Need advice with making an electric violin... :)

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi Jarno,
the "electrification" of acoustic instruments (apart from guitar) is stil very much "uncharted" territory (if you compare it to guitar).
You're partially right...up to a certain level of professionalism the el.violin is a "white spot on the map",comparing with the huge guitar industry.This can be explained by the very poor interest of violinists when "electrifying" their instruments (most still prefer mikes!).Another possible reason is a nearly total lack of technical application and disponibilities regarding this cathegory of musicians (I'm one of them up to the technical stuff,where I bliss!:D ),but these are supplementary reasons not to leave things "as they are" or at some BIG companies'will.
why did you use a 12" driver? Even with a whizzer cone these go only up until about 5kHz max., at least nowhere near 25kHz.
Well,this might be a "longer-than-needed" story...to keep things short, 15 years ago I went to tube amplification both for home high-end and instrument purposes,because I couldn't take anymore that endless game of buying/reselling transistored components wich didn't fulfilled my "ears'needs".(...mind you,I'm a pro musician,not a millionaire,so I cannot afford those Mark Levinsons....).Shortly after the "tube enlightment era",I went to one-way way (horns with Lowthers),as a direct developement of the saga.
...So, you see,I'm pretty much into this kind of drivers and aside of the Lowther products I'm able to appreciate wether a given full-range driver is appropriate for a certain application or it's only an "all-round duty" driver.
The driver I choose has a fairly high magnetic field and a relatively low membrane mass,so I'm not concerned at all about it's upper freq.response.(...I quit looking at the diagrams a long time ago!...like I quit buying components by reading some "well-established" publications...)

You could try the Jordan JX-92 aluminium full range driver
In fact,I did once...excuse me,that was two times:the first and the last!:D
....and all I can say is that I don't wish to try dealing with a METALLIC membran:dead: !
Maybe a coaxial 10" driver like SEAS makes them could be the solution.
Yes,maybe a 10'' unit should solve the speed issue and I was about to reccomend that...but,again,NO tweeters (as found on a coax design) because the reasons I already exposed.I also thought about Fostex drivers!
Regards,
 
magnetic pickups only work with steel strings
This is a statement wich maybe explains the overall confusion about violin strings and their caption by means of an electro-mechanic transducer.(No offence,amroe,:D ,just keep reading the following lines!)
Does that mean that violin strings are steel?
Not necessarily...
There are a lot of brands and types of violin strings out there and maybe it's time to clarify some details regarding a violin string's construction.
There are 3 major types,depending of the core's string material:
1.The gut strings.
Having a long history background ('till the 19th century,these strings were the only kind available due to technological aspects of string making),these strings are made from cat gut.This is the same biologic material as found in old surgery when closing an open wound or incision.
Up to a certain historical moment,the cat gut strings were used "as-is",meaning that there were no wrapped with some metallic outer "shield".This partially explains the evolution of the violin AND the absolute pitch,because the raw cat gut is very sensitive to humidity and temperature,thus being a very unstable material.
At the end of 18th century,some strings makers tried to improve the string design by wrapping around the gut core a thin metallic layer.This is the very beginning of the modern string's era,as known today.
The modern production of gut strings is a highly-regarded one,because the gut strings are the best sounding products on most older instruments.
Brands producing gut strings:
-Pirastro
A wide sellection of gut-based strings as well as metal-core and composite-core strings.
The Pirastro's gut strings have a precisely-machined gut core,a silk layer tightly streched on the gut and an outer metallic protective flatwound layer.The metals involved are aluminium for A and D strings and silver for G string.
This are the most common Pirastro's features,but there are also some variations,e.g. on the most expensive sets (Pirastro Olive) the metallic wrap is silver on all three (A,D,G) strings.
The only string wich involves the use of steel is the E string because of thickness,tone and mechanical resistance reasons,but please note that there's allways a composite steel there (containing significant ammounts of nickel,magnesium and other metals),NOT the traditional steel as known from the electric guitar strings.Also,there are specific situations (the Pirastro Olive E string) when there's an additional layer of a precious metal (18-karat gold) covering the surface,for long-life stability and tone considerations.
-Kaplan
A genuine American brand wich was bought in the '80's by the D'Addario Corporation.
Kaplan products are an excellent replica of the Pirastro's,but somewhat hard to find on the market.
2.The "metal-core" strings:
These are the most common used strings nowadays,from pupils to pro's.
The design of these strings imply a steel core (round-or hexagonal-shaped),on wich is wound a thin synthetic silk and the outer metallic flatwound layer.
Again,the outer layer is most often made of nickel or aluminium,not of steel.
Brands producing metal strings:
-Pirastro:a wide variety of designs and prices,adapted to each pocket and taste
-Thomastik-Infeld:
Austrian brand wich patented the use of a six thin steel core instead of one thicker core.The advantage of this design is an increased string's flexibility regarding the "one-core" design.
-D'Addario:
American brand specialised in guitar and bass strings,but currently making a wide variety of violin strings,due to the fusion with the defunct Kaplan brand.
3.The"composite-core"strings:
Instead of using cat gut or steel as a core,these strings have plastic composites.The most common is sylon (something similar to the tennis strings),but there is a whole industry out there developing those composite plastics under different exotic names.
The use of the composite core is a "gut wannabe" thing,meaning that these strings exhibit a tone similar ot a gut string,soft and expressive,but offers a more extended stability on external factors and a better durability.
Brands producing composite-core strings:
-Pirastro: (...again!;) )
Good and reliable products
-D'Addario
-Thomastik-Infeld:
With the "Dominant" variety of strings,the Austrians keep a meritory place.Dominant strings are the preferred strings for students,average players AND electric ones.
-Corelli:
A relatively new brand,very good-sounding but slightly over-priced.
***********************************************
Please note that this is only a surface scratch of the entire story.There are also numerous other brands manufacturing violin strings,but I intentionally kept the things short because I don't intend to write a novel about this subject.Also,please note that there are some other "exotic" brands,such as "Wolfram",wich makes the entirely string production out of....wolfram! (...and please,don't you dare to ask about thir prices...).To have an idea how they sound,please give a listen to the Finnish cello quartett "Apocaliptica" (some of the members use "Wolframs").
**************************************************
Back to the basic amroe's question,when choosing the "right" string to be played on an electric violin fitted with a magnetic pickup,you have to look on both core AND outer wrap materials.
If at least one of these two elements are made of a magnetic metal (steel,nickel),than it should be OK.
My point about this issue is that I'd NEVER use a string type just because it has to be "sensed" by a magnetic pick-up.In my oppinion wich follows my experience,I never saw or heard a magnetic violin pick-up,to be at least of the same quality as the most average piezo or mike is.Unfortunately,this is another aspect of the "electric violin's childhood",because a magnetic pickup for violin was never developed as the electric guitar counterparts.
If somebody asks me,I'd choose the best string set regarding playability,tone,feeling,tonal balance and endurance,put them up and stick with the best microphone,piezo or optical ("Lightwave") transducer I can afford.
The rest can be easily set by using the most appropriate electronics (preamp,processors,etc) wich suits my taste.
Hope you got something helpful!
Regards,
Le Basseur
 
