Hi @3eaudio
Recently ordered 4 of your boards from Aliexpress (not shipped yet, but hopefully will be shipped in the next few days).
I'm going to build a dual mono amp configuration for my active 4-way crossovers (two boards / 4 channels per amp for lows, lower mids, upper mids and highs).
On boards intended for the upper middle and highs I plan to replace the TPA3255 with the TPA3251. The two lower ranges have 8 Ohm speakers, the two upper ones have 4 Ohm speakers, so boards with TPA3255 will be powered by 48 Volts, and with TPA3251 - by 36 Volts.
As far as I understood from the circuit diagrams, I should replace:
1) TPA3255 -> TPA3251 (found genuine ones);
2) L_out: 10 μH -> 7 μH (found VER2923-682K);
3) C_out: 1 μF -> 680 nF (found B32529C1684J000);
4) C_fb_out: 220 pF -> 1 nF;
5) R_fb_gnd: 10 kΩ -> 2 kΩ;
6) R_FREQ_ADJ: 30 kΩ -> 10 kΩ;
7) C_START: 47 nF -> 10 nF ;
8) C_VBG: 1 μF -> 100 nF.
Could you help me determine the sizes and types of SMD components for points 4-8, please? Or maybe I missed something?
Thanks in advance!
English is not my native language, please forgive me for any language errors..
Recently ordered 4 of your boards from Aliexpress (not shipped yet, but hopefully will be shipped in the next few days).
I'm going to build a dual mono amp configuration for my active 4-way crossovers (two boards / 4 channels per amp for lows, lower mids, upper mids and highs).
On boards intended for the upper middle and highs I plan to replace the TPA3255 with the TPA3251. The two lower ranges have 8 Ohm speakers, the two upper ones have 4 Ohm speakers, so boards with TPA3255 will be powered by 48 Volts, and with TPA3251 - by 36 Volts.
As far as I understood from the circuit diagrams, I should replace:
1) TPA3255 -> TPA3251 (found genuine ones);
2) L_out: 10 μH -> 7 μH (found VER2923-682K);
3) C_out: 1 μF -> 680 nF (found B32529C1684J000);
4) C_fb_out: 220 pF -> 1 nF;
5) R_fb_gnd: 10 kΩ -> 2 kΩ;
6) R_FREQ_ADJ: 30 kΩ -> 10 kΩ;
7) C_START: 47 nF -> 10 nF ;
8) C_VBG: 1 μF -> 100 nF.
Could you help me determine the sizes and types of SMD components for points 4-8, please? Or maybe I missed something?
Thanks in advance!
English is not my native language, please forgive me for any language errors..
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The 3255 board runs at 36v minimum according to the manual (and my brief testing), is swapping for the 3251 going to be worth the effort?
@emu77 some of the feedback value is not same as Ti app note.
what is the benefit you change to TPA3251?do you have any proved data show it will better in terms of sound?
in a short word, we don't suggest to do that just run in 36V if you don't need so much power.
or just replace TPA3251 to try if you are capable on soldering, but again any modification has its risk.
what is the benefit you change to TPA3251?do you have any proved data show it will better in terms of sound?
in a short word, we don't suggest to do that just run in 36V if you don't need so much power.
or just replace TPA3251 to try if you are capable on soldering, but again any modification has its risk.
Thank you gentlemen, I'll try to explain..
The reason is that there appears to be a big difference when running the TPA3251 and TPA3255 at their maximum voltages into a 4 ohm load in terms of THD+N in the desired frequency band (upper mids and highs), at least based on the data provided by the manufacturer. The next two graphs illustrate this.
Unfortunately, there is no frequency-dependent THD+N graph for the 4-ohm load of the TPA3255, but it can be seen that the THD+N for the 4-ohm load of the TPA3255 is even higher.
Therefore, it seems correct to conclude that in the frequency band above 1 kHz when operating with a 4-ohm load, the TPA3251 has a significant advantage. Since my amplifiers will be used for dedicated bands, I would like to get the highest possible quality that TPA can provide on one of the best boards for it, especially in such an important range as mid-high.
@3eaudio, I read above that model 140-2-29A is not currently in production, but perhaps it was being worked on and the details of the element base for it are known?
The reason is that there appears to be a big difference when running the TPA3251 and TPA3255 at their maximum voltages into a 4 ohm load in terms of THD+N in the desired frequency band (upper mids and highs), at least based on the data provided by the manufacturer. The next two graphs illustrate this.
Unfortunately, there is no frequency-dependent THD+N graph for the 4-ohm load of the TPA3255, but it can be seen that the THD+N for the 4-ohm load of the TPA3255 is even higher.
Therefore, it seems correct to conclude that in the frequency band above 1 kHz when operating with a 4-ohm load, the TPA3251 has a significant advantage. Since my amplifiers will be used for dedicated bands, I would like to get the highest possible quality that TPA can provide on one of the best boards for it, especially in such an important range as mid-high.
@3eaudio, I read above that model 140-2-29A is not currently in production, but perhaps it was being worked on and the details of the element base for it are known?
@emu77
interesting but i am really doubt graph one as it is against with app note and TPA3255/50 series
the reason we don't build TPA3251 is that the test performance is not in big number different and only few people like 3251, they actually want MORE POWER (even they don't need so much power)when pay almost same amount money.
interesting but i am really doubt graph one as it is against with app note and TPA3255/50 series
the reason we don't build TPA3251 is that the test performance is not in big number different and only few people like 3251, they actually want MORE POWER (even they don't need so much power)when pay almost same amount money.
our module also review by ASR:
https://www.audiosciencereview.com/forum/index.php?threads/3e-audio-tpa3255-amplifier-review.50208/
https://www.audiosciencereview.com/forum/index.php?threads/3e-audio-tpa3255-amplifier-review.50208/
Hi @3eaudio! Can you say where I can source the exact chassis with XLR connectors shown in the build at https://www.audiosciencereview.com/forum/index.php?threads/3e-audio-tpa3255-amplifier-review.50208/ ?
I'm interested in building the exact configuration, with XLR balanced inputs.
Thanks in advance.
I'm interested in building the exact configuration, with XLR balanced inputs.
Thanks in advance.
Actually I've looked and can't find even a single 3e audio product searching at AliExpress. Tried many variants: 3e audio, 3e-audio, 3eaudio. Some audio or electronics stuff show up but none of your products. BUY links on your website lead to specific products but none appear to be available. It's too bad; I'm sure there's a lot of interest right now. 🤔
Here's their URL with the name in it, so it should be an official link: https://3eaudio.aliexpress.com/store/1101467610
Hello 3eaudio. My case height is about 45 mm, so the board does not fit in it. I want to desolder 4 1800 uF capacitors and then place 2 capacitors horizontally. The total capacitance will decrease to 3600 µF. Will this affect the amplifier parameters?
