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Help with arch top project


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5/25/1999 9:00 AM
B. Holden
Help with arch top project
I put in a p-90 gibson pu in a B&J Serenader. its one of thoses violin looking guitars. anyways It sounds way to bassy and there is no sustain. I know thats the nature of the beast but I would like it to sound good since the pu cost over 200 Canadian.  
 
The pu is located near the neck, if iI had my time back I may have put it near the bridge.  
Also I used a 0.022 uF plastiseal capcitor (its old but vintage)and two 500 k-ohm pots for vol and tone. the tone does very little--bass and more bass.  
I could try and replace the cap with a 0.01 uf of the same type, but thats a pain to get those pots out for the f hole again.  
 
Oh, and for the bracket to hold the pu in place I used some metal from a shelf bracket and drilled some holes and fitted two nuts in the hole and welded them in. Could this metal be deading the sound.  
 
Anybody have any ideas.  
Oh my god I just wrote way to much, but its all there.
 
5/25/1999 7:28 PM
Mark Hammer

Well, my son. Have a pint at Bridget's in my honour, and when you're done that, stick a cap between the tone control and the volume control like so:  
 
- have the pickup lead go directly to the tone control (which would be wired up as a variable resistor, going between the tone cap and the pickup lead)  
- have a moderate value cap, say .05-0.1uf for starters, going from the junction of the pickup lead and tone control to the input of the volume control  
- stick another small value cap, say about 470-1000pf across the input and output lugs of the volume control  
 
The first cap in line simply cuts out the low end. It's an old trick used on some Fender guitars (e.g., the Jaguar). The second cap serves to function like a "bright" switch on amps, allowing the high end to bypass the volume control as you start to turn down the volume. This is also a tried and true circuit used in many Telecasters. In both instances, I've used cap values somewhat larger than Fender uses, because your goal is to retain the soulful parts of the bottom while losing the flubbiness from exaggerated bottom. Fender goes for a skinnier sound. Feel free to play with the values.  
 
Arch-tops are MEANT to have a meaty attack and quick decay. Remember, these babies were originally intended to keep chunka-chunka rhythm, and only eventually evolved to be played in competition with piano. Sustain is generally not a feature of be-bop or swing, and is certainly not found in the Charlie Christian repertoire that often, if at all.  
 
Part of what makes them behave that way is a floating wooden bridge. Centre blocks underneath the bridge, that connect top and bottom of the guitar, will tend to improve sustain (as evidenced in the ES-335), but obviously if you are fidgetting about taking the pots off...again...rebuilding the guitar with a centre block is pretty much a non-starter.  
 
(I spent a couple of decent months going to MUN and living on Gower St. before many of the readers here were born; even got to jam with Figgy Duff in their heyday, when Noel was alive and Art ruled the buttons, Mayor Dottie ruled the headbands, and Codco was still the mummers. MUN's computing facilities were shared with Nfld Tel and the Hydro company, and there was many a time that we got bumped from the stack in mid-batch, and had to wait by the 300 baud acoustic couplers, and teletypes to get back on line before computing shut down for the night. Half the university was in temporaries, all journals older than 10 years were in deep storage, and the library stacks were 2 deep just to make room - but that's another story. I'm sure Brian has made it all better.)
 
5/27/1999 10:41 AM
B. Holden
I did what I think you said but now the tone and vol act as vol controls. Is this right.  
 
to put it in schematic form:
 
 
 
Vol. Tone  
 
0---~p~> (braded wire to Grnd.)  
0---~p~.001 0 pu  
0---~p~-----(.1)---0----lead----  
0----~p~>
 
5/28/1999 11:16 AM
B. Holden
sorry that didn't come out right.
 
5/29/1999 8:33 PM
Mark Hammer

Boy, I'll say!  
 
What you want is this.  
Looking at the volume pot from the back, you should normally see this:  
 
CHASSIS/COVER  
 
In---Out---Grnd  
 
The cap goes from In to Out.
 
5/30/1999 8:15 AM
B. Holden
I have that done. What I don't under stand is  
when you said to wire the lead directly to the tone control instead of the volume control.  
 
so it should look like this
 
 
(tone)  
 
Lead---cap---none  
~p~  
~p~  
In---Out---Grnd (Vol.)
 
5/31/1999 4:56 AM
Steve A.


B.  
 
    If you remember to leave cookies and milk out the elves will come in while you are sleeping and clean up your posts with the proper HTML tags... < g >  
 
Steve Ahola  
 
P.S. Whenever I forget the proper HTML tags I will just alternate periods and spaces to line up the columns. Some boards won't accept HTML tags at all, or will only recognize a few of them so that can be a handy trick to use practically anywhere.
 

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