Tweet
I always test caps with an ESR meter and inspect them for leakage and bulges. I also test them for unusual temperature rise in old amps. There's an increased frequency of electrolytic replacement in tube amps compared to industrial or other audio use. How many people go around the house (or factory) re-capping everything that's 10 years old? I'm not entirely convinced about the automatic replacement of caps when an amp reaches a certain age - I see too many old amps that have their original caps to make me think that there's necessarily a problem. Sure, old Marshalls may have bulging or leaking blue LCR cans, and the grey Illinois caps fitted to Fenders fail often and their ESR will measure 100 ohms or more. I see amps that have been butchered to get the cans out (Champs and Ampegs especially) and a nightmarish tangle of replacements that have been shat there rather than properly fitted and wonder if they needed replacing in the first place.
I take a view of the condition of the caps, the brand and series, the intended use, the operating voltage compared to their rated voltage, and their position in the circuit.
Guitarists worry more about re-capping a 10 year old amp than replacing the 10 year old/120,000 mile timing belt on their car.
I take a view of the condition of the caps, the brand and series, the intended use, the operating voltage compared to their rated voltage, and their position in the circuit.
Guitarists worry more about re-capping a 10 year old amp than replacing the 10 year old/120,000 mile timing belt on their car.
Comment