3e Audio TPA3255 Amplifier Kit 480-1-29A Review

[IPunchCholla]

Looking at the board, it is set up to be able to be used in multiple configurations (SE, BTL, 4channel, PBTL). But it also seems pretty damn close to the specs in the data sheet. In the data sheet, they provide ideal layouts based on usage. This seems to stray from them in terms of the PCB trace width. Might there be a little more performance squeezed out if it was built as a dedicated use PCB?

 

[IPunchCholla]

Yepp - here we go by the numbers - what you (think) you hear does not weigh in. Hopefully the measurements are complete...

//

You do understand, if the measurements are incomplete, it is likely because we don’t understand something fundamental about electrical circuits and/or psychoacoustics.

The current state of knowledge is freely available at any public higher ed facility. So if you’re looking to contribute, you could research the state of knowledge, propose a mechanism that hasn’t been thought of, and test that proposal. You know science rather than FUD. Might even be fame and fortune in it for you.

 

[Sokel]

It’s been awhile, but isn’t the power dissipation for the heat sink calculated at 1/8th full load (I think Hypex’s white paper on cooling said that). So even 20 watt dissipation would be overkill for the 8 ohm application.? It would be a sink suitable for 75 watts in the 2 ohm application and 5 watts in the 4 ohm?

Rather than guessing,there's a robust science consensus about this stuff:

3e audio TPA3255 260-2-29A Amplifier Review

This is a review and detailed measurements of the 3e audio 260-2-29A TPA3255 chip based stereo amplifier. It was sent to me by the company as a complete unit even though they only sell the amplifier modules. As you see, it is a generic box which is something you can easily build yourself. I...

www.audiosciencereview.com

(search for John R. Gyorki's credentials and you'll see)

 

[sarieri]

I'm not saying its a finished product for that kind of money. It is when DYI.

You can get a NC252MP finished in a case for under €500 (its stereo). Lower SINAD, slightly more power, also seems to have lower distortion at higher frequencies (remember, the SINADscore is only for 5W @ 1kHz).

We also have a Topping PA7 for €500, similar power, slightly lower SINAD, but better multitone performance.

So this product is not some kind of magical leap or anything, just another solid competitor in this market.

$500 is almost twice the price. And also, it is arguable whether distortion at higher frequency or distortion with capacitive load is more important. If you look around, I believe pma tested Ncore before and pretty much all ncore designs cannot handle capacitive loads well. This problem is solved in NcoreX but that’s at another price level.

Sure you can argue his capacitive load test is not realistic enough, but it should be given a weight. No speaker is purely resistive load.

 

[IPunchCholla]

Rather than guessing,there's a robust science consensus about this stuff:

3e audio TPA3255 260-2-29A Amplifier Review

This is a review and detailed measurements of the 3e audio 260-2-29A TPA3255 chip based stereo amplifier. It was sent to me by the company as a complete unit even though they only sell the amplifier modules. As you see, it is a generic box which is something you can easily build yourself. I...

www.audiosciencereview.com

(search for John R. Gyorki's credentials and you'll see)

I’m working on a pre board (fault indication, clipping indicator, auto on an off), so have been really interested in this amp board and have even thought of producing my own to the reference design. What I can’t tell from the specs or from the pic is if they followed recommendations for PCB trace size for the filter and speaker outs or if they did a ground pour that is basically everything which isn’t signal. The ground pour is really recommended by TI as that will greatly help with thermal issues. The big advantage this board has is the large heatsink/spreader on the bottom. Without a detailed pcb I don’t think I can model the heat differences accurately enough (given my own state of knowledge) to come to a conclusion. Hence the question.

 

[museguy]

@amirm, thank you for the excellent review!

Last night I was thinking about the impact you have had on the industry; the industry is now following you and taking your lead, only a few years ago the audio industry was putting down your objective approach. Kudos for your work!

Could someone put together an idiot's guide to building this amp with a parts list and instructions? Thank you!

 

[musicforcities]

Thanks again Amir for this review. I was impatiently waiting for it)
I am currently working on a DIY dual Mono project based on this 3E Audio module. I will soon open a thread for this purpose for those interested.
In all this already confirms what had been demonstrated with the Stereo module, the performance remains excellent with a phenomenal performance/price ratio)

I look forward to that. Are you going to put two mono boards and two psu in a single case, or build it as two mono blocks? Or two cases for the amp board connected to a case holding the psu?

I have been thinking that a vertical design that mounts the board and psu on their sides, or at least one that can be rotated vertically might be very space efficient. Like the Marantz ma500u monoblocks, but smaller. That way a thick side plate could operate as the heat sink, and dissipate heat to the side and up rather than to below (and which therefore also moves upward as well. The thin top and bottom sides could have vents as needed for convection cooling of the rest. Just a thought.

