What TPA3255 Module??

sjt711

Member
2020-01-21 8:10 pm
I apologize in advance if I bring up an exhausting topic, my friends. But I am relatively new to the very expansive, ever-growing Class D amplifier experience. I have the Yeeco TDA7498 board it's pretty good but everyone says TPA3255 is miles ahead.

I'd like to buy one of these amp modules based off the TPA3255. It can be a little overwhelming trying to pick and decide which brand or vendor as one can pay anywhere from ~$40 from aliexpress to ~$160 or more from Digikey for the TI evm module.

Does anyone have recommendations for which to buy? I've seen this one on amazon recently: https://www.amazon.com/TPA3255-clas...1+channel+TPA3255&qid=1579710451&sr=8-2-fkmr1

What about the ones from aliexpress?

If allo had a module based off the TPA3255 I would buy it instantly as they have great reviews and look to be of excellent quality. But for now, they offer just the TPA3116. I plan to use a relatively power-hungry set of Polk S20's so I want just a bit more power than the TPA3116.

I can't wait to build one of these!

Thanks in advance.
 
You may notice that these are modules, not finished amplifiers. Instead, for about 50-70$ you can get some kind of mini amp with case and volume control, that uses the TPA3255.

If you ask a serious builder about these amps, you will get a mixed answer. Yes they work. Most sound very good (compared to what?), but usually these are made with very cheap components and the chips do not reach their possible potential. The power supply is critical. If you expect a serious amp with 2x300W power, somehow this energy has to reach the amp. With the usual laptop connector these amps have, this is very questionable, also there are no 400W adapters around. Usually 120 W are the limit. Second, the voltage has to fit. Such an amp expects 36-48 volt, but your laptop uses only 19v. So you run into a serious "how to power it" problem. You do not want to spent hundreds of $ to supply a 50$ amp.
Anyhow, for someone uncomfortable with a balanced input and "no volume" this is the best solution, maybe even wit a low power supply, as you do not need more than a few watt for normal listening.

Building amps from naked modules is easy, but only for those that know how to build amps. Like riding a bike. You have to learn it and while you learn you probably get hurt a few times...

Last, if you have a good 7498 amp and replace it with a not so well made 3255, you might replace a very good amp with a not better or worse one.
Even with a very good 3255, do not expect too much. You need very, very good speakers, to hear the difference of two modern, well done D-amps. Some even tell you it is impossible. Until today I have not seen any cheap Aliexpress 3255 amp nodule I would buy. Hardly none is build to spec, important parts seem under dimensioned.
My least expensive pick for a 3255, which could be better than your current amp, would be the 3e-audio product, done right. If you buy it, be clever and take their power supply.

With the 7498 and 7498E, this is different, there are quite some cheap, but well made versions at ebay, Alie etc.
 
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Thank you! That looks like a decent build quality. I'm a little confused on the configuration of some of these. This one appears to have balanced input connections and no volume control. Is this correct?
It has jumpers to select unbalanced input and they make a nice dsp as well, which can be use to used as volume/bass/treble control (or config it like you want).
The 4 channel TPA3251 is great is you don't need all the power but more channels. To bad the 3 channel version is sold out.
 

sjt711

Member
2020-01-21 8:10 pm
I definitely have the know-how to build one of these. What I'm uncertain about is whether it's worth the time and money to build a 3255 amp. Take the NAD 3020D for instance. For around $400 you get a very nicely built Class D amp with integrated DAC. Or Yamaha's WXA 50 for around the same price. I like the idea of building one, but it just doesn't seem practical. Not to mention the sound quality. When I compare my 7498 build to my old Yamaha AVC-30U, something just seems to be missing. The 7498 is crystal clear, the bass is punchy and tight but it just lacks that nice, smooth, slightly warm space between the speakers created by the Yamaha. It sounds a little artificial for lack of a better word. I was hoping maybe a 3255 build would be an upgrade but your very thoughtful response has my reconsidering. Thank you for your input, I greatly appreciate your thoughts on this.