Kay 703-C Hum

Amps

Ampeg
SVT CLASSIC • shuts off
SVT-VR • won't balance
Epiphone
Electar-Zephyr • tubes • capacitors
Fender
DEVILLE • bad input jack
MINI-TWIN • convert to stompbox
PRINCETON 5F2-A • re-cap
SUPER CHAMP • replacing AC inlet
SUPER TWIN • intermittent volume
VIBRO CHAMP • shock prevention
Kay
703-C • re-cap
Marshall
DSL100 • choke & o.t. install
Montgomery Ward
VALCO 62-9033 • 6973 tube substitute • broken trem. control
Peavey
6505+ • tube filaments
CLASSIC-30 • power resistor
Selmer
LITTLE GIANT MK 3 • loose transformer
Vox
AD50VT • power resistor
VALVETRONIX • pot replacement

Keyboards

Akai
MPC2000XL • bad jog wheel
Casio
PRIVIA PX-130 • broken power jack
E-Mu
VINTAGE KEYS • broken volume pot
Ensoniq
SQ-2 • battery change
Farfisa
MINI COMPACT • divider problems
Korg
01/W • keybed removal
KARMA • key contacts
KRONOS • key clacking
M1 • worn-out buttons
POLY-61 • envelope problems • battery upgrade
SV-1 • removing the keybed • removing the keys • replacing the tube
TRITON • disassembly
TRITON • worn-out buttons
X3 • floppy drive belt
X3 • worn-out buttons
KEYS & CONTACTS • m1, 01w, i2, i30, t3 • triton, trinity, oasis...
Kurzweil
PC88 • worn-out buttons
M-Audio
KEYSTATION • broken USB jack
Moog
MICROMOOG • dirty keys & controls • contour problems • calibration & tuning
MINIMOOG • key bushings
PRODIGY • key contact cleaning
ROGUE • broken power jack
Roland
D-50 • key contact cleaning
JUNO-60 • battery upgrade • key contacts
JUNO-106 • 3-prong AC jack
TR-808 • cracked ribbon cable • worn-out switches • new battery holder
Sequential Circuits
PRO-ONE • key contact cleaning
Vox
CONTINENTAL • key contact cleaning • drawbar problems • new panel switches
Yamaha
DGX-530 / YPG-535 • no sound
MOTIF 6 & 7 • disassembly
MOTIF 6 & 7 • worn-out buttons
SY77 • battery change
KEYS & CONTACTS • motif 6/7, w5, kx76, • dx7, sy77/85/99 ...

Technique

Kay 703-C	View the Repair
60-Cycle AC Hum	View the Repair


This Kay 703-C guitar amp arrived in the shop with a low-level hum in the background.
Hum can mean that one or more filter capacitors are worn out in the power supply. This would let a 60 Hertz ripple get past the power supply and into the amplifier.

View the Repair >