Or a similar design idea but with a more cubic extrusion like form, with more squarish front and back with one mono channel mounted on either side and vents on the top and bottom. Or I suppose one could mirror the lay out and have the boards mounted to thick slab of aluminum or two thin heat sinks facing each other in the center, and wrap the entire assembly with bent perforated metal on the sides (sort of like two old Luxman tube amps shrunk and turned sideways and rotated. Ac power routed at the bottom and inputs on the top with speaker connections just under them. One likely would need to find a custom case, or perhaps repurpose a couple cases made for hard drives.

Or one could go with a form factor more like those old quad amps with the heat sink find on the front, screwing the amp boards into two separate standard thin enclosures with curved sides, and vented end caps, turn them vertically two the end caps are on the top and bottom, and mount both to long a heat sink facing outward or inward.

Or use three rounded rectangular extrusions turned sideways, stacked against each other. The two on the side rotated so the end caps are facing the front and back with a third one in the middle rotated so its end caps would face up and down, but leave the end caps off. yhe middle one should be the same height of the side ones, or maybe a bit shorter. central thermally couple the three together maybe with an aluminum plate in between. the two on the sides hold one amp board and psu each along with with line level connections and speaker terminals, mount the boards to the sides coupled to the third extrusion, which serves as a heat chimney and and contains the ac inlet & fuse. For that matter you might be able to put the psu in the middle Or something like that.

Plus an option for analogue VU meters.one can dream. Could be in its own module/enclosure or the end caps of the amp modules or even stacked in the middle in a way that integrates into a whole.

With a dual mono design I think one could come up with a pretty great looking design by using relatively inexpensive and small enclosures in a clever modular way.

But maybe sideways mounting is a bad idea for other reasons.

 

[daniboun]

I look forward to that. Are you going to put two mono boards and two psu in a single case, or build it as two mono blocks? Or two cases for the amp board connected to a case holding the psu?

I have been thinking that a vertical design that mounts the board and psu on their sides, or at least one that can be rotated vertically might be very space efficient. Like the Marantz ma500u monoblocks, but smaller. That way a thick side plate could operate as the heat sink, and dissipate heat to the side and up rather than to below (and which therefore also moves upward as well. The thin top and bottom sides could have vents as needed for convection cooling of the rest. Just a thought.

Or a similar design idea but with a more cubic extrusion like form, with more squarish front and back with one mono channel mounted on either side and vents on the top and bottom. Or I suppose one could mirror the lay out and have the boards mounted to thick slab of aluminum or two thin heat sinks facing each other in the center, and wrap the entire assembly with bent perforated metal on the sides (sort of like two old Luxman tube amps shrunk and turned sideways and rotated. Ac power routed at the bottom and inputs on the top with speaker connections just under them. One likely would need to find a custom case, or perhaps repurpose a couple cases made for hard drives.

Or one could go with a form factor more like those old quad amps with the heat sink find on the front, screwing the amp boards into two separate standard thin enclosures with curved sides, and vented end caps, turn them vertically two the end caps are on the top and bottom, and mount both to long a heat sink facing outward or inward.

Or use three rounded rectangular extrusions turned sideways, stacked against each other. The two on the side rotated so the end caps are facing the front and back with a third one in the middle rotated so its end caps would face up and down, but leave the end caps off. yhe middle one should be the same height of the side ones, or maybe a bit shorter. central thermally couple the three together maybe with an aluminum plate in between. the two on the sides hold one amp board and psu each along with with line level connections and speaker terminals, mount the boards to the sides coupled to the third extrusion, which serves as a heat chimney and and contains the ac inlet & fuse. For that matter you might be able to put the psu in the middle Or something like that.

Plus an option for analogue VU meters.one can dream. Could be in its own module/enclosure or the end caps of the amp modules or even stacked in the middle in a way that integrates into a whole.

With a dual mono design I think one could come up with a pretty great looking design by using relatively inexpensive and small enclosures in a clever modular way.

But maybe sideways mounting is a bad idea for other reasons.

To be honest I have already designed everything. I am waiting to receive the missing material to share the project. I'm keeping a bit of a mystery for the thread in question but in what you cited, there are some good clues)
The project also consists of controlling the overall cost, so I will not go into esotericism and I must therefore remain reasonable)I will therefore stick with a dual Mono design with a single case

 

[musicforcities]

To be honest I have already designed everything. I am waiting to receive the missing material to share the project. I'm keeping a bit of a mystery for the thread in question but in what you cited, there are some good clues)
The project also consists of controlling the overall cost, so I will not go into esotericism and I must therefore remain reasonable)I will therefore stick with a dual Mono design with a single case

That’s cool. I just went on a reverie of sorts. lol.

