Guntars Smits describes TPA3255 PFFB isn’t necessary!

[Guddu]

This gentleman ‘Guntars Smits’ reads TI PFFB implementation document and describes its too complicated and mostly not really needed unless application demands like running horn tweeters.

Is he making any sense?

 

[wwenze]

>100dB SINAD isn't necessary to begin with

But we still do it anyway

 

[Guddu]

Don’t know if already have or would like to follow his video till end, but he is kind of suggesting that it’s not completely safe to do so and PFFB needs some additional chip type development for safe/effective deployment.
And in some ways, he is trying to point out to IcePower’s ICC5 conduct chip as a solution.
PE. To add, He has been supporting IcePower stuff and even sells full DIY kits.

 

[respice finem]

From a "common sense" perspective: There is probably a large number of units with this chip already "in the wild", and I've heard no "horrors", so it can't be too bad, probably.

 

[lewdish]

PFFB is great for class leading high end, but not really necessary for most electronics. Building a design w/o it is functional and cost effective. Most companies just want to optimize for cost and more objective performance. Out of the box the TPA amps are plenty good as is, maybe even just as good as Icepower amps in many cases.

 

[Bruce Morgen]

As I wrote in my comment under Guntar's video, the major improvement that comes from PFFB is eliminating the effect of output load impedance on high frequency response, which may or may not be audible depending on other factors, e.g. the use case, the impedance curve of the speakers, and the (mostly age-related) hearing ability of the listener with regard to the affected frequencies.

 

[terryforsythe]

As I wrote in my comment under Guntar's video, the major improvement that comes from PFFB is eliminating the effect of output load impedance on high frequency response,

Yes. The issue becomes more pronounced with real-world complex imedance loads. The class D amplifiers I have seen using PFFB have significantly flatter frequency response above 10kHz with complex imedance loads as compared to those that don't have PFFB.

Another benefit is that PFFB lowers the output impedance of the amplifier, though that probably would not be audible with typical passive speakers - the output impedance still tends to be lower than that introduced by a typical crossover. If used without a passive crossover, for example in an all active setup, perhaps the difference in output impedance would be audibly detectable, i.e., slightly tighter bass control, but I don't know.

 

[dcolak]

Is this why I find FOSI V3 MONO with PFFB sounding unnatural, horrible, while I find FOSI BT20a PRO sounding really good (no PFFB)?

 

[solderdude]

That could depend on the attached speaker's impedance.

I would not expect a difference to be as big as 'unnatural/horrible' vs 'really good'.
That would suggest the V3 is defective somehow.

 

[dcolak]

That could depend on the attached speaker's impedance.

I would not expect a difference to be as big as 'unnatural/horrible' vs 'really good'.
That would suggest the V3 is defective somehow.

It's not deffective.

 

[Panelhead]

Digital switching amps have been around a long time. Think Bruno and others have made them so good that it is hard to hear a difference.
The SINAD numbers really are not indicative of amplifier use. Maybe the test needs to be run at 500mW. That is in the range with most systems power output. Outputting 5 watts is for peaks.

 

[Redacted]

Is there that acrid smell of vested interest somewhere on this thread?