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Old 1st March 2010, 02:45 PM   #971
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Join Date: Feb 2004
Location: Davis,CA
Default Power Supply

Quote:
Originally Posted by adamus View Post
I sorted my chattering by dropping the 2.2r to 1r, and the 1k to 700r.



Try just dropping less through the resistors, or get rid of them entirely and jumper, just watch the heat on the reg.

Edit - just noticed i misread your post. I'll whip the cover off and measure for you. Give me ten mins.
I am at the point of testing my supplies.

Adamus:

Did you change each of the 2.2R resistors to 1R?

Is the problem that 9V is not enough at the input?

Thanks

Bob
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Old 1st March 2010, 03:00 PM   #972
adamus is offline adamus  United Kingdom
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I did indeed. I would test it, and if you are having trouble regulating then jumper them out, or use a smaller value (0.5ohms).
1r 3w is ok (they dissapate 0.75w)

There is a larger than expected drop through the bridge on both my build and apellizo's

IF you dont have a scope then you'll have to look for ac ripple with a dmm, but the relay buzzing or chattering is a good indication you are out of regulation. My reg needs 1.5v to drop to regulation, hence it slightly marginal.

Last edited by adamus; 1st March 2010 at 03:04 PM.
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Old 1st March 2010, 03:07 PM   #973
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Join Date: Feb 2004
Location: Davis,CA
Default Power Supply

Thanks

I do have access to a scope. Will follow closely what you guys have done.

I also have a 12V 1.5A transformer.


For Andrea (Audiodesign)
Did you use the 0-12V, 0-15V R Core for the Salas?

Thanks again

Bob
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Old 1st March 2010, 04:13 PM   #974
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Join Date: Dec 2009
Quote:
Originally Posted by quanghao View Post
I show some member still need PCb of DAC so ,I will make about 10 set DAC_end 2, If you like you can write please!
thank you.

1. Strosek: full set
2. boudy : full set
I also would like to purchase full set.

Thanks
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Old 1st March 2010, 05:21 PM   #975
toufu is offline toufu  United States
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Join Date: Jun 2008
Location: San Francisco
Originally Posted by quanghao
I show some member still need PCb of DAC so ,I will make about 10 set DAC_end 2, If you like you can write please!
thank you.

1. Strosek: full set
2. boudy : full set
3. ksnider1
4. toufu
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Old 1st March 2010, 07:48 PM   #976
Ekkeri is offline Ekkeri  Finland
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Join Date: Dec 2008
Quote:
Originally Posted by apelizzo View Post
The heater power supply is not strong enough and I experienced the relay chattering because the regulator has not enough headroom so it passes AC.
Quote:
Originally Posted by adamus View Post
I sorted my chattering by dropping the 2.2r to 1r, and the 1k to 700r.
What kind of transformer do you have? 9VAC & 3A? What regulators? LM338 have >2V voltage drop, LT1084 & LT1085 have only ~1V? Just wondering if I need to order more resistors.. Still waiting for the parts. Thanks..
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Old 1st March 2010, 07:53 PM   #977
adamus is offline adamus  United Kingdom
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i have 1085, which is 1.5v drop.

I would only just meet the lm338 criteria... so the 1085 is safer.

and yes, 9vac 3A.

I would order a couple of extra resistors, but to be honest, if you have a 9vac transformer then jumpering them out is probably wise if its marginal.
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Old 1st March 2010, 07:58 PM   #978
Ekkeri is offline Ekkeri  Finland
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Yeah, I have that R-core so only 8.15VAC spec.. I will change those to 1R at least, I won't be using on-board bridge, maybe MUR860s because I already have those..
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Old 1st March 2010, 08:02 PM   #979
adamus is offline adamus  United Kingdom
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8.15vac just jumper them straight off. they arent going to do much ripple filtering at that low impedance, so just get rid,
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Old 1st March 2010, 08:35 PM   #980
Ekkeri is offline Ekkeri  Finland
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Ok.
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