Building a symmetrical PSU B1 buffer

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Salas

Salas

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ClaveFremen said:
Salas,

which temperature is safe for the mosfets?

After using 2cm spacers mines are at 53°C and before the case is ready another month will pass...

Is it better to disconnect it until case is ready?

Thanks in advance
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45C is good for life. 55-60C sustainable but precarious. Does your Ref C pass DC if it gets it in the input?. Because your only fear would be to lose one supply and get full DC of the working supply on DCB1's output. If not, the most trouble would be to exchange a burned Mosfet, but unlike at 53C in a month's use.
 
ClaveFremen

ClaveFremen

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Salas said:
45C is good for life. 55-60C sustainable but precarious. Does your Ref C pass DC if it gets it in the input?. Because your only fear would be to lose one supply and get full DC of the working supply on DCB1's output. If not, the most trouble would be to exchange a burned Mosfet, but unlike at 53C in a month's use.
Click to expand...

Thanks Salas,

the MyRef at the moment is DC-coupled too since I'm experimenting with components change and the input cap can mask a lot of differences...

The amp has a DC protection but... I'll think about it...
 
Salas

Salas

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Install a proper value input cap regarding REF C's input impedance. Russian K40Y bypassed with FT1 22nF. Its a cheap and effective combo. That will guard your speakers in any case (except main amp's failure) in the future. Don't forget sources failures and experiments that can give something bad too. Unless that REF C's DC guard is bomb proof, better be safe than sorry for the years to come.
 
Salas

Salas

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It will not make any real difference, but you can parallel a 75R 1W resistor to the one resistor already installed on the 197mA side at a point, and get them currents almost the same. But don't lose sleep over it. Is the negative polarity the 197mA running one?
 
Salas

Salas

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Its due to VGS variations between PMOS-NMOS and their batches if the LEDS are exactly the same. Natural. They also change VGS a little depending on current and voltage scale they work. Nothing to think about twice. Enjoy you integrated. See ya.:)
 
wushuliu

wushuliu

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Joined 2008
regiregi22 said:
AFAIK, it hasn't been tried yet (higher current than 205mA) in this design.

Looking at your picture, I can see a radioshack transformer. This has been VERY bad reported by other builders of this boards. The say that it runs very hot and buzzes.

I like your case, BTW

Regards,
Regi
Click to expand...

Huh. Well since this entire enclosure is the heatsink maybe I'll be the first. I don't know if I can fit a 12w Mills in there though. Maybe 2 7R 5w in parallel for 3.5ohm?
 
U

udailey

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Joined 2008
picasaweb.google.com/udailey/MyRef#
I dunno what you will bias to, but you need to figure the draw of the entire circuit and get one that will cover that much power. Since you wont be worrying about taking care of big transients or increases in music draw I would multiply your bias by the number of devices by the voltage and perhaps double that. You dont want to push your transformer to the point of getting hot and saturating.
 
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