What is wrong with TPA3255?

[diytoon]

Will buy a top class smps when this is the fix...this one is just for testing...do not believe this is the solution...

Rta on my ipad is the only (poor) spl measuring tool I have...but I hear the difference in bass against 10 other amps...they cannot all be wrong...even my quad 303 has not this gap in bass...(50 year old workhorse)...

I will see what the result of the other yj board will be...is shipped I hope...

 

[diytoon]

according to IR basic classD troubleshooting: treble->output, bass->input

It feels like a very high subsonic filter...

 

[doctormord]

Then use RTA to plot the response of this amp against another and show the results. This should make it clear, even if not calibrated.

 

[diytoon]

It is clear to my ears...do not need confirmation from my Ipad...

 

[DPH]

That's the very issue doctormord is trying to give a differential on. There may be a response difference or, well, it may be entirely in your head.

 

[irribeo]

An old 303's outputcapacitor poorly affects damping and its value limits bass (frequency). You do not miss bass with 3118 ?

 

[doctormord]

It is clear to my ears...do not need confirmation from my Ipad...

So it might be only in your mind. Without any measurements no-one can technically help, as no-one can "see" the problems as we don't have insight in your mind.

With plot-data things can get calculated to see where a potential problem is.

 

[SanjeevM]

Diytoon, why dont you measure with your iPad and post comparative results. At least there will be objective data, however inaccurate !

 

[diytoon]

I will do this weekend...

 

[Kjeldsen]

I guy in Denmark had the same problem with Hypex and B&W N801. The bass was missing. I was the very complex load that the Hypex module did not like. He had to remove the passive woofer filter, and replace with active filter, and then no problem. The Hypex sounded fine on many other speakers, just not the B&W N801

PWM ekspert soges - HiFi2You

 

[diytoon]

An externally hosted image should be here but it was not working when we last tested it.

This is how it looks for TPA3118...

I will post TPA3255 next time I connect it...(this weekend probably)

 

[diytoon]

I guy in Denmark had the same problem with Hypex and B&W N801. The bass was missing. I was the very complex load that the Hypex module did not like. He had to remove the passive woofer filter, and replace with active filter, and then no problem. The Hypex sounded fine on many other speakers, just not the B&W N801

PWM ekspert soges - HiFi2You

I also have hypex...no problem in bass...

 

[doctormord]

It would be useful if you do the test with highest band resolution and both tests at the same day/timeslot without moving the ipad or changing settings between the tests. Otherwise it isn't comparable.

 

[Kjeldsen]

I also have hypex...no problem in bass...

You have the same B&W model? It's only one specific model. Other version of 801 is no problem to the user

 

[diytoon]

It would be useful if you do the test with highest band resolution and both tests at the same day/timeslot without moving the ipad or changing settings between the tests. Otherwise it isn't comparable.

Ipad will be on the same place...settings will be the same, time or day is not a parameter...lets keep it simple...I am not hoping to find a solution for my problem with these measurements...just objectively showing it is not in my head!

Btw...next amp is on the way...and I am confident that one will not have the bass problem...if it does, exit TPA3255 like the TAS5630 because they are way to noisy ( at least the ones I tested)...

But hey, it is fun to experiment with these low cost class d amps...

I was only hoping to hear some feedback from other TPA3255 users, so far not much to find here or elswhere...(maybe I am not searching good enough... )

 

[diytoon]

You have the same B&W model? It's only one specific model. Other version of 801 is no problem to the user

No b&w speakers for me...not my cup of tea... I prefer full range speakers...

 

[Kjeldsen]

Ok. My point was that a very complex load can affect a class d amplifier, but not that Hype don't play bass. It was a hint to try other speakers to see if the problem is the same.

 

[doctormord]

I am not hoping to find a solution for my problem with these measurements...just objectively showing it is not in my head!

Why then did you wrote an email to the vendor of that particular board? If you aren't interested in a solution you don't need to do any measurements at all.

(Maybe it's just a picture polarity issue)

 

[SanjeevM]

[

So that the manufacturer can suggest improvements. If diytoon can implement them on his own board it will be fine; the manufacturer can implement them in his future boards, which will benefit other hobbyists.

 

[doctormord]

If so, this discussion should be moved to the vendor section.