Dx Blame MKIII-Hx - Builder's thread

[meanman1964]

Carlos,shall I start a new groupsbuy?

 

[crispycircuit]

I've been waiting for a group buy for a while. I feel many people would buy them...

 

[a.wayne]

Fitter maybe,me personal don't like those big caps direct on the boards due the charging currents,I could be wrong.

Yes i would use the brute force in the PSU and have smaller value on the boards, nearest to outputs , 5000 uf each close to outputs is good

As I can recall 9 Euro a piece by 70 boards ordered

Is this the 4Pr or 5Pr outputs ...? that's a lot less than the original run of boards ....

 

[Ranchu32]

Meanman, if you get approval and decide to go ahead with this group buy, I will purchase 10 boards to supply Australian members.

 

[radioFlash]

Finished etching my board

I finished etching my and drilling my board.

 

[meanman1964]

Sorry guys the price of the previous groupsbuy was set at 12 Euro a piece but I drop to 10 Euro a piece.
So 10 Euro for one board with 5 pair outputs.
As soon Carlos gives me green light I start the groupsbuy.

 

[Junie]

Junie has very kindly offered me two partially built boards. I am most grateful for his assistance, and will put his boards to good use.

Does anyone have any suggestions on the heat sinking and transformer?

Hi Christian,

Package on the way. Thanks

Best regards,
Junie

 

[destroyer X]

Meanman can open a group buy the day he decide

Patrick Roovers is a very important and respected member of the Dx Corporation, he does not even need my order to move.....he is just being kind asking me.

Meanman, or Patrick Roovers is Executive from the board.

regards,

Carlos

 

[meanman1964]

New groupsbuy is started here http://www.diyaudio.com/forums/group-buys/239084-blame-mkiii-hx.html#post3558723

 

[destroyer X]

This is very good.

You movement has my support and blessings dear Patrick

regards,

Carlos

 

[Newton BBN]

Look at my DX MKIII.
48012_626667174012371_347453836_n (1) - Download - 4shared - Newton Costa

1002295_626667637345658_992110443_n (1) - Download - 4shared - Newton Costa

><>Newton J. Costa<><

 

[radioFlash]

It looks nice Newton. Do you have a chassis planned for it?

 

[meanman1964]

radioFlash,can you send me a pdf file of your layout?

 

[radioFlash]

meanman1964,

I've been working on populating the board. I noticed I had a missing track for R08A to R08B. I also increase the hole sizes for some of the electrolytics. Attached is a PDF with some of these corrections.

 

[vargasmongo3435]

mister radio flash that is what I call, "talent" a really well put it together a truly DIY concept art, thumps up sir

Regards
Juan

 

[wiljj78]

mister radio flash that is what I call, "talent" a really well put it together a truly DIY concept art, thumps up sir

Regards
Juan

Yess very nice indeed... But i'm thinking on Q12 and Q10 Heatsink are enough to handle the heat if R13 used 22R??
Regards,

 

[Newton BBN]

It looks nice Newton. Do you have a chassis planned for it?

radioFlash not yet, but I'm thinking of a model.


><>Newton J. Costa<><

 

[Newton BBN]

Can see other photos here.
Flickr: Newton J. Costa's Photostream

><>Newton J. Costa<><

 

[radioFlash]

Thanks for your kind comments vargasmongo. As for the the heatsinks on Q12 and Q10, they're rated at about 7°C/W. I'm not sure what the power dissipation of Q12 and Q10 are, so I'm not sure if that's sufficient.

 

[radioFlash]

I finished installing all the components on the board using my layout and turned on the amp using the lightbulb tester and no load connected and a +/- 40V power supply. The lightbulb flashed as the caps charged and then went out, but I see +35V on the output without any input signal. The oscillocope shows DC. The good news is it provides another "learning opportunity" for me!

So far, I've done the following in-circuit checks with the amp powered off:
* Set VR midway
* No short to heatsink for output transistors
* Inspected soldering and did continuity check--did not find any shorted tracks
* Verified correct transistors installed in correct locations
* Diode check Q12 ok (b to c, e)
* Diodes 1n4007, BAV21 ok on diode check
* Checked all transistors, no shorts
* Did not note any unusually hot components or observe any obvious physical damange such as scorched/smoking resistors or capacitors
* Checked resistor value R10-correct 2k2
* Checked orientation of electrolytics-ok
* Checked continuity of rails to OP transistors: only saw continuity with collectors as expected