Using a HD500 to control an EVH 5150 with midi and effects via 4 cable method. Cannot get volume or wah pedals to work with a level control? Have looked at every youtube video I could find and tried different cabling and settings but no avail. Using another pedal (morley volume/wah) to run into HD500 which works for this purpose but seems overkill as the HD500 should be able to do this???. CAN YOU PLEASE HELP????? Seems like I'm missing some basic process?? Just want to have a volume control (exp 1 or 2) and a wah control (exp 1 or 2) with a EVH5150 III 50w using 4cbm & midi??. massively hugely appreciate any response, doinmaheadin.....