In reading some P22 reviews, I see folks using a volume pedal from the electric jack to help control the mix of magnetic to piezo sound ... anyone who uses this setup, please advise how it helps you with your sound ... I have a very simple pedal board and don't currently have a volume pedal (haven't used one since the early 80's in my former band-playing life) ... also any recommendations on brands/types would be appreciated. Thanks.