replace 5y3

[ardan77]

Hy,

I want to do this guitar amplifier and i don't have the 5y3 so i think to replace him with some 1n4007 but i don't know how.
So please help me.

 

[Geek]

Using 1N4007 with 100R, 10W resistors in series with each on the AC side is the standard practise, IIRC.

 

[kathodyne]

as far as i know
(pls correct me if i'm wrong!)

1. lose the heater winding.
2. use center tap on mains secondary
3. replace rectifier with SS diode, both in the direction of the circuit, one on each leg of mains secondary (1n4007,byw96d)
4, -you could use a higher value for the input cap-
5. -you might need an extra resistor before the input cap, due to a higher voltage because of using SS diodes-
6. use a standby switch to let the tubes heat before applying HV


that's it...
you don't have a slow turn on of HV now.....

-hey greg!! you beat me with typing! 🙂......

 

[ardan77]

Thank you for yours reply
But i don't understand i have to put the 100ohm resistors in series with every diode, and where i put the standby switch?

 

[Witchdoctor]

The reason for putting 100 ohm resistors in series with the diodes is that sand rectifiers have a lower voltage drop (approx .7 volt) than their hollow state forebearers, which have a voltage drop measured in volts.

Take the centre tap from the high voltage winding on the transformer, remove it from where it's connected, and connect it to one terminal of the standby switch, and connect the other terminal of the switch to where the centre tap was connected.

The next time you turn the amp on, turn on the main switch, wait about 30 seconds, and then turn on the standby switch and enjoy the toob sound.

 

[kevinkr]

You might want to reconsider and possibly just purchase a 5Y3, the sound will differ significantly if you switch to solid state rectifiers.