Bare Knuckle Pickups Forum
Forum Ringside => Tech => Topic started by: Dmoney on September 20, 2009, 12:27:48 PM
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hello!
so im working my way through slowly turning my JCM800 2205 into an Avenger.
I've been looking for a few mods to use up the three spare holes in the front of the chassis.
one idea is a slope resistor replacement, for a pot, to give a variable midrange (a bit like the krank rev1, but better, and not fed from the plate).
Another idea ive had, is to use the spare triode stage up around V1 as a parallel triode (a la matchless, rivera, etc)
If i did this, what resistor values need to change?
do i half the plate and cathode resistor values at V1 and tie across the plate, cathode and grid pins of the socket?
so go to a 110K/120K plate resistor and a 1K cathode resistor?
does the 1M grid leak resistor at the junction of the grid and 68K resistor need to be reduced to 470K?
I guess the bypass cap stays the same value?
I really want to try this out! if it sounds good i might open up my actual avenger and see whats going on inside, see if i can apply the mod there. chances are that wont be possible.
cheers for any help
(and yeah! any ideas for the 3 pot holes in the front chassis would be cool! there is also a hole at the back where the D.I output level control was. As of today i have...
Gain, Volume1, Treble, Middle, Bass, Depth, PPIMV, Presence)
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I like what HTH did on my 10w amp project
I have the slope resistor as a pot
I have a 6 position mid boost - similar to the Lee Jackson one found on Ampeg and Metaltronics amps
I also have a second gain control to allow control over how much gain from each stage is cascaded into the next stage
You could put a resonance control to control the bottom end - like on the 5150, and Egnater/Randall amps
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i have the resonance already. im debating just getting some blanks to fill in the panel. plastic plugs or something, ive been looking but i cant seem to find any
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i have the resonance already. im debating just getting some blanks to fill in the panel. plastic plugs or something, ive been looking but i cant seem to find any
get a new front panel made when you've settled on what you want to keep.
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i have the resonance already. im debating just getting some blanks to fill in the panel. plastic plugs or something, ive been looking but i cant seem to find any
You can use blind grommets (aka blanking grommets) to fill any holes. I've got these in Maplin electronics, but Rapid, Farnell etc will sell them.
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i have the resonance already. im debating just getting some blanks to fill in the panel. plastic plugs or something, ive been looking but i cant seem to find any
get a new front panel made when you've settled on what you want to keep.
I like this idea. I looked into it a while ago but I could only find places in the usa that would do panels and lettering. Cost of using those was a bit much. Was gonna get a guy I know who does metalwork to sort me'
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i have the resonance already. im debating just getting some blanks to fill in the panel. plastic plugs or something, ive been looking but i cant seem to find any
get a new front panel made when you've settled on what you want to keep.
I like this idea. I looked into it a while ago but I could only find places in the usa that would do panels and lettering. Cost of using those was a bit much. Was gonna get a guy I know who does metalwork to sort me'
It ain't cheap thats for sure - I paid £90.00 each for the panels on Feline's amp. when you're talking one-offs, its expensive as you have the design/setup costs to figure in.
I use a local engraver that typically makes industrial panels for ovens and such - you might want to track down somewhere like that local to you.