Do you recommend chinese TPA3255 amps?

CowCat

Member
2019-04-05 12:12 am
Which chinese TPA3255 amps do you recommend?

3E doesn't ship its amps to me.
TI EVM is quite expensive.

Thus, I'm looking into chinese TPA3255 amps.

What about

* A generic no-name chinese TPA3255 amp like this
(This one seems to use TI LM317 voltage regulator with maximum input voltage of 37V. Other chinese TPA3255 products use LM2575T-12 with maximum input voltage of 40V)
* A 32V 5A adaptor like this or Mean Well LRS-350-36
(Would it be safe to use a 36V power supply with chinese TPA3255 amps?)

I haven't yet seen a chinese TPA3255 amp that can comfortably work with 48V power.

If chinese TAP3255 amps sounded properly and lasted long, I would consider buying one.
 
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CowCat

Member
2019-04-05 12:12 am
Hi, I would go for a TI EVM. I managed to pick mine up through the Sell section with P/S for$125 & love it.

Cheers

I may want to buy a passive pre-amplifier such as Schiit SYS with TI EVM in order to control volume. Controlling volume from the sound card can decrease its dynamic range and degrade audio quality. I don't want to spend that much money on a power amp, yet.
 
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CowCat

Member
2019-04-05 12:12 am
I bought the 2.1 version of the chinese TPA3255 and the mounted a XL7005 buck-converter which works at max 65v


The amp hat bad Stand-by implementation but crossover works fine.
With some new caps it works very good.

I just want to buy a finished product and use it.
Are finished chinese TPA3255 amps ready to work with 36V or 32V power without modification?

Or, are there finished TPA3255 amps that I can use out of the box without an issue?
 
...are there finished TPA3255 amps that I can use out of the box without an issue?

I have used the eBay TI EVM Chinese knock offs at 51v just fine. They don’t blow up or anything - but their logic indicators are not working right. In normal operation, the error and clip lights are on. I bought a second one from Amazon and it had the same problem.

It’s the “Nobsound” one:
Nobsound TPA3255 Digital Power Amplifier Class D Audio Amp Assembled Board 300W+300W HiFi https://www.amazon.com/dp/B07544FJYC/ref=cm_sw_r_cp_api_i_gxaKDbFQ582G4

They work, but not sure if they “are without issue”.
 

CowCat

Member
2019-04-05 12:12 am
I have used the eBay TI EVM Chinese knock offs at 51v just fine. They don’t blow up or anything - but their logic indicators are not working right. In normal operation, the error and clip lights are on. I bought a second one from Amazon and it had the same problem.

It’s the “Nobsound” one:
Nobsound TPA3255 Digital Power Amplifier Class D Audio Amp Assembled Board 300W+300W HiFi https://www.amazon.com/dp/B07544FJYC/ref=cm_sw_r_cp_api_i_gxaKDbFQ582G4

They work, but not sure if they “are without issue”.

That's an amplifier board. Without a volume knob and an enclosure and binding posts, it is not very useable out of the box.
 

CowCat

Member
2019-04-05 12:12 am
I think that if I wanted to buy an affordable class-D amp end product, TPA3251 amps would be the best for now.

Right now, a finished TPA3251 amp model is being sold on aliexpress.com without bluetooth connectivity which often degrades audio quality.
The seller recommends 32V 5A adapter as the power supply.
TPA3251 is more powerful at 32V than TPA3255 according to datasheet.
 
I guess we have different interpretations of what is usable out of the box! Indeed it is usable out of the box! It had banana multi-way binding posts so just connect wires from PSU and speakers. It comes with RCA inputs so connect your source. What could be more out of the box than that?

I think the descriptive word you are looking for is “Finished amp” with case and PSU.

TPA3255 is not quite mainstream enough like TPA3116 so I don’t think at present you are going to find one with a built in case, input IEC for AC mains, and volume knob with internal SMPS for 48v to 51v PSU. At least not for “cheap” prices. A ZeroZone one is $300 with shipping. I suppose that’s a fair price but it’s a linear transformer with bulk caps - going to have mains hum.

Finished HIFI TPA3255 Class D Power amplifier BTL High Power amp 150W +150W | eBay

Here is another one but the photo doesn’t look right. Where’s the amp? Don’t see inductors and heatsink. Perhaps it is bottom mounted? But the price is too low.

