PlayJazzGuitar.com Forum Index PlayJazzGuitar.com Forum
Jazz Guitar Discussion
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Tips on shielding archtop with Charlie Christian single coil
Goto page Previous  1, 2
 
Post new topic   Reply to topic    PlayJazzGuitar.com Forum Index -> Guitar Repair & Upgrades
View previous topic :: View next topic  
Author Message
randyc



Joined: 14 Sep 2006
Posts: 407
Location: Eureka, CA

PostPosted: Sat Apr 10, 2010 2:15 pm    Post subject: Reply with quote

I got up early this morning so that I could continue this discussion. When my wife wakes from the sleeping pill she's going to be very sick and I'll be busy for a while -

Go to the above link and download the tone control circuit. After downloading, play with the sliders on any of the amplifier configurations for a few moments to note their effect on frequency and attenuation.

Now we'll configure one of the circuits to represent a simple tone control, where a capacitor is connected to ground through a tone control potentiometer, forming a variable lowpass filter (or high-frequency reject filter, as you like). We'll have to adjust the circuit values to be very large or very small, simulating open circuit or short circuit components.

Select the "Vox" configuration and click on the following components in the schematic diagram, changing the component values to the ones indicated below except omitting the quotation marks:

Zsrc change value to "10k" to approximate the guitar pickup resistance of a 'bucker (single coil would be about 4k)
R1 change value to ".001" (it's now become a short circuit - R1 has disappeared)
C1 change value to "47n" this will be the tone control capacitor, change it as you like
R2 change value to "1000M" (it's now an open circuit - R2 is gone)
C2 change value to "1" (it's now 1 Farad and is a short circuit - C2 doesn't exist)
R3 change value to "1000M" and set slider to "10" (it's an open circuit - it's gone - but the output is connected to C2 by virtue of the slider position)
R4 change value to "500k" this will be the tone control potentiometer, change as you like
R5 change value to "1M" this is the input impedance of the amplifier

By varying the slider position of R4, one can get an approximate idea of the effect of the tone control. Changing the values of R4 and C1 will give you a feel for the interaction of these two component values.

This is ONLY an approximation because it doesn't account for the inductance and the parasitic capacitance of the guitar pickup, the capacitance of the guitar cable or the input capacitance of the amplifier. Nevertheless it should serve to answer a few questions about guitar tone control circuits.

cheers, have fun -
randyc
Back to top
View user's profile Send private message
M



Joined: 02 Jan 2009
Posts: 331
Location: Northern VA (USA)

PostPosted: Sun Apr 11, 2010 5:17 pm    Post subject: Reply with quote

Sorry - just a small tangent: I think it's very cool of you to share your obvious electronics expertise with us, randyc. I've read your detailed comments in several threads, and it's folks like you that make forums interesting places to frequent.

Thank you for your participation!

As you were ... Smile
Back to top
View user's profile Send private message
randyc



Joined: 14 Sep 2006
Posts: 407
Location: Eureka, CA

PostPosted: Sun Apr 11, 2010 11:10 pm    Post subject: Reply with quote

Why, thank you very much, that's very kind.

cheers,
randyc
Back to top
View user's profile Send private message
sunflower



Joined: 09 Mar 2007
Posts: 581

PostPosted: Mon Apr 12, 2010 6:24 pm    Post subject: Reply with quote

I think that'll be a little too much for me

No hurry on any of this stuff man
Of course you must take care of the important things

Be well you two
Back to top
View user's profile Send private message
randyc



Joined: 14 Sep 2006
Posts: 407
Location: Eureka, CA

PostPosted: Mon Apr 12, 2010 9:43 pm    Post subject: Reply with quote

sunflower wrote:
I think that'll be a little too much for me ...


LOL, I always forget that this stuff is not as much fun for others as it is for me.

cheers,
randyc
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    PlayJazzGuitar.com Forum Index -> Guitar Repair & Upgrades All times are GMT
Goto page Previous  1, 2
Page 2 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group