Piezos, Mics , Pickups - Transducer selection

synaesthesia · #1 06-01-2008, 06:06 AM

Hey There

I am part way through a lefty EUB build from scratch having built several electric slab basses. Early days....Need advice on transducer selection.

I am hoping to seek your opinions on the types of piezo, mic or magnetic pickups you use or have used. Sonic, Gig or recording experience comparisons are more than welcome. Placement ideas etc. I will be building my own buffer preamp without EQ, and will use EQ in either of my amp rigs. (my jazz gig rigs are alembic preamp, carver power amp, 3 way 1X12, 1X6, peerless tweeter cab - effectively a mini PA, or an AI Clarus with GK MB112 cab modded with a tweeter, pedal graphic EQ)

Hope to learn from your experience, it would save me a bit on experimenting with the various (expensive) systems out there and give me some kind of starting point. I know there is the Fishman full circle, the K&K (FWIW, I was a K&K agent when their core business were drum mics about 10 years ago- I hope I can still get a deal), Barbera, Realist, etc. I don't know how they compare sonically.

tornadobass · #2 06-01-2008, 07:31 AM

I have an early Azola BugBass with just a K&K BassMax in one wing of the bridge. It works okay and is a simple solution. At that point, there was no onboard preamp and the pickup went straight to a volume pot and then to the jack.

**Francois Blais** · #3 06-01-2008, 09:00 AM

I did a lot of experiments with pickups, with three EUBs.
The first one was an original Ampeg Baby Bass.
I replaced its cast aluminum bridge with a custom maple bridge and an Underwood pickup in the wings.
The tone was not even across the four strings though.

When I sold it and bought an Azola BugBass, it was the first model, as described by tornadobass.
I replaced its bridge with the maple one I had kept from the BB when I sold it.
I had the same unevenness of tone.

Then I sold it and bought a Carruthers SUB-1.
With this one, I also replaced the bridge. The original one was a solid piece of maple, with no heart or wings.
I tried a Bass Max, an Upton Revolution series I, a Fishman BP-100 and ended up with a K&K Big Twin.
However, I mounted it like an Underwood pickup, and am using wine cork as a shim.
I have the best tone with this setup.
A BP-100 could be mounted the same way, by the way, if you have one, or can get one cheap.
The Big Twin is basically the same thing, with smaller elements.

Hope this helps!

synaesthesia · #4 06-01-2008, 11:26 PM

Thanks, look forward to hearing more comments.

powerbass · #5 06-02-2008, 11:34 AM

I built my own EUB and used the K&K Double Big Twin which has 4 transducers. I tried every placement option w/this PU and found it very difficult to get even string volume and response. I used Dyamond wood for the FB and bridge - this is a very dense material and produces a very bright sound. I ended up taping 2 of the transducers together w/foam and sticking them into the body cavity. I placed the other 2 under the bridge feet and I put auto gasket material between the instrument body and the PU. It works great now - even string response and volume, mildly thumpy w/excellent sustain and sound. Here is a picture of my bass. I took the photo when I attached 2 transducers to the body.

synaesthesia · #6 06-02-2008, 01:31 PM

Cool design.

powerbass · #7 06-02-2008, 07:00 PM

Thanks for the compliment. I wanted it to have some acoustic tone which it does. It is 34" scale length, the next one will be a DB scale length. You can't see it in the photo but the whole bass comes a part in minutes. The neck and tail piece have T-nut fasteners, allen head bolts hold it together. It is super light weight and it fits into an electric bass gig bag. It has taken a bit to get used to playing - The action is higher than my electric and I haven't built up my finger strength yet. DO you have pics of your design?

bassbob · #8 06-02-2008, 08:57 PM

I did this youtube video off the cuff awhile back. Check it out.

http://ca.youtube.com/watch?v=immQzm7GzIc

synaesthesia · #9 06-18-2008, 09:21 AM

Quote:

Originally Posted by powerbass

DO you have pics of your design?

