Hey all, I've come up with a design for a tunable pickup that is free for personal, non-commercial use. It allows you to install one pickup and tweak the sound to your heart's content with swapping pickups. I did a video explaining the science and construction, as well as some sounds samples. I hope you like it! I plan to put a pair in a new build soon. This is specifically for guitar, but can be adapted to bass by changing filter corner frequencies.
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DIY Tunable Pickup
- Thread starter Ripthorn
- Start date
Nice, thanks for sharing this!
One comment: in spice you modelled your preamp as a 5M ohm resistor, but in your schematic there is a 1M ohm resistor to AGND followed by a decoupling capacitor and another 100k ohm resistor to AREF, which is effectively another ground. Thus in guitar frequencies I expect your pickup is actually seeing a ~90k ohm preamp impedance and a ~2 Hz HPF. Does that make sense? The reason I point that out is it will likely significantly color the output of the pickup compared to your model. Might be interesting to model the actual preamp input (and transformer for that matter) and see how much effect it really has.
One comment: in spice you modelled your preamp as a 5M ohm resistor, but in your schematic there is a 1M ohm resistor to AGND followed by a decoupling capacitor and another 100k ohm resistor to AREF, which is effectively another ground. Thus in guitar frequencies I expect your pickup is actually seeing a ~90k ohm preamp impedance and a ~2 Hz HPF. Does that make sense? The reason I point that out is it will likely significantly color the output of the pickup compared to your model. Might be interesting to model the actual preamp input (and transformer for that matter) and see how much effect it really has.
This is very interesting. Would love to hear a demo of the pickups/circuitry on bass.
Love the idea that it is "free for personal, non-commercial use." If only more things were like this ...
Love the idea that it is "free for personal, non-commercial use." If only more things were like this ...
Hey @Ripthorn,
Thanks for sharing! Coincidentally I was watching your other video about 3D printing metal guitar parts:
Very interesting in the best of ways!
Thanks for sharing! Coincidentally I was watching your other video about 3D printing metal guitar parts:
Very interesting in the best of ways!
- Apr 18, 2008
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- I'm highly opinionated and extremely self-assured
I watched the video with interest, even though I don’t know a Sallen key from a Salle en quay…
But this sounds a lot like some of the filter preamps that have recently come to market, such as the Lusithand, JTEX, Underhill, etc, which are based on the functionality of the LPF electronics pioneered by Alembic.
Can someone explain to me, in fishmonger terms, how this differs?
But this sounds a lot like some of the filter preamps that have recently come to market, such as the Lusithand, JTEX, Underhill, etc, which are based on the functionality of the LPF electronics pioneered by Alembic.
Can someone explain to me, in fishmonger terms, how this differs?
Thanks for sharing! I am very interested in it.
It's the analog version of what cycfi does with their XR and Nu pickups and software. They use 38AWG and 1000 turns or 46AWG with 1300 turns. I once bought 4 cycfi Nu pickups for an experiment, but haven't played with them yet. The cycfi approach is probably more flexible in the end (they also have some software to reproduce the frequency response of various pickup positions), but I find the approach presented here more exciting because it's more DIY and analog.
Can someone create a circuit board layout for the approach presented here?
It's the analog version of what cycfi does with their XR and Nu pickups and software. They use 38AWG and 1000 turns or 46AWG with 1300 turns. I once bought 4 cycfi Nu pickups for an experiment, but haven't played with them yet. The cycfi approach is probably more flexible in the end (they also have some software to reproduce the frequency response of various pickup positions), but I find the approach presented here more exciting because it's more DIY and analog.
Can someone create a circuit board layout for the approach presented here?
This is definitely one of those topics that I couldn’t just whip up a quick prototype without the basic understanding. Parts I understood, and others left me thinking I need to brush up on x, and y… ¯\_(ツ)_/¯
So this is my project (and me in the video)
The biggest differences are:
1. Full adjustability of all parameters (For example, the JTEX only allows changing the filter cutoff frequency and has 3 resonant peak amplitudes). That means you can dial in the Q to be as wide or narrow as you want, etc.
2. With the coils wound to be super flat, they can be shaped in any way you want. I actually did an experiment where I ran the pickup through my acoustic preamp pedal and into my DAW with an acoustic guitar IR. It was actually a quite good acoustic sound. In theory, you could build all that into a pedal and get a very convincing acoustic sound without a separate piezo, it could just be a separate setting on your onboard switching.
3. I tell you exactly how to make them. I'll build one-offs for people who ask, but I do all of this as a hobby and share my knowledge in the spirit of the DIY community. I give schematics, parts lists, etc. and all I ask in return is that you only use this for personal, non-commercial use.
In my files on my Github repo for this project (GitHub - brianthornock/TunablePickup: An Infinitely Tunable Guitar Pickup System), I have an SMD layout for the circuit that has 5 trim pots on there for setting things up however you want. You are looking for the file PickupShaper.zip. It is a zip file of the Gerber files needed to have a PCB house make you some PCB's. I use JLCPCB, but PCBWay, OSHPark, and any others will work as well. I also provide the schematic so that someone can produce a through hole layout, if so desired. You could even make one with all the controls on the front of the instrument, though I personally would find that overkill.
Ah, I had already looked at your repo but overlooked it. Thanks!
I had briefly looked on JLCPCB, but since there's no related BOM in the files, they can't solder the components on the PCB - and I can't solder SMD myself. I may try to develop a version with pin holes if I can find the time at some point.
Any suggestions to tweak the values of some components for bass?
Ah,I suppose I should upload the files for SMD assembly. I'll have to do that when I'm back in a week.
For values to tweak for bass, I would need to look at the schematic, but it should be fairly straightforward. It's just changing values to shift center frequencies down, usually by making caps larger.
Thank you! If you could provide the files for the SMD assembly, I would greatly appreciate it. A bass specific version would be perfect. I would really love to test this.