High Power Audio Amplifier TPA3255 Class-D Bluetooth HIFI Amp Audio Decoder | eBay
 
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CowCat

Member
2019-04-05 12:12 am
TPA3255 is not quite mainstream enough like TPA3116 so I don’t think at present you are going to find one with a built in case, input IEC for AC mains, and volume knob with internal SMPS for 48v to 51v PSU. At least not for “cheap” prices. A ZeroZone one is $300 with shipping. I suppose that’s a fair price but it’s a linear transformer with bulk caps - going to have mains hum.

Finished HIFI TPA3255 Class D Power amplifier BTL High Power amp 150W +150W | eBay

I read that allo.com is going to release its own implementation of TPA3255 in a few months.
 

CowCat

Member
2019-04-05 12:12 am
So you don’t like the ZeroZone “Finished” amp above? Allo is going to cost way more than that.

I don't like the high cost of ZeroZone. I also want a volume knob somewhere.
Controlling the soundcard volume is going to decrease dynamic range.
So, with a pure power amp, I might want to add Schiit SYS passive pre-amplifier just for a volume knob.

How do you know allo's TPA3255 implementation is going to cost more than 250$?
Allo's TPA3116 implementation doesn't cost significantly more than chinese TPA3116 implementations.

Allo Volt+ With Stepped Attenuator costs 69USD without a power supply. SMSL SA100 costs 74 USD and comes with a power supply.

TPA3255 itself doesn't cost a lot. I suspect Allo will leverage economy of scale to release its minimal TPA3255 implementation at a cheap price.
It could cost less than 100$ without a power supply.
 
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I read that allo.com is going to release its own implementation of TPA3255 in a few months.

250 $ + 50$ freight is pretty expensive, I would also have to pay tax and vat. I understand the hype when it's cheap. I do have sinewave tpa3251, and it's fine for the pmoney. You can get pro made 4 channel 250 watt 8 ohn in l DSP for around 400$.
 
How do you know allo's TPA3255 implementation is going to cost more than 250$?
Allo's TPA3116 implementation doesn't cost significantly more than chinese TPA3116 implementations.

Allo Volt+ With Stepped Attenuator costs 69USD without a power supply. SMSL SA100 costs 74 USD and comes with a power supply.

TPA3255 itself doesn't cost a lot. I suspect Allo will leverage economy of scale to release its minimal TPA3255 implementation at a cheap price.
It could cost less than 100$ without a power supply.

I think you will be disappointed. Allo is mostly in the business of selling hobbyist boards, if you look at the price of the Allo Volt+ board alone, it is $39. Take a look on AliExpress at the cost of the TPA3118 boards - they typically go for $4-$8 without bluetooth. There is a $30 increase because the higher spec parts and assembly that Allo puts into their boards. A basic TPA3118 board in an acrylic box like the Allo Volt+ goes for $15.

So a bareboard Allo Volt+ costs 5x the typical no-bluetooth 3118 board, and it costs 2x a cheap turnkey solution with a cheap acrylic case (not a nice solid anodized aluminum case like the SMSL SA100). Whatever economies of scale Allo may have, their boards still end up costing 5x (or +$30) the cost of the cheap 3118 boards. The SMSL SA100 also has more features than the Allo Volt+: much nicer enclosure, tone controls and BT5.0. The $69 Allo Volt+ should be compared to the $15 acrylic enclosed amp that I linked, not the SMSL SA100 - then you get an idea of the kind of an enthusiast level 3118 board versus the inexpensive mainstream 3118 solutions.

You were scared away from buying the FX502s by the ASR review - have you read the ASR review of the SMSL AD18? Amir was super critical of the SMSL AD18 as well saying "In some sense I should have tested the SMSL AD18 to get a better perspective of how low one could go in that department." These inexpensive amps from FX Audio and SMSL are not the kind of stuff that produce good numbers on Amir's instruments - if you are using a positive ASR review as the requirement, then you simply won't get it in a turnkey TPA325x amp for the price you want to pay.

