Lookin' good :)
Also, I got three piezo transducers with the set I bought. They are currently wired in parallel on the one socket, but I was planning to snip two off anyway as I don't need all three. Happy to mail one up to you.
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Lookin' good :)
Also, I got three piezo transducers with the set I bought. They are currently wired in parallel on the one socket, but I was planning to snip two off anyway as I don't need all three. Happy to mail one up to you.
An update on my attempts as I play along at home.
I tried a single coil with a thin metal sheet but couldn't really get it to sound any good. To be fair, I didn't spend a lot of time on it, but it wasn't really doing much for me.
Tried a piezo, but also found it made a tiny tap rather than a thud (probably unsurprisingly).
Raided my random speaker box and found I only had these three to choose from. The big guy is a 4" 4 Ohm, then there's a small 8 Ohm and the two small 4 Ohm speakers from an old bluetooth unit. After trying all three the bluetooth speaker gave the best result - a good thud, which was quite loud when I ran it through a boost pedal
Attachment 35702
Attachment 35703
It's looking more and more like a small speaker is the way to go with these things. I have a 5" driver and can salvage some smaller 3" speakers from the remains of the PC speaker set that I got the broken sub speaker from.
When the 4" one went thump it was impressive, but I really needed to give it a whack. I only had to tap the small one for a good sound, so that seems ideal for the application. Glad I salvaged that little bluetooth speaker from my old job!
Interesting, thanks.
Awesome!!!
I had better crack on with the FS-808. Taking a break tonight. One too many Coopers Extra Stouts for good soldering :)
Umm, I might have gone a little OTT on sanding this afternoon.
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This result is particularly exciting, as the blank that generated the top and bottom of the enclosure came off of the plank that generated this puppy:
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I hadn’t thought to ask what finish you wanted on this before I started sanding, if you want to paint or clear it you’ll probably need to knock it back to 320 or 400, as opposed to the polished finish I’ve got it to.
Sent from my iPad using Tapatalk Pro
the image quality isn’t fantastic but hopefully it conveys how much grain feature has come up on this thing.
http://youtu.be/tSFlq7p4ON0
That looks fantastic. There is no way I could put paint over that. I have some satin poly, but maybe an oil finish of some sort would be better. I am open to suggestions.
I also love the connection to one of your other builds. Do you have a link to the build diary of that guitar? I made good progress on the FS-808 yesterday, and should be able to wire it up for testing tonight.
That build is just a body blank at this point, it doesn’t yet have a defined plan. And to be fair it is about 6th in the queue of things I need to play with. With the exception of this stomp diversion, build efforts are focusing on Build for a Mate and Igor gets the blues.Quote:
Originally Posted by jugglindan
Igor gets the Blues
I like that!
Those little 4 ohm ones just look thumpier :p
Applying the electrodes to this project now that the beautiful box has arrived in the mail.
The parts I need to finish building the preamp are still en-route from Tayda, so I loaded the Xtomp mini with some of the preamp patches.
First experiment: piezo transducers. I stuck one underneath the box top, and ran it through the xtomp and into my THR on the guitar input.
Result: the same unsatisfactory clicks and taps as before. Using a piezo pickup will require some serious EQ. The best sound I could get was with the Xotic RC Booster patch loaded into the Xtomp, with gain and volume maxed, bass maxed and treble to zero. And when I say best it still wasn't good. I tried the Aux input on the amp: less volume and clearer sound as it wasn't getting hit with the reverb. But still not what I am after.
Second experiment: A small speaker salvaged from old PC speakers taped to the underside of the box, wired through the RC Booster.
Attachment 36180
Result: much better. The speaker only responds to the lower frequencies, so I get less of the stuff I don't want. With the same RC Booster settings as before this is much closer to a usable sound. I won't get the same result from the preamp I am building though. While I can boost the gain/volume sufficiently, it only has a passive EQ while the AC Booster is active so it can really push the low end.
Future experiments: Different speakers, an old bass pickup (once I can get hold of one).
Clearly more to these magic boxes than I first thought!
Revisiting the piezo option might be worth doing. This video shows a cigar box build with a piezo and simple passive circuit and it sounds quite good. I think the key difference is that it's plugged into a decent acoustic amp.
https://www.youtube.com/watch?v=7h1VF1fsTAw
It doesn't have to be a bass pickup. They aren't any different to guitar ones except in relation to pole spacing and number of poles.
A bigger diameter speaker would probably give more bass end. And a low power one should have a softer speaker compliance than a higher power one, so the cone will move more for a given input.
Thanks Simon.
