Don't look for the cheapest way out with an audio interface. It's the heart of the system so get something decent.

I'm a huge fan of Focusrite and have used the Saffire for many years with great success.

Be sure whatever you get has a few things..... phantom power for condenser mics, built in audio preamps on each channel, and that it can run NATIVE ASIO... not wrappers and codecs.

Get that, in USB and you'll be fine. I'd figure on spending between $150 to $250 for a new one. Get looking on Ebay and some other places like craigs list and find a second hand interface that someone is selling to upgrade..... you can get them at greatly discounted prices and get years of use from it.

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www.herbhartley.com
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You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.