Vox V848 Bass Mod

[deltre]

Hello,

I have a Vox Clyde McCoy V848 Reissue that I want to set up for a bass rig. The top end its a bit too harsh  and there is no bass at all when it's on. I have read that I can swap the 0.01uf cap on the Q2 transistor for a 0.068uf cap to give it more bass. What else can I do?

I have a Crybaby bass wah, sounds too processed for me, I was thinking about snatching some of the parts out of it.


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[Tsaddeous]

Hi,
68nf or 100nf instead of 10nf, for the Q2 capacitor, is enough.
it will do a big difference.

[deltre]

Cool I'll get both and try them, anyone know a good spot to get components? RadioShack is not what it use to be.

[deltre]

So I did the mod with the .1uf cap, btw I got it from radio shack  ,

It  affected the sweep trying to grab more bass, but it still cut the bass before the sweep could get to it.

Any suggestions to boost the bass before it gets to the sweep? Thanks.

[joegagan]

there was a dunlop factory schematic that had a never released wah listed called ' clav-wah'. it showed a .22 uf for the sweep cap but similar to the bass wah had few other changes from gcb95 we all know and love.

for giggles i entered the exact circ into LT spice and not surprising, the freq curve was a total wreck.  it was flawed, the lows were all crossed over each other ( no definition), there was a huge dip in the 400 to 800 range, then more mahyem above 1k.
no wonder thye never released it. did not work.

i wish i could give you an easy answer to make a ' normal' wah circ work for the low frequencies, it is not easy. i have spent many hours in spice and building wahs for bassists who never really like the end result.

a few things to try that worked for me:

leave the stock dunlop buffer in place, increase input cap to .02 to .047.
also increase the regular wah input cap from .01 to similar .02 to .05.
a 100k trimmer in place of the 68k in-put R is helpful, as is an adjustable 500 ohm from the first wah trans to ground, in -place of the 390 ohm.

i found that anything larger than around .03 .- .04 for the sweep cap just makes a mess. you not only lose treble, the circ just goes out of the range it is optimized for.

to really start to make this whole concept work , two wahs in series, with the super large sweep cap in the first one in line is going to get a lot closer to working. google  ' superpuke talking weasel  + gagan "  or  'redneck wah bizness' for a glimpse.