Hello, in the past, in Europe the standard main voltage used to be 220 Volts. This mains power voltage has been increased over the years and at the moment it appears that the standard is 240V, raised again from 230V that used to be the standard in recent years.
When I measured my mains power voltage where I live, it is at times even 245 V, partly due to solar generated excess power when the sun shines brightly.
Now, the potential problems I face with these elevated voltages is with my older equipment. I use a diy tube amp with a power transformer (ex-Lafayette from the seventies) that is rated for 220V, and an older Rotel RB-850 power amp that is also rated for 220V. Besides that, I also use a Rotel RB-980BX amp that is rated for 230V. All according to the labels on the back. For the 220V tube amp it became obvious, that the B+ tension is too high when connected to 240V mains power and I use a variac (1000W) to bring the voltage back to 220V and the working voltage for the EL84 tubes back to 300V. I do have more tube amps from old times, when the mains power used to be 220V.
I would like to know what the (long term) consequences could be if older gear is exposed to elevated mains voltage. Is there a difference between solid state and tube amps? Does solid state amps may also "wear out" quicker or would it affect sound quality? What would be a good work-around besides a variac (may be bad for sound quality?). It is mostly not possible to rewire the power transformer because the needed taps are simply missing.
Thanks for the advise!
When I measured my mains power voltage where I live, it is at times even 245 V, partly due to solar generated excess power when the sun shines brightly.
Now, the potential problems I face with these elevated voltages is with my older equipment. I use a diy tube amp with a power transformer (ex-Lafayette from the seventies) that is rated for 220V, and an older Rotel RB-850 power amp that is also rated for 220V. Besides that, I also use a Rotel RB-980BX amp that is rated for 230V. All according to the labels on the back. For the 220V tube amp it became obvious, that the B+ tension is too high when connected to 240V mains power and I use a variac (1000W) to bring the voltage back to 220V and the working voltage for the EL84 tubes back to 300V. I do have more tube amps from old times, when the mains power used to be 220V.
I would like to know what the (long term) consequences could be if older gear is exposed to elevated mains voltage. Is there a difference between solid state and tube amps? Does solid state amps may also "wear out" quicker or would it affect sound quality? What would be a good work-around besides a variac (may be bad for sound quality?). It is mostly not possible to rewire the power transformer because the needed taps are simply missing.
Thanks for the advise!
I've seen - might even have, buried somewhere in my Google Drive - an article (from 50s or 60s) that detailed tube life related to filament voltage. IIRC a modest decrease helped extend tube life, while an increase definitely shortened it. I may be wrong (won't be the first time) that a 10% increase in B+ won't, typically, have a deleterious effect on the tubes, or circuit, while it might well have on the filament supply.
