Hissing sound when Tone Control is turned on


Hello all,

Wonder if any one of you experienced the same issue with your Mcintosh preamp ? If you did and what was the solution to it?
I have noticed that apparently audible hissing sound can be heard from my speakers during idle while the "tone control" is enabled on my Mcintosh C49 preamp. As soon as i toggled the tone contol switch off from the front panel the hissing sound is completely gone and the background is dead silent like it supposed to. 

Is this considered normal ? Any advises will be appreciated.

Thanks

Larry

larrymanadgn
Crack me up.. Of course there is a reason for tone control. That's why the OP opted to have it just like me for the last 50+ years.. You don't need it until you do.. LOL One a month or so always ask "I need a bass boost, or they are a little boomy on certain albums"  It really doesn't matter.. When you need it.. You need it.

AND no I don't want to know what it sounds like live.. That's usually REAL bad... so... Tone control...  You get in your car you don't adjust the tone control? BS yes you do and or you did or it auto sets the tones to some preset EQ.... No Tone Control is just a CHEAP way to make a piece of distribution equipment, nothing more.. Not because it sounds better. The purpose of a preamp is to color the sound...

I don't care what anyone else thinks, that is what they use to be made for and what I still use them for.  Somethings just never change..

Regards
Ha! I haven't used a tone control since 1987. Never found a need to "color" the sound. Each to his own.
Well, there is certainly a purpose for a tone control.  Unless your listening room is an anechoic chamber and your system is perfectly tuned to deliver 144dB SNR and perfectly balanced signal from 20Hz-24kHz, you're going to find situations where you need/want to correct for something. 
Never had a pre with tone controls but will likely try in the future.   You guys make a good point.