Hi just wanted to introduce my self my name is Evan and i just picked up a LP II second hand. This is my first moog and i f*&kin love it. One question should i be getting audio hiss when a key is pressed and osc 1 and osc 2 volume are at zero. Other wise this thing is amazing. Glad to be part of the community woooo!
Welcome! The hiss you describe seems to me, perfectly normal. It’s called “subtractive” synthesis, because you start with everything, and filter out the undertones you don’t want. Therefore, the oscillators are ALWAYS on, and there’s no way to completely silence them…unless you power the synth down. 
why thank you kind sir 
hopefully in some time i will contribute some patches and more to the forum. all thats left to do is make custom hard wood sides and summon the ghost of bob moog to autograph it and im ready to roll. seems like real great and helpful community!
You could join the Yahoo group Knob Tweak. GregAE has been pushing that for sysex file sharing. Also, we like to see YouTube and Vimeo movies, so feel free to make some of those as well. Don’t forget pictures of your rig and anything else you’d like to post. 
Sorry if I overwhelmed you…I’m kinda a fanatic. 
I don’t believe this is entirely accurate.
If the volume of the oscillators are both zero then no sound should be coming from them. Period.
It is possible that there is some small amount of noise (hiss) coming from the electronics themselves and this may or may not be normal. However, this hiss is not part of the “subtractive” nature of the synthesizer - it’s merely an artifact of the electronic components used (or being caused by something else - like the settings of the filter or LFO or somesuch.)
I’ll take a listen to mine a little later today and tell you if I hear anything similar but it’s probably nothing to worry about especially if you can’t hear it when you are otherwise playing.
I forgot something…my amp makes a hissing sound when turned up past 3. Also, is the filter turned all the way down? The filter also outputs a signal. Overall, I agree that it is indeed normal, due to the nature of the electronics if nothing else.
As another data point…I have an LPStageII…when the oscillators are turned down to nothing (and every other parameter is set to it’s equivalent “nothingness”) I get a slight “tick” sound when hitting a key that is only audible when the volume is at about 50% or higher. No hiss or extended sound - just a quick “tick” sound.
That would be the envelopes firing. This one I know is true.
yea i think the noise coming from mine is just normal analogue synth noise. I do have a question since i also picked up cp 251. Does it matter if you use tr or trs patch cables. Do they need to mono or is stereo fine? im a noob at the patch cable department. thanks
OK, here’s how this works. 
TS cables are fine for patching stuff. TRS cables are required for using an external source to control the white ringed parameters via foot pedal or Voltor box, which is merely a bunch of potentiometers connected to TRS jacks. In this case, there is no mono/stereo. The internal voltage is connected to the ring terminals in the TRS jacks that are the white ringed jacks. Read the manual for a better explanation.
Hello there! Yes when the oscillators are at zero but the output is turned up, and you press a key, you get some background hiss… when the key is pressed the synthesizer’s VCA is open and sound is coming out of the synth, but you’re not putting any oscillations into the VCA so all you are hearing is the synth’s natural noise floor, which is nonzero. It’s all part of the charm of analog, as long as the noise level is low enough that it’s completely masked by the sound of the oscillators when they are turned up. Normally the noise floor is low enough that you really only hear it when the oscillators are at zero as you described.
Cheers,
Amos
If my understanding is correct, it is also true that plugging things into the KB Gate CV jack on the side panel may open the VCA, as well. I know just plugging a patch cable in (nothing on the other side) will leave it open; I believe grounding the patch will close it, and applying a voltage will open it.
yes, that’s exactly correct about the gate input jack. If you ground and un-ground that connection (like the action of a foot switch, which is what we had in mind) it will fire the envelope generators and open the gate.
Thank you for the help glad to know my lp is A ok. now time to let this thread disappear into the abyss. Also thank you for the clarification on patch cables. Finally a forum where actual help is received lol.