Not yet but will post something some stage later. Thanks for the info so far.

ricobasso · #10 06-19-2008, 05:23 AM

Quote:

Originally Posted by synaesthesia

Need advice on transducer selection.I am hoping to seek your opinions on the types of piezo, mic or magnetic pickups you use or have used.

I have some thoughts on the transduction method and direction, based on my experience with two URBs I play and one EUB I have made.

I have found that piezo pickups on the body or even some types under the bridge feet pick up too much body sound and not enough string sound. They sound very dull.

Conversely a magnetic pickup at the end of the fingerboard picked up substantially only string sound and so sounded too much like a BG for my liking. Great for reducing feedback problems. No good for arco as there is very low output (the string moves mostly side to side when bowed).

Piezo pickups on the bridge sound best to my ears. Further, I think the ones you jam into the wing work better than the ones stuck or clipped to the surface. The reason for this is that the wanted bass sound is generated from the force of the strings at right angles to the string line. i.e. compression of the bridge in the line from strings to feet. This is what the wing pickups predominantly output.

Pickups on the bridge surface are more sensitive to surface bending of the bridge. This means they are less sensitive to the wanted string sound described above and more sensitive to forces from the string along the line of the string itself. i.e finger noise, scratching and scraping noises.

Try tapping the bridge in different directions if you want to hear for yourself what I am talking about.

buddyro57 · #11 09-07-2008, 07:35 PM

Many of you have had more trial & error experience in this area than have I. I have had a very frustrating experience trying to fashion a reliable pick up for my Ergo. Riccobass points out (and I agree)

Quote:

Piezo pickups on the bridge sound best to my ears. Further, I think the ones you jam into the wing work better than the ones stuck or clipped to the surface.

My question is this: I have the stock Ergo maple bridge, and a K&K Double Big Twin (4 elements). I have tried using the adhesive tape to place them on the topside and underside of the bridge, where as Ricco pointed out, they mostly pick up thump and extraneous noise.... not much pitch or sustain.

Do you think somehow wedging the elements into the bridge (either by cutting "wings" into it, or some other method) might work? Do any of you have an idea of how to install those elements into the bridge ( I also have a skilled luthier here who could cut a new maple bridge if I had an idea for a way to install the elements).

I guess one main problem is that the Ergo bridge is short,maybe 2.5 inches at highest point.

Any thoughts?
Many thanks
Jon

ToneRanger · #12 09-08-2008, 07:08 AM

I've done quite a bit of experimenting, first with a 1-string stick 'test-bed', then on my Paulin EUB. I tried a few different types of mag & piezo pickup.
I tried a Moses mag pickup - it was noisy and had uneven string volume. I've messed with a P-Bass pickup strapped to lumps of foam, but once I found a piezo arrangement that had solid low-end response I gave up on the mag pickup idea.
By far the best result I've had is with my home-made piezos, under the bridge feet, sitting on a sliver of cork gasket. It's a solid-bady bass; with this pickup it has a huge fat sound; a little more sustain than a URB, and I need to EQ out some of the highs. Not going to make a purist acoustic player happy, but for the blues/rock/jazz I play it's a great sound.
I think that the under bridge position works best for solid-bodies where there's less flex in the wood, but can get boomy on an acoustic.
I initially had trouble with erratic volume levels with the slightest bridge movements, but I solved that with the gasket material providing a more consistent, flexible coupling. I also think the slight flex under the bridge makes the solid-body bass sound a little more acoustic.
My pickup: www.fittell.id.au/piezo

ricobasso · #13 09-09-2008, 06:01 AM

Hi Toneranger. I tried your design out on my EUB without any success. The output was very low and there was too much top and not enough bass. I tried eq but then the hiss from the preamp was too much. Maybe the problem is that my EUB top is too rigid for this type of pickup. I went back to some Ashworth piezos in the bridge wings and got a good sound.

How did you do it? Can you share your preamp design?