Keyboard thru guitar amp

[natmj]

I've got a Marshall 65 watt combo amp for my guitar. I don't have a keyboard amp. Would it hurt the amp to run my keyboard thru it for a show (and the rehearsals)? I can't afford a keyboard amp right now.

I know a keyboard amp is higher quality than a guitar amp, but other than that I'm not sure much about the difference and how you can mess them up.

Thanks.

[Blue Bear Sound]

A keyboard amp is designed to work with a line-level signal compared to a guitar output. As well, keyboard amps have a much greater range of frequency response. It is unlikely that you will damage anything connecting your board to your guitar amp, but it sure won't sound that great -- the guitar amp will cause the keyboard to be very mid-range heavy and possibly slightly honky.

Bruce

[Wide Awake]

I have run synths through guitar amps many times to get distorted lead sounds, and ballsy organ sounds. In fact, Jon Lord of Deep Purple and Keith Emerson (ELP) ran their Hammond organs through Marshall guitar amps all the time.

What Bruce said about guitar amps being mostly mid-range is correct. For the most part, keyboards sound awful through a guitar amp. I also believe you could damage certain amps and I wouldn't recommend doing it at all. I might be wrong about that but why take the chance. Now that amp modelers are available I am having lots of fun using them to "dirty up" synth sounds.

[Roel]

The difference between the output of a guitar is 1) the impedance, guitar have a high impedance output, keyboards low, and 2) the level. Guitars will give a lower signal, and need a preamp. Your keyboard will give a line output, and doesn't need a preamp. So, if you aren't aiming at distorted sounds, I would suggest running your keyboard in the power amp input, effects return (which is the same, effects send is your preamp output...) or preamp input (if you want to use another preamp). This is 3 times the same input, labeled differently...

The reason that it might hurt your amp is that your keyboard output might contain very low frequencies, and since your guitar can't produce those, the amp isn't designed to deliver enough power to get these out. But it will try anyway. And that's when it hurts...

[Bluzdelux]

I've run keyboards thru amps...just depends on what you're looking to get sound-wise. But those amp simulators..wowee! That IS the ticket. I have a Line 6 POD v.2. That's the coolest thing I have picked up in ages. Serious bang for the buck.