Relying on an automatic program is a compromise between time and end result. If the letters are not well defined from the background you will get poor results.
You can use the Pen tool, but if you are not familar with it there is a learnig curve.
Here is a link to a method that requires a little work, but the results are good. http://www.muvipix.com/phpBB3/viewtopic.php?f=23&t=6754
It would be helpful to see what your are dealing with. If you can upload an image would help.
If there is a defined white area all around the text, you could use the majic wand to select the white, then invert the selection to get the letters. Contracting the selection by a pixel or two sometimes helps clean up the edges.
As Curt said, the pen tool is the best, but there's a learning curve. If you plan on being profecient with photoshop, then you must learn to use the pen tool. I bit the bullet years ago (photoshop 5.0) and said I would only use the pen tool to make all selections until I mastered it. Today it's my first choice. Once you master it, you will find in most cases it is the quickest, and most versital selection tool.
Well....the pen tool will give you the most accurate selection. I can't tell if the white outline is part of the type font / effect or halo from over sharppening. It looks like it has a 360º drop shadow. The pen tool would not retain the soft shadow, but you could get the white outline (if desired). I use the select color range and got a quick selection of just the lettors. You could add the other effects ( white outline and shadow). Here it is on black. It needs a bit of tweeking, but only took a few minutes.
The other consideration is how large you are going to use the logo. That will dicktate how accurate you will need to be.
You mentioned: The text I want to use in in the form of an eps file.
It's a good possibility that this eps is the vector logo. When you opened it in Photoshop did it ask you for a resolution, color mode and bit depth?
If so you just rasterized the vectors and flattened everything to one layer. Try opening this eps in Illustrator instead.
Illustrator is a vector drawing program and is what logos are generally created in since vectors can be scaled to any size without any loss of detail.
I'll bet the logo is all vectors inside this eps file. If you need to change anything in the vector file, use Illustrator, not Photoshop, That is what Illustrator is made for.
Even if the files is not vectors, you could still use it as a template in Illustrator and recreate the logo as a vector file.
Click the image in the forum to see an enlarged view.
A different thought...
WhatTheFont.com shows that the big letters are in the Times Bold font and the small letters are probably Machinato Light. Since the graphics are minimal and the effects are pretty basic, you *could* go get these fonts and recreate the logo in a form that you can then use as the basis for whatever you need.