300v supply from champ PT

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Andy Le Blanc
Posts: 2582
Joined: Sat Dec 22, 2007 1:16 am
Location: central Maine

300v supply from champ PT

Post by Andy Le Blanc »

Here's a quick and dirty PS from a fender champ PT.
The resistors are 10w, you could get away with 3-5w.
The caps are a recycled can still in the champ chassis.
You could use any rectifier(s) as long as its rated for the reverse voltage.

Its a way to enable the exploration of simple gain stages.
A PS and a few tube sockets to build upon.
lazymaryamps
Andy Le Blanc
Posts: 2582
Joined: Sat Dec 22, 2007 1:16 am
Location: central Maine

Re: 300v supply from champ PT

Post by Andy Le Blanc »

Here's simple gain stage with component value's and voltages.
Zero bias, attached to the first tap of the champ PS.

207 mv. 1k Hz applied resulted in 14.3v output.
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Andy Le Blanc
Posts: 2582
Joined: Sat Dec 22, 2007 1:16 am
Location: central Maine

Re: 300v supply from champ PT

Post by Andy Le Blanc »

Here's a Rightmark report on this little gain stage. Its not impressive.
It is after all a very basic, and old fashioned way to use a tube.

But..... the rightmark package is a free download for home use.
And... it is very useful as another design tool, without investing cash on
expensive diagnostic equipment wasted on the hobbyist.

Check out the harmonic spectrum.
lazymaryamps
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guitardude57
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Re: 300v supply from champ PT

Post by guitardude57 »

hmmmmm ............nice combing! LOL!!!!
Mike


I am never surprised and always amazed
Andy Le Blanc
Posts: 2582
Joined: Sat Dec 22, 2007 1:16 am
Location: central Maine

Re: 300v supply from champ PT

Post by Andy Le Blanc »

Ya huh :lol: ..... It does have a nice even decent of even and odd order harmonics.
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Structo
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Location: Oregon

Re: 300v supply from champ PT

Post by Structo »

I like this stuff you show Andy.
I try to learn at least one thing a day! :D

Why no cathode resistor or bypass?
Tom

Don't let that smoke out!
Andy Le Blanc
Posts: 2582
Joined: Sat Dec 22, 2007 1:16 am
Location: central Maine

Re: 300v supply from champ PT

Post by Andy Le Blanc »

Happy 4k..........

Its zero bias, or grid-leak bias, as opposed to self-bias which your used to seeing.
With in it's limitations, it provides voltage regulation in the grid circuit.
The value of bias is determined in part by the amplitude of the input signal.
lazymaryamps
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