IMO, saving few dollars would not be a major factor in deciding whether to purchase of the amp. But if you have access to NE5532 or other opamps that would be compatible with the circuit, you could sell them to buyers as an added option, and they can have fun swapping opamps themselves if that is what they would like to do.
-
WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!
3e Audio TPA3251 TPA3255 Finished Amplifier with PFFB is coming!
I think stick with one like for example OPA1656 that you think improves performance (assuming it does) rather than NE5532P which is almost to say "for you to swap"! Even if unfairly. I think it positions your products better versus the other brand you mention.
Just keep the single SKU with OPA1656 and make your life simpler.
I am not sure I understand, does PBTL not also increase the power or 'load' ability with the 3251, even though it is lower power? Just curious.
- Thread Starter
- #25
@SMen PBTL config 2 BTL in paralell mode (2 channel combine into 1 channel) can increase output current then it can increase load ability, and also can increase power by reduce power drop of the chip itself, but that increase is limited.
i posted one note on aiyima thread before maybe can help to understand more.
Aiyima A07 Max Amplifier Review
Wow, how come that poor channel imbalance? Faulty pot?
audiosciencereview.com
Thinking more and to be more specific:@SMen PBTL config 2 BTL in paralell mode (2 channel combine into 1 channel) can increase output current then it can increase load ability, and also can increase power by reduce power drop of the chip itself, but that increase is limited.
i posted one note on aiyima thread before maybe can help to understand more.
Aiyima A07 Max Amplifier Review
Wow, how come that poor channel imbalance? Faulty pot?
Are both your new units (so both 3255 and 3251) PBTL, or are you making 3251 BTL, and the 3255 PBTL and if so why?
I can understand advantage of 3251 chip for decent power and optimized for say 36/38v 6A power supply compared to 3255 with 36v/38v 6A power supply.
And then 3255 with 48v 10A for more power, but also needing more cooling.
So you would then have two units each optimized at different power ratings in similar configurations and boards.
I understand the limiting that you referred to with 325* going from BTL to PBTL.
But I don't understand doing one BTL and another PBTL for your new 3e Audio TPA3251/TPA3255 series if I have understood correctly. Why not do 3255 BTL and PBTL versions? What is benefit of 3251 then in this second scenario? I understand benefit in first scenario.
Does it hurt the <0.0004% performance by more than 1dB? If yes then nope.
It's also spiritually significant - For decades people have been saying even a cheap decent 5532 won't bottleneck performance. Finally we are at a point where 5532 bottlenecks performance, it's an event to be proud of.
What kind of $ difference are we talking about? $5?
PlasticDoc
Member
Well, I have a question:
- has quality control improved since that 3e Audio TPA3255 PFFB board with the electrolytic capacitor mounted the wrong way round?
Your boards may be well designed and sound good, but if you start cutting corners on basic quality control, such as visual inspection of finished boards, what other corners will be cut?
Regarding this new amplifier:
a) Drop the TPA3251 chip. What is the special "job to be done" that this chip has to do that the TPA3255 chip cannot do? Does it justify the complexity of different power supplies and slightly different PCBs?
b) Use the case as a heat sink and design the case to be more like a collapsible Ghent DIY case kit, or better still, talk to them so they can sell a kit for your amplifier. This will save shipping costs and leave some DIY space for the end user. Let the consumer choose to pay extra cost to have a fully assembled amplifier from you.
d) Leave out the op-amp sockets. Use the soldered op-amps you are using (your board seems to work well with them, and has been reviewed and praised here at ASR).
Last edited:
My understanding is that with the 3251 chip and a 36v/38v supply you get more output before clipping vs 3255, and less heat. The question for me though is, if it follows the same topology (parallel) would it be cheaper?
Then next question, if running in BTL mode would the unit be more appealing than a 3255 which could be run with the same higher 48v power supply for more power? For me it's a power before clipping question.
Keep the op amp sockets unless the circuit design has been optimized for one particular op amp. If on the test bench you try a few because they are compatible, then pass on the option. You will just lose sales in the current marketplace. I speak as an op amp neutral!
PlasticDoc
Member
This has been refuted time and time again.
Can you point us to any published TI papers or data sheets that support this assumption?
3e Audio's power dissipation design and PFFB circuitry take care of any remaining differences in power output "cleanliness" and heat dissipation.
In 2024, there is no audio design reason to use a TPA3251 instead of a TPA3255, nor is there an economic reason, since the TPA3251 costs only a few dollars less than the TPA3255 (and this one costs only $12 USD).
Last edited:
SylphAudio's High-Performance Amplifier Modules (2024 and Beyond)
Would you be interested in making products for car audio using these boards as a base for 4 - 6 channel, 12 V amplifiers? No time yet for other projects, after the 2024 roadmap products, I will proceed on preamp and active crossover. -Lester
www.audiosciencereview.com
Might be PFFB implementation related.
But I was partly agreeing with your statement here, if you see my previous posts, and in the absence of feedback as yet, speculating about a possible positive, only when using a lower powered supply with PFFB.
PlasticDoc
Member
In fact, it is not a TI paper. It is not even a dubious source, it is just garbage. This has been discussed before, see post #2,630 at the Fosi Audio V3 Amplifier Review thread.
3e Audio has a good design (proper circuit layout, fair PFFB implementation, good components, good thermal design) and an honest developer,
SylphAudio has... neither.
Last edited:
Seems well reviewed here: https://www.audiosciencereview.com/...sylph-d100-p02-amplifier-module-review.46613/
and way back in 2021 here: https://www.audiosciencereview.com/...ics-sylph-d200-amplifier-module-review.25295/
and I think I agree with the previous reply you got to your post you refer to!
I have asked the question here also from @3eaudio "why the 3251" and also "if the 3251, why not in parallel" ?
These are perfectly reasonable questions to ask. So I am looking forward to the answer.
What @3eaudio is the benefit of the 3251 version vs a 3255? Heat? Performance @38v? Do let us know.
- Thread Starter
- #34
Right, datasheet has all data.
@SMen @PlasticDoc
not sure my understanding is correct, assume question from my end will be what is the advantage of TPA3255 except higher power than TPA3251?
my answer is nothing, today many product use TPA3255 is not means it is better or best but more manufacture keep build it and people keep buying it.
It is more "what is the advantage of TPA3251 over TPA3255"? It would be good to state the benefits of each when your new models are being launched (a good move I think certainly).
Sokel
Master Contributor
- Joined
- Sep 8, 2021
- Messages
- 7,307
- Likes
- 7,539
TPA3251 is slightly cleaner. If you don't plan to go over 38V it is the better option.
Also 3255 is not very stable at high voltage lower impedance in stereo setup, requiring a dual mono for reliability.
You see that in Topping line-up- PA5 one 3251, PA7 dual 3255.
Also 3255 is not very stable at high voltage lower impedance in stereo setup, requiring a dual mono for reliability.
You see that in Topping line-up- PA5 one 3251, PA7 dual 3255.
I'm not sure why we don't have 8R TPA 3251 but I suppose it is safe to assume THD would be lower also.
I'm interested in this, depending on the price, because I am running a 38v with 3255 and so would try a 3e 3251 because of their reputation here. The balanced input is interesting also: I baulked in the end at doing a full DIY. Interesting also if 3251 is slightly better when speakers dip below 4Ohms in stereo BTL.
yes we do, in the datasheet:
TPA3251 BTL 36V:
PBTL 36V:
The graph posted above (probably from 360customs website) is 8 years old, maybe the data was not available at that time. btw, i suspect it is mistakes as is probably THD+N not THD.
Similar threads
