Amp question

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antispatula

antispatula

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This topic is about an amp that is going to be used for a keyboard, but it's more like a general amp question, so I thought I'd post here.

I tried plugging my digital stage piano into a 30w solid-state Marshall and it seems to distort, even when it's on it's clean channel. It seems like I really have to turn down the volume on both my keyboard and the amp to get a clean sound.....but then it's not loud enough.

What should I do?! Help! :p

Should I get a amp specifically made for a keyboard or should any, including my guitar amp, suffice?

Thanks!
 
I think you need to connect your stage piano to a line input.
 
That's a Marshall for you, if you push the "clean" channel much at all, it really isn't "clean" anymore, which is real cool for guitar, but not necessarily so cool for piano.

I gig with a guy sometimes that uses a Roland jazz chorus amp for his piano, it sounds really cool. Works nice for regular piano sounds and sounds great when he hits a Rhodes or Wurli type setting.
 
Would you buy a keyboard Amp? Something thats more neutral tone-wise?
 
TelePaul said:
Would you buy a keyboard Amp? Something thats more neutral tone-wise?
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Absolutely. Keyboards' needs are totally different from electric guitars. You want something solid state with a tweeter. Go to Zzounds or Musician's Friend and do a search for "keyboard monitor" and you'll find plenty of them. A powered vocal monitor will work as well.
 
I might get shit for this, but I'll say it anyways. Check out the Behringer acoustic combo amps. Dirt cheap, and they have a pretty good clean. My friend used to use it for a cab with a line 6 combo amp, and the clean sounded 10x clearer through the behringer than through the line 6 speakers. Also we used it for my keyboard, and it help up wonderfully. Good luck!
 
TravisinFlorida said:
I think you need to connect your stage piano to a line input.
Click to expand...

Yeah, I would think it would have something to do with connecting a line level output to an instrument level input. Does the amp have an effects loop? You could plug it into the "Power Amp In" jack. You would most likely lose control of the amp's volume control though, and have to rely on the keyboard's volume.
 
Adam P said:
Yeah, I would think it would have something to do with connecting a line level output to an instrument level input. Does the amp have an effects loop? You could plug it into the "Power Amp In" jack. You would most likely lose control of the amp's volume control though, and have to rely on the keyboard's volume.
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It will still sound like crapola. A guitar amp is voiced for electric guitar, which is concentrated in the midrange, and prone to harmonic distortion, which sounds good for guitar but really sucks for keys.
 
Ggunn is on track, guitar amps are for guitar. For the most part keyboards simply sound bad through them. Pa systems are a little better but if you want a really good keyboard sound (especialy piano) you need an amp designed for keyboards. Even a cheap keyboard amp is likely to sound better than a guitar amp. I have a Marshall 30 watt which in my opinion isn't even that great for guitar and I've tried a keyboard through it and it proved to be a terrable sound. I don't know how your budget is, but for less than $300 you can get a decent keyboard amp. I use a Johnson 150, which for around $230 is a fairly decent small keyboard amp.
 
Im a guitar player but I have always heard that a Hammond b3 into a leslie is pretty hard to beat.
 
Check out the Yorkville stuff, for keyboard or acoustic guitar. The best prices on Yorkville/Traynor are from the authorized dealer at

www.affordableaudio.com

He posts the MSRP list, and he will tell you up front he charges 60% of list + shipping. Hard to beat that anywhere else. I know cuz I've looked, and I bought my Yorkie stuff from the guy.

The only thing I've learned to watch out for is that some of the solid state Yorkie stuff is not actually manufactured in Canada. The tube amps are, but (for example) the solid state TRM40 is not. I dont know about the other amps, but I know the build quality is good and I always like the sound. Seems like you always get a great raw sound and a little extra db bang for the buck with Yorkville.

Another thing you might try is - IF you are using a small mixer like 4 or 6 or 8 or 12 channels - is just run your keyboard into the mixer, then run the mixer into a small power amp that pushes 200 or 300 watts. That way you'll have inserts for fx, and you'll get a stereo source, lots of clean power, and the only thing you'll be missing is speakers to plug into the amp. Or you can feed your mixer to the soundman and go direct to the PA and stage monitors. Total control over your sound.
 
try a small pa type setup... i've used JBL G15 powered before with great results... though it may still need a direct box or preamp to drive it properly...
 
