Double Bass Piezo-preamp-vol & tone

[josiah goldfish]

Hey everyone,
I'm building an EUB and notice that someone built one with part from maplins. They included plans for it but there wasn't a tone pot. I have some questions, and I'd like to know how to wire in a tone pot.
I'm thinking about ordering:
A preamp
A piezo transducer
A volume pot
A tone pot
A 9v battery case

What do I need to solder where? I have instructions on how to do everything except adding a tone pot, which I really want to do.
Thanks in advance, and sorry for all the nooby questions.
Joe
Btw, the picture shows the preamp I'm thinking about buying. If you go to maplins.com it's the £7.99. It's labelled 'universal amp' rather than 'preamp'.

 

[oerk]

I don't think that preamp is particularly suited for a piezo. If you can solder, and want an easy solution, try building fdeck's quick and dirty piezo preamp: Invalid Link Removed

A tone pot is just a simple low-pass filter, and might not be needed for an EUB. If you really want one though, you can add it together with a treble bleed cap to the output of the preamp, just like in a guitar (look at simple Vol/Tone guitar circuits to get an idea). Experiment with different cap values.

 

[josiah goldfish]

That looks cheaper than the maplins one! It's worth giving it a go just to see if it works, just need some decent pics now. The ones on the PDF are black and White and they're all fuzzy (It might just be my phone though).
Thanks for sharing

 

[iiipopes]

+1 on downloading and building the schematic of the fdeck HPF Pre II, which is very popular as a buffer amp with volume control & variable high-pass:
Invalid Link Removed

 

[josiah goldfish]

+1 on downloading and building the schematic of the fdeck HPF Pre II, which is very popular as a buffer amp with volume control & variable high-pass:
Invalid Link Removed

Is the volume control a knob (like on a pot) or is it just a little thumb-wheel or something? I'll definitely give it a go. Looks fun

 

[oerk]

It's a pot. The HPF Pre is definitely the better solution, but if you have limited electronics skill and just need something to interface with an amp, the Quick&Dirty version is sufficient too.

Don't know if the high pass is really needed on an EUB.

 

[mje]

I built one of fdeck's quick and dirty preamps into my Azola as a temporary measure, to get some linearity out of the passive volume control- and I liked it so much I just left it there. I just wired the components together, keeping the leads short, and potted the whole thing in silicone sealant in a piece of heat string tubing. My luthier pal put more work into inletting the battery case than I did in building the preamp ;-)

 

[Matthijs]

You dont need the hpf pre for an EUB because there's no real need for the high pass filter. Fdeck's simple buffering amp works just fine and the sound quality is on the same high level as the hpf pre. It was an immense improvement for my NS Wav 4