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Old 19th February 2011, 03:37 PM   #101
AndrewT is offline AndrewT  Scotland
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Yes, the "R" in the rCRCRC can be used to adjust the voltage available at the last capacitor, if there is constant current draw on that supply rail.
The F5 does not have constant current draw when processing a signal.

If you make the last C very large you can compensate to some extent for the effect of variable current draw on the supply rail.

The balanced F5 or F5x do have constant current draw, but only while operating in ClassA output mode. A current transient that demands speaker current to be higher than the ClassA limit will increase the current draw on the supply rail and the capacitor voltage will sag significantly.
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Old 19th February 2011, 04:05 PM   #102
EUVL is offline EUVL  Europe
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Unless of course you use a regulator.




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Old 19th February 2011, 04:14 PM   #103
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So, i'm doing a standard stereo F5, and after having your guys input, it sounds like i might be able to make it work. but the real question is, will i be able to reduce it enough, to keep the amplifier a live?

Andrew, do you know the proper formula, to calculate how to drop voltage? and roughly estimate what my final voltage will be without and resistors? so that we can tell obviously how much to reduce it?

EUVL, What are my options for reglators?

And again thank you guys for thew help, i'm pretty fresh to this stuff!

And i want to give my apologies to 6l6, i didnt want to turn your thread into a power supply guide! i only asked because this was a good spot that obviously people are dealing with F5's! is there a chance that you have any further progress? i'm excited to see how your amp is going!
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Old 19th February 2011, 04:30 PM   #104
AndrewT is offline AndrewT  Scotland
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Sorry 6L6, I forgot this was your thread to describe your build.
Crazy,
go back to the original F5 thread or start a new one for your self.
However, I suspect a team of us could be typing away for weeks (continuously) to bring you up to speed.
Simply asking about Ohm's law tells us that your electrical knowledge is lacking.
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Old 19th February 2011, 05:19 PM   #105
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Quote:
Originally Posted by crazycody1993 View Post
So, i'm doing a standard stereo F5, and after having your guys input, it sounds like i might be able to make it work. but the real question is, will i be able to reduce it enough, to keep the amplifier a live?

Andrew, do you know the proper formula, to calculate how to drop voltage? and roughly estimate what my final voltage will be without and resistors? so that we can tell obviously how much to reduce it?

EUVL, What are my options for reglators?

And again thank you guys for thew help, i'm pretty fresh to this stuff!

And i want to give my apologies to 6l6, i didnt want to turn your thread into a power supply guide! i only asked because this was a good spot that obviously people are dealing with F5's! is there a chance that you have any further progress? i'm excited to see how your amp is going!
I would just order the appropriate transformer, if that one isnt returnable, just set it aside for a later project. Dont know who you got it from, but Antek is a good source for economical transformers.

I used 2 of his 300VA 18 + 18 in a dual mono setup. My build I'm beginning now will use a single transformer, Antek, 500VA 18 + 18. If regulators were necessary, Mr Pass would have utilized them. Just build the basic amp for starters. This is an excellent thread to watch for pointers

Good luck,

Russellc
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Old 19th February 2011, 05:49 PM   #106
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So after doing a little math, assuming the gain in voltage is a constant ratio, switching from AC to DC, I will be at roughly 29.3V without any resistors. So say we drop 6 volts, with a 1.3 amp bias, I would need 12 .38 ohm resistors, or could I reduce that down to 3 1ohm resistors, and have a little larger voltage drop... right? Assuming I'm still at 1.3 amps bias
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Old 19th February 2011, 06:00 PM   #107
Zen Mod is offline Zen Mod  Serbia
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burning more than few hundreds of millivolts on R part of CRC filter is waste of power and TES
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Old 19th February 2011, 08:34 PM   #108
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Quote:
Originally Posted by AndrewT View Post
Sorry 6L6, I forgot this was your thread to describe your build.
Crazy,
go back to the original F5 thread or start a new one for your self.
However, I suspect a team of us could be typing away for weeks (continuously) to bring you up to speed.
Simply asking about Ohm's law tells us that your electrical knowledge is lacking.
Quote:
Originally Posted by Russellc View Post
I would just order the appropriate transformer, if that one isnt returnable, just set it aside for a later project. Dont know who you got it from, but Antek is a good source for economical transformers.

I used 2 of his 300VA 18 + 18 in a dual mono setup. My build I'm beginning now will use a single transformer, Antek, 500VA 18 + 18. If regulators were necessary, Mr Pass would have utilized them. Just build the basic amp for starters. This is an excellent thread to watch for pointers

Good luck,

Russellc
As Unfortunate as it is, yes. my electrical knowledge is lacking, heavily. And i'll go search around, and find all the necessary formulas, and similar things, so i can hopefully do most of the number figuring i need. and take notes for sure! If i cant figure something out, i'll ask the experts.

And i probably will just set the 24V aside for another project, and order the proper one.
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Old 19th February 2011, 09:18 PM   #109
tinitus is offline tinitus  Europe
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Quote:
Originally Posted by crazycody1993 View Post
As Unfortunate as it is, yes. my electrical knowledge is lacking, heavily.

And i probably will just set the 24V aside for another project, and order the proper one.
you dont need to know very much, or how to calculate anything

its all in the F5 manual, in every detail

even a supply schematic clearly showing 18Vac trafo
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Old 19th February 2011, 09:27 PM   #110
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Quote:
Originally Posted by crazycody1993 View Post
As Unfortunate as it is, yes. my electrical knowledge is lacking, heavily. And i'll go search around, and find all the necessary formulas, and similar things, so i can hopefully do most of the number figuring i need. and take notes for sure! If i cant figure something out, i'll ask the experts.

And i probably will just set the 24V aside for another project, and order the proper one.
To save you some time. The first one you want to know as Andrew mentioned is V=IR.
Start your own thread and I am sure many people will help you out.
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