Hi!
Wire the two switches such that the filament switch not only switches the filament transformers, but also applies the mains voltage to the HV switch. This avoids that the HV can be accidentally switched on without filament voltage.
Best regards
Thomas
Wire the two switches such that the filament switch not only switches the filament transformers, but also applies the mains voltage to the HV switch. This avoids that the HV can be accidentally switched on without filament voltage.
Best regards
Thomas
I personally strongly like to mix whatever needs to get better results. And can't understand why somebody would want to set meaningless boundaries.
Looks like it is the best solution of the initial problem. Such approach was used in radar stations. Also, antenna switches (actually, doors between waveguides) had additional switches to prevent powering on high voltage source until it switches properly. It was the requirements for magnetrons, to have hot emitting cathode, and properly tuned output, before applying anode voltage. However, I don't understand why it would be needed for audio amps, but since it is a hobby everyone is free to go for own personal goals.
In this case the answer is...because I want to!
Maybe I have a switch fetish.
Please don't use "the brand of a switch with 4 letters that start with Ni."
😀
Two switches are the only right way to power on a tube amp, it is less expensive and simpler too, I fell afraid when I see just a sole switch in a amp.
Temporized relay, clocks etc are more expensive and prone to fail with age, a 2ºclass solution, some tubes had long heating time as 6C33(600 seconds) for the cathode to reach the proper temperature, a 600 seconds timer is too long.
Ralph Karsten use two switches in the Atma-Sphere amps and its run alot of tubes.
Temporized relay, clocks etc are more expensive and prone to fail with age, a 2ºclass solution, some tubes had long heating time as 6C33(600 seconds) for the cathode to reach the proper temperature, a 600 seconds timer is too long.
Ralph Karsten use two switches in the Atma-Sphere amps and its run alot of tubes.
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Nonsense. In most cases one switch with no sequencing at all is the correct way to power an amp. If sequencing is needed (rare with normal audio valves) then it should be automatic. If you are "afraid" then use proper interlocking so the switching is failsafe. Two switches is either a DIY fad (it's a free world) or a marketing ploy for ignorant people. Why not add a third switch for the input signal?FullRangeMan said:
I do not like to apply the grid & B+ with the cathode yet cold, the usual 30 seconds is ridiculus short time, cathode takes various minutes to reach the proper work temperature.
The Almarro 318 6C33 SET had a too short delay, but others 6C33 amps had nothing, they apply the HV supply just after the power on.
In these hard conditions the 6C33 last few hours and they blame the factory quality control.
Here in Argentina, valves are scarce and expensive.
I build regulated DC PSUs, with soft start, and time delay between filament power and B+, in order to minimize cathode ion bombardment.
And if I find some evidence, theoretical and/or experimental, also would use garlic if necessary. 😀
I build regulated DC PSUs, with soft start, and time delay between filament power and B+, in order to minimize cathode ion bombardment.
And if I find some evidence, theoretical and/or experimental, also would use garlic if necessary. 😀
Not only tubes. Here, in the "*** of the world", is a tendency to believe that automatically that new thing appears in the market, older ones are trash. Not only happen with tubes, TV´s, monitors, older PC's still perfectly functional, and all other electronic sets.
So, you can walk by the streets viewing not so old CRT TV´s scrapped by "Cartoneros" o "Cirujas" to get the copper from them, and I'm speaking of TV's with no more than 2 years of use. This has been happening from I'm a student. (Sorry to moderators, no translation is possible to this words).
I like vinyl disks, and buy a new vinyl of recent musicians (DJ´s) is extremely difficult, added to the "Presidenta's" staff who believe that block importing is the solution to the economical catastrophe they themselves are creating. This way, neither a tube nor insulin are easy to find.
Che loco, cortala con que somos el culo del mundo, la gente nos va a mirar peor que antes.🙄
No contés mas, que me hago cartonero, a diario me toca reparar TVs de mas de 20 años.
Acá en Traslasierra no tiran ni la tapita de la Coca Cola.😀
No la invoques mas, Cristina y la p...
Your so poetic terms for our country, people will be excited about coming holiday.🙄
Don't say more, I become a homeless, every day I repair TVs for 20+ years.
Here in Traslasierra don't throw away neither the cap of Coca Cola.😀
No name to our dear Mrs President.😀
If you want one switch with two functions,consider the standby switch guitar amp professionals use.
Here is one example: Carling Off/Standby/On Switch Blackheart Champion 600 | eBay
no doubt other sources can be found. I've used them myself. With a 1000V dielectric strength,switching B+/HT+ is not a problem.
Here is one example: Carling Off/Standby/On Switch Blackheart Champion 600 | eBay
no doubt other sources can be found. I've used them myself. With a 1000V dielectric strength,switching B+/HT+ is not a problem.
OT
Could not resist to link the video (Polish crazy engineers) - two wheel small Fiat
MALUCH-tuning - YouTube
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