GoatGuy: I know what you mean as I am a bit of a never give up, dog with a bone type of guy myself. However, whilst the amp is now nice and calm, I think I'll stick for the moment as I do have other pastimes that are now screaming out for my in depth attention. For now, if I can find a couple of valves as spares that are as quiet as the one fitted, I'll be happy.
Thank you so much for your ideas and support.
Roger
Thank you so much for your ideas and support.
Roger
"Hello power company? I'm frightened!! My lamps are real bright and burn up in a day, the Hoover roars and almost sucked-up the cat, and I hear electricity in the walls. Am I going to be electrocuted??"
I ran a similar cry for help at my power company when they took out some bad wires and my wall voltage rose. (To 123V, but this was 29 years ago.) The lamps WERE burning-out too often, and I'd had enough, so I played the scared customer role. Next day they had took off 5 or 6 Volts (which matters in 120V land).
PRR,
I have never knowingly noticed any detrement to any of our electrical appliances that has caused any concern but we are in a unique situation in the UK in that our mains supply is '240 VAC' whereas the EU is '230 VAC'. When we belonged to the EU they covered this by declaring that all EU countries were to be '230 VAC' -6% +10% which covered the UK as it had massarged the spec to 216.2 - 252 VAC so as the UK didn't have to adjust their voltages. I think that is still the spec for the UK. Yesterday was over the top for the UK, but this morning I measured it at 243.5 VAC which is about normal for us. Sadly, many amplifiers for the UK market have their mains voltages set for 230 VAC and have no tapping for 240 VAC. I changed the mains transformer in the amplifier in question for one with a 240 VAC tapping.
Thanks for your concern.
I have never knowingly noticed any detrement to any of our electrical appliances that has caused any concern but we are in a unique situation in the UK in that our mains supply is '240 VAC' whereas the EU is '230 VAC'. When we belonged to the EU they covered this by declaring that all EU countries were to be '230 VAC' -6% +10% which covered the UK as it had massarged the spec to 216.2 - 252 VAC so as the UK didn't have to adjust their voltages. I think that is still the spec for the UK. Yesterday was over the top for the UK, but this morning I measured it at 243.5 VAC which is about normal for us. Sadly, many amplifiers for the UK market have their mains voltages set for 230 VAC and have no tapping for 240 VAC. I changed the mains transformer in the amplifier in question for one with a 240 VAC tapping.
Thanks for your concern.
Looking at that new UK quality mark they are looking to introduce, I wouldn't be surprised if we see right hand drive electricity before too long.
Two new Sovtek 12AX7WC valves arrived today and both of them quiet in the V1 position. No hum whatsoever from either of them. Just a very tiny hiss when placing an ear next to the speaker, which is what I would expect.
I'm now a very happy bunny.
My thanks to you all for your very valued relies.
Roger
I'm now a very happy bunny.
My thanks to you all for your very valued relies.
Roger
I suspect the issue is defects or lacking filament coatings, which allow emission direct from heater wire to cathode. The heater coating is there to stop the heater being emissive and to stop it evaporating away, as well as simply electrically insulate it. The ends of the heater wires are uncoated where they are clamped/welded, and this allows a portion of heater wire to be both hot and uncoated, depending on how close the coating ends to the clamp.
You could have a look next time you have a badly humming valve to see if the heater has poor coating.
You could have a look next time you have a badly humming valve to see if the heater has poor coating.