3e Audio TPA3251 TPA3255 Finished Amplifier with PFFB is coming!

[PlasticDoc]

Worth resurfacing this 3251 vs 3255 comparison

• xx51 has slightly lower THD than xx55 up to around 5 watts
• 5 watts to 100 the chips perform similarly
• above 100 watts the xx51 starts to break up, the xx55 goes to over 200W before also breaking up

if you don't see yourself pushing serious power (either for high volume or insensitive speakers), I would choose xx51 for providing slightly better performance for most typical listening ranges. I concede the point that both amplifiers are well in to inaudible THD range, so the real world difference is negligible. Still, the engineer within me would be happier knowing I have the more optimal chip for my use case.

Since the 3e Audio amplifier is the TPA325x PFFB variant, the relevant papers for further investigation are:

TI Application Report SLAA702 - July 2016, by Matthew Beardsworth
TI Application Report SLAA788A - September 2017, by Dan Kisling, Matthew Beardsworth

The original design started around 2014, so these TPA325x chips are now 10 years old !

From the TI papers, you can see that TI measurements and comparisons were (almost always) done using:

TPA3251, PVDD = 36 V, Fpwm = 600 kHz
TPA3255, PVDD = 51 V, Fpwm = 450 kHz

Neither the 3e Audio A5 (TPA3251) will be driven at 36V (it will be driven at higher voltage with slightly higher distortion), nor the 3e Audio A7 (TPA3255) will be driven at the higher 51V (it will most likely be driven at 48V with slightly lower distortion).

As a side note you may find that the SLAA702 paper (mostly by Matthew Beardsworth) has valuable tuning insights regarding IMD, Gain Compensation and Zobel network (to deal with speaker impedance issues); even there the TPA3255 looks better.

Over time, you may find that the A7 (TPA3255) is the better value.

 

[harkpabst]

Neither the 3e Audio A5 (TPA3251) will be driven at 36V (it will be driven at much higher voltage with much worse distortion), ...

Where did you find this information in the specs published by 3e Audio?

Taken from the Archimago review (even if these are pre-production samples):

 

[harkpabst]

What is the tester talking about? DAC overshoot? Come on, this overshooting is typical TPA behavior ... you can see it on Ti specsheets.

The tester clearly knows what he's talking about.

 

[SMen]

Since the 3e Audio amplifier is the TPA325x PFFB variant, the relevant papers for further investigation are:

TI Application Report SLAA702 - July 2016, by Matthew Beardsworth
TI Application Report SLAA788A - September 2017, by Dan Kisling, Matthew Beardsworth

The original design started around 2014, so these TPA325x chips are now 10 years old !

From the TI papers, you can see that TI measurements and comparisons were (almost always) done using:

TPA3251, PVDD = 36 V, Fpwm = 600 kHz
TPA3255, PVDD = 51 V, Fpwm = 450 kHz

Neither the 3e Audio A5 (TPA3251) will be driven at 36V (it will be driven at much higher voltage with much worse distortion), nor the 3e Audio A7 (TPA3255) will be driven at the higher 51V (it will most likely be driven at 48V with slightly lower distortion).

As a side note you may find that the SLAA702 paper (mostly by Matthew Beardsworth) has valuable tuning insights regarding IMD, Gain Compensation and Zobel network (to deal with speaker impedance issues); even there the TPA3255 looks better.

Over time, you may find that the A7 (TPA3255) is the better value.

I am slightly scratching my head on this because we should hopefully get measurements for the two chips in the 3e implementations both here, and at Archimago's Musings. It looks like the two power supplies are 38V 5A and 52V 9A. There is so much measurement chasing that goes on that if 3e could get better measurements with 36V and 48V I would have thought they would.

We shall see ...

2024 implementations of a 2014 chip, but surely effectively measured for distortion etc. both here (soon hopefully) and at Archimago's Musings?

Post edit - the Archimago review is looking very interesting. I'm looking forward to part two, and his impressions of power when using the two different units.

 

[3eaudio]

Archimago is reviewing the upcoming models

Part I: 3e Audio - A5 Stereo and A7 Mono Class D + PFFB, TI TPA3251/3255 Amplifiers - Features and initial measurements.

A blog for audiophiles about more objective topics. Measurements of audio gear. Reasonable, realistic, no snakeoil assessment of sound, and equipment.

archimago.blogspot.com

let's share this to more people after a great thanksgiving holiday.......

 

[V.b.]

Neither the 3e Audio A5 (TPA3251) will be driven at 36V (it will be driven at much higher voltage with much worse distortion), nor the 3e Audio A7 (TPA3255) will be driven at the higher 51V (it will most likely be driven at 48V with slightly lower distortion).
...
Over time, you may find that the A7 (TPA3255) is the better value.

TPA3251 max voltage is 38V. PA5 uses a 38v PSU and it has lower distortion than PA7.

