For TPA3255 operating in BTL you definitely need a symm input signal. To achieve H2-distortion, I propose a H2 distortion Block, followed by a linear single-ended to double-ended converter that drives the symm input of TPA3255. The single-ended to double-ended converter maybe some OPA based chip (TI...) or a transformer - whatever suits you.
Just want to clarify: my comment was based on the fact that hardly anyone has responded to his various posts in the class D forum. Not that he holds a different view towards audio DIY.
The subjective vs. objective debate has been around since the dawn of audio, no point to discuss it here. Anyone is entitle to his or her own opinion.
Regards,
Appreciate the clarification - I got the impression that because you responded to his comment about his ears being his measuring instrument that it was that comment which was the reason.
Thanks Voltwide,
Well understood (even it makes the thing more complex for me).
I will include in my board some header and shunt to allow to include a future h2 block in the loop between the DSP and and amp part of the TAS3251. In case I decide to experiment this in the future... but such addon will need Balanced to SE => H2 module => SE to Balanced.
Other way is to include the H2 distorsion digitally upstream. I will experiment with VST plugins. However, this is off topic here.
Best regards,
JM
Received the new Aiyima bluetooth 5 TPA3255 amp.
AIYIMA TPA3255 Bluetooth Amplifier Audio AMP 325W*2 Stereo Class D Bluetooth 5.0 Amplifiers DAC PCM5102 Decoding-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
Run it for 3 hours today at 50% volume on 34v 10a powersupply.
Bluetooth audio quality is good. heatsink gets quite warm to the touch after 2 hours run.Bass is good or more. I feel my previous LJM L15D amp has better high frequency reproduction and tighter bass than this.
AIYIMA TPA3255 Bluetooth Amplifier Audio AMP 325W*2 Stereo Class D Bluetooth 5.0 Amplifiers DAC PCM5102 Decoding-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
Run it for 3 hours today at 50% volume on 34v 10a powersupply.
Bluetooth audio quality is good. heatsink gets quite warm to the touch after 2 hours run.Bass is good or more. I feel my previous LJM L15D amp has better high frequency reproduction and tighter bass than this.
Attachments
Power with 34V supply should be 65W in 8 Ohm and 120W in 4 Ohm. Per channel. I see one electrolytic decoupling capacitor with probably 4700uF-6800uF. My guess is not enough for a really tight bass.
Heating of components inside a closed space is (always) a problem. The temperature inside the enclosure slowly builds up. If possible, the heatsink should rather be a cooling bridge put in contact with the outer casing.
I'm trying to select the "rail caps" for my TAS3251 project. The value is expected to be about 2200uF (as of the EVM) and 50V.
The EVM uses Panasonic EEU-FC1H222, which ESR is 23 mR
Doctormord and Chermann advise using EGPD500ELL242MM30H, which ESR is 28 mR, and are more expensive.
Can both fit ? Some advantage to one of those 2 models ?
(for information, following the advices, i'm changing the 10uF between the DAC and the amp to SILMIC II, instead of X7R).
JMF
The EVM uses Panasonic EEU-FC1H222, which ESR is 23 mR
Doctormord and Chermann advise using EGPD500ELL242MM30H, which ESR is 28 mR, and are more expensive.
Can both fit ? Some advantage to one of those 2 models ?
(for information, following the advices, i'm changing the 10uF between the DAC and the amp to SILMIC II, instead of X7R).
JMF
Hi KCN
yes this ready amp is the next compromise of a TPA3255 implementation.
anatoliy has the same question or topic:
https://www.diyaudio.com/forums/cla...iy-discussion-design-etc-106.html#post5728942
if iam right with reading the pcb traces then its a just a fat cap on the begining of the power supply socket and a too small cap on the TPA chip rails !!!and its just 1 cap. i mean the cap which is axial on the pcb.
its recommended here to use 4700µF low esr/esl about 20mohms..or lower
so change the 220µ to 2x 2200µF low esr in minimum.
at the thread "what is wrong with TPA3255" if found that the opamps in the YJ boards are good TL072 but with opa1602 its much better.
can you measure the coils? what L they have..
for speaker impedance use 7µH and for 8R use 10µH
chris
yes this ready amp is the next compromise of a TPA3255 implementation.
anatoliy has the same question or topic:
https://www.diyaudio.com/forums/cla...iy-discussion-design-etc-106.html#post5728942
if iam right with reading the pcb traces then its a just a fat cap on the begining of the power supply socket and a too small cap on the TPA chip rails !!!and its just 1 cap. i mean the cap which is axial on the pcb.
its recommended here to use 4700µF low esr/esl about 20mohms..or lower
so change the 220µ to 2x 2200µF low esr in minimum.
at the thread "what is wrong with TPA3255" if found that the opamps in the YJ boards are good TL072 but with opa1602 its much better.
can you measure the coils? what L they have..
for speaker impedance use 7µH and for 8R use 10µH
chris
Last edited:
hi
yes doctor "magic" caps are really expensive, but this cap can deliver about 5-6amps at 100khz so its really fine
i use in my TPA3255 "fake amp" 3x of the nichicon UHE1H102MHD6 25mR per rail.
on the TPA3220 micro board there are 100µF/50V by Würth...860010678024
...but i think the EVM caps..Panasonic EEU-FC1H222...are fine
chris
Thanks. There will be no space for 2x2200uf caps unless i leave the top cover open. is one 4700uf enough/Ok?
cannot measure coils.
Hi, mates. My amp after worshop checking verdict: the tpa3255 is broken. All the i/o and power signals are ok, but no output. There are no visible damages on the chip. Any ideas? To replace chip would cost 10$ for chip and 10/20$ for work...seems like protection sometimes cant prevent overheat/overload . My guess it is due overheating.
i am sorry to read this...
i have 8x YJ TP3255 but no board died during listening.... if i had adead board it was my fault....e.g. destroyed traces, wrong polarity
chris
same here. I am building with TPA3118 and TPA3255 for several years. Failures have been rare events, never spontaneous but due to some fault(s) from my side.