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DIY Stompboxes => Building your own stompbox => Topic started by: mat on February 03, 2005, 01:55:44 PM

Title: LPB question
Post by: mat on February 03, 2005, 01:55:44 PM
Can i leave the greyed part away when not needing a led ? Or does any of these 'grey' parts affect the sound ?

(http://tinypic.com/1j52jn)

thanks,
mat
Title: ...
Post by: petemoore on February 03, 2005, 02:06:31 PM
http://www.generalguitargadgets.com/diagrams/lpb2_sc.gif
Title: ..
Post by: petemoore on February 03, 2005, 02:08:19 PM
http://www.generalguitargadgets.com/diagrams/lpb2_sc.gif
 This should help? Just another different LPB voicing caps option. Works as shown.
Title: LPB question
Post by: NaBo on February 03, 2005, 04:40:36 PM
mat, those parts just make up the millenium bypass ckt for using an led with a dpdt switch.  if you dont want an LED or are using a 3pdt switch, you don't need them.  if you're drawing the pcb by hand, you can save a bit of copper-clad and space if you move the level pot connections over near the 0.1 cap and omit the traces for the millenium components altogether.  either way, they have no effect on the signal.

you can also leave out the somewhat insonsequential trace for lug 2 and wire it directly to the output jack if you are so inclined.  the new board would look something like this:
(http://img.photobucket.com/albums/v515/Nabotics/lpb1.jpg)
Title: Re: ...
Post by: mat on February 03, 2005, 04:46:00 PM
Thanks ! , i followed the signal path and yes, i dont seem to need them (i use 3pdt)

mat

Quote from: petemoorehttp://www.generalguitargadgets.com/diagrams/lpb2_sc.gif
Title: LPB question
Post by: mat on February 03, 2005, 05:03:01 PM
HI NaBo,

Thanks for the suggestions. The thing is that i did my lpb as point to point wiring. the transistor is 2n4401 and the .1u caps are tantalum or ceramic ones. (this is the first effect i bought parts for about 6 months ago and i'm redoing it)
the problem is that the circuit cuts out way too much of the highs. it boosts alright, the pot works but it lacks the highs. maybe it is the transistor.
i have j201's 2n5089's and bf245c's. the schem points to use 2n5088 and at store they did not have it and offered the 2n4401 instead. i also have .1u polystyrene caps to try in.

i'd like to try a trimmer on place of the 10k resistor. would a 10k trimmer be good or should it be bigger (and why ? =o)) or is it a good idea at all ?

thanks,
mat