help! i've got piano distortion!

[edwinr]

Before you do anything, check the interconnects and the speaker cable connections - if there's a poor connection this could contribute to some distortion. But overall it sounds like your amplifier is working under duress. As has been pointed out before, the impedance does dip to around 1 ohm at high frequencies. I reckon the amplifier is breaking up.

Martin Logan speakers are virtually indestructible - most amplifiers will surrender before the Martin Logans start waving the white flag...

P.S. I read the rest of the thread. You were plugging your electric piano straight into the inputs of your receiver? Usually that's a no, no if you want to avoid overloading your receiver, but you tried differing volume levels and a mixer etc... Hmmm. I would have thought that might have worked with your old receiver - even if it was a bit under powered. There may be another problem there as you've identified. Maybe there an impedance mismatch. If your headphone amplifier runs off a different feed, and has it's own mini amplifier, this could explain why you hear okay sound through the headphones.

Hopefully your new receiver will be a proper electrical match with your keyboard and will fix your distortion problem. I'll be interested in your findings...

 

[macallan]

PCAR928fan is right you should be looking into an amp designed for a keyboard. I play guitar and would never connect it to my receiver or home speakers, that is just not what they are intended for. The goal is just different and instrument amplifier is supposed to introduce distortion, feedback, reverb, tone, etc. home speakers are strictly for playing back the finished product.

 

[Pcar928fan]

As for PCAR928fan.... You ask why would I want to hear my piano through a Martin Logan surround sound room and NOT a synth/keyboard amp??? I got 2 strong words for you.... Come On!!! There's no comparison my friend. I'm gonna take my chances and stretch what this stuff is "designed" to do. No matter how improper I am.

I am not saying the speakers can't take it, I am saying you are not driving the properly and not using the keyboard with a product for which it was intended and there is a high likelyhood of damage to any one of the components by doing something this stupid. I defy you to find me a keyboard or guitar that gives recomendations for playing it directly through a home theater system! NOT THERE MY FRIEND! Good luck to you, you will need it.

Get an amp!

Thanks, macallan for the support, I too am a guitar player and back when I was SIXTEEN I tried not so smart stuff like this and it was not good for the sound of the guitar OR the system (cheap!) that I was playing it through. The REAL guitar amp made all the difference, just as a REAL keyboard amp would be the correct answer here...

 

[jjqiv]

PCAR928fan is right you should be looking into an amp designed for a keyboard. I play guitar and would never connect it to my receiver or home speakers, that is just not what they are intended for. The goal is just different and instrument amplifier is supposed to introduce distortion, feedback, reverb, tone, etc. home speakers are strictly for playing back the finished product.

I wonder what it would sound like if you used a Marshal amp to drive a pair of ML's instead of a Marshal stack? I would think it could handle the load.

 

[Pcar928fan]

I wonder what it would sound like if you used a Marshal amp to drive a pair of ML's instead of a Marshal stack? I would think it could handle the load.

That would be interesting...not sure if it could handle the load actually...most cabinets are 8 ohms or more...many are 16, I think I have seen some listed at 24, so the amps are geared for that not the 4 ohm load of a pair of ML's...