FINAL THOUGHTS
Am I surprised by the improvement by adding capacitance to the power supply? No. Some highly regarded TPA3116 amps also have extra capacitance at their input; Allo's Volt+/Volt+D, and the (cheap) Breeze Audio on AliExpress, for example.
Am I surprised by the difference between differential input mode and single-ended input mode? Yes. I wasn't expecting a difference here, and even if there was a difference, I would assume the differential mode to be the winner! It wasn't.
The difference might (?) be due to my DAC. Possibly the balanced/unbalanced output modes of the DAC's transformer have critically different output impedance? Also transformer output stages can be fussy about amplifier matching.
But if you have a DAC with balanced outputs, using conventional opamps, then I suspect there may be a sonic benefit to using differential input mode of the TPA3221. And if your DAC has a well designed opamp output stage, it makes sense that you don't need an additional opamp stage at the TPA3221's inputs.
I suggest if you want a tweaked/optimised TPA3221 amplifier, don't buy a cased version of the amplifier (as I did), instead start with a TPA3221 bare board -
Sunbuck TPA3221 Audio Amplifier Board 100W *2 High Power Class D Digital Power Amplifier Board|Amplifier| - AliExpress
or
TPA3221 Digital Class D Power Amplifier Board Module 100W + 100W High Power Amplifier|Amplifier| - AliExpress
No need to bypass the opamp input stage on these boards - they don't include such.
It should be quite easy to lift the audio input GND connection, to provide full differential inputs.
And finally I recommend trying extra capacitance at the power supply output, or maybe even try a linear power supply.
On the other hand if you want a fully cased TPA3221 amp requiring no DIY effort, then the "FR" amp is a good product, though slightly expensive. The dual mono version is no longer available, but the single chip version is still available for US$79 -
Fever digital power amplifier TPA3221 high definition high power HIFI power amplifier|Home Automation Kits| - AliExpress
It includes good quality OPA1652 opamps, which are fine, especially if your source device is less than great.
Am I surprised by the improvement by adding capacitance to the power supply? No. Some highly regarded TPA3116 amps also have extra capacitance at their input; Allo's Volt+/Volt+D, and the (cheap) Breeze Audio on AliExpress, for example.
Am I surprised by the difference between differential input mode and single-ended input mode? Yes. I wasn't expecting a difference here, and even if there was a difference, I would assume the differential mode to be the winner! It wasn't.
The difference might (?) be due to my DAC. Possibly the balanced/unbalanced output modes of the DAC's transformer have critically different output impedance? Also transformer output stages can be fussy about amplifier matching.
But if you have a DAC with balanced outputs, using conventional opamps, then I suspect there may be a sonic benefit to using differential input mode of the TPA3221. And if your DAC has a well designed opamp output stage, it makes sense that you don't need an additional opamp stage at the TPA3221's inputs.
I suggest if you want a tweaked/optimised TPA3221 amplifier, don't buy a cased version of the amplifier (as I did), instead start with a TPA3221 bare board -
Sunbuck TPA3221 Audio Amplifier Board 100W *2 High Power Class D Digital Power Amplifier Board|Amplifier| - AliExpress
or
TPA3221 Digital Class D Power Amplifier Board Module 100W + 100W High Power Amplifier|Amplifier| - AliExpress
No need to bypass the opamp input stage on these boards - they don't include such.
It should be quite easy to lift the audio input GND connection, to provide full differential inputs.
And finally I recommend trying extra capacitance at the power supply output, or maybe even try a linear power supply.
On the other hand if you want a fully cased TPA3221 amp requiring no DIY effort, then the "FR" amp is a good product, though slightly expensive. The dual mono version is no longer available, but the single chip version is still available for US$79 -
Fever digital power amplifier TPA3221 high definition high power HIFI power amplifier|Home Automation Kits| - AliExpress
It includes good quality OPA1652 opamps, which are fine, especially if your source device is less than great.
Hi, I received my TPA3221, the delivery was fast, also the packaging was perfect.
I quickly plugged in and turned the volume to max, no whistling or anything else, dead silence.
I'll come back to you with my comments. To date it is playing well, very satisfied.
I opened the case to check the versions of the power supply condos. It is indeed changed, as well as the 2 x OPA1656 changed to OPA1602.
I quickly plugged in and turned the volume to max, no whistling or anything else, dead silence.
I'll come back to you with my comments. To date it is playing well, very satisfied.
I opened the case to check the versions of the power supply condos. It is indeed changed, as well as the 2 x OPA1656 changed to OPA1602.
Attachments
I don't own the MX50 SE but rather the MX50 X2, not the same circuit and has 4 transistors for the X2. I have never heard the SE.
Hi,
I played the FR TPA3221 for several days and compared it with my Sabaj A20a 2019 amp (double Infineon MA12070).
The subjective comparison was much more difficult for me than I thought.
While my 2 TPA3255 amps that I built, compared to the Saba, were quickly put aside because I find the sound a bit clinical. While the TPA3221 is quite the opposite, extremely lively and above all a much more solid bass than the MA12070.
The dual TPA3221 is powered with a Meanwell 24V 8.8A (210w) SMPS, the bookshelf speakers have 4 ohms with an impedance dip at 2.7ohms and efficiency at 87db. I tested the power cuts, by closing the DAC (connected to the amp) before and after the amp, by unplugging the SMSP direct from the AC, there is no noise even the most tic.
Also the volume at maximum without signal and the ear more than 2 cm from the tweeters, there is no hiss.
I do not regret the purchase of this amplifier, for me at the new price, it's a deal.
I played the FR TPA3221 for several days and compared it with my Sabaj A20a 2019 amp (double Infineon MA12070).
The subjective comparison was much more difficult for me than I thought.
While my 2 TPA3255 amps that I built, compared to the Saba, were quickly put aside because I find the sound a bit clinical. While the TPA3221 is quite the opposite, extremely lively and above all a much more solid bass than the MA12070.
The dual TPA3221 is powered with a Meanwell 24V 8.8A (210w) SMPS, the bookshelf speakers have 4 ohms with an impedance dip at 2.7ohms and efficiency at 87db. I tested the power cuts, by closing the DAC (connected to the amp) before and after the amp, by unplugging the SMSP direct from the AC, there is no noise even the most tic.
Also the volume at maximum without signal and the ear more than 2 cm from the tweeters, there is no hiss.
I do not regret the purchase of this amplifier, for me at the new price, it's a deal.
Notice to those interested, there is a good reduction on PCBs only (-30%).
DLHIFI TPA3221, classe D, 2 canaux, audio HIFI, 200W x 2, DC24V 2-8OHM 108db
https://a.aliexpress.com/_m0m6XLw
DLHIFI TPA3221, classe D, 2 canaux, audio HIFI, 200W x 2, DC24V 2-8OHM 108db
https://a.aliexpress.com/_m0m6XLw
hi, Made up Boards x 1 @ around $35.
https://fr.aliexpress.com/item/1005...6!sea!NZ!161172495&curPageLogUid=SGZNRa5k7lpT
Cheers
https://fr.aliexpress.com/item/1005...6!sea!NZ!161172495&curPageLogUid=SGZNRa5k7lpT
Cheers
Fever digital amplifier TPA3221 amplifier HIFI amplifier high-power class D amplifier
https://a.aliexpress.com/_mNISaMS
https://a.aliexpress.com/_mNISaMS
The AB MX50 X2 is better for ears than the TPA3221. I bought the dual fr TPA3221 to have a desk or room amp, but which is compact. Okay, the SMPS is deported.