Kay K-504 1960s Amplifier Cab With Mojotone Princeton Amp Kit Upgrade

No sales tax for US customers outside California.

Here's a cool piece - a Kay amp chassis and cab with a Mojotone Fender Princeton kit built in, in place of the original electronics.

Kay Musical Instrument Company was one of the largest American guitar and amplifier manufacturers of the postwar era, producing instruments and amplifiers under the Kay name and for dozens of other brands from their Chicago factory. The Kay amplifier cabinets of the 1950s and 1960s are distinctive in their own right — covered in the black and cream paperbacked vinyl that collectors call "Kayhide," built from plywood with the straightforward construction that Kay applied to everything, and aged to a character that no new cabinet reproduces. This 1960s Kay cabinet has been put to new purpose as the housing for a 2017 Mojotone Princeton-style amplifier kit build — a thoughtful combination that puts a proven modern circuit inside a cabinet with genuine vintage character.

The Mojotone Princeton-style kit is based on the classic Fender Princeton circuit, widely regarded as one of the most recorded amplifier circuits ever made — a Class A all-tube design with the smooth, balanced negative feedback character that produces clear, chimey tone at low volumes and warm, musical saturation as the volume climbs. This build runs two 6V6 power tubes rather than the single-6V6 of the standard 5F2-A kit, producing approximately 12 watts alongside onboard vibrato — a more versatile platform than the basic Princeton circuit while retaining the same fundamental tonal character. The 5Y3 tube rectifier provides the supply voltage sag and dynamic compression that players associate specifically with vintage Class A circuits — the feel of the amp responding to pick attack in real time rather than delivering a stiff, regulated signal. Two 12AX7 preamp tubes complete the tube complement.

The Celestion Eight 15 (G8C-15) 8" speaker is a British-made alnico unit rated at 15 watts — a speaker with a well-documented character of warm, detailed midrange response and early, smooth breakup that pairs naturally with Princeton-style circuits. Mojotone power and output transformers, both dated to 2016-2017 production. Grounded power cord. The original Kay cabinet, original die-cast metal handle, original knobs, and original Kayhide covering are all intact — the grille cloth is original and in poor condition, noted honestly. At 16 lbs 9.5 oz this is a light, portable combination that fits easily into a car or on a recording session.

SPECIFICATIONS:

• Case/Cover?: no
• Case/Cover Brand: n/a
• Case/Cover Condition: n/a
• Weight: 16lbs 9.5oz
• Dimensions: w 17.5" x h 14.75" x d 8"
• Watts: 12 Watts
• Covering Material: paperbacked vinyl, aka "Kayhide"
• Covering Color: black and creme
• Covering Original?: yes
• Cabinet Material: plywood
• Cabinet Condition: good
• Cabinet Repairs/Changes: n/a
• Cabinet Original?: yes
• Grille Style: plain
• Grille Condition: poor
• Grille Original?: yes
• Baffle Material: plywood
• Baffle Conditon: good
• Baffle Original?: yes
• Baffle Repairs/Changes: holes for new speaker
• Chassis Material: sheet metal
• Chassis Condition: good
• Chassis Original?: yes
• Chassis Repairs/Changes: Mojo Princeton mod kit
• Knobs Original?: yes
• Handle Original?: yes
• Handle: die cast metal
• Date: 1960s
• Where Is Date Noted?: determined by internet research
• Speaker 1 Brand: Celestion Eight 15, G8C-15
• Speaker 1 Size: 8"
• Speaker 1 Manufacturer Code: T
• Speaker 1 Date Code: n/a
• Speaker 1 Cone Code: n/a
• Speaker 1 Condition: Excellent
• Power Transformer Manufacturer: Mojo 
• Power Transformer Manufacturer Code: 996
• Power Transformer Date Code: 1647
• Power Transformer Original?: no
• Output Transformer Manufacturer: Mojo
• Output Transformer Manufacturer Code: 996
• Output Transformer Date Code: 1730
• Output Transformer Original?: no
• Choke Transformer Manufacturer: n/a
• Choke Transformer Manufacturer Code: n/a
• Choke Transformer Date Code: n/a
• Choke Transformer Original?: n/a
• Reverb Transformer Manufacturer: n/a
• Reverb Transformer Manufacturer Code: n/a
• Reverb Transformer Date Code: n/a
• Reverb Transformer Original?: n/a
• Reverb Onboard: no
• Reverb Tank Original?: n/a
• Tremolo Or Vibrato Onboard: vibrato
• Pedal Included?: no
• Pedal Condition: n/a
• Pedal Original?: n/a
• Rectifier Tube: 5Y3
• Rectifier Tube Brand: RCA
• Power Tubes: 2 x 6V6
• Power Tube Brand: RCA
• Preamp Tubes: 2 x 12AX7
• Preamp Tube Brand: Sovtek, ?
• Potentiometers Original?: no
• Filter Caps: replaced/mod kit
• Internal Repairs: Mojo Princeton mod kit
• Power Cable: grounded
• Documentation: n/a
• Smells?: n/a
• Accessories Included: n/a

SHIPPING POLICY:

When you purchase this item you are hereby agreeing to this shipping policy. We remove tubes from amps that could be damaged in shipping.  These cases require the buyer to re-install them on delivery - it is very easy with this amp, and we label them so you know exactly where to put them.  We do this because we have experienced shipping issues in the past, and this is our prevention measure.  Vintage amps are sold as-is because they can need service intermittently.  Everything is tested here in our shop on the way into our inventory, and again before shipping.  We will cover shipping damage, but we cannot be responsible for the failure of vintage components in 20-to-50-plus year old amps. Shipments will require signature on delivery, no exceptions.  If there is damage, the buyer must retain all packing materials intact and picture them immediately and send them to sales@maharsvintageguitars.com.  Less than 1% of our shipments are damaged in transit, and we are committed to making sure your item arrives safely, but we are taking these additional measures to make sure you are happy with your purchase.