Kay K-504 Amplifier 1960s Cab with Mojotone Princeton Amp Kit Built In 2017 - Black and Creme
Description
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 . 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.
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 . 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.