Keyboard Amp or PA?

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SKYflyer

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Currently, i use a crappy PA my band has for my keyboard.

We are not completely sure, but we think the problem with the setup is the bad quality of the PA head (we think the speakers are fine and not the source of the crappy sound).

Anyone know if it would be better to get a new PA head, or a keyboard amp?

Right now, i am considering this keyboard amp: http://www.musiciansfriend.com/srs7/g=key/search/detail/base_pid/701761/

or one of these PA heads (as you can see, the list of these has not been narrowed down :) ) : http://www.musiciansfriend.com/srs7/g=live/search?c=5334&page=1

Any input on what the advantages of either setup is? PA vs Keyboard amp?

PS: anyone know if there is a way to determine whether our current PA setup sounds crappy because of the PA head or the speakers that we use with it? It would suck to buy a new PA head only to find that it still sounds crappy because of the speakers...
 
Check your settings. Is the volume on the keyboard channel cranked and the master volume down? that could cause a bit of distortion. What type of amp head are you using and speakers would help with answering your dilema.

L8
 
The problem with buying a new PA head is that you need some kind of preamping between your keyboards and the amp. That will mean an additional expense unless you buy a 'powered mixer'.

If possible, try that Behringer amp and see if it gets loud enough to suit you. If it does, buy it. It's an all-in-one solution and is cheap enough to buy a new one every year if necessary.
 
ssscientist said:
The problem with buying a new PA head is that you need some kind of preamping between your keyboards and the amp. That will mean an additional expense unless you buy a 'powered mixer'.

If possible, try that Behringer amp and see if it gets loud enough to suit you. If it does, buy it. It's an all-in-one solution and is cheap enough to buy a new one every year if necessary.
Forgive my apparent noobness, but i dont understand your statement about needing a preamp if i get a PA head, but not needing it if i get a powered mixer. I thought that a keyboard was already line level, meaning that it is already preamplified. Arnt PA heads and powered mixers both designed to take line level signals and power speakers to make the line level signals loud?

PS: i'm assuming your subtle remark concerning the possibility of buying a new behringer amp every year means you have little faith in their products :) (i suppose this means if i purchase it, i should invest in an extended warranty from the shop :) )
 
Keyboards do put out a line level signal, but not a level that a power amp can see or utilize. That's what mixing boards are for - to lift signals up so that they're usable to power amps, tape machines, hard disk systems and so on.

You're probably using a powered mixer now so you haven't run into the concept of two separate entities - a preamp and a power amp - until now. The preamp/poweramp thing is something that you'll encounter if you stay in the music racket in any capacity. That Behringer Keyboard Amp has both a preamp and an amp in it, it's just presented as one unit.

And you can do what you want about buying an extended protection plan if you do go with the Behringer. I wasn't making any judgements as to the quality of the stuff they make, just saying what I meant - it's cheap enough to buy a new one if this one fails. I use one of their Bass V-Amp Pros, and it's proved quite reliable and trouble free.
 
Concerning your comments on me needing a preamp before my line level keyboard signal is amplified to produce sound from the speakers by the power amp, I am still confused.

Quoted from the newbie guide (https://homerecording.com/bbs/showthread.php?t=96047) is the following:
"Power amplifier - An amplifier that takes line level audio signals and make them strong enough to power a speaker."

Thus I would think that because my keyboard outputs a line level signal, I would need no preamp before it goes into the PA head which contains the power amp.

Additionally:
"Preamp - An amplifier that is used before the main amplifier in a system. Usually this is an amplifier that takes microphone level signals and brings them up to line levels."

Well, I thought my keyboard was already line level, so wouldn't a preamp be redundant, since it seems preamps are devices that bring signals up to line level?

Please help me understand this apparent contradiction between ssscientist and the newbie guide!

PS: ssscientist, i believe you are correct that my band is currently using a powered mixer, not just a PA head.
 
SKYflyer said:
Please help me understand this apparent contradiction between ssscientist and the newbie guide!

The newbie guide is correct. The only way ssscientist's advice works is if he meant that a DI should be in the signal path after the keyboard outputs, and just didn't mention that in his posts. The business about needing a powered mixer before the amp and preamping line level signals is just plain wrong. Sorry.

Line level is line level. End of story. Whether it's line level coming out of the keyboard or line level coming out of the mixer, it's still line level. Yes, of course you still need an amp after the keyboard to drive the speakers, whether it be an all-in-one keyboard amp or an amp for a PA. But you don't preamp line level signals.

Normally, you'd plug the outs of the keyboard into the keyboard amp and you are all set. If you are using a PA you'd plug the keyboard outs into your mixer and then that of course would go to the amp and then the speakers. There needn't and shouldn't be a preamplifier between the keyboard outs and the amp, or the keyboard outs and the mixer, unless you are using DI's. The DI's bring the keyboard line level signal down to mic level, which you would then re-amplify with a preamp.

As far as PA versus keyboard amp, I personally would recommend a keyboard amp. If all you are doing is using it for keyboards--definitely. Roland makes some good ones, and so does Barbetta. I'd avoid those Behringer thingies, they are like made out of cardboard. I wouldn't trust them to hold up well at all. The Roland KC line is very solid and sounds good, I use a KC-300 and it has been trouble free. If you need more power there's a KC-500 that is packs a pretty big punch.
 
Ahh crap! Now i don't know who to believe! SonicAlbert or ssscientist?

Can we get a 3rd opinion or perhaps a rebuttal from ssscienist?

