3e Audio A7 - TPA3255 Stereo Amplifier Advanced PFFB -First Look

[Guddu]

Dear FMs,
I just got 3e’s 2nd Gen advanced PFFB based TPA3255 stereo amplifier - A7.
Simple design but excellent build quality with considerations to thermal performance.
While I plan to test this unit in many ways I could, I am sharing here some pics of the product.

*Pls ignore the DC input voltage marking.
Thanks @3eaudio

 

[ppataki]

Looks good!
Is this going to be commercialized?

 

[yo!]

Thanks! We want to peep the coils and cooling, please send some uncovered views

 

[SMen]

Looking at this with a just in case alert - it gives D5 voltage (36-38volt) on the back, and it says D7 on the front, which I thought was 48v.

 

[harkpabst]

Looks good!
Is this going to be commercialized?

Yes, see this statement by @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

 

[harkpabst]

View attachment 408368


*Pls ignore the DC input voltage marking.
Thanks @3eaudio

Can you spot the op-amps used through the replacement openings?

 

[SMen]

Looking at this with a just in case alert - it gives D5 voltage (36-38volt) on the back, and it says D7 on the front, which I thought was 48v.

Actually, just saw the ignore message!

I'm sorry in a way it's not the D5 you have.

 

[Kagemusha]

Looking nice, any idea of price ? Size? Seems bigger than a Fosi za3?

 

[somebodyelse]

*Pls ignore the DC input voltage marking.

How about the L/R labels on the RCA inputs not matching the standard colour coding?

 

[V.b.]

Looks nice. The board is inverted, which frees up the underside for passive cooling, letting the hot air on the sides and gives an uninterrupted top panel.

 

[Bruce Morgen]

How about the L/R labels on the RCA inputs not matching the standard colour coding?

Yup -- obviously the easiest imaginable fix!

 

[xschop]

Looks to be a quality continuous-cast alloy housing and faceplate. I see a silverface mod in the future.

 

[Tell]

Yup -- obviously the easiest imaginable fix!

Still really weird that it's on this preproduction unit.

 

[Bruce Morgen]

Still really weird that it's on this preproduction unit.

Agreed -- I think it has to do with the jack assembly's orientation with respect to the PCB layout. It seems like those colors weren't considered when they decided on the position of the PCB in the case. Not worth changing -- they should just buy an otherwise identical jack assembly with two white jacks to avoid confusion in the production model.

 

[xschop]

I'd swap out the RCA's for gold plated jacks regardless.

 

[harkpabst]

Still really weird that it's on this preproduction unit.

I'd say, that's why it is a pre-production unit, not a production unit.

Also, the production units won't come with a trigger input. Auto input sensing will be used instead. I can hear the outcry, but that's perfectly fine with me.

 

[PlasticDoc]

I just got 3e’s 2nd Gen advanced PFFB based TPA3255 stereo amplifier - A7.

The overall design of the case looks good. The front button and rear connectors look good and are well placed.

The heat dissipation still seems problematic:

• When these TPA325x chips get hot, they start to degrade in performance, output power, and lifetime. A big part of the success of the 3e audio 260-2-29A PFFB module design was the huge aluminum heat sink under the board.
• Using the amplifier box to achieve the same effect can work, but care must be taken to provide a reliable interface between the chips and the box.
• A strip of U-bent aluminum between the chips and the box and a few dabs of thermal grease won't do the trick.

I'd like to see a preliminary reading with an infrared thermometer pointed at the TPA325x chips and the top and bottom plates of this case. If the case does not get hot, it is not a good heatsink.

 

[MCH]

The overall design of the case looks good. The front button and rear connectors look good and are well placed.

The heat dissipation still seems problematic:

• When these TPA325x chips get hot, they start to degrade in performance, output power, and lifetime. A big part of the success of the 3e audio 260-2-29A PFFB module design was the huge aluminum heat sink under the board.
• Using the amplifier box to achieve the same effect can work, but care must be taken to provide a reliable interface between the chips and the box.
• A strip of U-bent aluminum between the chips and the box and a few dabs of thermal grease won't do the trick.

I'd like to see a preliminary reading with an infrared thermometer pointed at the TPA325x chips and the top and bottom plates of this case. If the case does not get hot, it is not a good heatsink.

The surface area of this enclosure is for sure much larger than that heat spreader of the boards whiczwas, by the way, intended to be mounted in an enclosure.

 

[3eaudio]

Can you spot the op-amps used through the replacement openings?

it is OPA1656

 

[3eaudio]

Agreed -- I think it has to do with the jack assembly's orientation with respect to the PCB layout. It seems like those colors weren't considered when they decided on the position of the PCB in the case. Not worth changing -- they should just buy an otherwise identical jack assembly with two white jacks to avoid confusion in the production model.

it is silk print mistake. correct it already