TPA3255, TPA3251 with Post Filter Feedback(PFFB)

[CharlieLaub]

Actually as of this morning I own four of them, except they are in Asia somewhere and must be shipped to me before I can take custody.

 

[bloqhed]

I have a stereo one, but I let someone borrow it. It measured and performed well enough for the price point, there are better TPA3255 boards out there but at a higher cost.

 

[zek]

there are better TPA3255 boards out there but at a higher cost.

Please name some of them.

 

[TNT]

... and how.

//

 

[bloqhed]

Jlester's boards such as the Sylph D200 MKII or XRK's boards.

 

[Fsatsil]

I have both the new and old 3e Audio amp boards and the new one is a clear step up in every way. My only complaint about thenew amp with PFFB is that the gain is a bit low.

 

[geek101]

Hi, I would like to order a couple of 260-2-29A from http://www.3e-audio.com/amplifier-kits/tpa32xx-with-pffb/, could you please recommend a case and power supply I could put together easily to maximize the amp performance?.

 

[3eaudio]

many people use meanwell LRS series like LRS350-48, it is cheaper for a common SMPS.
https://www.digikey.com/en/products/detail/mean-well-usa-inc/LRS-350-48/7705033
for some better option and size compact, I suggest one China brand - Mornsun,almost can say it is China Meanwell SMPS vendor.
LOF350-20B48-C also can be find in our aliexpress store.
https://www.digikey.com/en/products/detail/mornsun-america-llc/LOF350-20B48-C/14306717

 

[3eaudio]

here is Aluminum heatsink dimension for mounting on some chassis panel.
all holes are common M3 size.

 

[sokool0]

Can I disassemble the board? I'd like to use the punch to check the screw holes.

 

[3eaudio]

@sokool0 all holes are 3.0mm.

 

[muducu]

People hi

@ Fsatsil:

You are very lucky to have already obtained this new version

(What operational amplifiers are used ?)

It is a beautiful assembly that you have made

However, I have two questions for you:

1> you seem to have used a MEANWELL open frame EPP series power supply (EPP 400-48 ?).

Some say that it is not really efficient or even noisy:

can you give us your impressions please ?

2> You added a 10000µF capacitor (?) in parallel with the power supply (a diagram would have been welcome):

what is the purpose and/or the interest of this assembly ?

Thank you in advance for your answers

Cordially.

 

[muducu]

Hi 3eaudio

You recommend here and distribute (ALIEXPRESS) LOF350-20B48-C and LOF500-20B48-C power supplies.

Can you provide us with measurements concerning the noise of these, a bit like those made by LESTER (SYLPH AUDIO) on AUDIO SCIENCE REVIEW

(thread "JL ELectronics Sylph-D200 Amplifier Module Review", post #193) ?

This would allow us to have a better view of the quality of these power supplies and would indirectly impact your sales

Thank you in advance

Cordially.

 

[Fsatsil]

People hi

@ Fsatsil:

You are very lucky to have already obtained this new version

(What operational amplifiers are used ?)

It is a beautiful assembly that you have made

However, I have two questions for you:

1> you seem to have used a MEANWELL open frame EPP series power supply (EPP 400-48 ?).

Some say that it is not really efficient or even noisy:

can you give us your impressions please ?

2> You added a 10000µF capacitor (?) in parallel with the power supply (a diagram would have been welcome):

what is the purpose and/or the interest of this assembly ?

Thank you in advance for your answers

Cordially.

1>
The Meanwell power supply I used is the RPS-400 and I don’t find it to be noisy at all in fact I was very impressed with how quiet it is since I’ve had noise issues with the cheaper Meanwell Eps series.
2>
As for the 10000uf/63V capacitor, it was originally used because it was in my parts bin and I figured it couldn’t hurt to add some power storage to the power supply. The cap has since been removed since I couldn’t hear any difference with/without it.

I hope this answers some of your questions. Enjoy the weekend!

 

[muducu]

Good evening (I'm from France) Fsatsil.

Thank you for your answers

I think they will be very informative for everyone regarding MEANWELL power supply models and the use or not of an additional reservoir capacitor.

For the latter, I think it can even be counterproductive for different reasons

It's a pity that you couldn't make measurements with and without this capacitor...

I also wish you a good and pleasant weekend

Cordially.

 

[CharlieLaub]

The Meanwell power supply I used is the RPS-400

Note that this PS when used wtihout a fan only can supply about 250W of power at 20C, and the derating curve in the datasheet shows the max power decreasing steeply when the ambient temperature is above 35C (like in a poorly ventilated area, e.g. cabinet or enclosure)

 

[muducu]

Hello CharlieLaub

This is a relevant point !

(I was asking myself the same question while looking at the 'TEST REPORT' of MEANWELL).

Taking into account this temperature concern when using without a fan in a case, I think it may be wiser to use a MORNSUN LOF550-20B48-C power supply to have significant power while remaining within values of sound very correct.

What do you think ?

Have you done any tests with other power supplies that you might recommend ?

Cordially.

 

[Fsatsil]

I should add that the main reason that I used the Meanwell Rps400 is that I got a great deal on it and only paid about $55.

 

[CharlieLaub]

I am currently in the process of getting the chassis for several class-D amps that use TPA32xx chips. For these I am using Meanwell UHP series power supplies, which are fanless. As long as they are bolted to the amp chassis they should be able to meet spec.

 

[muducu]

@ CharlieLaub

Indeed: the MEANWELL UHP-350R-48 power supply would seem to be suitable with 7.3A for a maximum of 50°C and even hotter if it is attached to the chassis according to the manufacturer's technical sheet !

Have you already made measurements with this power supply ? 👈