Impedance mismatch...as it was said before, wrong amp for the job. You'll need a DI like impedance matching device.
 
punkin said:
Impedance mismatch...as it was said before, wrong amp for the job. You'll need a DI like impedance matching device.
Click to expand...

Most keyboards I have seen have a high Z output, and the Marshall has a high Z input, so impedance is not the issue, it's amplifier voicing and speakers. Marshalls are designed to distort in ways that guitar players like and emphasize the midrange, which sucks for keys. Keys players also like having a tweeter.
 
antispatula said:
This topic is about an amp that is going to be used for a keyboard, but it's more like a general amp question, so I thought I'd post here.

I tried plugging my digital stage piano into a 30w solid-state Marshall and it seems to distort, even when it's on it's clean channel. It seems like I really have to turn down the volume on both my keyboard and the amp to get a clean sound.....but then it's not loud enough.

What should I do?! Help! :p

Should I get a amp specifically made for a keyboard or should any, including my guitar amp, suffice?

Thanks!
Click to expand...
i think you have a gain staging problem


i've plugged different things into guitar amps

and while the sound may not be optimal, frequency-wise,

it is often usable


the distortion is not caused by the way the amp is "voiced"

but by a voltage level mismatch



the amp input expects a low voltage (millivolts)

high impedance source (guitar pickup)

the keyboard is putting out line level voltage (~1 volt -

i believe - i'm not a keyboardist)

which may also be relatively high impedance (but not very important)



so you are overdriving the guitar amp's preamp from the get go

and you turn down the keyboard volume

(thus decreasing the signal to noise ratio)

and turn down the amp's volume (further attenuating the signal)

and you get a thin, weak, noisy resultant sound



so if you put a potentiometer of value approximately

that of the keboard output or somewhat higher

between the keyboard out and the amp in

you should be able to pick off a relatively usable signal


.......................................~100k ohms
keyboard out______________/\/\/\/\/\/\/\_______________ground
amp input_____________________^ (wiper)



sorry about the hokey schematic :)
 
Whatever; your problem is that you are using the wrong tool for the job. You can't change a tire with a screwdriver. Get a keyboard amp, acoustic guitar amp, or powered vocal monitor, and your problem will be solved.

PS: If you indeed are overdriving the input of the guitar amp with a too-hot keyboard signal, all you have to do is turn down the keyboard.
 
ggunn said:
Whatever; your problem is that you are using the wrong tool for the job. You can't change a tire with a screwdriver.
Click to expand...
well, yes you can

it just takes a lot longer :)
PS: If you indeed are overdriving the input of the guitar amp with a too-hot keyboard signal, all you have to do is turn down the keyboard.
Click to expand...
true, but you are increasning the snr tremendously

the keyboard output has a noise floor

independent of the volume control

and by decreasing the signal level

down to where it is usable

you're applying tremendous gain to the noise also


sure it would be best to buy an appropriate amp

but i still contend the marshall is usable

with proper gain matching
 
antispatula said:
This topic is about an amp that is going to be used for a keyboard, but it's more like a general amp question, so I thought I'd post here.

I tried plugging my digital stage piano into a 30w solid-state Marshall and it seems to distort, even when it's on it's clean channel. It seems like I really have to turn down the volume on both my keyboard and the amp to get a clean sound.....but then it's not loud enough.

What should I do?! Help! :p

Should I get a amp specifically made for a keyboard or should any, including my guitar amp, suffice?

Thanks!
Click to expand...


Ok, with the electronics lesson out of the way, and it is clear that you need proper equipment to make your keyboard sound good. I'll just key in something in your original post that you stated this is for your digital stage piano, with the word "stage" being the key word.

Couldnt you just use the stage monitors provided by the club/venue to hear your keyboard?

Otherwise just man up and get something decent that you can hear yourself clearly with. Most likely the audience will hear a direct signal that is eq'd/compressed,limited,verbed, whatever through the house board and speakers anyways so whatever you get I dont think will alter the final mix anyways. All it is for is so you can hear yourself on stage right?
 
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