max9709

[doctormord]

Yes. Heatsink is kinda useless.

 

[Kjeldsen]

It is not useless, but requires fan. If it was useless then all motherboards have useless heatsinks

 

[chienmort]

Does any one still have cobs for this amp?

 

[chienmort]

Sorry, spell checker went mad. I meant does anyone have PCBs for this amp?

 

[chienmort]

Does anyone have PCBs for this amp?

 

[doctormord]

It is not useless, but requires fan. If it was useless then all motherboards are useless heatsinks

Well, you should have a look for the main thermal path. Heatsinks on plastic are useless. The main thermal path on this chips is via the exposed pad on the bottom. As for the mainboards, those chips are coupled via direct substrate or heatspreader or sometimes top exposed pad.

 

[Kjeldsen]

Well, you should have a look for the main thermal path. Heatsinks on plastic are useless. The main thermal path on this chips is via the exposed pad on the bottom. As for the mainboards, those chips are coupled via direct substrate or heatspreader or sometimes top exposed pad.

I just had a look at the chip itself, and you are absolutely right. The cooling should be build into the PCB. I once had a 2x200 watt 8 ohm class d done this way. It's amazing to fire up such an powerfull amplifier without heatsinks

 

[doctormord]

Well then, got my new design ready and running.

Here: http://www.diyaudio.com/forums/class-d/87913-class-d-amp-photo-gallery-81.html#post3716821

 

[doctormord]

At moderate volume, its somewhat 35mA.

 

[von Ah]

Fantastic... I love it.

 

[doctormord]

There we go, party hard!

 

[blacklizard]

Hi. Do you have spare PCB to sell?

Thanks

 

[doctormord]

Sure, send me a pm.

 

[lutkeveld]

Very nice boards and original casing. I like it

 

[ledsscp7]

Golden hand!

 

[doctormord]

I still have some spare pcbs left (green ones).

If someone needs them, its $4 for one, including 3.5mm smt jack. (+shipping)

Regards,

Christian

 

[marce]

Neat design concept, cool.
I do wish that industrial design could be included in the Turner Prize fiasco, as much of it is more worthy of the term art, than piles of bricks and unmade beds....

 

[doctormord]

Thanks.

 

[TVEngineer]

These are in use by the Gilderfluke company

Gilderfluke uses these in the SD-25. We have a bunch and they work reasonably well.

https://www.gilderfluke.com/index.php?main_page=product_info&products_id=35

 

[doctormord]

Suitable crossover for the MAX9709 boards. (Same shape)

Linkwitz-Riley configuration, x-over at 200Hz, single ended configuration.

Input:

3.5mm jack pre-potentiometer
3.5mm jack bypassed potentiometer
4x pinheader post-potentiometer

Output:

3.5mm jack Highpass Stereo
3.5mm jack Lowpass Mono+Mono with adjustable gain
4x pinheader Highpass Stereo
4x pinheader Lowpass Mono+Mono with adjustable gain

Coupling caps are either MKS2 (Wima) or 1206 X7R ceramics.

aktive 2.1 Crossover/Frequenzweiche mit MAX4478 - #360customs