hamptone tape op article on jfet mic pre

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buschfsu

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OK so there is no way i can come up with 600 for the kit, but the schematic looks pretty straightforward. From the tapeop article the only thing i can't figure out is that 24VDC come from the wall wart but where does the 12VDC (volt regulator?) and 48VDC (phantom power) come from? I think i could even make a pcb board for this but the power thing has me stumped??? help!
 
The 24VDC comes from the wall wart (28-35VDC) after regulating by the LM7824. The 12VDC is just half of the 24VDC measured at the emitter/collector junction of the two transistors in the JFP gain module - it's a measured voltage, you don't have to supply it. The 48VDC phantom you have to supply from a separate power supply, or build a voltage doubler circuit for the 24V you have.

Go here and do a search for the Hamptone mic pre - lots of info. Join while you're at it - a great audio/recording DIY site.
http://www.prodigy-pro.com/forum/viewforum.php?f=2&sid=32e64a335915460fb2af5f0f5685509a
 
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Or you could use a 24 volt AC wall-wart and build a little board with your rectifiers, voltage doubler, and filtering caps. It wouldn't be too hard. This is how Paia does most of their kits.
 
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