Monday 5 July 2010

Pharaoh Class A Boost

Hey, it looks like a pyramid! :o)

10 comments:

  1. I built this and it works great! The contour control is subtle but adds a little edge if needs be.

    Great booster - and it looks good too! :)

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  3. finally got this boxed up and have taken some pics :)

    http://i177.photobucket.com/albums/w212/79silverburst/Pedals%20and%20Stuff/DSC01238.jpg

    http://i177.photobucket.com/albums/w212/79silverburst/Pedals%20and%20Stuff/DSC01233.jpg

    Thanks for the great layouts - this is currently my favourite boost!

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    1. Can't believe all the posts I've missed. Thanks a lot for the pics, glad you like the boost

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  4. can I use J201 instead of 2N5089?

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    1. Not really. Well you could but you'd probably have to change most of the resistor values too, so I wouldn't personally. 2N5089 or similar NPN transistors like MPSA18, BC550C etc should be pretty easy to get hold of.

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  5. Hey guys I built this circuit last night and its not working I have volume loss and I still get signal when the volume knob is down it does no kill my signal I hope you can help me. I have checked everything and I have all parts in the right place. Thanks.

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    1. Without seeing pictures of the soldering the fact you are still getting signal with the volume down sounds like the signal is potentially leaking past the volume pot or there is something wrong with the 3DPT foot switch wiring that is letting signal leak through. Foot switch wiring/soldering is often the cause of a myriad of big problems that can have simple solutions, I'd start there.

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  6. Hey. Thanks mate That was the problem.

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  7. Hey! This is one of my designs, glad you guys all like it. The Contour control should have been a 1kC / reverse log pot but at the time they were hard to source. The "pro" version of this had a tone control as well, just lug 1 of 100kA pot from the base of the second transistor, lug 2 to a 100n, 100n to ground. I'm making a slightly updated version of this with nice soft-touch switching here: http://www.alexanderpedals.com/shop/litho-boost

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