Pass Labs XA-25 on all the time?
chart showing internal impedance of capacitors going up as hours of use go by. this is a primary component of pulse power supply failure. https://www.researchgate.net/figure/Aging-test-of-electrolytic-capacitors-at-C-values-measured-at-C-... thus, all sub amps tend to go bye-bye,after a certain point. the caps go off in value and impedance, and then things overheat and the thing goes poof. And are then relegated to the trash bin. Conventional power supplies last much much longer. the same deal happens to these pulsed units, these class D amps. They start to sound off as they age. Especially true when they have a pulsed power supply hooked up to a pulsed amp circuit. this is why old gear needs to be re-capped. It is not vintage sound, it is dead slow dark capacitors, on the verge of dying and taking some circuitry with them. see this chart: https://www.researchgate.net/figure/ESR-measured-at-C_fig2_3279777 but wait, there’s more... Thus, not using your SS amps and gear? shut it off. Once or twice a day (Off-on, etc) is fine. No problemo. Leave it on all week? Never. Gear sitting in a hot sunroom? Or similar elevated temperature locations? No, don’t go there. To leave an amp on all the time, the result is...you age the capacitors, over a given time.. by a factor of at least two, or more, maybe four. You dull the high frequencies, close in the spacial aspects, and lose all the fine detail, dull the transients, misalign the circuit’s intended behavior, increase distortion and heat generation, and..well..just generally kill the amp. the distortions generated as the capacitors age will happen in the area of where we look, with our ears, for ’information’ in the signal. But that thing we hear, on aged capacitor gear..can be and generally is just crunchy noise we mistake as detail. It’s a hardening of the signal, where all of it tends to sound the same. It is actually distortions, and distortion patterns. Which, being in-harmonic, are easier to hear as the ear is designed to hear in-harmonics as separate. Think of the dark screech monotonous sound (everything sounds the same,and all bad) that comes from a 70's Marantz receiver, that has never been serviced. Do you hear it now? It’s what we use to detect threats, this detail distortion separated from the signal body. it can excite us. It’s a thing that people with unrefined hearing mistake for detail... as they can make it there, psychologically. Big breast implants and collagen lips ---for those with blunt senses. It’s what Class d and mediocre amplifiers do. Hearing that for what it is, is one of the big steps to getting closer to that unreachable goal. |
