Yes. To use both signals at the same time, you'll need a buffer.
Any buffer will do. You can just build a buffer in a box with two outputs. The signal from the input jack goes directly to output 1, and also to a buffer that feeds into a 10k volume pot (log or lin, up to you) to output 2. This should leave the tone of the direct signal completely unaffected. The tone of the buffered path may change, but probably not (depends on external factors).
You can also add an on/off switch to either or both outputs if you like.