Southern Belle 1n5817 schottky diode equivalent?

[frankenteletron]

Hello! Building a Southern Belle and wondering if there is an equivalent alternative for the 1n5817 Schottky diode? Or something "close enough". Thanks!

 

[Nostradoomus]

1n4001

 

[mistersparkle]

The 1N5817 Schottky diode in the Southern Belle is acting as reverse-polarity protection to prevent blowing up the circuit in the event you connect the 9V power supply backwards. The 9V supply must flow through this diode in order to power the circuit. However ALL diodes have a "forward voltage drop", meaning that you will lose some of your 9 volts just passing through the diode. The 1N5817 was chosen for its relatively low forward voltage drop (between about .3 to .4 volts) so your circuit will be running on 8.6 to 8.7 volts instead of 9. The 1N4001 is not a Schottky, and will introduce a voltage drop of about .6 to .7 volts, meaning your circuit will be running on 8.3 to 8.4 volts.

Now that you know what the purpose of this diode is and the primary characteristic that influenced its choice for this circuit (and many other FX pedal circuits), you can search for an equivalent. Other specs for this diode include a 1 amp current rating and a max of 20 volts. The 1N5817 has 30 volt and 40 volt brothers (1N5818 & 1N5819 respectively) that will work fine in this circuit, and if you're absolutely certain you will NEVER hook up your power supply backwards you can replace the diode with a wire jumper and not lose any voltage at all. Oh, and the 1N4001 will also work fine if you don't care about the additional voltage drop.

 

[frankenteletron]

The 1N5817 Schottky diode in the Southern Belle is acting as reverse-polarity protection to prevent blowing up the circuit in the event you connect the 9V power supply backwards. The 9V supply must flow through this diode in order to power the circuit. However ALL diodes have a "forward voltage drop", meaning that you will lose some of your 9 volts just passing through the diode. The 1N5817 was chosen for its relatively low forward voltage drop (between about .3 to .4 volts) so your circuit will be running on 8.6 to 8.7 volts instead of 9. The 1N4001 is not a Schottky, and will introduce a voltage drop of about .6 to .7 volts, meaning your circuit will be running on 8.3 to 8.4 volts.

Now that you know what the purpose of this diode is and the primary characteristic that influenced its choice for this circuit (and many other FX pedal circuits), you can search for an equivalent. Other specs for this diode include a 1 amp current rating and a max of 20 volts. The 1N5817 has 30 volt and 40 volt brothers (1N5818 & 1N5819 respectively) that will work fine in this circuit, and if you're absolutely certain you will NEVER hook up your power supply backwards you can replace the diode with a wire jumper and not lose any voltage at all. Oh, and the 1N4001 will also work fine if you don't care about the additional voltage drop.

Thanks for the great info!