Install a ntc thermistor type cl 60 in the primary side of maintransformer and the eating of tubes is over.
Shematic exsampleView attachment 113267
of course yes, an ntc resistor cl60 has 10 ohms when cold, limits the inrush current of the amplifier for 2 seconds, after that the ntc has about 0.15 ohms. This protects the filaments and cathodes of the tube.Please can you explain a bit how does it work ?
of course yes, an ntc resistor cl60 has 10 ohms when cold, limits the inrush current of the amplifier for 2 seconds, after that the ntc has about 0.15 ohms. This protects the filaments and cathodes of the tube.
That's right, you have to adapt an ntc to the amplifier if you want it to be perfect. Most amplifier nameplates show the contoured power consumption in watts. Dividing the wattage by the mains voltage gives the current. You may need to choose another NTC type. They should be in the range of 80-100%, then this has no audible influence. Since I don't know the power consumption of the amplifier, safety comes first with this NTC. it's easy on your wallet, especially when very good tubes are in use.As far as I remember this NTC has such resistance (around .2 ohm) at maximum current (5A) . At 25% the load it is around 1 ohm and this resistance modulates with the current - it is why I do not recommend them particularly in class A/B. .
That's right, you have to adapt an ntc to the amplifier if you want it to be perfect. Most amplifier nameplates show the contoured power consumption in watts. Dividing the wattage by the mains voltage gives the current. You may need to choose another NTC type. They should be in the range of 80-100%, then this has no audible influence. Since I don't know the power consumption of the amplifier, safety comes first with this NTC. it's easy on your wallet, especially when very good tubes are in use.
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