Hey, I'm looking for anyone with guitar tech experience that could tell me if a Digitech RP90 Expression pedal, http://guitars.musiciansfriend.com/product/DigiTech-RP90-Guitar-MultiEffect-Pedal?sku=153571
could be used with a Line 6 Spider Jam amp http://guitars.musiciansfriend.com/product/Line-6-Spider-III-Jam-75W-1x12-Guitar-Combo-Amp?sku=481289

What I really need to know is, will the output power jack from the pedal be able to fit into the pedal jack on the amp (I have a Digitech RP50 right now and the output jack doesn't look anything like the input jack on the amp).

Please Help!!
just get one of those special plugs?you can put them on the cord so it will fit in the input.
Marshall 50 Watt Vintage Modern
Marshall 1960AV
Fender Custom Shop Strat
Ibanez Prestige RG3120
Squier Classic Vibe Telecaster
Strymon Mobius
TC Polytune
TC Flashback
Mad Professor LGW
Fulltone OCD
JOYO Vintage OD
Behringer EQ700
the output jack on the pedal is for powering other pedals

the input jack on the amp is for connecting the foot switch which either came with the amp or you need to buy separately

the best thing to do is to sell the rp50 and buy the foot switch made for the amp here

the amp already has everything the rp has on it, the foot switch just makes it... foot switchable
Warning: The above post may contain lethal levels of radiation, sharp objects and sexiness.
Proceed with extreme caution!