Cheap TPA3118D2 boards, modding them and everything that comes with it

[lacro]

No turn on or off thump,

Your stock boards don't have turn on/off thump? Mine do.

 

[xrk971]

Your stock boards don't have turn on/off thump? Mine do.

It's a very light soft barely audible sound - much different than a real thump experienced on my other 3116 boards. Not absolutely silent, but it won't damage your speaker.

 

[Buehgemeiste]

It's a very light soft barely audible sound - much different than a real thump experienced on my other 3116 boards. Not absolutely silent, but it won't damage your speaker.

On the Vifa TC9FD's i have a turn on thump, too.
But the easily accessable MUTE is absolutely quite when used as on/off switch.

 

[irribeo]

Doesn't using multiple smaller caps make ESR lower? Could it be those stock VT caps may have an ESR in the ~50-80 mOhm range - is that typical? Whereas the OSCON's are in th 10 mohm range? Is that significant change from 25mohm to 50mohm (parallel)?

Impedance for Nichicon UD low impedance series 330/25 with 450mA ripplespec is 170mOhm.

* UUD series

 

[filholder]

Absolutely no ESR figures for the "genuine caps" , must be absolutely stellar

I've ordered some 220uf 25v sanyo oscons. They are 8mm and the price is right.

 

[jean-paul]

Absolutely no ESR figures for the "genuine caps" , must be absolutely stellar

I've ordered some 220uf 25v sanyo oscons. They are 8mm and the price is right.

And then... bam, the magic is gone

 

[xrk971]

Yes - why change it if it ain't broke?

 

[doctormord]

TPA3118D2

Less heat at full power.

 

[irribeo]

That sounds familiar, you waited long to replace Ydbz capacitors.

 

[jean-paul]

Yes - why change it if it ain't broke?

You won't be broke by changing caps but there is a chance the amp ends up broken. You don't want to fix an item that isn't broken.

This all adds up to : first break it, then fix it

 

[filholder]

actually one of mine arrived broken so you know...

But I'm definitely of the opinion that if it aint broke fix it ...in audio terms

 

[doctormord]

TPA3118D2

I would be interested in the performance specs of these caps, so if anyone can measure those caps in terms of capacitance and ESR please?

 

[jean-paul]

Nobody forbids you to buy two of those expensive modules, doctormord

Please help the local chinese industry !

 

[doctormord]

Oh I thought this is a community, is it not?

Hmm..

 

[filholder]

Just to say my snapped cap measures 305uf brand new so you can tel they are some precision device

 

[jean-paul]

+/- 20 % tolerance is standard with electrolytic caps, whatever the brand is.

 

[filholder]

Agreed but the high quality stuff usually measures much better than that.

 

[xrk971]

Nobody forbids you to buy two of those expensive modules, doctormord

Please help the local chinese industry !

I was going to say the same thing. Surprised he hasn't already - but then why when xrk can get you high res photos of the layout.

I would measure ESR, but mine ain't broke so I don't want to pull one of those magical Chinese caps off just to measure it.

 

[jean-paul]

Tomorrow I will remove the resistors for 20 dB operation, then I can tell how the PCB tracks behave. My experiences with PCB quality of other cheap boards have been not too optimal till now. BTW I heard the cheap caps have some sort of chinese cola in them to make them perform excellent (for a whole week).

 

[xrk971]

I will pull my resistors off tonight. Usually SMT parts are not as stressful on PCB tracks as through hole ones. How many volts does a preamp need to clip a PBTL 20dB gain amp? Pro audio levels are 3.4v p-P?