pre-amp for electro'/accoustic

[billkilpatrick]

just put "pre-amp" in "search" and brought up a lot of technical information and brand names which i don't understand and probably aren't available anyway, here in europe.

in words of one syllable, written for someone who 'll have difficulty understanding what you say no matter how you say it, may i ask what a pre-amp does and is it advisable to get one for my crafter m-70, hollow bodied, electo'/accoustic?

many thanks - bill

[PCypert]

They always help. The better the preamp the better you'll sound. Don't bother with a cheap one as it won't add too much to the overall sound. They can warm the sound or make it more round. If you get a good one it'll really help. Best of luck finding the one right for you and your needs. LR Baggs has some good ones.
Paul

[Ted Eschliman]

Bill, I'm fond of the Presonus Tube Pre (http://jazzmando.com/new/archives/000103.shtml). Tube-based technology preamps tend to "warm" or round the sound in addition to giving that extra boost in sound and control.
I think these street price under $100.



http://jazzmando.com/new/archives/tubepre.jpg

[wichitamando]

Bill, I have been running my Kentucky through and LR Baggs GigPro preamp. It has worked well for me.

As luck would have it, I was going to be putting it up for sell soon. I just bought a Fender Acoustasonic amp which I am running the mando straight into. It is less than a year old. It was about $100 new. I figure $70 would be a reasonable price for it. If you are interested, let me know.

Ronnie
red79vette@sbcglobal.net

[steve V. johnson]

An instrument preamp allows you to power the signal from the instrument's pickup so that you don't have to rely on the preamp in the PA system. The signal out of the preamp is called "line level" (usually) and the wire from the preamp goes to the mixing board (here's the good part) bypassing the preamp in the mixing board. Many preamps use a 1/4" connector to hook up to your instrument and then they have both 1/4" and XLR (the three-pronged connector that's used on microphones and microphone cables) for outputs. The 1/4" output can go to an amplifier onstage so that you can hear your own signal, and the XLR goes out to the house PA (or to recording gear).

Some preamps have EQ (short for equalization, which means 'tone controls' usually high, mid, and low) and those allow you to change the sound so that what goes down the wire out of the preamp is just the way you want it. If you use a PA that is run by a band member, you can say 'Don't use any EQ over there, I have it all here' and maybe they won't. <G>

In addition to EQs, many preamps have 1/4" outputs to go to a tuner, and some have mute switches so that you can silence the outgoing signal for when you tune the instrument(s) or unplug them. Some of them have "phantom power" to power condensor microphones (some folks put microphones in their instruments, in addition to, or instead of pickups), and have special inputs just for microphones.

Some preamps have tubes in them for "warmth", and some have several volume controls, so that you can add some distortion to the sound by overdriving the thing. Most tubes don't really do much because the voltages fed to them aren't really very high. while the tubes in serious studio gear are fed very high plate voltages, and this causes the tubes to change the sound of the harmonic structure of the signal going thru them. Sound engineers call the low-voltage tubes 'marketing tubes' or 'light bulbs'.

I don't know much about preamps that are made to specifically use with instrument amplifiers, but some are made to do that.

I have used a Raven Labs PMB-II, and I like it a lot. I use it because I have two instruments that use pickups, and the preamp has two inputs and one XLR output. I don't play both instruments at once, but it's nice to have them go into one box. It has a tuner output and a mute switch, and can be used with pickups or with pickup & microphone. It has EQ (three-band, high, mid and low) also.

I have recently gotten one called a Presonus Acousti-Q, and it is very similar to the Raven Labs (Raven went out of business, so I got this one as a backup unit), but I haven't really tried it out yet. I expect that it will work much the same as the other one.

My preamps are really backup systems themselves, because 99% of the time I use a single microphone on stage. If a PA engineer is not confident of how the mic will work in his room, I can plug in and make him feel better. When we use our own PA, we (an all-acoustic Irish trad trio) all use mics.

I hope this helps,

stv

[billkilpatrick]

thanks guys. my lips moved as i read what you wrote but i think i've got it.

the best thing is to take my mandolin along with me the next time i go up to siena and check out what's available. the brands you've mentioned may not be represented here in italy and ordering anything from the states - new or used - can sometimes result in a substantial underpinning of the italian national economy with who-knows-what in import duties.

thanks again - bill