Le Basseur said:
<snipped out lots of good info>Back to the basic amroe's question,when choosing the "right" string to be played on an electric violin fitted with a magnetic pickup,you have to look on both core AND outer wrap materials. If at least one of these two elements are made of a magnetic metal (steel,nickel),than it should be OK.
Regards,
Le Basseur

Thank you for the unquoted but excellent introduction to violin strings (I'm new to the subject).

But I'm unconvinced that my original post was incorrect - I agree that if either the core or the wrap are suitably magnetic, then a magnetic pickup should work, and didn't suggest otherwise.

On the subject of suitable magnetic materials we do differ - while Nickel (and for that matter higher grades of stainless steel) certainly are magnetic, IME they are nowhere near magnetic enough to be of practical use with a magnetic pickup - for that you need either plain steel, or a very low grade stainless steel.

Finally, my only real intention was to imply that magnetic pickups on violins are not a good idea; apart from string compatibility issues, the technology would be trivial to develop, but the extra mass on the body at a critical point and the "comb filter" frequency response would seem to detract from the idea.
 
......and the "comb filter" frequency response would seem to detract from the idea.

I still wonder why piezo pickups are not more common on electric guitars and basses for this exact reason. Why you see them once in a while on amplified acoustic instruments they are very rarely used on solid-body instruments.
I have a CD by Victor Wooten where he uses a bass with piezo-pickups on some tracks. The result: crystal clear sound !!!

Sorry for being off-topic.

Regards

Charles
 
Hi amroe,
I appologise if you eventually took my words as a direct attack to you,it wasn't intended in NO WAY to be something like that!:)
I just felt there are some unanswered questions hanging on the air and tried to communicate some info's/attitudes/approaches from a pro musician point of view rather than of a techie's...:D
(...and,besides,please note that English isn't my native language,therefore it might be some misunderstanding from my side...:smash: ).
I'm glad we agree on the main subject,this is the unsuitabillity of using magnetic pickups on violins,for the reasons you just mentioned!
For phase_accurate:
I'm also playing electric bass,so I might give some details about this by comparison.
The use of piezo transducers on guitars and basses,both solid-body and hollow-body is an entirely different story.
Please note that on a violin you might place the piezo either on the body,or on the wooden bridge,or on the final piece (the triangular one anchoring the strings),and is pick up a very robust ammount of vibrations.
On most guitars and basses,the piezo element is found ONLY at the bridge,under each string's node (...it's really weird why actually all brands stuck with that),thus picking up a totally different sound structure.
I agree about Wooten's clear sound when using piezo caption,but I know there are some other factors implied in his sound:very bright-sounding strings,his specific technique of playing,the electronics he uses,etc.I'd rather say that what you hear on Wooten's stuff is a mixture of top-class instruments (Fodera) using top-class active PU's wich are BLENDED with a certain ammount of piezo caption.
When I bought my 6-string bass 3 years ago I tested/played every bass I could find on the market,and I finally choosed an instrument having the best wood my money could buy fitted with two Alnico 5 magnetic pickups,but NO PIEZO.Of course,it's a matter of taste,but speaking of "accuracy" and "crystal clarity",I guarantee you that my non-piezo bass isn't muddy at all!
Cheers,
 
