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Tim
May 29th, 2006, 09:15 AM
I believe my hum buckers are just too hot for the PA sound system that I play through. As mention earlier, it has high and low impedance inputs.

When I use the high impedance input I must turn the PA system amp almost to full volume. When I use the low impedance input, even with the volume turned down to 2 I still distort the speakers. The PA system is probably 20 years old and all transisters. I have read where I may need a limiter to tame my input signal down some and use the low impedance input.

Does anybody have experience with limiters? I have no knowledge on limiters but will be doing a “Goggle” search right after I upload this post.

SuperSwede
May 29th, 2006, 11:10 AM
Perhaps a new PA system would be a better investment.. I use limiter sometimes, but I do not think that it is what you want.
Could you tell me what stuff you connect between the guitar and the PA? Perhaps you could turn down the output volumes of those units and turn up the guitar channel on the PA instead. Also, check that the PA does not have phantom power enabled for the guitar channels.

Not very guitar related, but this is from Wikipedia:
a limiter is a circuit that allows signals below a set value to pass unaffected, as in a Class A amplifier, and clips off the peaks of stronger signals that exceed this set value, as in a Class C amplifier.

Edit:

Also, check that the RP/VAMP is set to output to LINE not AMP.

Spudman
May 29th, 2006, 01:17 PM
Tim
You have a limiter (compressor) in the Vamp II.

If the p.a. is breaking up even after you turn down the guitar's volume then your problem is with the p.a. It could be the channel or the output transformer of the p.a.

If the break up goes away when you turn the guitar volume down then you are indeed putting too much signal into the input of the p.a. The high impedance inputs should be able to handle a guitar signal with no problem. Is it the Vamp that is pushing the input of the amp? Or are you over-driving the input of the Vamp and just amplifying that distortion through the p.a.?

SuperSwede
May 29th, 2006, 01:23 PM
Spud, I might have misunderstood your post but compressor and limiter is not the same thing.

Tim, I found another page for you that could be useful to explain various effects.
http://users.sa.chariot.net.au/~gmarts/fx-desc.htm