Alternative Component for 1N4748A in Clandestine Preamp

[Feral Feline]

The items in Fig's organiser looked like top-shelf stuff...


... I wonder if he needs a Jacob's Ladder to reach them?

The extra pads are there to fit different packages. You’ll notice the pads on the sides are shorted together.

That's what she...

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ESD = Emo Student Driver

 

[andare]

Unsurprisingly, this thread took a weird turn

I have 22V, 1/2W Zener diodes for my Clandestine build but they weren't labeled as 1N4748A. Can I still use them?

 

[Chuck D. Bones]

Yes.

 

[andare]

Yes.

Thank you, I know it was a dumb newbie question

 

[Chuck D. Bones]

The dumbest question is the one that isn't asked.

 

[Silver Blues]

... I'm new to this so I'm not entirely sure what function this component has in the circuit so any education in that regard would be much appreciated as well.

The Clandestine runs at an elevated voltage, which is generated internally from a standard 9v input by a bit of circuitry called a "charge pump", which is basically just a voltage multiplier. The Zener is present in this circuit to limit the output of the charge pump, which in this configuration would be close to 30V if I'm not mistaken, to the Zener voltage of the diode, so 22V.

 

[Chuck D. Bones]

The zener operates as a shunt regulator in this circuit. The peak voltage on D104's cathode will be around 26V. The zener will probably run around 21V because it's running at a low current. I would have put a 10uF cap from D104-K to GND, but that's just me, I used to design power converters for a living.

 

[Silver Blues]

Come to think of it yeah, my build has the output at the Zener at 21.14V... good call lol. One forgets how differently components can behave at low current.