Just to recap, the debate is about:
ssscientist says that while the output of a keyboard is line level, it is a weak form of line level. Thus there should be a preamp to bring the keyboard line level to a stronger form of line level that a power amp in a PA can boost further to power speakers.

SonicAlbert, on the other hand, says that line level is line level is line level! The output of the keyboard is line level, thus it does not need further preamplification to bring it up to another (nonexistant) form of stronger line level, before it can be inserted into the power amp inside a PA to power speakers.

Further question:
SonicAlbert, your recommended getting a keyboard amp as opposed to a PA, but you didnt say why... Could you please explain your reasoning?

PS: am i going crazy, or did ssscientist used to have a post in this thread that seems to have somehow gotten deleted?! I believe this post had a link to a Behringer mixer and a Behringer PA head that he recommended I purchase over the keyboard amp.
 
Well, line level is not just line level. For starters there's the +4 / -10 distinction.

This seems to be a silly conversation anyway since you have a head already and get good levels out of it (I assume) so you seem ok there. Just check the specs when you buy a new one - or better still try it out in the shop with a kb.

As for which, I'd go for the PA so you can mix yourselves in together properly.

To find out if it's the speakers take your head to a shop and try some expensive speakers with it. Then try another head with those expensive speakers - simple.
 
Levinin said:
Well, line level is not just line level. For starters there's the +4 / -10 distinction.

Right, of course. But with either of those levels you don't additionally preamp them, which is what I was getting at.
 
SKYflyer said:
Just to recap, the debate is about:
ssscientist says that while the output of a keyboard is line level, it is a weak form of line level. Thus there should be a preamp to bring the keyboard line level to a stronger form of line level that a power amp in a PA can boost further to power speakers.

SonicAlbert, on the other hand, says that line level is line level is line level! The output of the keyboard is line level, thus it does not need further preamplification to bring it up to another (nonexistant) form of stronger line level, before it can be inserted into the power amp inside a PA to power speakers.

Further question:
SonicAlbert, your recommended getting a keyboard amp as opposed to a PA, but you didnt say why... Could you please explain your reasoning?

The major distinction about line level is what Levinin brought up regarding +4/-10. Most keyboards output -10 unbalanced, though a few output +4 balanced. Both are line level. Your PA head should be able to handle both with no problem. No preamps are necessary.

The other reason for using a DI is to balance the unbalanced outputs on most synths. So you'd take the -10 unbalanced outputs from your synth, put it thought a DI and then use a preamp on it to get it up to line level again, only this time its balanced at +4.

I recommended a keyboard amp because in reading your posts what I understood was that you are using a PA system for your keyboards, and that a separate PA is being used for the rest of the band. For me personally, I prefer to have a keyboard amp for my own monitoring, and then send the keyboard outputs to the house mixer. Although I also have a more powerful amp than the Roland KC-300 that I use when I need to fill the house myself.
 
I'm also getting confused with this... I'm getting the feeling you're both saying you can't just plug the 1/4" TS outputs of the keyboard into a power amp, which feeds the speakers?

As SonicAlbert said:
If you are using a PA you'd plug the keyboard outs into your mixer and then that of course would go to the amp and then the speakers.

Why do you need to go through a mixer?

Stan.
 
Sorry, misread the post slightly - if it's just for you get a kb amp.

stanjanssen said:
I'm also getting confused with this... I'm getting the feeling you're both saying you can't just plug the 1/4" TS outputs of the keyboard into a power amp, which feeds the speakers?


Why do you need to go through a mixer?

Stan.

Well that seems to be what SKYflyer is doing at the moment so there is no *need* to go through a mixer. Usually though you wouldn't have an amp each in a band but would put everyone though the same mixer which then feeds to the power amp for the speakers - or you might even have active speakers and no separate power-amp at all. Easier to control and mix everyone in that way, also adds the ability to use eq settings etc.
 
stanjanssen said:
I'm also getting confused with this... I'm getting the feeling you're both saying you can't just plug the 1/4" TS outputs of the keyboard into a power amp, which feeds the speakers?

This is actually the opposite of what I'm saying.

It's so simple, I don't understand why there is any confusion. You don't need to preamp a line level signal, that's all I'm saying. Whether you go into the PA amp head or the mixer, you don't need to preamp the keyboard outputs. The only time you'd need to use preamps is if you put a DI between the keyboard and the mixer, which is actually very commonly done.

My comment regarding the mixer was in reference to if there was a house board being used and the whole band was being mixed by a house sound guy. If that is the case, then of course there is a send to the house system, and a feed goes back to the keyboard monitors. Or, and what I prefer to do, DI the keyboards and take the direct out from the DI and feed my keyboard amp with that. The balanced signal from the DI goes to the house board. I prefer this because then I can control my own monitor levels/eq, etc.

The other reason for my mixer comment was that I often use more than one keyboard, so I need to submix it before sending it to the house sound system. I so I very often am dealing with a little mixer. Almost inevitably what happens is that I take a direct line level feed off the mixer (or if one keyboard, directly off the keyboard) into my keyboard amp. The house sound guys DI my mixer or keyboard (if just one) and send that to their board in the back of the house.

The original poster didn't even ask about preamping line level signal, that was a bit of mis-information inserted into the thread that has been causing the confusion.
 
OK I understand, I was just confused why you mentioned the mixer in the thing... I thought it was the way you said it, SonicAlbert.

Stan.
 
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