Yes, I definitely need to try different speakers. And I have the old set of Schaller active HSS pickups that I took out of the G&L. Should be able to hook one up with a battery to test it.
And here's another video showing an interesting build from an elm log that uses 2 piezo pickups. Although he does say at one point that the best result comes from cranking the bass on the amp.
https://www.youtube.com/watch?v=3hmltXZKHLc
All these videos give me confidence that eventually I will find a combination of electronics that will work.
Final bit of research for the night: found this showing how to modify a small speaker to get an improved bass response by adding weight to the membrane:
https://www.youtube.com/watch?v=a5dUmReP6ls
In that position, technically his 'high-hat' is a 'low-hat' or 'low-boy'. That's the original position for them and they were known as 'low-boys' and weren't played with sticks, just a pedal. Then they got moved up a couple of feet to their now-standard position. One of the pieces of info I retained from a Carl Palmer drum clinic. #notadrummer
I didn't know that. Not planning on the whole cymbals thing, but I just tried taping a 20c coin to the small speaker and I definitely get a better bass thump. Boosting the signal and running through a low-pass filter and it's getting a bit closer to the sound I want. This time without the active EQ of the RC booster. Just a simple clean boost followed by the low-pass. This is progress because it's closer to what I can build easily.
Will need to ditch the piezo preamp circuit though, as it has a fixed gain of 2 (6dB). I needed maybe 18 or 20 dB boost. I will try replacing the fixed gain resistor with a pot, and if that doesn't work will just build a simple clean boost and add a low pass filter (standard passive bass control).
The roomy box has enough room to fit all this and a battery inside (switched by the jack) if the design works out.
Technically a low pass filter isn't a standard bass control. It passes all frequencies below the filter cut-off (and actually some above, but it's rolling them off at the filter slope rate and will already be 3dB down at the filter frequency). A normal bass control is typically a shelving boost/cut, which only affects the bass frequencies. But a low pass filter should do what you want in terms of just leaving most off the bass and low mids, especially when paired with that boost to get the level up.
A kick drum normally has a low component and then a high-mid component from the beater that provides some definition to the sound in the 2-4kHz region. I don't know how much of those frequencies your weighted speaker produces, but I wonder if you could somehow pair the low-passed speaker with maybe a high-passed piezo signal to more closely mimic a real kick sound.
Again it's something you could test quickly out in a DAW after recording the two signals to see whether it would work at all.
Should I have said "standard tone control"? I was thinking of using a first-order passive RC low-pass filter, which I see in circuits a lot labeled as "tone". I guess "bass control" implies an active control that can boost or cut in a band. I did try a 5 band EQ, but it was easier to get a good result with a one-knob low-pass filter.
To do the piezo mix I would need the booster and low-pass filter on the speaker, and a piezo preamp with high-pass filter, then a 2 channel mixer (either passive or with an opamp) to blend. Sounds like a lot but it could probably all fit on a single stripboard. Maybe.
The DAW test certainly sounds easier than breadboarding all those circuits. Hopefully Audacity can do simple filters, because that's all I have.
But I might be able to get something decent using just the weighted speaker by pairing a Baxandall bass/treble tone control with a clean boost. Time to pull the Rat off the breadboard!
Yes, probably a pedal standard tone pot. Though a standard, that LPF would probably be set a bit higher than what you'd require. You may not need piezo pre-amp if you just work with the sound it produces into a lower impedance input. The piezo preamp provides the high impedance required for a flat response if it's a single source transducer and needs to do full-range flat reproduction. But as a simple sound source, and with you 'throwing away' a lot of the sound it produces, and probably at a fairly low-level in the mix, you shouldn't need a special preamp for it.
Hence the suggestion to play with the two sounds in a DAW where you can adjust the LPF and HPF frequencies and mix levels to see whether you even think it adds anything extra or whether the speaker on its own is fine. As long as you record the two sounds at the same input gain level, you'll also find out how much relative gain one signal would need to the other.
Audacity should have LPF/HPF and shelving EQs available, so you can also test the Baxandall EQ and see what frequency settings/gain levels you'd need without having to even open your resistor box.
Still haven't recorded anything, but I built a mosfet-based boost on breadboard tonight. It's sort of a modified SHO (Soulsonic Crackle Not OK) set to max gain (no gain pot). Sounds quite good with guitar, and gets the level of the speaker transducer up high enough without too much noise despite being on a breadboard.
No bassy thump, but I haven't added a tone circuit yet. I think it would make an interesting boost pedal for guitar with the addition of tone and volume controls.
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