I had a look about this PFFB and even TI has document covering their class D chips (including 3250) with reference designs. However now I have the question - why they did not include this in the reference designs of the chips themselves? Or this "PFFB revelation" came later in their minds? I doubt some of the Chinese mass production will adapt something like this because we know they try to use as less parts as possible in everything. Also from the PFFB TI reference design it seems a lot of capacitors and parts have to be put additionally and this even connected to the Amp chip output and input - I can imagine how difficult will be to put this to the small crowded PCBs we currently have.
TI knew the goodness of PFPB, but until now it was not free to use due to patents. Recently, the patent has expired and can be used freely.
Just slightly different output filter component values as per the table in this thread.
From what I can see on the 502spro board already has the zobel recomended in the TI PFFB application notes, so the only thing missing is 2 resistors and 2 capacitor per channel, I've got parts laying around that would fit on the underside of the board. But I also saw that this would drop the overall gain to around 12db. This seems a bit low, my dac does have 2v outputs though.
Hello friends!
I have Diy Ncore and I am very happy with its sound. Fx TPA3250 arrived recently, I've been listening to him for two days. Its sound is harsh, tiresome, generally not like it. Measured THD, power and frequency response. Remarkable, 0.002 ... 0.006% and practically does not depend on power, frequency and load. But the sound is rare ****. Tell me what needs to be replaced first, OA, electrolytics or inductors.
I have Diy Ncore and I am very happy with its sound. Fx TPA3250 arrived recently, I've been listening to him for two days. Its sound is harsh, tiresome, generally not like it. Measured THD, power and frequency response. Remarkable, 0.002 ... 0.006% and practically does not depend on power, frequency and load. But the sound is rare ****. Tell me what needs to be replaced first, OA, electrolytics or inductors.
Hi UAN.
You should read the review here :-
Review and Measurements of Topping TP60 and FX Audio FX502SPro Amps | Audio Science Review (ASR) Forum
The FX502Pro does not have a very good reputation among the small Chinese amplifiers. The Aiyima A04 is probably the best in this category.
hi
The FX502Pro does not have a very good reputation among the small Chinese amplifiers. The Aiyima A04 is probably the best in this category.
without modification...like in audioreview...
with modification its better
TPA3250 somebody is listening?
The FX502Pro does not have a very good reputation among the small Chinese amplifiers. The Aiyima A04 is probably the best in this category.
without modification...like in audioreview...
with modification its better
TPA3250 somebody is listening?
Hey!
This review and measurements do not match the parameters of my amplifier. I measured THD, frequency response, output power and got excellent performance, post 1108.
Yours faithfully, UAN.
Hey people, finally got the chance to dig into my pair of fx502s pro’s after getting stuck half way around the world. I’m really happy with the way things are going and how things are sounding. Thermally coupling the back side of the board to the case has done wonders for temperatures. Quick question on adding a cap to pin 9 (avvd), can I just add a cap in parallel to c24?