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Old 26th February 2009, 12:05 AM   #231
schro20 is offline schro20  United States
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Default C9 and C21

Dear Dario,

than you for posting your observations. Why are C9 and C21 so important? I would expect C13 to be the most important...

I will try your experiments. But first I have to build a second set (I need to compare back and forth otherwise I can't tell what's going on). But before I do that, I have to put together a nice case for my first set... You'll get a kick out of this: I ordered one of those cases you used. I happened to be in Germany last weekend and had them mail it to me there and then took it back in my luggage. Did you use any more heatsinking than just the side walls themselves?

peter
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Old 26th February 2009, 02:18 AM   #232
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Dario,

Thanks for the capacitor testing results. You put those sockets to good use!

Do the C9 Elna's fit onto the board without too much trouble? It's hard to tell their relative size from your photo. They look to be similar size to the FM's.

Have you decided on a C13? I put a 1.5uf Bennic metalized poly cap in there, and it sounds a bit dull with loose bass. I have some other caps on order now.

Peace,
Tom E
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Old 26th February 2009, 02:35 AM   #233
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well, really need some help to try to fix the amps, i searched the forum and i see some other guys with similar problems, will try to recompile info about my fault.
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Old 26th February 2009, 03:43 AM   #234
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Default Re: C9 & C21 Caps comparison

Quote:
Originally posted by ClaveFremen
Click the image to open in full size.

I'm still asking myself why TP swapped MKS2s with BQs...
Well, they are 1/5 the price.

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Old 26th February 2009, 04:01 AM   #235
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R1 and R4 are really HOT is that normal?

I found some thread where i see that these 2 resistors come HOT, but someone recommend using 3W instead 1W Resistor.

All of you are using 1W? No problems with the resistors?


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Old 26th February 2009, 04:06 AM   #236
troystg is offline troystg  United States
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My apologies, today was just a VERY busy work day and I did not get to look at the pictures for lunch ( I didn't take a lunch).

I promise to look at them tomorrow and see if I can find anything.
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Old 26th February 2009, 04:31 AM   #237
schro20 is offline schro20  United States
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Quote:
Originally posted by samsagaz
All of you are using 1W? No problems with the resistors
Dear Samsagaz,

if you check the BOM (see post http://www.diyaudio.com/forums/showt...84#post1755284) you will see that we actually put 2W resistors in there just for good measure. And, yes, they are expected to get hot which is why they are off the board.

peter
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Old 26th February 2009, 05:36 AM   #238
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well, i will drop the boards to the trash, im really deseseperated, 4 Boards Build 1 works 3 NO

Btw, have any others in stock i will purchase another kit if have some in stock, i really dont want to still burning and broken components (removing it from the PCB), i will purchase more if have in stock and will try to get better luck next time.

Im really not good removing components i already ****** up 1 transistor, 1 Zener, 1 LM3886

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Old 26th February 2009, 06:30 AM   #239
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CHecking one of the PCBs i noticed 36 volts between C14 Pins its OK? in the schematic i see that i need to have 24 instead 36, or im wrong?
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Old 26th February 2009, 08:58 AM   #240
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Default Re: Re: C9 & C21 Caps comparison

Quote:
Originally posted by schro20
than you for posting your observations. Why are C9 and C21 so important? I would expect C13 to be the most important...
....
I ordered one of those cases you used.
....
Did you use any more heatsinking than just the side walls themselves?
C9 and its bypass(C21) are in the feedback loop so they're directly in the signal path. C13 is also directly in the signal path but it could be removed if you DC couple... and could be a film type too...

You'll find that the side walls of the case are more than enough.

With my Gainclone modules the side walls was cold, with MyRef they get warm (ca 42C/107.6F) in a room temperature of 20C/68F.

Quote:
Originally posted by marc brown
Well, they are 1/5 the price.


Quote:
Originally posted by madisonears
Do the C9 Elna's fit onto the board without too much trouble? It's hard to tell their relative size from your photo. They look to be similar size to the FM's.

Have you decided on a C13? I put a 1.5uf Bennic metalized poly cap in there, and it sounds a bit dull with loose bass. I have some other caps on order now.
The Elnas are 5mm lead spacing and 12,5mm diameter vs 5mm ls and 10mm dia of the FMs

In the attached picture you could see how a 12,5mm cap fits.
Attached Images
File Type: png c9.png (28.7 KB, 449 views)
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