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Old 07-03-2009, 11:18 AM   #28 (permalink)
jcmjmp
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Re: DLS 100 with Mercury Magentics Transformer

Quote:
Originally Posted by PaoloJM View Post
That's what I thought you meant.

A choke is not a load and does not demand current.
Valves demand current which flow from the power supply through the choke or power resistor. Chokes have a low DC resistance, usually lower than a power resistor, and so the voltage to the screens and preamp will be higher in the same amp
Yup - My wording was wrong there. The choke does not demand current, it only filters it and when a change in current demand occurs, it opposes it (slows it down) somewhat.

With a resistor, when current demand increases, the voltage drop accross the resistor is greater compared to a choke, resulting in much larger and faster voltage sag.

Sag will be reduced with a choke for sure, but there will still be sag present in the amp.

Placing a resistor in place of a choke is not the same kind of sag that, say, a tube rectifier would yield because the dynanics would be vastly different.

I'm not sure what you mean by the choke affects the preamp. The choke is part of the B+ power supply. That has an effect on all tubes, not just the preamp, unless you're referring to a circuit that I am not familiar with.
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