DIY URB Magnetic Pickups

jflojazz · #1 06-02-2006, 11:38 AM

I'd like to start a thread about DIY upright bass magnetic pickups.
I've designed one myself.
I built them with Alnico V magnets and premium Mogami cable.
The coils are fully shielded and Humbucking.
They can be easily mounted in a non-invasive way on basses with 3M dual lock velcro and quick release RCA to 1/4" jack mount, like the Gage' Realist and Upton' Revolution.
The casing is real hardwood stained to match the fingerboard.
I wound em with my wife's old singer sewing machine.
It is possible to make these but very labor intensive.

Other DIY experiences to share with us?

GutOil · #2 06-04-2006, 02:30 PM

Hi, I'm thinking about doing this. Where did you place the velcro? Do you have any pictures of the unit you made?

SBassman · #3 06-04-2006, 02:38 PM

Quote:

Originally Posted by jflojazz

I'd like to start a thread about DIY upright bass magnetic pickups.
I've designed one myself.
I built them with Alnico V magnets and premium Mogami cable.
The coils are fully shielded and Humbucking.
They can be easily mounted in a non-invasive way on basses with 3M dual lock velcro and quick release RCA to 1/4" jack mount, like the Gage' Realist and Upton' Revolution.
The casing is real hardwood stained to match the fingerboard.
I wound em with my wife's old singer sewing machine.
It is possible to make these but very labor intensive.

Other DIY experiences to share with us?

I'm interested.

We need pictures.

And sound clips.

Otherwise, your pickup doesn't actually exist.

fdeck · #4 06-04-2006, 04:42 PM

Quote:

Originally Posted by jflojazz

I'd like to start a thread about DIY upright bass magnetic pickups.
I've designed one myself.
I built them with Alnico V magnets and premium Mogami cable.
The coils are fully shielded and Humbucking.
They can be easily mounted in a non-invasive way on basses with 3M dual lock velcro and quick release RCA to 1/4" jack mount, like the Gage' Realist and Upton' Revolution.
The casing is real hardwood stained to match the fingerboard.
I wound em with my wife's old singer sewing machine.
It is possible to make these but very labor intensive.

Other DIY experiences to share with us?

Do a little search. One of the threads, fairly recent, has a picture of my DIY mag pickup. I pulled little coils on plastic forms out of small stepping motors that were discards from a project.

jflojazz · #5 06-04-2006, 11:56 PM

Hi everyone
I placed the velcro on top of the pickup and bottom of the fingerboard.
Keep in mind this is 3M dual lock INDUSTRIAL velcro which is very strong.
here are some pics.
soon i will post some pics of the process.
I dont have broadband so sound clips are hard to do except for crappy mp3s and those still take forever. ( dialup sucks!)

jflojazz · #6 06-04-2006, 11:59 PM

Hi Can everyone see the photos now?
There were some issues before.
I can email them too.
JFLO

Trevorus · #7 06-05-2006, 12:21 AM

That looks quite cool. Did you use a straight bobbin with varying pole piece lengths to match the curvature of the fretboard?

Another design that I have seen (that EMG uses actually) is pretty much an independent pickup for every string. Quite a bit more complicated, but I imagine that with some creative circuitry, you could achieve great amplified string balance.

jflojazz · #8 06-05-2006, 12:51 AM

[quote=Trevorus]That looks quite cool. Did you use a straight bobbin with varying pole piece lengths to match the curvature of the fretboard?

Hi Trevor
i used different polepiece lengths for each string AND each one is an individual independant pickup . then I wire all four in humbucking series
alternating magnetic polarities. this also means I can adjust slightly the height of each polepiece to balance the sound.
JF
here is a pic of an early polepiece pickup design with spring ajustability, unfortunately the spring acted like an antennae so i quit using them , now I shield the coils with copper foil to block
hum and RF

ToneRanger · #9 06-05-2006, 03:45 AM

Quote:

Originally Posted by jflojazz

I wound em with my wife's old singer sewing machine.

I'd thought of doing that using sewing machine bobbins for the coils and inserting magnets through the centre. Those metal bobbins would be robust and actually look pretty cool.

I experimented with coils I got from small relays. Sound was OK, but there weren't really enough winding on the coils. The ones fdeck recycled from stepping motors seem better.

(I gave up experimenting with magnetics when I figured out how to get a big fat sound from my home-made piezos - www.fittell.id.au/piezo )

SBassman · #10 06-05-2006, 04:51 AM

Quote:

Originally Posted by jflojazz

Hi everyone
I placed the velcro on top of the pickup and bottom of the fingerboard.
Keep in mind this is 3M dual lock INDUSTRIAL velcro which is very strong.
here are some pics.
soon i will post some pics of the process.
I dont have broadband so sound clips are hard to do except for crappy mp3s and those still take forever. ( dialup sucks!)

Wow. You're onto something here. Nice.

