Compact TPA3255 design with PFFB and single PS

[zdr]

THD for amp alone, calibrated out the rest of the chain since I have line out on PGA Pre. Have you seen anything prettier recently?

 

[454Casull]

All these fine folks coming up with wonderful TPA3255 designs and TI put out what now seems like a half-assed design with their EVM. sigh

 

[0hm5law]

THD for amp alone, calibrated out the rest of the chain since I have line out on PGA Pre. Have you seen anything prettier recently?

Lets see... Looks like low 12vac range linear ac voltage supply with nice reliable sinewave.

I see nice full musical range+ flat frequency response with 115 dbl average.

I'm missing more bits I'm sure.

What speaker impedence!? Any long operational real music testing? Any performance dips due to long time operation temperature spikes.

How does it sound?

I'm new here and don't have enough experience to really say much... But don't let the haters or distractors keep you from doing what you do. I see alot of excitement for this amp.

Thank you.

 

[zdr]

This is measured at 0.5W, 4.5ohm. It sounded great even before putting it in the box and tidying things around. I will soon do a proper listening test with comparison to RMI-FC100.

 

[0hm5law]

Thanks ZDR.

Looks very promising.

I'd like to see some 48-51v testing later on if possible.

Will probably require good enclosure with good heat sink design.

The voltage range I'm looking at is pushing this to the limits of it's Ti design.

 

[zdr]

Measurements are done with 24V/5A Lenovo PS. I don't think numbers will change with higher voltage, but it might blow up my aliexpress MLCCs in the output filter allegedly rated at 250V

 

[zdr]

Done.

 

[drMordor]

Done.

Very very nice)))

 

[chips666]

+1
Indeed very very nice
Enjoy...

 

[Vb15]

Very nice. Interior pictures?

 

[chermann]

Done.

View attachment 907679

WOW!!!


very very nicccce!

 

[zdr]

thanks.

I am listening now to RMI-FC100 and TPA3255 with A/B switching, can't say I hear any difference so far.

 

[pulexirritans]

PCB is also standard with 1oz copper.

I'm curious to know if the 1oz copper adversely affects the performance. Have you done any testing at higher output?

 

[zdr]

Only output traces can maybe benefit from thicker traces and those are already very wide and short (whole PCB is just 10x10cm), and can be additionally thickened with wire should someone want to run 260W per channel.

I did not do any tests with full power.

 

[pulexirritans]

Ok, thanks. As I'm sure you're aware the application note recommends 2 oz copper and says output will be higher, lower EMI margin, etc. But they do not quantify they benefits.

After using Jlcpcb's assembly service I am no longer interested in assembling my own boards, however they do not offer assembly on 2oz copper.

 

[drMordor]

I'm curious to know if the 1oz copper adversely affects the performance. Have you done any testing at higher output?

If the conductors are wide enough, it does not affect. I tried this on early versions of my amp.

 

[pulexirritans]

If the conductors are wide enough, it does not affect. I tried this on early versions of my amp.

Ok thanks. Now I see on your site the output of your 3255 amp is very close to the TI reference design.

 

[zdr]

I have been listening my ears off for days now, with A/B switching between this amp and RMI-FC100, and I can MAYBE hear a slight improvement on bass sections when TPA3255 is playing.

 

[adn6244]

Done.

View attachment 907679

Very nice.

Mind sharing where did you source the casing from?

 

[zdr]

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