In my edit suite/office, what I call the 'Casablanca Lab', I have my Casablanca Renommee Plus and my Casablanca S4000 PRO stacked to my left, feeding into a 27" LCD monitor. 

Depending on the tutorial or web lesson I am producing I use one of these editors as the source and one as the recorder.  Then I have my Windows tablet PC and my  Mac mini (Apple PC) running directly in front of me on my desk. 

Now for the question at hand, for my audio I use a Behringer 802 audio mixer. 

This nifty little mixer (only 7.5 inches wide x 9" long) packs a lot of punch for a small tool with a reasonable price tag - I purchased mine for $60. 

There is a smaller model (the 502) that is more affordable but I like the fact that for $10 or $20 more, I get 1 more XLR microphone input that may come in handy if I want to use this for a location mix.

How my mixer is set-up: 

I have my Voice Technologies VT500 (wired lavalier) connected to Channel 1 via XLR cable.  I then feed whichever Casablanca editor is the source (playback) from it's audio out (RCA/Phono) into the 'CD/Tape' inputs on the mixer. Then I take the 'CD/Tape' Output and feed that pair (RCA/Phono) into the Casablanca audio in which serves as the Record or destination editor.  I will connect a pair of headphones or the speaker for my 27" LCD monitor to the head-phone output on the Behringer which has it's own volume control. 

What I like about this little audio mixer:

• It has two XLR inputs that allow me to connect professional level microphones (I could also choose to insert 1/4" mic connectors instead). 
  
• The mic jacks supply phantom power for professional microphones that need that option
  
• There are two additional inputs for line level inputs (1/4" jacks which can utilize an adapter to accept RCA/Phono plugs from other audio components like CD player, etc).
• The CD/Tape input allows quick connection of my Casablanca audio input (or CD player,etc)
• The headphone output has its own volume
• It has strong reviews from audio experts with clean sound (a lot of cheaper mixers have poor performance, usually with a lot of 'noise').
• It offers me professional options and results at a very affordable price
  
• It's small size allows me to take it out of the studio - I often take this mixer with me to record my hands-on workshops.