 

[Koeitje]

$500 is almost twice the price. And also, it is arguable whether distortion at higher frequency or distortion with capacitive load is more important. If you look around, I believe pma tested Ncore before and pretty much all ncore designs cannot handle capacitive loads well. This problem is solved in NcoreX but that’s at another price level.

Sure you can argue his capacitive load test is not realistic enough, but it should be given a weight. No speaker is purely resistive load.

No its not twice the price. the 3e Audio TPA3255 kit is around 110 for a single channel. while a power supply will set you back like 80. Then you need a case and some connectors. So in terms of raw materials you would be around 220,- for a single channel. I don't expect ready made solutions for under 275 per channel.

For 500 you can buy a stereo setup that is already built and matches performance with the Topping PA7.

The stereo version of this amplifier is much more interesting.

 

[musicforcities]

That's what my thoughts are.
A relatively large and beefy aluminum enclosure must be used to keep the chips cool enough.
Possibly one of those with the side heatsinks. And this would be about 150
euros +-
So the whole project for the dual mono in EU would be 400-500E. And may it be a very nicely performing and futureproof amp, but at that price range, there's strong competition...

Get one of these pre drilled cases with ac Inlet for $50 or so. It will hold two amp modules and psus I believe. Need more thermal mass? Get cheap plate of aluminum and thermally couple to bottom with past and or thermal tape.

Want cheaper? Mount it to decent an off the shelf heat sink. Stick that onto some off the shelf plastic box from IKEA or office supply store, designed to hold ream of paper or something. the right box could hold two of these puppies. if you want, line interior with thin sheet metal or metallic tape for shielding. Drill holes. put in shelf or Velcro to the back of your speakers.


Or I might even take the case of an old broken NAD C272, reuse its heat sinks and put in two amps on each and four psus in the middle. or adapt/ reuse the existing power supply. I’d have room left over, a standby circuit and 12v trigger built in.

 

[sarieri]

No its not twice the price. the 3e Audio TPA3255 kit is around 110 for a single channel. while a power supply will set you back like 80. Then you need a case and some connectors. So in terms of raw materials you would be around 220,- for a single channel. I don't expect ready made solutions for under 275 per channel.

For 500 you can buy a stereo setup that is already built and matches performance with the Topping PA7.

The stereo version of this amplifier is much more interesting.

This module should be compared to pa7plus. And actually even pa7plus only comes with a 52V 6.5A SMPS, which is merely more than 300w. A dual mono kit+350W SMPS is still below $300 shipping, tax included.

 

[musicforcities]

No its not twice the price. the 3e Audio TPA3255 kit is around 110 for a single channel. while a power supply will set you back like 80. Then you need a case and some connectors. So in terms of raw materials you would be around 220,- for a single channel. I don't expect ready made solutions for under 275 per channel.

For 500 you can buy a stereo setup that is already built and matches performance with the Topping PA7.

The stereo version of this amplifier is much more interesting.

You could put two mono modules in one case and share one bigger ps or use two power supplies for full dual mono amp. Or yeah. Just get the stereo version.

Or if you don’t mind a bit of a hit to SINAID, and power, pick up two Ayima a07 max and run them bridged for around $250 or so. Depending on your speakers you may not notice.

Or yeah, pick up an ncore from IOM or elsewhere for around 5-600USD.

 

[RickS]

I wasn't paying attention. Looking at the picture, I don't see a ground to the chassis.

Lighting makes it difficult to tell and wire colors are poorly chosen. There is a second black wire running from the IEC power inlet to an apparent ground terminal on the power supply. Not sure if it may indirectly ground the case.

For your own safety, please be sure reference builds are properly wired.

 

[charlielaub]

There seems to be many people with reservations and complaints about this amp board and the stereo version reviewed very recently. But most seem to miss the point.

This amp module is NOT a consumer product - it's for DIY. Being a DIYer I love to see these sorts of products reviewed and am glad that it has demonstrated a high level of performance. I have purchased a bunch of the 2 channel boards and a custom chassis that can hold four boards plus a PS. Combined with a 1.5kVA smps I will be building an 8-channel amplifier for under $1k. I can swap out two of the stereo boards for two of the mono boards and will be left with a 6-channel amp, where 2 channels can deliver up to 450W into 2R. Very nice.

For what it is, this is really a nice product. But it's not the "everything for everyone".

 

[jayapple]

It is difficult for DIY products to maintain consistency. I used to like to make some radios and amplifiers, but in the end, the cost of DIY will far exceed that of qualified products with quality inspection and quality assurance. And you can't guarantee that the product you make will be consistent with the official data.

 

[CedarX]

I think two of these amps in bridged mode would be great for a powered sub-woofer solution.

Can you do that? The TPA3255 in this module is already in PBTL mode, I thought it was not possible…. Using two modules with a dual-coil sub should work.

