Thank you you for something that so quickly responded)
3. About the power I'm just worried that it is a very low for amplifier. This is my first class D amplifier. Now I don't worried)
4. “Wrong separation by high low”. Oooh, this is all the Translator Google. I mean, it seems to me that the sound is not properly distributed over the frequencies. Very loud high frequencies(sound "ringing" "squeaking"), a lot of low frequencies but poor quality(bass "gurgles" "rattles" not dense), and the middle frequencies are quiet. No matter how I adjust the timbre.
I knew d class no load but I do not think it is necessary for every channel to load, thank you for the help) But I think sound is bad just because amplifier thinking that subwoofer is connected and part of the sound goes into the resistor, good bass going into the resistor. Because of this, the frequency balance is violated ?Maybe I can change config tpa3255 and board so to make it work in 2.0 mode?
Thank you you for something that so quickly responded)
3. About the power I'm just worried that it is a very low for amplifier. This is my first class D amplifier. Now I don't worried)
4. “Wrong separation by high low”. Oooh, this is all the Translator Google. I mean, it seems to me that the sound is not properly distributed over the frequencies. Very loud high frequencies(sound "ringing" "squeaking"), a lot of low frequencies but poor quality (bass "gurgles", "rattles", not elastic), and medium frequencies are quiet. No matter how I adjust the timbre.
I knew that it is impossible to include class d without load but I do not think that we need each channel to load, thank you for the advice) But it seems to me that bad sound I can be because the low-frequency amplifier sends to the resistor thinking that there is a subwoofer and because of this disturbed the balance of sound frequencies? I can change konfiguraciju tpa3255 and fees so to make it work in 2.0 mode?
3. About the power I'm just worried that it is a very low for amplifier. This is my first class D amplifier. Now I don't worried)
4. “Wrong separation by high low”. Oooh, this is all the Translator Google. I mean, it seems to me that the sound is not properly distributed over the frequencies. Very loud high frequencies(sound "ringing" "squeaking"), a lot of low frequencies but poor quality (bass "gurgles", "rattles", not elastic), and medium frequencies are quiet. No matter how I adjust the timbre.
I knew that it is impossible to include class d without load but I do not think that we need each channel to load, thank you for the advice) But it seems to me that bad sound I can be because the low-frequency amplifier sends to the resistor thinking that there is a subwoofer and because of this disturbed the balance of sound frequencies? I can change konfiguraciju tpa3255 and fees so to make it work in 2.0 mode?
Hi
power
forget this nonsense what the chines seller report about the power of this amps....its the lab values of a original board with ideal conditions. 30V is enough! if the amp is working fin you can decide to go up with the voltage.
i do not have this amp- so sorry its not easy...i personally do not like for my listening these BT modules...if you go through some threads you will find some comments with hiss...noise ..etc.
i really sure that it is not a problem to start with a resistor on the sub channel.
why it sound so strange ? this is the bigger part to solve.
1
try to use another amp to check if the speaker sound "normal" with the other amp. if the sound is ok the speakers are fine and the amp is really the problem
2
do not use the BT module in the first step. use please you source (DAC, CD player) or smartphone to go into the amp via RCA connectors.
sound ok???
chris
It seems to me that all my problems are with him because this is not real YJ Audio. fake I went to their site and their amplifier looks completely different inside. I disassembled my own, but I do not understand what they did, it seems to me that the schematics are completely wrong, especially with regard to the output part
I opened a dispute on aliexpress, at first only about a bad sound, now I added evidence that the amplifier board is fake. the seller is silent and the product he took off the sale. but I don’t worry about money, aliexpress always protects the buyer. just infuriates the situation itself. I have been waiting for this amplifier for so long, and now I’ll wait it again(
but I want to try to make a normal amplifier out of it. only with the level of my knowledge of circuit design is very difficult.
but I want to try to make a normal amplifier out of it. only with the level of my knowledge of circuit design is very difficult.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Is the hiss with bluetooth and line-in/aux the same? Is it getting better without the heatsink? Is the heatsink blank/polished at the thermal pad? It should and get connected to GND on one side.
Connect a thick wire between the VIA connecting the 4 MLCC power decoupling caps at the chip to the GND connection of the blue cap.
May i see the DCDC secton in detail please?
(And please attach the images to the thread here)
Connect a thick wire between the VIA connecting the 4 MLCC power decoupling caps at the chip to the GND connection of the blue cap.
May i see the DCDC secton in detail please?
(And please attach the images to the thread here)
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In the instructions from the TI site in the datasheets there is no power scheme 2.1. it is mentioned in the text, it is written that TPA3255 works in 4 modes, while there are schemes for 2.0, mono, 4 channels but 2.1 is not.
2.1 is BTL + 2 SE, i use this mode as well.
Just take half the circuit of page 22 and half the circuit of page 26.
Just take half the circuit of page 22 and half the circuit of page 26.
Unfortunately, I do not yet have a device with rca outputs to check without Bluetooth. I ordered a separate converter with a good Bluetooth module - rca. so I can remove it from this board at all. there is a radiator, but it is placed through a thermopaste and not a thermal pad and is not connected to the ground in any way. It is not only the noise that bothers me, after listening to this amplifier, the noise is the least of my problems. in general, the sound is terrible. I think that as the first option, it is not able to play normally in the system without a subwoofer or the Chinese circuitry is fundamentally wrong. above asked a question about the speakers, forgot to answer. that before this tpa3255 amplifier came to me, they played with the pioneer av receiver every day and the sound was excellent, no problem. acoustics 4ohm.
upload photos
I can not understand why in the place where I have marked question marks, they connect 2 lines of 1 channel through a capacitor together? and output electrolytes which are 470uf, are they properly connected?
maybe you have a connection scheme in 2.1 mode? I will thank
Now i see it, they connected the SE ouput legs between PVCC and GND via elytic caps, that makes no sense at all. (Looks like a capacitive bias voltage divider..)
The easiest fix would be to connect the 470uF in series with the inductor for speakers +++ like shown on page 26 here:
http://www.ti.com/lit/ds/symlink/tpa3255.pdf
Minus --- then directly connects to ground.
The easiest fix would be to connect the 470uF in series with the inductor for speakers +++ like shown on page 26 here:
http://www.ti.com/lit/ds/symlink/tpa3255.pdf
Minus --- then directly connects to ground.
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The fact is that I do not understand in the schematics(very very small). maybe you can tell me what can be fixed. I would like to get 2.0 out of it, but if it’s difficult, I’m ready to stay on system 2.1, my main desire was to sound normal.
thank you very much. I will do it. Do you think the rest of the scheme is normal? I’m also worried that nothing happens when the bass control is rotated. and the most important thing for me to understand is if I don’t have a subwoofer, will the sound be normal if I leave the rest of the amplifier board as it is and won’t figure out how to remake it in 2.0?
Back to anti-pop...
If your version of 3255 amp does not contains power supervisor, & you suffer of power-off pop: remedy is here =) (calculated for 30v linear PS)
nostromo495 - TPA3255
If your version of 3255 amp does not contains power supervisor, & you suffer of power-off pop: remedy is here =) (calculated for 30v linear PS)
nostromo495 - TPA3255
Hi doc
i am happy that you help here.
i wonder about all these ready amps with "2.1-mode" because of just 4 coils in total. as you wrote its a mix of TI datasheet page 22 + page 26...but..... is it possible with a correct design to use BTL + SE at the same time with 1 chip???
chris
