives 5.1V, but on load it falls to 4.6 volts and a low-voltage sign shows up on the display. The RPi still plays, though the screen becomes a tad unresponsive.
I have also built an adjustable regulated 5V 5A PS using LM338, but somehow the 338 is heating up considerably, going into thermal shutdown even at 1.5A current drawn by the RPi+DAC+LCD combo, so I am not using it right now. Perhaps the voltage drop is quite a lot from 9V to 5V at 1.5A.
The sound quality of this board is much better than what I got out of the 3116. Highs and lows are both clearer and resolved. The amp sings with an 'open throat'. Since the distortion and noise figures for this chip are markedly lower, the instruments sound more authentic and the background is black. You can hear even the faint sounds which got drowned out by noise in 3116.
I am very appreciative of the sound quality of this 3251 board. Perhaps it will outshine quite a few boxes and heaters
I will strongly recommend it to all FMs.
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