What is it called?

I have a McIntosh MC-252. And a CDP. The Mc has no gain control. I do not have preamp $$$ right now. I need a volume control. Does Raio Shack have what I need? If so what is it called, because the local RS ppl say they have nothing like that. Or, what other ways can volume be controlled, cheaply. thanks.
Maybe what you're looking for is an attenuator. Not necessarily cheap but very transparent if you don't mind getting out of your chair to adjust volume.

Check this out:

You are looking for a passive volume control. Try the forums. You could read for days on this topic. Don't waste your time at Radio Shack.
Rat Shack actually has a nice volume pot, you will have to buy a little plastic box and some input and output jacks as well as some wire. If you are handy, you can build yourself a nice little one input passive preamp in less than an afternoon. I built one for a friend and he preferred it to his $1800.00 preamp. When you get a bit more scratch, you can replace the pot with a stepped attenuator for even greater transparency, upgrade the wire, jacks, etc.
Check out the Luminous Audio Axiom.

Good luck.
How much can you afford right now for a pre-amp? I have a Yamaha Pre-Amp C85 that is non-remote I could sell for 75.00 plus shipping. It has a decent phono stage plus 4-5 inputs. It's been a while since I have looked at it so memory is off a little but it is in original box w/manual.
Problem you ask? Yes a few broken RCA inputs but enough remain for a CDP, Tuner and maybe a third component.
Viridian has the best idea. If you can solder you can build a passive with Radio Shack parts for about $10 that will amaze you with how good it sounds.

Project Enclosure 3x2x1" $2.29
Catalog #: 270-1801

Phono (RCA) Jack, 4 pack $3.99
Catalog #: 274-346

100K Ohm Stereo Control $3.29
Catalog #: 271-1732

A little wire and solder and a knob if you wish and you are in business. I can email you instructions if you wish.

Thats awesome Herman. Even with part/catalog info and instructions. I know what i am doing tomorrow. My email is aburger@kc.rr.com. I am sorry Theo, I just bought a pair of Klipsch RF7s and a Sony 400 disc CDP yesterday, and there was not any $$$ for audio purchases for June's budget! In a week from now, $75.00 will have more value than it did yesterday. Thanks anyway.
Here is an excellent way to improve on the basic volume pot attenuator, use the best resistor (Caddock etc.) that you can afford... http://www.lara.on.ca/~gandalf/
I'll email some instructions.

You shouldn't post your email as there are programs that can search for them inside forums like this and start spamming you. One way to get around that is to change a portion and then describe the changes in the text.

So instead of your real email, post xxxxxx@kc.rr.com with instructions to change the xxxxxx to aburger.
I agree with Gordus. I don't know why I didn't suggest the same. That is the scheme I am using with good results.