Upgrading or replacing capacitors
Capacitors DO make an audible difference !
Electolytic and tantalum capacitors have fairly poor audio characteristics and ideally should not be used in the audio signal path but are used in other parts of the amplifier. Replacing electrolytic capacitors in the audio signal path of your amplifier or preamp with film capacitors will improve sound quality. Polyester (Mylar) capacitors make a significant sound improvement and are the minimum quality audio capacitors that should be used in the audio signal path. Better are polypropylene capacitors, and even better are polycarbonate capacitors when available. The very best audio capacitors are polytetrafluorethylene (Teflon) capacitors, but they are generally very, very expensive and available in only a relatively few sizes.
Electrolytic capacitors (aluminium)
These are easy to spot and look like little round cans, with two wires coming out of the bottom.
You can also tell if one is about to or is failing as they either will buldge like they are about to burst or they may get a crusty residue around the top.
To replace an electrolytic capacitor
First work out the specifications of the capacitor you wish to replace. These are normally printed on the outside of the capacitor.
for example, 470ohms 50V
Electrolytic Capacitor polarity
Capacitors need to be connected in one direction to work effectively.
The will normally have two wires coming out of them, one longer than the other. The longer wire is a positive connection and the shorter negative. Often capacitors also have marking on their cases in the form of a line of "-" symbols runing along the case. This is to indicate which side is negative.
You can work out which way round the capacitor should be connected
- from the circuit digram
- by looking at and making a note of the orientation of the old capacitor
- most of the positive wiring in the Separo amps is red and most of the negative wiring is black
Polycarbonate, polypropylene and other types of capacitors
These can come in a mixture of shapes and sizes so it is worth checking the make and details printed on them.