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Old 11th July 2007, 02:53 PM   #901
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Jesper! Right! We do not have hot" and "cold". Both are "hot" so to speak.
And I forgot that Norway differs from the rest of the world with regards to mains. With the possible exception of Albania, if I remember right.

-rk
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Old 11th July 2007, 03:27 PM   #902
lykkedk is offline lykkedk  Denmark
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On some Pass schematich, the inrush thermistor, is connected in series with the hot line, and in other it's connected to safety earth. I don't know what's best in the F4. ?

I also think, its something to do, with the PSU, so i atteched a link, i will use.

LINK

Hope you don't mind cviller

Jesper.
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Old 11th July 2007, 03:48 PM   #903
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If you have a pair of safety goggles, you can try without the inrush limiting NTC, the fuse will simply blow all over the place. The thermistor to safety earth is there for completely different reasons.
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Old 11th July 2007, 03:49 PM   #904
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I leave it to NP or someone who has built the F4 (anyone?) to comment.
But another thing worth mentioning is panel fuse holders: Be careful to solder the leads so it is NOT possible to get a shock when changing fuses. This means connecting the "hot" lead to the rear terminal of the fuse holder.
ALso, always use mains fuses. The large fuse box fuses are dimensioned after the house wiring, e.g. 15 A, and will probably not blow if the equipment fails. However, the equipment in the best case may be destroyed, in the worst case catch a fire and/or hurt/kill someone.
RK
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Old 11th July 2007, 04:09 PM   #905
lykkedk is offline lykkedk  Denmark
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Ok... I will just leave space, and shorts-jumpers, where i could put in the thermistor if needed. ! - It's just that i am in for making a sort of connection pcb. For connection of fuse - thermistor - diodes - wires from torrids etc...

Thanks anyway guy's...

Jesper.
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Old 11th July 2007, 04:46 PM   #906
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Quote:
On some Pass schematich, the inrush thermistor, is connected in series with the hot line, and in other it's connected to safety earth. I don't know what's best in the F4. ?
When Pass has a thermistor to ground in most of his schematics; It is being used where a connection to ground is necessary, but the small resistance of the thermistor will break a potential ground loop.

The thermistor is not necessary... a straight ground is ok.

When it is in series with the primary it may be necessary - due to inrush..

This is how I understand it.
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Old 11th July 2007, 05:42 PM   #907
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We do both in the F4.

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Old 11th July 2007, 08:08 PM   #908
lykkedk is offline lykkedk  Denmark
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OK... Thanks papa , I will do both in serie with phase, and to safety-earth...

Jesper
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Old 16th July 2007, 07:09 PM   #909
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The F4 manual states that when in mono balanced operation one can attain 100w into 8 ohms , I assume no less as it isn't quoted..

If I were to attempt to run a 4 ohm load in balanced mono, could I lower the rails on each module to - say +-18v ....? I'd use irfp140/9. If so would I not still be near that same ~100w mark safely ? would I want to lower the source resistors to keep the bias current up?

Thanks!
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Old 16th July 2007, 09:54 PM   #910
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Quote:
Originally posted by mpmarino
If I were to attempt to run a 4 ohm load in balanced mono, could I lower the rails on each module to - say +-18v ....? I'd use irfp140/9. If so would I not still be near that same ~100w mark safely ? would I want to lower the source resistors to keep the bias current up?
I think it would be fine stock. I wouldn't bother to alter anything.
I would expect a little shy of 200 watts.

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