Comment

Comment by Mark Vickroid on January 11, 2009 at 6:01am

Regarding using Peizo pickups with volume/tone knobs:

A piezo is in the neighborhood of 1,000,000 ohms. Right ONE MILLION ohms.
Using a 500k pot is going to present an impedance mismatch that is going to severly impair the performance and output of the pickup. Using two 500k pots doubly so. A 1meg ohm pot is minimum, but is still not the proper value to avoid negativly impacting performace.

Think about this: A guitar pickup is in the range of around 4k - 20k Say 10k for an average [actually that's kinda high but it makes the math easy] and are usually used with either a 250k or 500k pot. Let's use 250k for this example.
This gives us an impedance ratio of: 1:25 or .04 for pickup:pot [it would be 1:50 for a 500k pot etc]
Using a 1meg pot and a piezo pickup gives us a ratio of: 1000000:1000000 or 1:1 or 1 for Piezo:Pot
You can see you would need a 25,000,000k or 25meg pot to achieve a proper impedance match for a completely passive system. Try finding one of those at Radio Shack!

If you want to use a volume and tone knob with a piezo pickup, it MUST be an active system to avoid sounding like crap, or at least about 10% as good as it could sound

This means an active volume/tone system like used for an acoustic guitar. They can be purchased as an outboard unit for use with multiple guitars.

Or just skip the knobs plug it in and use the knobs on the amp - they are there for a reason!!!

But also note that due to the incredibally

Comment by Wichita Sam on January 8, 2009 at 4:32pm

the post will have active links to McNally StrumStick website to a couple obscure pages with specs and "how to play info....

specs link.... http://www.strumstick.com/html_pages/Strumstick%20Strings%20&%20tuning.htm

playing resources link... http://www.strumstick.com/html_pages/Instructions%20And%20Resources.htm

hope these work... cut and paste into your browser window...

Comment by Wichita Sam on January 8, 2009 at 10:10am

nothing wrong with the link... try again...

and, you do very nice stuff....

Comment by Wichita Sam on January 7, 2009 at 4:41am

anyone interested in building strumstick-type CBG should check out this post at the CigarBoxGuitarBuilders Forum
http://launch.groups.yahoo.com/group/CIGARBOXGUITARBUILDERS/message/7402

Comment by John Sims on January 2, 2009 at 7:54am

Most piezo's are high impedance. I recommend using 500K ohm pots and a .047 or .05 microfarad capacitor.

Comment by Charlie on January 2, 2009 at 7:06am

hey
So i'm electrifying a cbg and I need a bit of help. I'm using piezos for the pickup and I want to add a volume and tone knob. What kind of pots should I be using? Like how much Ks should they have?
Thanks
--Charlie

Comment by Wade on December 25, 2008 at 8:53am

If you already have a nut and bridge installed, lay a straight edge flat on the surface of the box, then add another straight edge that runs from the nut to the bridge. When the angle is where you want it, clamp or duct tape the 2 straight edges together- there's your angle.

Comment by bucky on December 21, 2008 at 8:07am

thanks for the ideas. I tried to join that forum through cigarboxguitars.com and couldn't get it to load up. It could be my computer though. I will try to go directly to it.

Comment by Wichita Sam on December 20, 2008 at 12:38pm

OK, you might also consider joining CigarBoxBuilders yahoo forum...
http://launch.groups.yahoo.com/group/CIGARBOXGUITARBUILDERS/

There's a lot of folk there who love helping each other.... and many have membership here and there too.

Really try breaking the plastic housing. Be careful with the piezo itself (the brass disc with a ceramic back and two wires coming out). I messed up a couple before I got the hang of it. I found that if you take a pair of side cutters and just nibble at the plastic, it goes away pretty quickly... The problem with feed back is far worse when the piezo is left in the housing.

as far as "cushioning" goes, some sandwich the piezo between layers of mouse pad and then glue that to the top. some CA the piezo to the top and then encase the piezo with hotglue (I like silicone caulk). Another design possibility is to put the piezo between the top and a bridge plate...

Comment by bucky on December 20, 2008 at 11:28am

I haven't tried removing the piezo from the plastic. I just glue it to the lid of the box under the bridge by the bass string. I've never considered using any kind of cushion. I have only made about six cbg's and haven't really found a site to learn more of these types of solutions until now! I've just been trying different designs and learning as I go. Any advice is helpful and I am really enjoying this site. Thanks for the explanation wichita sam.

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