TPA3255 Reference Design Class D Amp with PFFB

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#341
As long as they are the “best” to you is all that matters. But I have heard many systems and I can tell yours is up there. The frequency response in your thread is right on target with the slight tilt of the Harman House curve. I know what the GRS planar can do and I know Tang Band paper cone full ranges works well as a mid. I know you have got a great amp! 😂

You have a system to be proud of and can enjoy now. So spend some time relaxing and listening to music for a long time. Until the itch to build the XSD creeps in. 😉

Speaking of Pearl 3, I am listening to Jhofland’s version and it sounds fantastic. I have a much more basic TT though but nice cartridge.

Cheers,
X
 
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#342
Many thanks for the kind words, X!
It's great to read this from someone who is light years ahead of me in speaker design!
Yes, now I enjoy the music, I listen to it since many hours now 🙂 and it's just beautiful.
However... I have so much itch when it comes to building... HyperSET, Pearl 3, some linear PSUs...
And of course I have to finish the xo of The Open Baffle (currently it's a lump of components with point-to-point soldering) and the birch ply baffles will also arrive soon (instead of the MDF ones)... so, very much to do 🙂
But that's fun 🙂

Many thanks again!
Cheers
 
#343
She likes it too 😍

PSX_20240128_175759.jpg
 
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#345
After discovering how great this power amp can handle my speakers, it is now my main power amp, period.
I listen almost every day and it's simply gorgeous.
Just wanted to say😀
I'm curious, X, when you will offer another great power amp like this :cheers:
 
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#346
I have the A40 Class A amp coming out soon. It sounds amazing - full time SE push pull Class A Alpha Nirvana topology with 250 damping factor for bass so unbelievable woofer cone control.

I will also be developing a hybrid tube buffer Class D amp with 350wpc for a client as a commercial amp. Still early stages.
 
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#347
Thanks for the reply. My concern with Class A amps is the behavior at "weird" speakers on terms of strange impedance curve. It's mostly not in the bass range, rather in the mids, and it can cause a shouty midrange without control.

Your Class D plan is great - but being a commercial thingie, no chance🙄
 
#350
You could just build the Alpha Nirvana. Same amp. Add the SFPP and SSR speaker protects. Add the SLB power supply if you want to go all out.

https://www.diyaudio.com/community/threads/alpha-nirvana-39w-8ohm-class-a-amp.344540/

Here is an example of the Alpha Nirvana in an exquisite build by Sledwards:
1708749531928.jpeg


Here is listening impressions by Poseidonsvoice:
https://www.diyaudio.com/community/threads/alpha-nirvana-39w-8ohm-class-a-amp.344540/post-6987070

His build is also very impressive but I can’t find the thread off the top of my head.

The amp itself is quite simple all through hole parts.

1708749862208.jpeg
 
#351
Wow. Thanks X, I have to think about it, but it looks really great.
What's the difference between A40 and Alpha Nirvana, if any (if it's not a secret, which of course I would understand)?
The boards are in the shop; there is an SFPP with lot of SMD (no go for me), and an SFP with soldered SMDs - would it be okay too?
I fear a new project is born... 🙈
 
#353
rhing said:
Hi X, it really seems to work well from the start. It really does perform as many of the LSA Discovery Warp-1 reviewers have stated.
Click to expand...

rhing said:
It does not sound like most Class D amps, and it really has a rich tonality. I really like it.
Click to expand...

Hi X - or anyone familiar with both

How do the original xrk TPA3255 Reference amps sound, compared with the newer version with PFFB?

more so in terms of tonality. I highlight that, as it’s probably the last good attribute you might not expect from class D
 
#355
Yes sound quality is subjective, most people who’ve heard a fair amount of different gear do develop preferences

to clarify what I meant by tonality -
apart from the level of measured THD - with/ without PFFB in circuit … can you hear a subtle amount of more 2rd or 3rd harmonics in either?
 
#356
xrk971 said:
The PFFB has about -6dB less THD bit sound wise, it is subjective. I personally can’t say one way or another but if I had to pick, I kind of like no PFFB. It’s easy to change by putting a jumper across the 3k6 feedback resistors or change to 0R.
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Don't forget that the system response also improves a little.

I am mostly talking about the peak you can get from the LC filter at higher impedances.

I have seen cases where this has quite an effect already around 10-20kHz.
 
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