Would you consider building one for sale? I have been thinking about adding a magnetic pickup to my Sinsonido. But, I would need a very low height pickup. Think you could build something thin?

jflojazz · #11 06-05-2006, 11:28 AM

Hi
the pickup can be thinner but there needs to be at least 1/2 in.
aperture for the coil windings so thats the thinness limit.

jflojazz · #12 06-05-2006, 11:31 AM

I tried the msi piezos but the output in all circumstances was to low to be usable. What was your signal chain?
how long of cord did you use.
did you use a preamp close by?
JFLO

ToneRanger · #13 06-07-2006, 07:46 AM

Quote:

Originally Posted by jflojazz

I tried the msi piezos but the output in all circumstances was to low to be usable. What was your signal chain?
how long of cord did you use.
did you use a preamp close by?

I've made quite a lot of pickups from the msi piezos, and attached them to basses, fiddles and a cello. In all cases they were placed under the bridge foot (bass side, or a pair under both) and gave good level with smooth sound.

As always with piezos it's best not to run along cable, but I've used standard guitar leads to me Eden amp with no noticeable signal degradation. My EUB has a Jack Orman MosFet Booster on board, but it works just as well without that in the signal chain.

A sliver of cork or gasket material under the pickup helps it to seat better and improves output level.

mje · #14 06-07-2006, 10:38 AM

Like jflojazz, I found that the MSI elements didn't have anywhere near enough output to drive any amp I used, unless I added a lot of outboard preamp gain. Curious. I've ordered some of their inexpensive accelerometer elements (like the film element with a small weight riveted through) and i'm going to try to make a table-mounted pickup with that.

fdeck · #15 06-07-2006, 06:15 PM

Quote:

Originally Posted by ToneRanger

I experimented with coils I got from small relays. Sound was OK, but there weren't really enough winding on the coils. The ones fdeck recycled from stepping motors seem better.

The recycled stepping motor coils definitely work, but with the caveat that my DIY pickup produces a relatively low output. However, I just crank the gains on my amp. Stacking two coils would give me a 6 dB boost, but I have to wait for more motors to materialize.

I have also thought about using a stepping motor to make a winding machine, so the motor could run at a moderate speed while counting the exact number of turns.

Note in edit: I could also experiment with different voltage rating motors that might have more turns of wire, but I have to admit that I may have returned to the piezo fold after resolving the preamp situation nicely. More on that later I hope.

mje · #16 06-08-2006, 06:31 AM

Quote:

Originally Posted by fdeck

The recycled stepping motor coils definitely work, but with the caveat that my DIY pickup produces a relatively low output. However, I just crank the gains on my amp. Stacking two coils would give me a 6 dB boost, but I have to wait for more motors to materialize....

What's the resistence/impedance of the coils you're using? Since you're not trying to drive a Marshall head into clipping, I'd think low impedance and a buffer would be the better way to go. ;-)

fdeck · #17 06-08-2006, 09:04 PM

Quote:

Originally Posted by mje

What's the resistence/impedance of the coils you're using? Since you're not trying to drive a Marshall head into clipping, I'd think low impedance and a buffer would be the better way to go. ;-)

Admittedly, I never measured those things. I have used a low noise buffer with some gain, and it helps. But then laziness takes over and I often go out the door with minimal gear. Cranking the gains definitely works, even if it gets a bit noisy.

In my recent spate of projects, I will probably build a little pre with 20 dB of gain and absurdly low noise. If successful, I will post the design.

Joe Smithberger · #18 07-21-2006, 05:57 AM

Thought I would pop in here and post a qualified rave for jflo's pickup. I got mine yesterday.

Installation is pretty clean. Output is not real high, but definitely workable. It is pretty quiet except for the grounding hum that pops up when I am not touching the strings. This hum however can be minimized with EQ and probably wouldn't come through at all in a group setting. I found that the pickup works really great with my Fishman Platinum preamp/DI and can get a decent double bass tone that I think will work great for dense mixes and pop/rock applications. I was surprised how woody it sounded and how well it picked up string and fingerboard sounds (in a good way), almost like a piezo but with much more sustain.

I will post again after my outdoor gig tomorrow where I will be running with a pair of Berg 112's and a Focus 2R.

jflojazz · #19 07-21-2006, 07:51 PM

Thanks for the kudos Joe
I am glad you are enjoying the pickup.
If you have the capabilities to post mp3'S that would br great.
my dialup is too slow.
let us know how you it for the gig
JFLO

fdeck · #20 07-22-2006, 11:02 PM

Quote:

Originally Posted by Joe Smithberger

Thought I would pop in here and post a qualified rave for jflo's pickup. I got mine yesterday.

Installation is pretty clean. Output is not real high, but definitely workable. It is pretty quiet except for the grounding hum that pops up when I am not touching the strings. This hum however can be minimized with EQ and probably wouldn't come through at all in a group setting. I found that the pickup works really great with my Fishman Platinum preamp/DI and can get a decent double bass tone that I think will work great for dense mixes and pop/rock applications. I was surprised how woody it sounded and how well it picked up string and fingerboard sounds (in a good way), almost like a piezo but with much more sustain.

I will post again after my outdoor gig tomorrow where I will be running with a pair of Berg 112's and a Focus 2R.

You can get rid of the grounding hum by grounding the strings to the output jack of the pickup. This is how most electric basses are configured. The simplest trick is simply to wind some bare wire around the ball ends of your strings, then to the metal part of the pickup output jack.

Of course if you ground the strings, then you are in danger of shock if your system develops a ground fault. I never trust electrical systems outdoors, and have a cheap wireless setup for outdoor gigs.