Q: Class-D Amp Kits, All, Turn-on Thumps

[speaker]

I noticed on the datasheet for the TAA4100 that it includes "pop-free start-up & shutdown".

Is this a characteristic on all the Tripath chips?

If not, how are you dealing with it in your own projects?

[Xspunge]

On my AMp 6 Basic, the turn on thump is there. Many people have already spoken at length about turn on thumps (and not just on that particular amp). but it is caused by DC offset. If you have really large input caps then the louder the thump will be.

I don't know how to get rid of it other than using smaller value caps, but I am sure someone out there knows a better way, I'm just too lazy to experiment.

The input caps are 3.3uF electrolytics on both my Amp 6 Basic and Amp 32. For some reason the Amp 32's turn on thump is at a lower level than my Amp 6 basic. In both cases its still not too bad so I don't mind it, besides it lets me know my amps are working. Someone did suggest leaving the amp plugged in and not using the mute switch, but that is not practical for me. When you flip the switch and you don't hear a thump, then you know something is wrong.


In both amps it is pop free when you flip the mute switch on.

I think the pop free performance on turn on is dependent on which model you are using and what input caps are selected.

Surely someone will give you a good solution to work with.

[Pano]

Originally posted by speaker
Is this a characteristic on all the Tripath chips?

It is, and has been covered pretty well in this forum. Its something that I. ot someone, needs to add to the Wiki.

Try a search on this forum for "Sonic pop" or "turn on pop" "soft start", thump, etc.

If you don't find what you are looking for, let us know.

[speaker]

Originally posted by panomaniac


It is, and has been covered pretty well in this forum. Its something that I. ot someone, needs to add to the Wiki.

Try a search on this forum for "Sonic pop" or "turn on pop" "soft start", thump, etc.

If you don't find what you are looking for, let us know.

I could only find 2 threads with pop or thump in the title. I did not search those terms bundled into other threads so there may be more discussion/solution inside them. Neither of the threads however went into much detail other than ways of dealing with it after the fact via turn-on sequence, etc.

What led me too this was that I have a Tripath demo board amp EB-TAA4100 on my desk. Even though the data sheet calls out "Pop-Free startup and shutdown", the pop is mighty in both states. Secondarily, the background hiss is enough that from desktop, speakers 2' from ears, you can hear it.


Tripath EB-TAA4100

[nicoch58]

http://www.diyparadise.com/charlize.html

look at the end of page......works fine

[speaker]

Originally posted by nicoch46
http://www.diyparadise.com/charlize.html

look at the end of page......works fine

I like that.

Simple, elegant.