I am playing the bass guitar too, and neither are my basses muddy. Though they are not that fashionable anymore nowadays (a Kramer DMZ 6000B in it's original state and an Aria Pro II fretless with added preamp and exchanged pickups) and they don't belong to the "Rolls Royce section" either.

My main concern is just that the place where you put your magnetic pickups is always a compromise. Depending on what note you play, they will always be positioned (more or less) under a node for one or more overtones. You said that the piezo under the bridge is also in a node for ALL notes (and all their overtones). That is true of course. While the magnetic pickup's output voltage is proportional to the string's velocity, the piezo pickup's output voltage is proportional to force so placing it under a node shouldn't be a problem.


Regards

Charles
 
Hi Till,
...Marleaux,huh?
.....mmmm,goodie-goodie.....;)
I had the honour to listen Mr.Weber's live recital and workshop last summer in a jazz festival and I was for a few minutes at a close distance from his bass.Unfortunately,I'm not able to tell you what kind of transducer he uses (I didn't ask him such details,because there was a crowd there and everybody was talking music,not techie stuff),but judging by what I heard during sound probe and workshop/recital,it's surely a piezo thing.
...though,a weird-sounding one,without any trace of the harshness and brittle usually associated with such kind of transducers.

For Charles:
I had for a long time the same dilemma trying to figure out what is "the best sweet spot" for a PU's placement.Actually,my interest was concentrated in this issue for the virtual placement of my Roland V-Bass PU,because I was very curious about a certain instrument's "sweet spot" (Fodera AJ Signature model).
I launched this questions in various bass forums,but no one was able to give an exact answer....obviously,who owns such an instrument plays it day and night and doesn't have time to post on the Net!:D
However,I found some other link containing some valuable informations:
http://www.till.com/articles/PickupResponse/index.html
Hope you'll find something interesting here!
Regards,
 
I build instruments together with Gerald in the same workshop before he really started his own business. Thats ... years ago. I made some bass guitars and guitars that time, if i will find some time i will post pictures. I never managed to do this work for a business, to much other things happened inbetween and also i´m involved in woodworking still i make other things now. i don´t know if the harshness is really from the piezo - and i´m not so sure if the transducer itself is the main part responsible for sound quality. In the instruments we have low power circuits for preamplification, and my impression always was these circuits have shortcomings alone from the fact they are made from low power opamps. How good they are adapted to piezos ... Another thing with influence on the sound is the connection between piezo and wood, and the place. A few mm may change a lot - a lot of coincidence involved here.

I never really seriosly did play these instruments, and also i would still be very interested in building and experimenting this does not happen because i´m not into the musician scenen.

For the sweet spot of pick up placement i don´t think it exists. The sound is different, more full to the middle and bright and more overtone to the end of the string. But this does not mean one place is really the best. I think mostly they are placed were is enough space and it looks good - and a lot of myth is spread around for marketing reasons. You may find a place that is really not good, but this happens incidently same as acoustiv instruments may have a fundamental resonance by accident. An old instrument builder i knew had this, he build string instruments and one of a series of identical had a bad resonance ("Wolf"), so he descided not to sell the instrument but hide it away on his attic...
 
i went over to the workshop - build a piezo monocord. Piezo is from an old cheap piezo tweeter . At the scope i can make something that looks pretty like a sine. With the scope 10MOhm in get up to +-5Vpeak! i don´t know what input impedance opamps they use for the preamp inside the instruments, but high impedance with 9V block batterie may be a reason for bad sound.
 

Attachments

  • moncocord.jpg
    moncocord.jpg
    38.8 KB · Views: 122
Hi Till,
Thank you for sharing your experiment and it's results.
I had the same impression regarding the true reasons of a piezo's harshness.I remember the first generations of Ovation guitars fitted with piezo transducers (...apart from the initial spectacularity,on a second listen,they showed THAT caracter),and things being somewhat improved on the later versions.
Do you have an idea on how to build a "harsh-free" on-board piezo preamp for our beloved instruments?
...Maybe a hint?...Anything?
Thanks,
 
I think for a better in - instrument preamp the problem is we would need more voltage. Batterie power and low power design may be not the best way. An external powersupply providing real voltage and the opportunity to build something with discrets or opamps at +-18V and some more bias would be my way. I also wonder why mostly dynamik PUs and sometimes piezos are used, but i don´t know any case of build into instrument micophone capsule. I woudl really like to experiment with these, but i would need an instrumentalist for the testing and valuation.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.