18-04-2012, 11:40 PM
Ah well - if the bad ones were Daly, then that's the answer. I change these on sight now. As I say, the Philips are good, but the older red Electromolds are a mixed bag - sometime OK, mostly not, but I take each of those on their merits...
Depending on where they are, a bit of leakage can be bad - typically upsetting the DC conditions throughout the amplifier. If they are just supply decoupling, they might just run the battery down a bit faster, or drag down a rail if there is a resistor between them and the battery - the answer is "it depends". But they need to be changed either way.
As for ESR, I've had leaky capacitors that have read really well on an ESR meter. Including some that were totally short! With capacitors, you have to measure all 3 (value, leakage - at the working voltage - and ESR). Arguably, ESR is the least useful in a radio, though as you know, it's public enemy number 1 in a typical power supply
When the RP18 arrives, you'll probably find that the amplifier is full of those Daly capacitors, and will probably not work as a result. I'd recommend a blanket swap, but if you decide to apply logic (why not - it's a good way to learn), you ought to change C7 and C10 - even if the set appears to work. Otherwise, they'll put DC onto the bass control, causing crackles that might eventually damage the track.
How are you getting 6Music into it - straight in at the volume control?
Cheers,
Mark
Depending on where they are, a bit of leakage can be bad - typically upsetting the DC conditions throughout the amplifier. If they are just supply decoupling, they might just run the battery down a bit faster, or drag down a rail if there is a resistor between them and the battery - the answer is "it depends". But they need to be changed either way.
As for ESR, I've had leaky capacitors that have read really well on an ESR meter. Including some that were totally short! With capacitors, you have to measure all 3 (value, leakage - at the working voltage - and ESR). Arguably, ESR is the least useful in a radio, though as you know, it's public enemy number 1 in a typical power supply
When the RP18 arrives, you'll probably find that the amplifier is full of those Daly capacitors, and will probably not work as a result. I'd recommend a blanket swap, but if you decide to apply logic (why not - it's a good way to learn), you ought to change C7 and C10 - even if the set appears to work. Otherwise, they'll put DC onto the bass control, causing crackles that might eventually damage the track.
How are you getting 6Music into it - straight in at the volume control?
Cheers,
Mark
