After more than 10-15 years, you can be certain that the electrolytic capacitors in your amplifier will have aged, leaked, if not worse, and will not perform at their best, making your amplifier a worse performer.
Some of those capacitor are important because they provide an electrical power reserve when volume peaks are needed, some others are on the signal path, some are within the phono pre-amplifier.
A replacement of those capacitors (a recap) is something that is needed at that stage.
Here are the capacitors that will need changing on this amplifier, on the schematic diagram:
Here are the capacitors that will need changing on this amplifier, on the wiring diagram:
In order to visually help, here are a few shots of the real thing. The two main 8200 µF capacitors for the power supply are not shown here, but you can't miss them, they are the biggest things on the board!
Here is the list and description of the capacitors to change:
|Item||Number||Voltage (V)||Value (µF)||Diameter (mm)||Comments|
|1. Power Supply|
|C903||35||8200||30||10,000 µF 35-40V would be ok too|
|C904||35||8200||30||10,000 µF 35-40V would be ok too|
|C605||100||10||6||Something like Panasonic FC series|
|C606||100||10||6||Something like Panasonic FC series|
|3. Phono stage|
|C405||10||4.7||"Bead"||Something like Panasonic FC series, use 10 µF instead|
|C406||10||4.7||"Bead"||Something like Panasonic FC series, use 10 µF instead|
|C417||50||10||6||Something like Panasonic FC series|
|C418||50||10||6||Something like Panasonic FC series|
Here are suggestions for replacement, with references from RS Components:
|Item||Number||Description||Pack of||Diameter (mm)||RS Stock No||Manufacturer part #||Price||URL|
|1. Power Supply|
|C903||Nichicon Aluminium Electrolytic Capacitor 10000μF 35 V 22mm Through Hole 5101-4 VY Series Lifetime 1000h +105°C||1||22||739-5324||UVY1V103MRD||£3.02||http://uk.rs-online.com/web/p/aluminium-capacitors/7395324/|
|C904||Nichicon Aluminium Electrolytic Capacitor 10000μF 35 V 22mm Through Hole 5101-4 VY Series Lifetime 1000h +105°C||1||22||739-5324||UVY1V103MRD||£3.02||http://uk.rs-online.com/web/p/aluminium-capacitors/7395324/|
|C901||Nichicon Aluminium Electrolytic Capacitor 2200μF 25 V dc 16mm Through Hole PW Series Lifetime 8000h +105°C||5||16||715-2684||UPW1E222MHD||£4.64||http://uk.rs-online.com/web/p/aluminium-capacitors/7152684/|
|C902||Same as above, in the pack of 5||-|
|C605||Nichicon Aluminium Electrolytic Capacitor 10μF 100 V 5mm Through Hole JIS C 5101-1 VY Series Lifetime 1000h +105°C||1||5||862-4190||UVY2A100MDD||£0.24||http://uk.rs-online.com/web/p/aluminium-capacitors/8624190/|
|C606||Nichicon Aluminium Electrolytic Capacitor 10μF 100 V 5mm Through Hole JIS C 5101-1 VY Series Lifetime 1000h +105°C||1||5||862-4190||UVY2A100MDD||£0.24||http://uk.rs-online.com/web/p/aluminium-capacitors/8624190/|
|3. Phono stage|
|C405||Nichicon Aluminium Electrolytic Capacitor 10μF 50 V dc 5mm Through Hole PS Series Lifetime 2000h +105°C||5||5||519-4289||UPS1H100MDD||£0.93||http://uk.rs-online.com/web/p/aluminium-capacitors/5194289/|
|C406||Same as above, in the pack of 5||-|
|C417||Same as above, in the pack of 5||-|
|C418||Same as above, in the pack of 5||-|
Removal and clean-up of all capacitors:
Installation of the new components, plus bias readjustment:
This little amp is now singing like a champion!
For your reference, here are the owner's manual and service manual: