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View Full Version : Amplification, pickups, etc



arktrav
05-30-2013, 11:38 AM
I own a couple of amps, have two ukulele's with passsive pickups, guitars , etc. The thing is, (confession) I really don't know anything about amplifiers, pickups, : i.e how they work, how to use them, which one for what and so on. Where is a good place to learn? How is the best way to use an amp with a uke (for instance) with a passive pickup? What do the differing amp controls do and how do you use them? If all this makes me sound ignorant, it is because, in this area, I am! How do I learn? books, etc, websites? Thanks and blessings to all, arktrav

Jon Moody
05-31-2013, 01:14 AM
If all this makes me sound ignorant, it is because, in this area, I am! How do I learn? books, etc, websites? Thanks and blessings to all, arktrav

I would say the best place to learn is to try everything out; you have the amps and pickups already.

In terms of amps, what I do with a new amp is to have the EQ flat (for most amps, it's usually with all of the knobs pointing up, or at 12 o'clock, although there are exceptions) and then play something on your uke. This is your "control" sound, and is what the amp sounds like naturally.

Then, pick a knob (I usually go left-right) and move it completely counter-clockwise and play that same "something" again. Try to notice what frequencies are being cut and how that's affecting your sound. From there, turn the same knob all the way clockwise and note your tonal changes again by it being boosted. Repeat this with all of the knobs on the amp, and hopefully you'll figure out not only what an amp can do with the uke, but more specifically what YOUR amp can do.

arktrav
05-31-2013, 01:47 AM
Thank you "one bad monkey" I appreciate your response and will do as you suggest. I was hoping to have a source of learning (something to read or look at, etc) but may be the "trial and error way" is best. Blessings, arktrav

Tootler
05-31-2013, 02:51 AM
Thank you "one bad monkey" I appreciate your response and will do as you suggest. I was hoping to have a source of learning (something to read or look at, etc) but may be the "trial and error way" is best. Blessings, arktrav

Trial & error is sometimes the best way to go. With amps & effects, what sounds best is often very personal.

Tele295
05-31-2013, 04:32 AM
Amplifiers are strange little beasts. They vary so much from brand to brand and even model to model. Find the owner's manual for your amp, which should give you ore information on how the various controls interact. Unless you're using a pickup and amplifier by the same manufacturer (eg, LR Baggs), you won't necessarily find a lot of instruction on "this pickup goes with this amp" etc. Is your amp designed for acoustic string instruments, electric guitars, or is it an all-purpose sort of amp?

Passive pickups on acoustic instruments are also complicated matters, due to the impedance issues and other engineer gobbledygook (I am NOT an engineer, and don't pretend to understand most of that stuff, like resonant frequency response, etc). Acoustic instruments are less "plug and play" than electric guitars, because of the difference in the pickups. E-guitars use magnetic pickups which only work with metal strings. Ukes have nylon strings, so they must use other kind of pickups. There are a few different types that work off different principles, and some are more "amp friendly" than others. Some types of passive pickups need a buffer or preamp between the amp and uke to sound their best. Again, the manufacturer ay have the best information to use as a starting point.

Sorry we can't be more help. There are just too many variables, and you have hunt his information down from a lot of different sources until you find out what works for you.

Johnny GDS
05-31-2013, 04:46 AM
The passive pickups in your ukuleles "hear" the sound of the strings through the bridge saddle. There is a small filament that sits under the saddle and listens to the vibrations. This signal is sent as a very low voltage signal to the output jack of your uke. If you play the "A" string, it vibrates 440 time per second, and the voltage frequency that the pickup creates is also 440 vibrations per second. This is sent out to whatever amplifier you use where the voltage is increased, shaped, and sculpted to taste and ultimately output to a speaker, which then vibrates at 440 times per second and we hear the note "A".

With a passive pickup (that usually has no onboard "tone shaping" tools such as Mid, Treble, Bass, or presence) you must rely on your amp to shape the sound to taste. An electric guitar amp is not at all the ideal tool for this. It is designed to work with a very different signal coming in the front end and will be limited in how good it can sound.

Something with a "full range" speaker (such as a PA speaker, or an acoustic amp, or even a bass or keyboard amp) will do a much better job of this. The other option is to use some sort of D.I. (direct injection) box between the uke and the amp input. An example of this would be and L.R. Baggs Para acoustic D.I. or L.R. Baggs Venue D.I., or the BBE Acoustimax pre amp pedal. This gives you tons of appropriate tone shaping tools.

Some pickups will sound better straight into a guitar amp than others, it depends on the impedance and frequency response of the pickup itself, as well as on the amp.

The best thing to do is just get in there and try it. The EQ (bass, treble, mid, presence) knobs will have the most effect, and you may have to turn the volume up much higher than you are used to when plugging a guitar into the amp.

