Volume knob... line mixer?

[punkdISCO]

I use a SM M-Patch 2

http://www.soundonsound.com/sos/dec06/articles/smprompatch.htm

I chose this over the Big Knob, Presonus, etc as the M-Patch is totally
passive.  I don't even have mine plugged into the power supply as this is
only required if you want to use the headphone amp.

But, like the Big Knob and Presonus, it might be a bit overkill for what you
are looking for..

Paul
London
www.punkdisco.co.uk
Text SLUT to: 29 7 29 7
Here's the video:  www.youtu.be/Zl0PTZKy7fg