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Permalink Reply by David L. on October 24, 2016 at 12:05pm

A normal electric guitar usually has only passive tone controls based around a potentiometer with a capacitor controlling how much of the high frequency is bled to ground.  The sound goes from clean treble to mushy bass.  It is okay, but nothing compared to the tonal control you get using the amp controls or an equaliser pedal (where the active circuitry lets you boost parts of the signal as well as reducing other areas so you can shape the sound to what you want).  Also due to the different electrical properties piezos don't have much/if any tonal change using a "normal electric guitar"passive tone (you can make a passive low pass filter but much more complicated than a pot plus capacitor).

You can add an active equaliser to your guitar by adding a normal guitar preamp (meant for a piezo rod) and passing the magnetic signal through it (you can send both piezo and/or magnetic signals together if you wish).  If you use a preamp with a tuning function you get an onboard tuning function too.

If you are starting to experiment with electric guitar circuits there are several other things you can do to get different tones:

Pickup position ie nearer the bridge = clean treble, nearer the neck = warmer, less clarity which is why a stratocaster has 3 positions.  Combinations of these different positions vary the tone.

Using the stracciatella guitar mod (adding a diode to a volume pot for each pickup you are using lets you add 0 to 100% of the signal from each pickup to the final signal).

Video demo https://www.youtube.com/watch?v=vWJeR_O5p44

original post http://www.strat-talk.com/threads/the-stracciatella-3-volume-w-vari...

I tend to add both piezo plus magnetic pickups so use 1N5819 diodes for all pickups.

By adding a piezo pickup (disc, rod or cable) along with the magnetic signal it will also give you other distinctive tones.

Probably too much information but better than not enough and 2 or more electrical pickups + piezo (with diodes = infinite tones & infinite fun ;0) 

Then you get onto coil tapping humbuckers and phase switching magnetic pickups....

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Permalink Reply by Matt Quinney on October 24, 2016 at 2:58pm

Wayfinder & David,

Thanks for your excellent replies!  As you may have guessed, I don't know much about audio electronics, and your replies gave me some great starting points for learning more - way beyond just a simple answer to my question.  It's great to be part of such a supportive and knowledgeable community!

Matt

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Permalink Reply by Kigar on October 24, 2016 at 3:04pm

These guys are way more knowledgeable so I'll go the simple route - for your first electricification consider a piezo and a LM386 amp.  Look up the Ruby amp for a more refined version, or a cheapo LM386 kit on ebay for under $2 ( $1.08 a minute ago) that gives a whopping 1/4 watt.  You have to add a jack, speaker, piezo, etc, but you can learn how to put things together and see how it all interacts, and when you blow one it is only a couple bucks.

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Permalink Reply by Timothy Hunter on October 25, 2016 at 4:10am

the embarrasment of all Aussies...Fosters...no one drinks it here its all exported..ha ha ha

Matt, the tone control in a guitar amp is usually in between the pre amp and the power amp sections. This way they have the possibility to both boost and cut. usually the bass and treble are based at fixed frequencies. same with a Mid if the amp has one. they are just low pass, band pass and high pass filters.  you can also get an active mid called a parametric filter . this adds the possibility of doing 3 things . 1 you can move the frequency it is based on up and down. 2 you can change the width of how it affects the tone ie broad or narrow it right down to just a small band.. and 3 you can set the depth of the cut or boost.

having tone controls on both guitar and amp give you much greater control of how you sound. a lot of the difference between fender and marshall tone is in the position in the frequency spectrum the bass and treble controls are set.

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Permalink Reply by Timothy Hunter on October 25, 2016 at 4:14am

i just received 5 of these   http://www.ebay.com.au/itm/222213880107?_trksid=p2057872.m2749.l264...

supposed to be 3W per channel... all run from 5 V . cant bridge the outputs though. Going to try a 2 x 4" speaker amp using a cheap 5V USB ph charge bank.... and just feed the input to both sides... or you could build one with 2 inputs mike and git.... may need a preamp havent powered it up yet....

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Permalink Reply by Matt Quinney on October 25, 2016 at 6:59am

Kigar,

I do plan on using a 386 based amp, specifically this one  http://mylkstuff.com/page35.htm  .  It has a 741 op amp pre-amp with a 386 power amp.  Between the two is a "insert tone control here" notation, which prompted me original question as to whether I needed it. 

Timothy,

Thanks for the additional info on tone control.  I'll definitely add it to the amp. 

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Permalink Reply by Timothy Hunter on October 25, 2016 at 11:48pm

if you can get one replace the 741 with a TL071. 741 is a very noisy op amp. the TL071 should be pin compatible but a much better op amp.

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Permalink Reply by darryl kernaghan on October 25, 2016 at 1:56pm

Not a lot to add to this thread, but i did run in to this interesting stereo amp for 13 aust. dollars yesterday, DC 6-12 V/AC 120-240 V, naturally i had to get one to try out.             http://www.ebay.com.au/itm/291830770787?_trksid=p2057872.m2749.l264...

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