YO Der 666 and extensions:]
Plug your guitar directly into the recorder or a mic pre and buy a Yorkville mic. They make two modes; I own the cheaper one, less than 200 pezzutos. It works fine.
Also, once I had a good bass player, a friend, do some lines for a cut I had recorded. I ran his plug into my Gallian Kruger Amp through a by-pass-the speaker circuit and then into the recorder.
Great take. Easy to regulate the volume. As you know, guitar and bass don't need much amplification.
To mic bass or guitar through a speaker requires much more work than I care to do.
Green Hornet