Hope this helps a little!

PhilUSAFRet
05-31-2013, 05:59 AM
If your amp doesn't have a pre-amp/eq system, may need to get an external one such as the Baggs Parametric eq. Passive pickups often do not mate up well with an amp that doesn't have such a system built into it. I set my amp flat, fine tune my sound with the active pre-amp/eq, then dial in the amp features I want. Any way you look at it, there's going to be a lot of trial and error until you figure out how to dial in the settings you want to use repeatedly.

siesta171
06-01-2013, 02:21 AM
Thanks so much for this thread. It answers a lot of my questions and will having me amping up soon. Keep the advice and suggestions coming!

gyosh
06-01-2013, 04:10 AM
The passive pickups in your ukuleles "hear" the sound of the strings through the bridge saddle. There is a small filament that sits under the saddle and listens to the vibrations. This signal is sent as a very low voltage signal to the output jack of your uke. If you play the "A" string, it vibrates 440 time per second, and the voltage frequency that the pickup creates is also 440 vibrations per second. This is sent out to whatever amplifier you use where the voltage is increased, shaped, and sculpted to taste and ultimately output to a speaker, which then vibrates at 440 times per second and we hear the note "A".

With a passive pickup (that usually has no onboard "tone shaping" tools such as Mid, Treble, Bass, or presence) you must rely on your amp to shape the sound to taste. An electric guitar amp is not at all the ideal tool for this. It is designed to work with a very different signal coming in the front end and will be limited in how good it can sound.

Something with a "full range" speaker (such as a PA speaker, or an acoustic amp, or even a bass or keyboard amp) will do a much better job of this. The other option is to use some sort of D.I. (direct injection) box between the uke and the amp input. An example of this would be and L.R. Baggs Para acoustic D.I. or L.R. Baggs Venue D.I., or the BBE Acoustimax pre amp pedal. This gives you tons of appropriate tone shaping tools.

Some pickups will sound better straight into a guitar amp than others, it depends on the impedance and frequency response of the pickup itself, as well as on the amp.

The best thing to do is just get in there and try it. The EQ (bass, treble, mid, presence) knobs will have the most effect, and you may have to turn the volume up much higher than you are used to when plugging a guitar into the amp.

Hope this helps a little!

Thank you Johnny GDS, you just explained all of that in a way that was very easy to follow and understand.

And thank you Arktrav for putting this question out there.

My new uke has a (what I now know is a passive) pick up, and I'm just starting my search for an acoustic amp. I knew I needed an "acoustic" amp, but now I also know why.

Great explanation.

PereBourik
06-01-2013, 05:35 AM
If you find you do need to shape the signal between the ukulele and the amp, an affordable choice is a Behringer ADI21. This tames the quack of the Kremona UK-1 pickup I use and lets me make the amp sound pretty much like the ukulele. I'm not looking for performance quality. I just need to hang with the guitars and drums at camp. Then I'll put it all away and have to learn it all over again next year.

Trial and error, and how it sounds to your ear are the best ways to get the system working. Hanging out with someone who has been doing it awhile helps.

arktrav
06-01-2013, 08:16 AM
Thank you, all, for very helpful and thoughtful replies to my "expressed ingnorance". I appreciate it very much. I have read your posts carefuly, read as much as I could find on the "net" and now feel more confident in learning to use some of the tools I have. After all ths, I have determeind to purchase a DI preamp and then just play and try or maybe I should say "try to play". Blessings, arktrav

ricdoug
06-01-2013, 02:44 PM
With passive piezoelectric pickups, you get a sound known as "piezo bark". An active D.I. box helps to tame that for a variety of amplifiers:

http://www.ukuleleunderground.com/forum/showthread.php?74603-Behringer-ADI21-active-DI-preamp

A P.A. system will give a more accurate sound than a guitar amp. Here's a nice P.A. system that won't break your piggy bank, the Kustom PA50:

http://www.ukuleleunderground.com/forum/showthread.php?71210-Amp-in-a-band/page2

jackwhale
06-02-2013, 06:40 AM
My amps have knobs for both volume and gain. I've never quite figured out the relationship between the two.

ricdoug
06-02-2013, 08:28 AM
Volume adjusts the headroom, or output level of the amp, jackwhale - basically it's how loud you are allowing the amp to get.

Gain adjusts the input level from the instrument - generally the more you increase the gain, the more you increase the distortion. Gain can also increase the amp's volume.

jackwhale
06-02-2013, 08:48 AM
Thanks Ric: I'll play around with those knobs. There are times when I have a little more distortion and it makes the sound a little fuller/fatter. Maybe I can find that sound more consistently.