It is easier for an end user to estimate the max voltage they need for their setup. You can feed 52V to the amplifier bit it will only amplify to what the final gain is set by the volume. You may only need 24 volts but In the meantime the amplifier works internally at 52V in a small box. Why? It is wasteful and does not help reliability. There are people happy with a Fosi 32V PSU

Amperage is a bit more difficult to estimate.

V

 

[PlasticDoc]

The Archimago review is looking good.

Meanwhile, just seen at the 3e Audio store:
It seems that the PSU will be 38V/5A and 48V/5A and the amplifiers will be expensive: 119591,70€ /each(*)

(*) Yes, I know these prices are how some aliexpress sellers prepare to sell a product not yet available.

 

[yo!]

The tester clearly knows what he's talking about.

No, in this case it's not clear and not defined at all. Unclear information has no quality in it. But whatever ...

 

[harkpabst]

No, in this case it's not clear and not defined at all. Unclear information has no quality in it. But whatever ...

I'm very sure it's clear and correct.

 

[Inertiaman]

The Archimago review is looking good.

Meanwhile, just seen at the 3e Audio store:
It seems that the PSU will be 38V/5A and 48V/5A and the amplifiers will be expensive: 119591,70€ /each(*)

(*) Yes, I know these prices are how some aliexpress sellers prepare to sell a product not yet available.

It seems they are discounting to U.S. Only $99,999 shipped here.

Seriously though, they have placeholders for all 5 products in both US and Europe plug style. So perhaps all the models will be available at same/similar times.

Shipping to U.S. is showing $28. I suspect that's accurate (unlike the current price) since it aligns with the shipping costs on modules from 3e.
So a $200 A5se will be >$250 after tax and shipping to USA.

I can get a Fosi V3 delivered, no tax, for $88 from Fosi directly. Or two V3 Mono for $224. Hard to imagine that Fosi is absorbing $28-ish shipping on a V3.
Sure wish 3e could find a lower cost shipping method and/or sell direct to minimize tax that goes w/ Aliexpress.

Definitely paying a premium for PFFB, and a further premium for 3e (in part due to ship/tax).

I expect that eventually some company will produce a sub-$200, dual-3255 amp with integrated power supply that is reliable and tests well. Until then, the 3e models look like a good, albeit (modestly) pricier option.

 

[Guddu]

In Short
@3eaudio I hooked up pre-production A7 unit past weekend, replacing Topping PA7 (I did go back to PA7 after spending some time with A70 mono).
No hick ups, no background noise or hiss, no pops.
With 48v 10a PSU, its has impressive powerful presentation. I am experiencing better lower end response (my Sierra-LX haven't been easy for similar amplifiers) and excellent low volume performance. High damping factor might have helped here.
Thermal performance is very good as well, it gets slightly warm which should not be anything to worry about.
Sound signature wise, I totally love it's super smooth and non-fatiguing presentation. I am in the process of borrowing a pair of Dali speakers to listen with A7, I have always found TPA3255 amps quite fatiguing with Dali and may be these 3e amplifiers could help with that.

I don't know how large or small scale business 3e have, but this piece shows their excellent engineering skills. This one is going to get lots of praise.
I will put together User Impressions and Owner's Thread for A7 after trying all the features and a few different speakers.

 

[harkpabst]

Luckily, AliExpress doesn't show anything but the well known DIY boards 260-2-29A and 480-1-29A to German customers, so I don't have to worry about costs, shipping costs and taxes, yet.

Btw:
For the DIY boards I see shipping for <14 € and a price <135 € containing VAT for the 3255 stereo board.

 

[daniboun]

A little summary to help everyone:

 

[Inertiaman]

@daniboun, you're late to the party!
That table was posted here three weeks ago by 3e in post #128

 

[daniboun]

@daniboun, you're late to the party!
That table was posted here three weeks ago by 3e in post #128

My bad )
I have less and less time.... but my heart is in it)

 

[ppataki]

just share some progress here, release postpone to 10/Dec due to factory over capacity,sorry for this delay.

Will there be an early-bird discount?
I am planning to have two A7 Mono units
Looking forward to this marvelous product!

 

[SMen]

Will there be an early-bird discount?
I am planning to have two A7 Mono units
Looking forward to this marvelous product!

I think if you check back, a link was posted by 3e audio for people here to post which units they would be interested in for their first batch. I think (from memory) there may be an early bird associated - but I filled in mine a while back so you will need to look up 3e posts on this thread.

 

[wkamil]

3e Audio TPA3251 TPA3255 Finished Amplifier with PFFB is coming!

@3eaudio , will any of the amplifiers make it for the 11.11 sale? aggressive but early of Dec should be ok.

audiosciencereview.com

 

[ppataki]

I filled this in, thank you!

 

[3eaudio]

3e Audio TPA3251 TPA3255 Finished Amplifier with PFFB is coming!

@3eaudio , will any of the amplifiers make it for the 11.11 sale? aggressive but early of Dec should be ok.

audiosciencereview.com

anyone fill in will get extra discount.