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Old 23rd September 2011, 01:23 PM   #3121
labjr is offline labjr  United States
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15,000 seems a little overkill. Maybe inrush current is a little high. But don't those three pin regulators have overcurrent protection? I'd think a discrete shunt regulator circuit would work better.
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Old 23rd September 2011, 02:06 PM   #3122
tinitus is offline tinitus  Europe
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isn't the B1 supposed to be used with a 'standard' external regulated supply
I even think a particular one is suggested in manual

with this low 'power' draw, I guess its basicly like running on batteries

unless...maybe shut down bleeders may be working against this


funny....but I think I have read that high capacity caps will be replacing much more battery functions in the future
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Old 23rd September 2011, 02:18 PM   #3123
tinitus is offline tinitus  Europe
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actually, with a 100.000uf cap I reckon a B1 would work all day, dissconnected from power source

mind you, I'm not suggesting to do that
only saying it might be possible
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Old 23rd September 2011, 02:49 PM   #3124
6L6 is offline 6L6  United States
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The stock value of 15,000uf is there so the original PCB can be used with an unregulated supply, such as a wall-wart.

If you have a regulator, a smaller value cap could be appropriate.
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Old 23rd September 2011, 04:07 PM   #3125
Bengali is offline Bengali  United States
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Quote:
Killing it in what sense, making it useless?
not useless but not as effective(?) I read somewhere the output of the regulator does not want to see a large capacitance. The large capacitance should be on the input side of the regulator. that's why I'm asking.

Mr. Pass says anywhere between 1000uF to 15,000uF so there is a good reason for the wide range. justed want to know why.
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Old 25th September 2011, 10:46 PM   #3126
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I once tried one LM3886 with a total of 200.000uF at +-35v. It stayed playing for half a minute at moderate volume with the power cord disconnected.
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Old 25th September 2011, 11:47 PM   #3127
tinitus is offline tinitus  Europe
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I thought that it was large inrush current on power-up that could kill the regs ?

If you deal with that, and stays well inside the current draw limit, what else problems could there be
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Old 26th September 2011, 04:54 AM   #3128
clm811 is offline clm811  United States
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Quote:
If you have a regulator, a smaller value cap could be appropriate.
Care to be more specific(Please)?

(If it helps for me to be more specific, I have a choice of the following caps: 4,700uf, 1,000uf, 330uf, 100uf, 10uf, or 1uf.) Which one?



Quote:
Maybe inrush current is a little high. But don't those three pin regulators have overcurrent protection? I'd think a discrete shunt regulator circuit would work better.
I'm planning on using what I have on-hand (a finished LM1084 adjustable series regulator, built according to the manufacturer's applications sheet).

I have little interest in undertaking construction of another regulator circuit, (especially one that approaches the B1 in complexity).

I want to be done with it so I can listen to music soon!

Thanks all!

-Chas
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Old 26th September 2011, 10:14 AM   #3129
AndrewT is offline AndrewT  Scotland
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Clm,
the B1 has only 2 active devices in each channel.
It does not need a regulated supply.
Just follow Pass build instructions.
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Old 26th September 2011, 10:45 AM   #3130
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100/200uF plus 0.1uF film should be OK.
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