Sunday 15 August 2021

Ampeg Phazzer

 Schematics avaiable at FSB.

 



 



6 comments:

  1. shit, i guess i should take a crack at this mofo if nobody else will jump ;)
    maybe this weekend.
    stay tuned
    PjP

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    1. oh, shit, pinkdter is here! What a honour. I stay tuned!

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  2. hahahah maybe a curse? lol
    i dunno. i LOVE your site tho, i been drifting thru here for a couple days checking it out ;)
    hopefully i can vero-fie your layout fuzzhead. i was stoked to come up with the dox for it on fsb, but too lazy to do a layout, so lets see if we can make this happen!
    stay tuned!

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  3. gonna be a bit before i can get to this, need to order more vero, nothing big enough here at the moment

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  4. I built this, and it works. The sweet spot for the trimmer to get symmetrical sweep is very narrow (and it seems to depend on D1 diode used, even if it's from same type/batch - 5.1 Zenner also worked), I wished I used precision trimpot (which I would recommend). For IC2-4 I tried TI MC1458, Tesla MA1458 and TL072, all of which worked (difference was very subtle if any, I kept the Teslas). You can actually pull out any or all of IC2-4 and it will still work, just with sort of incomplete sweep. Also pretty much any PNP transistor I tried worked with little to neglectable difference, germanium as well. If you add a switch between B26 and C26, you will get optional half cycle mode, which is interesting. Make it 250k pot and it's adjustable.

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    Replies
    1. Thanks for verifying andfor the build report!
      Tagged.

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