Cello pickup, have anyone done it?

[Peter Naglitsch]

I am building an electric cello for the daughter of one of my friend. She is extremely talented and I'm going to give her the cello on her 18th birthday. I am planing on using an "acoustic" pickup integrated in the bridge to produce something similar to a natural cello sound. In conjunction with that I would (of cause) like to wind a magnetic pickup. I remember the single loop low impedance pickup someone showed here some time ago (bbsailor???) but I wounder if anyone have any experience with a more traditional pickup for a bowed instrument, hopefully a cello. I have started to play around, checking out placement etc, but the problem with a traditional pickup design for cello is the greater distance from fingerboard to strings at the end of the fretboard (in the 1/2" range) with makes a traditional pickup very week when the strings are played near the head and producing much higher output when the strings are played closer to the end of the fingerboard. The cello is also going to be played mainly with a bow, which means that standard placement for a single coil type pickup right under the strings is out of the question. I have made a test coil with three magnets just to be able to play around but I don't consider the experiments very succesful... I an a bit out of ideas right now so I would really like to know if anyone would like to lend a helping hand.

This is as you might understand a pro bona job for a very talented young musician.

[Possum]

...

Will it have steel strings? A magnetic pickup won't work unless it does. I think those types of instruments usually have a pickup under the bridge, a piezo type. You should look into pickups for acoustic upright bass probably for starters....

[Dave Kerr]

Maybe try a blade humbucker with neo magnets? David S uses some pretty powerful ones on his bass pickups, they might give you enough oomph. That and a simple preamp might be all you need.

[FunkyKikuchiyo]

I'll second the blade/neo-d idea. Probably the easiest way to go if you're starting from scratch, and something with a full range will sound best. Bad cellos tend to drone in the midrange, and that is just where traditional electric guitar pickups are voiced. Being far away isn't a bad idea either, isn't the string displacement on a cello pretty dramatic?

Placing the pickup closer to the bridge would greatly help with the unwanted dynamics with fingerboard position. Also, that effect is alive and well in electric guitars and is perhaps responsible for weedly-weedly-wee leads as we know them. If the volume didn't nicely increase as you move up the neck (and acoustic volume decreases) we wouldn't those effects, and that sweet child o'mine may never have been born. So, eliminating this "problem" might negate the electric-ness of your cello project.

[Peter Naglitsch]

Will it have steel strings? A magnetic pickup won't work unless it does. I think those types of instruments usually have a pickup under the bridge, a piezo type. You should look into pickups for acoustic upright bass probably for starters....

Jup, steel strings. I have played around with a magnetic pickup, but I’m not satisfied with the result…yet. And the cello will have a bridge with built in piezos. But I would like to also try a magnetic pickup to see if I can get something useful out of it

Maybe try a blade humbucker with neo magnets? David S uses some pretty powerful ones on his bass pickups, they might give you enough oomph. That and a simple preamp might be all you need.

I’ll try and play around with a blade to see what happens. The thing is that a traditional "Fenderish" pickup placed directly under the string sounds OK when the string is plucked (Ok, ok, I know that it is called pizzicato...) bit when the string is bowed it moves more or less only in a plane perpendicular to the magnet and thus doesn't induce much current in the coil. Placing the pickup pole between the strings work for bowing, but the result for plucked stings is not so good. Now with a blade and radically curved blade and a coil that will be significantly further awy from the two middle strings compared to the outer once I might get problems with string to string balance. But still worth to explore.

Bad cellos tend to drone in the midrange, and that is just where traditional electric guitar pickups are voiced. Being far away isn't a bad idea either, isn't the string displacement on a cello pretty dramatic?

Hey! Who said that it will be a bad cello? I will build it…well that might explain the “bad” part…

isn't the string displacement on a cello pretty dramatic?

Yeah quite so.

Placing the pickup closer to the bridge would greatly help with the unwanted dynamics with fingerboard position. Also, that effect is alive and well in electric guitars and is perhaps responsible for weedly-weedly-wee leads as we know them. If the volume didn't nicely increase as you move up the neck (and acoustic volume decreases) we wouldn't those effects, and that sweet child o'mine may never have been born. So, eliminating this "problem" might negate the electric-ness of your cello project.

Hmm, I will have to think about that. You might be right. Thanks for your replies.

[Sock Puppet]

Hi,

You might find further ideas on here:

Electronic Hardware

Good luck.

[David King]

Lace used to make bass pickups for upright that used a single turn of thick copper wire around 4 neodymium disks. You could bend the pickup to match the fingerboard radius. Bartolini's upright bass pickup was also magnetic, 4 single string pickups that had vertical tabs that let you bolt it right to the front of the bridge.

I'd probably go with a staggered alnico magnets and a high impedance coil.

[Sam Lee Guy]

Big problem for electric cello - feedback. Many good solution for magnetic pickup. Piece of iron inside, attached through bass bar with pickup below attached to support between end blocks. Coil attached to inside front with magnet attached to inside back. Many ideas but feedback always problem.

[FunkyKikuchiyo]

Sorry, nothing personal in the "bad cello" remark! I just know that something about the size and shape tends towards a sort of honk, and good cellos (especially with some age to them) have more highs and lows. I think it has as much to do with its range on the staff as anything else - above bass clef and below treble clef if I remember right. Acoustic guitars do the same thing, think of that honk sound you get when you stand in line for a loud feedback loop. I honestly wouldn't know what to guess whether it'll be exaggerated or reduced by making a solid body design. Any guesses?

[Peter Naglitsch]

Hi,
You might find further ideas on here:
Electronic Hardware
Good luck.

