Hi

With the Spider and Spider Valve series, you have TEST mode which bypasses the DSP and pre-amp section entirely.  It also disables ALL controls including the MASTER VOLUME on the amp.  This is a viable option in terms of achieving an uncoloured sound from your Spider III 150 (I have a Spider III 150 and the TEST mode option definitely works )

Basically to get into TEST mode you hold down the TAP button as you pwer the amp ON.

Beware that having no master volume control from the amp, you need to control your master volume level from the POD's MASTER control or you could blow the roof off LOL.

Set the POD HD AMP/LINE switch to LINE and the output mode to Combo Pwr Amp and you should be good to go.

Nick

hello chris

to bypass all preamp stages and effects on your Spider III, please use the Mp3/CD input

this way you'll use only the power amp stage

don't forget to insert a dummy jack in the guitar In, otherwise the amp output is muted

line6antonio