Need some help. Iv got a boss compression sustainer. I dnt no how to get the best out of it. All it does is make so much noise and feedback.
Its a fuuuckin noisy man, but work with it and it will help on Gilmour like stuff.

My CS-3 is like this:

Tone: 12oclock

Level is a tit, have it middle and get ya a noise gate or a better CompSus.
to be honest im kinda unsure of their purpose. Sounds a bit daft me havin one. I thought they just held the notes longer. i hav a marshall avt stack, partly tube i think
i its the cs-3 iv got. im gonna need to get me a noise gate. My eq makes a fair bit o noise aswell. sounds good but
The AVT isn't tube. A compressor generally just makes all the sound coming from your amp the same volume...so it makes the louder sounds quieter and the quieter sounds louder.
My Gear:

Squier Affinity Stratocaster w/ SD Hot Rails (Bridge)
Yamaha F-310 Acoustic

Peavey Studio Pro 112
VOX AD50VT Valvetronix
Ross Fame Series Bass 50

BOSS DS-1 Distortion
BOSS DD-6 Digital Delay
^ yeah.

"This device does not radically alter the tone of an instrument the way the previously mentioned pedals do, but many guitarists use it as a kind of effect. A compressor acts as an automatic volume control, progressively decreasing the output level as the incoming signal gets louder, and vice versa. This evens out the overall volume of an instrument, and can make a guitar appear to sustain much longer than natural. Compressors can also change the behaviour of other effects, especially distortion. When applied to instruments with a normally short attack, such as drums or harpsichord, compression can drastically change the resulting sound."