Phonoland

I recently picked up a Seeburg S-100 that works fine except for the sound. As soon as the needle touches the record there is static, during the music it usually isn't bad but sometimes it turns to a loud crackle sound. Sometimes the volume will increase on it's own like it just got turned up and when it does there is no static sound. I tried different speakers and nothing changed. Where should I start looking? Thanks

Start by un-plugging the input plugs on the amp. Play a record. If the static remains now, you have an internal amp problem that MUST be repaired NOW (playing it more, will "add" to your problem, most likely). If there is no static now, suspect that the cartridge terminals are defective. Speakers. IMHO, should never be "replaced", as they were specifically designed for that cabinet enclosure.
My "Seeburg Mechanism Guide" explains how to repair the cartridge problem, Contact me off forum, if you wish to purchase a copy. ronnnrich@yahoo.com .
I also offer rebuilding services for the amp-- Ron Rich

What exactly is the input plug on the amp? I'm new at electronics stuff. I have power supply, speaker wires, volume control, 4 wire block labeled mech and red mech and blue mech wires. Thanks

Red mech and blue mech

No static after unplugging the input. I will PM you.