pre amp output delay circuit?

[tomat]

anyone can give suggestion for simple delay output circuit for tubes preamp?,that could be delayed about for 15 to 20 second.
thanks

[aardvarkash10]

and would help in identifying the best solution

[ashok]

You could use a NE555 timer chip to get you any time delay you want. It could drive a relay connected to the output. Use a small resistor in the output circuit ( series with the output capacitor ) and relay contacts shorting to ground when the coil is not energised. That way the relay contacts will not be in the signal path.
The whole circuit could be powered by the heater supply.

[Geek]

Hi,

I have a critter that may be of help:
http://www.classicvalve.ca/surplus.html#DELAY

Cheers!

[tomat]

Originally Posted by ashok

You could use a NE555 timer chip to get you any time delay you want. It could drive a relay connected to the output. Use a small resistor in the output circuit ( series with the output capacitor ) and relay contacts shorting to ground when the coil is not energised. That way the relay contacts will not be in the signal path.
The whole circuit could be powered by the heater supply.

thank you ,and may you have the schematic for this?

[tomat]

Originally Posted by Geek

Hi,

I have a critter that may be of help:
http://www.classicvalve.ca/surplus.html#DELAY

Cheers!

thank you ,i will look for this

[ashok]

"...............and may you have the schematic for this? ........."

No I don't but I could put one up for you. However I am going out of town in a few hours time and will be back on Monday. So if you don't see one please post again.
What is the power supply for the heater? Can you put up a circuit diagram of the heater power supply. Transformer rating and rectifier circuit if you use dc for the heater. It could be 6 V or 12 V or something close to it.