Mike's Oud Forums

pre amps

oudplayer - 8-3-2006 at 05:22 PM

hey all

can someone tell me what exacly does a pre amp do
bc i am planing on getting a K&K twin spot which i hear dwas great for ouds and i wanna know if i need a pre amp
thx sammy
and you you think i should get a K&K pre amp or whast good for it

Jason - 8-3-2006 at 07:21 PM

A preamp accepts a line level signal and can boost the signal or shape the tone. Most amps have a preamp and poweramp section. The tone shaping is taken care of in the preamp and the actual amplification is taken care of by the poweramp. If you're going to be playing through an amp with an EQ and stuff I don't see why you'd want an onboard preamp unless you just want the option to change things whilst playing.

I don't have experience with those pickups though so I could be wrong.

jshead - 8-3-2006 at 08:43 PM

You probably do need a pre-amp for the K&K twin spots. I bought a nice Fishman pre-amp for my pickups. As Jason says the pre-amp boosts the signal coming from the pickup. Generally, pick out put is very low. You can keep the little pickup pre-amp close by for each volume adjustment. Not all preamps have tone controls.

preamps

Monty88 - 8-3-2006 at 09:02 PM

Jshead is right,

Preamps boost the signal of piezo contact pickups which are generally quite low in output. I have been told however that the K&K pickups do not require a preamp to the extent of cheaper pickups, the twinspot apparently has a lot of volume.

I recently bought a L.R Baggs Para Acoustic D.I. It is awesome, great for absolutely any acoustic pickup.

I will post a comparison soon, I use on my Turkish oud a Barcus Berry transducer, which sounds fantastic, but when you combine it with the Para acoustic DI the results are phenomenal. The volume is loud enough anyway, but the sound is so much more shapable. It sounds very natural and clean.

I've used this preamp with my oud, cumbus, sazes (they now come in Turkey with undersaddle pickups, and some with onboard fishmans ;). It works fantastically for contact piezo pickups and bridge pickups. It works with magnetic pickups as well on greek bouzoukis and cretan laouto, these don't sound natural but you can adjust the tone which is so classic to the live greek sound.:xtreme:
As well as mandolins and good old guitar, I really reccomend
The L.R. Baggs Para Acoustic DI.

Soon i will post a comparison of my oud plugged straight into the computer with no preamp, then a soundfile of the pickup through the preamp.

oudplayer - 11-29-2006 at 07:31 PM

hey all
how sticky are these twin spot if i install them under the face will they get undone and fall off or do i need to put electrip tape to hold it down
thx sammy

Dr. Oud - 1-10-2007 at 11:29 AM

Quote:
Originally posted by oudplayer
hey all
how sticky are these twin spot if i install them under the face will they get undone and fall off or do i need to put electrip tape to hold it down
thx sammy
The internal mounting should be done with a drop of epoxy.

billinpitt - 1-10-2007 at 12:14 PM

I have good things to say about L.R baggs para di with any stringed instrument. I have the K and K twin on my oud and it sounds really nice. My only complaint is the jack is very microphonic and you have to be careful not to move too much.
Sansamp makes a nice DI type preamp as well which works great with acoustic guitar. I have not tried it with the oud yet. It seems to shape the sound a bit more than the Baggs, but in a pleasing way.

stringmanca - 3-25-2011 at 11:43 AM

I just came across this preamp in the new Sweetwater catalog and thought it looked promising, especially for multi-instrumentalists:

Radial Tonebone PZ-Pre
http://www.tonebone.com/tb-pzpre.htm

Anyone have any experience with these?

Sazi - 3-26-2011 at 04:19 AM

Hi Sammy, I've used the k&k twin spot on many ouds and sazes, they really don'y need a pre-amp but if you want more control over your sound a pre-amp is the way to go.
I have heard from others and now I have one I agree, that the k&k pre's are not that good.
The pre's listed in the above posts are probably the better ones, personally I prefer mic's but if I have to use a pick-up I use a Fishman Pre EQ II , as I have a tight budget, but it does everything I need, and sounds great.
Quote: Originally posted by Dr. Oud  
The internal mounting should be done with a drop of epoxy.


Yes, but try them with the sticky tape first, as it can make a huge difference in sound depending where you put the transducers, and you will probably move one or both a few times before you find the sweet spots, then once you are happy mark the positions and glue them, I believe k&k recommend using superglue.

Jaffa Road - 3-28-2011 at 12:19 PM

in my experience you need some kind of preamp for shaping the tone. for example, you might set the eq to something that sounds great in your living room, but then when you get to the gig, and you are in a bigger room, with your ensemble, what sounded great at home, now has way to much bass, or mid, or whatever, so you need to be able to adjust.

You also get different "eq" from where you stick the pick up and this can make a huge difference to output tone.

All of the preamps mentioned so far by other posters are standard professional grade pre amps for acoustic instruments.

That radial tone bone that you mention looks great - I have not tried it but that unit was reccomended to me, and generally their stuff is very well designed, built and high end.

Fishman Aurapro is worth considering also.

fernandraynaud - 3-29-2011 at 05:58 AM

There are three things a preamp does with a piezo pickup.
1- boost the signal. Sometimes needed, often not.
2- provide tone/eq controls near the player's reach. Handy.
3- match impedance. This is seldom understood. Impedance is resistance, but where resistance is constant, impedance changes with frequency. But for practical purposes, it's resistance.

A pickup will sound very different depending on the electrical "load" it is connected to. A low resistance, low impedance load decreases the signal, it's too much current demanded for the weak generator that the pickup acts like. A very high impedance allows the pickup to "open up", as the load is practically invisible. Open air has almost infinite impedance, but to convey the signal, SOME load is needed, SOME current has to flow.

Most mixers and sound cards have line input impedance around 50,000 ohms. That's fine for connecting a tape recorder or CD player, that have low impedance outputs, that can drive stiffer loads. But guitar amps generally have input impedance around 10,000,000 ohms, which is like a feather. That's why an electric guitar connected to a guitar amp sounds so different from a guitar connected to your home stereo. Same with an oud with piezos, piezos sound different with a lighter load. K&K duals can work OK directly connected to a mixer, but sound different on a high impedance input.

A preamp is a very simple circuit. A direct box, or DI, is a pre-amp with no tone controls, sometimes not even volume controls and no boost, just a high impedance input used to plug guitars into a mixer. ART makes AC powered DI preamps with tubes and compression ability that give a fat sound at under $50, though it takes some trial and error, switching tubes etc, even this works, at $29:

http://pro-audio.musiciansfriend.com/product/ART-Tube-MP-Studio-Mic...

More tone controls add parts cost. You can find unpackaged battery powered preamps as little circuit boards on eBay for $20. Even ones with many bands of tone control, in enclosures designed for mounting in or on guitars, for under $50. You can adapt them to an oud, make your own box.

A circuit may be more or less flattering to a specific pickup. A phase reversal switch is very important in combatting feedback. But you can get this very inexpensively. Beyond that, the nicer the packaging, the more famous the name, the higher the price. People who can afford $700 preamps I am sure will like them, but the position of the piezos on the oud will have more effect on the sound.

Jaffa Road - 3-29-2011 at 10:28 AM

"People who can afford $700 preamps I am sure will like them, but the position of the piezos on the oud will have more effect on the sound. "

great point fernandraynaud

just like when recording, proper microphone placement of a $200 mic will always yield way better results than a poorly positioned $5 000 mic