Polytone Mini-Brain 75W + 1×15 Cab

Polytone is one of the classic “working jazz” amp names, built around compact, loud, reliable solid-state designs that could live in clubs night after night. The company was started in North Hollywood, California by jazz accordionist and inventor Tommy Gumina in the mid-to-late 1960s, and Polytone amps quickly became a common sight behind jazz guitarists and bassists who wanted clean headroom in a small footprint.

The Mini-Brain is the separate head version of that idea: simple controls up front, plenty of volume for real-world gigs, and a direct, uncompressed response that works well for archtop guitar, hollowbodies, and electric bass. This Mini-Brain is the 75W Lead/Bass model, rated 75W into 4 ohms, and it includes onboard spring reverb plus an effects loop, so you can keep the core sound clean while adding pedals as needed.

Polytone’s user list is long, but it is firmly linked with mainstream jazz and smooth-jazz era backlines. Players commonly associated with Polytone include George Benson, and the brand is widely tied to the small “Mini” format for gigging jazz players who wanted consistency and fast setup.

This particular rig is the Mini-Brain head paired with a matching Polytone 1×15 cabinet. Cosmetically it is very worn from years of gigging, with plenty of marks to show for it, but it is fully functional and sounds great. If you want a straightforward, proven jazz amp setup with a bigger 15″ footprint, this is it!

SPECIFICATIONS

• Manufacturer: Polytone Musical Instruments, North Hollywood, California
• Model: Mini-Brain Lead/Bass
• Amp type: Solid-state amplifier head
• Rated output: 75W output into 4 ohms
• Power consumption: 135W input
• Mains rating: 120V, 60Hz
• Fuse: 2A, 250V, slo-blo
• Front panel controls: Bass with concentric Mid control, Treble, Volume
• Front panel switching: Power, Reverse polarity, Gain switch, Bright and Dark switches
• Inputs: 2 x 1/4″ instrument inputs labeled Hi and Lo
• Outputs: Main Out (1/4″)
• Speaker outputs: 2 x 1/4″ jacks labeled SPKRS OUT
• Headphones: 1/4″ headphone output with dedicated Volume control
• Effects loop: 1/4″ Return and Send jacks with level controls
• Reverb: Internal spring reverb