I have owned a Sony TAN-5550 VFET power amp since 2003. I believe I am the second owner and once received I had the amp gone through to replace the "death diodes" and other needed items.
So my question has to do with the longevity of the VFETs (all original). As this amp is approaching 50 years old, and being used a few times a week for several hours each time, should I expect that the VFETs will last for another xx number of years or are they on borrowed time?
So my question has to do with the longevity of the VFETs (all original). As this amp is approaching 50 years old, and being used a few times a week for several hours each time, should I expect that the VFETs will last for another xx number of years or are they on borrowed time?
I would keep on top of electrolytics, trimmers and diodes and the amp should last another 50+ years.
Read up, they are unique to Sony, and replacements are not easily available..
Some corrosion or other manufacturing issues led to their withdrawal, and replacements are not considered as good.
And do take up preventive maintenance.
Some corrosion or other manufacturing issues led to their withdrawal, and replacements are not considered as good.
And do take up preventive maintenance.
Seconded, and it’s more likely smaller value electrolytic caps on power amp board would make the circuit they’re in unstable, the trimmers could cause instability of bias for instance.
So it’s not the devices themselves per se , but the circuitry around and behind them. Dry joints unattended to could also put them under threat.