 

[Bruce Morgen]

This amp module is NOT a consumer product - it's for DIY.

DIYers are a subset of consumers, albeit relatively small one.

 

[JDS]

This is a review and detailed measurements of the 3e Audio 480-1-29A, TPA3255 based class D amplifier module. It was sent to me by the company in a reference design for ease of testing:
View attachment 332950
The module is the PCB to the right and costs US 89.99 from company Aliexpress store. This is the mono version (I reviewed the stereo version earlier). The differentiation is pulling the required class D filter into the amplifier feedback loop (PFFB) and with it, essentially eliminate the effect of speaker load on frequency response. Low cost implementations lack this which can make the tonality somewhat variable. Other optimizations are done to extract better performance out of the TI TPA3255 class D amplifier module.

When swapping the stereo module for mono above, I was impressed by the hefty machined aluminum heat coupler. It is quite substantial and spreads the heat nicely to large area of the case bottom.

The included power supply in this sample is MORNSUN LOF550-20B48-C. Specification is 48volts at 6.5 amps with air cooling and 11.5 amps with forced air. Latter allows more than 550 watts to be provided to the amplifier.

3e Audio 480-1-29A Amplifier Measurements
The initial set of measurements match the stereo version so I will quickly go over them:
View attachment 332953
View attachment 332954

View attachment 332955
View attachment 332956

View attachment 332957
View attachment 332958

View attachment 332959
View attachment 332960

We get more power:
View attachment 332961
View attachment 332962
We had 206 watts in stereo. Same improvement with 8 ohm load:
View attachment 332963
Stereo version produced 92 watts.

Interesting to see the transfer function change some in this version:
View attachment 332964
Cleaner than mono at first but then worse at higher frequencies. Here is the stereo version again:

I captured the switching frequency and was impressed by how low its level was, and how high the frequency was:
View attachment 332965

Amplifier Reactive Load Test
This is one robust amplifier, essentially not caring about the load down to impressive 2 ohms!
View attachment 332966

View attachment 332967

You get nearly 600 watts here! Note that the test only keeps the amp at these power levels for short period of time so this is not "continuous" amount of power in the pure sense of that term.

Conclusions
I don't know what to be more impressed by: the TI TPA3255 or 3e Audio's engineering skills. This is an incredibly well performing at this price level. Of course you have to account for adding a capable power supply and case to get these numbers but still, one can't help but be impressed.

I am happy to recommend the 3e Audio 480-1-29A, class D Amplifier.

Manufacturer Specifications Amp Module:

• < 85uV Output Noise (AES17,A-weighted)
• 480W @ 1% THD+N, 1kHz, 2Ω
• 600W @ 10% THD+N, 1kHz, 2Ω
• 111dBA dynamic range
• THD+N < 0.01%, 0.3W – 300W, 3Ω
• 90% Efficient Class-D Operation (4 Ω)
• Fully differential layout design for lowest noise and distortion
• Very Compact size(105mm*90mm*38.5mm – L*W*H)
• Additional power ON/OFF reset circuit for Pop noise suppression
• BTL configuration only for best audio performance
• AUX Power Supply Output(12V/0.2A) for DSP Pre Amplifier
• Single supply voltage range 24V~51V(UVP:24V)

------------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Amazing stuff. While true excellence in loudspeakers and over-ear headphones still requires significant spending, there's simply no longer any *audible* justification for kilobuck DACs, power amps or in-ear monitors. I expect the repercussions of this sea change to take a while to ripple through the "hifi" industry, but the writing is on the wall.

A couple of years ago I started accumulating the parts needed to rebuild/upgrade an old Hafler DH220 I used for years. At this point I can't imagine why I would bother with it -- this amp will run rings around it, and won't heat my house doing it.

 

[restorer-john]

Yepp - here we go by the numbers - what you (think) you hear does not weigh in.

Absolutely it does with IMD. What makes you think it doesn't? And what 'number' do you think is audible when it comes to IMD? Amir is not giving you an ITU-R/CCIF, SMPTE IMD or DFD test here and he's not providing you a specific 'number'. He's feeding the device two frequencies, eyeballing the FFT and commenting based on his experience.

But the device clearly has a fair amount of IMD and the distortion it produces is also assymetric (notice the 'difference' signal and its harmonics). And consider this is only at 5W output. It will get a whole lot worse as the power goes up.

Many class Ds (like these) have terrible trouble with the ITU-R/CCIF 19/20kHz IMD test and produce an easily heard difference signal of 1kHz and 2,3,4,5,6,7kHz etc. You won't hear the 19/20kHz tones, but you will easily hear the intermodulation/beat products.

And those audible difference products are not considered in actual IMD calculations. Ironic isn't it? You can hear something that doesn't reflect in the numbers...