From that site:

A pickup placed under the string as the bow moves horizontally above it will pick up only a very weak signal due to the direction of vibration. If the pickup is oriented so that it points at the string from the side, the signal will be strong.

Hmmm, single magnet pickup, placed in double rows with two mags pointing towards each string in a X, or upside down V-pattern…Might work. And it can be wired to be hum cancelling too. Thanks for the link.
[quote=David King;136951]Lace used to make bass pickups for upright that used a single turn of thick copper wire around 4 neodymium disks. You could bend the pickup to match the fingerboard radius.
Something like what was discussed here:
http://music-electronics-forum.com/t5447/#post43064
http://music-electronics-forum.com/t5578/#post44107
and with a good picture (can’t find original thread for that pic…)
http://music-electronics-forum.com/t10638/#post83642
That is for sure an alternative.

Bartolini's upright bass pickup was also magnetic, 4 single string pickups that had vertical tabs that let you bolt it right to the front of the bridge.

I will check out the Bartolini pickup. Mounting it to the bridge will solve some problems with the great displacement/deflection (can’t find the right word right now…) of the strings when playing high up on the finger board. Thanks for the suggestion.

Big problem for electric cello - feedback. Many good solution for magnetic pickup. Piece of iron inside, attached through bass bar with pickup below attached to support between end blocks. Coil attached to inside front with magnet attached to inside back. Many ideas but feedback always problem.

Interesting idea and surely no problem if taking account to this while building the cello. Wouldn’t want to add that pickup system to a already finished instrument. I realized that I failed to mentioned that this will be a solid body instrument so, alas, this is not going to work

Sorry, nothing personal in the "bad cello" remark! I just know that something about the size and shape tends towards a sort of honk, and good cellos (especially with some age to them) have more highs and lows.

I know that you didn’t intend any personal insult with the “bad cello“ comment. Just my silly humor.
As it will be a solid instrument (as menitioned before in this post) the “honk” will probably not be a problem. It will have a piezo equipped bridge but I would like to add a magnetic pickup to complement the sound of the piezos as my experience from solid body guitars equipped with piezos and magnetic pickups shows that the combination makes up for some of the warmth that usually lacks if only piezos being used.

[David King]

What about a Lightwave optical pickup? Those are actually very simple and don't require a steel string either. They mount very close to the bridge but have a fantastic fundamental and blend very well with a saddle piezo since they are close to being in correct phase alignment.

I don't know if Bartolini still makes the upright pickups. The last set I got was back in the 1990s. I think Bill did try to implement two magnets set in a 60º V angle but they are still single coils so I don't know how that would have worked. Mounting them to the bridge gives a very thin, whiney tone. You want them at least a couple of inches in front of the bridge I think. They worked just fine at the end of the fingerboard but the signal is a bit weak because they need to be so far from the strings to stay out of the way.

[Peter Naglitsch]

I have been experimenting a lot with two coils per string in a 60 deg V configuration and everything you say is 100% right David. Close to the bridge works just fine but with a too wining sound. Close to the end of the board and they get too far away from the strings to produce a good output. The thing is that a single one-magnet coil in a placement perpendicular to the top of the instrument can be used on the top and bottom strings as the bow is actually mowing the string a bit up and down and thus producing enough vibrations in an angle to the magnet but for the middle two strings the movement of the string is more or less perpendicular to the magnetic field and the signal gets week and very thin. I have drawn up a pattern of 8 small coils to be able to do the 60 degree assembling but everything gets in the way of anything and I cannot see that I will be able to fit it in a nice way. I think I'll just have to ditch the magnetic pickup all together and go for the bridge mounted piezo. Still have to try a blade thou.

Regarding the lightwave pickups they looks interesting. I'll have to check them out a bit more to see if they can be fitted on a cello bridge. Thanks for the tip David

[Peter Naglitsch]

It seems like the lightwave pickups arn't availible "over the counter". There is a "Luthiers Kit" but I can't find any info and I can't really judge if it is possible to use with a cello bridge.

[David King]

Peter,
You'll want to get some of the first generation lightwave monoliths which were designed to bolt onto an existing metal bass bridge (electric bass guitar). I have a set of these in a box. I think you need a minimum 15 mm space between strings. I have used a few of the Luthier's kits back when these first hit the market. They weren't cheap, about $400 ea. You could buy a whole LW bass guitar for $600 new for a while...

There was a French company doing a lightwave-type pickup for a while. It never was a terribly well accepted idea so I wouldn't be surprised if they dried up shortly afterwards.

I can tell you how they work. You have an IR source on one side and two tiny PV cells on the other that are out of phase. If you get the string centered in the gap you will have no DC offset at rest. As the string moves the two PV's generate an AC sin wave that gives you a pretty good 1 dimensional image of the string movement. You can run that signal straight to an amp.

[Peter Naglitsch]

You have an IR source on one side and two tiny PV cells on the other that are out of phase. If you get the string centered in the gap you will have no DC offset at rest. As the string moves the two PV's generate an AC sin wave that gives you a pretty good 1 dimensional image of the string movement. You can run that signal straight to an amp.

I'll try to whrap my mind around this and try to understand how this all works, and most important, how to place the PV's Do you mean that, locking at the assembly from above, with the instrument on its back, neck away from you, that the infra red source is placed on one side of the string near the bridge and the two Photo Volt cells are place on the other side of the string? Above each other? or along the string? I ask all those questionas as it seems like a system that I easily could make up myself if i could get the placement right. And the components are like a few bucks instead of 400$