People on this forum have reported that the TPA325x boards that sound better than a Volt+D are the 3e Audio boards, the TI EVM boards, or the cheaper boards with upgraded capacitors. Otherwise the "old tech" 3118 boards sound better. I believe that based on observed facts (not wishful thinking) your options are:

  1. If you want the best sounding cheap-ish amps in a turnkey product right now, then get the Allo amps.
  2. If you want a better 325x amp right now, then buy a soldering iron and start practicing your DIY electronics skills and practice drilling holes in enclosures.
  3. If you want an inexpensive amp that many, many people enjoy and has the newest tech, get something like the FX502s and stop worrying what the ugly graphs it produces on the ASR reviews.
 

CowCat

Member
2019-04-05 12:12 am
  • If you want a better 325x amp right now, then buy a soldering iron and start practicing your DIY electronics skills and practice drilling holes in enclosures.
  • If you want an inexpensive amp that many, many people enjoy and has the newest tech, get something like the FX502s and stop worrying what the ugly graphs it produces on the ASR reviews.

I am not interested in bluetooth. A bluetooth chipset with its DAC can raise noise floor.
For the features that I want, Allo Volt+ With Stepped Attenuator is a good competitor to SMSL SA100.

What about TPA3251 amp that is being sold at about 38~39 USD without bluetooth? One thing that worries me about this TPA3251 amp is that the seller recommends 32V 5A adapter and it uses 35V capacitors in a product picture.
I read that if I turn the volume knob beyond 2'o clock, protection circuit can shut down FX502S Pro.
 
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What about TPA3251 amp that is being sold at about 38~39 USD without bluetooth?

You are in denial. Read the threads - have you seen any thread that has a 325x board cheaper than the 3eaudio outperforming the Volt+ without modding the components? I haven't seen such a message, and nobody who has responded to you on these threads has pointed out the unicorn you keep asking for.
How loud do you expect to play your music on your desktop? Do you really believe you need to turn the volume nob past 2 on the amp?
 

CowCat

Member
2019-04-05 12:12 am
I may take my chances with the chinese TPA3251 amp and a 32V 5A adapter. I want more clean power than the amount of clean power TPA3116 delivers.

In a product picture, it uses RJD 35V capacitors. I think it's RJD 35V 3000uF capacitors since the seller says it uses 3000uF capacitors. Theoretically, It can endure at least 7 years at 75 degrees celcius.
The amp will stay idle for ~90% of the time and will not be pushed beyond 1 watt for the vast majority of listening sessions.

If the power adapter doesn't deliver power surges, it will probably be ok.
 
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CowCat

Member
2019-04-05 12:12 am
How loud do you expect to play your music on your desktop? Do you really believe you need to turn the volume nob past 2 on the amp?

It's beneficial to have some headroom. A powerful amp improves accuracy of woofer response even at low and moderate volumes.

Also, the volume knob problem means a product misdesign which could have leaked into other aspects. For example, amirm had to turn FX502S Pro on and off several times before the amp stopped producing extreme distortions which he could hear. I don't know whether it was a defective unit or a product misdesign. Extreme distortion is what I was worried about.

Toku had a better luck with a chinese TPA3251 amp than with FX502S Pro.
 
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CowCat,
Numerous people have made suggestions and you seem to have an issue with each and everyone of them. Tell us what are your must have requirements?
What power, what impedance, etc. from reading your replies you seem to want performance of a custom TPA3255 in a case with PSU for the price of a TPA3255 amp board ($80). That’s not going to happen.

However, if you want more headroom than a TPA3116, I can highly recommend this amp. I have two of them and love the sound - quality is excellent, massive external brick SMPS. No hiss or hum. Has BT, but you don’t have to use it. Plenty of power at 60w.

It’s the Dayton DTA-120BTV2. I have V1 so V2 is even better. The case is superbly made and looks very nice. The older version can sometimes be found for under $80.

Dayton Audio DTA-120BT2 Class D Mini Amplifier 60 WPC with Bluetooth

Review here:
YouTube

60w is probably all you need, and really, a good 15w is all you need for most music. The TPA3255 is a 120w Class A with much more expensive psu requirements. My TPA3255’s CoilCraft SER inductors are $24 alone. BOM is about $140 total. PSU is another $45. No case or connectors etc yet. You can’t expect premium parts from eBay/Aliexpress budget amps.
 
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