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Usually I do this with small fragile glass housing diodes. I use a little screwdriver as guide, and wind the leads on it.

They take more space, but I'm no longer a diode destroyer!

Got it. the zener is not the best solution, better a 7815 and "passa la paura".
BUT... I have only one 7815 and it doesn't work. It became hot and in output I measure 0.peanuts volts.

I don't remember the source, but I read that the 5817 should act as a resistor.
in fact the DMM shows about 50 ohms. Is it not correct?

I've seen this schematic used in many project. That's why I omitted the CLR.

I bought them from musikding.
Is there a way to test a zener diode?

Hi all,
I'm building a preamp pedal based on sunn O))) beta bass.
My idea is to use different input voltage (9 or 18v), so I'm planning to use this schematic as "power section":


I tested the circuit without any chip, and with 18v input the DMM shows 17,8 volts.
Am I doing something wrong?

The rule is different for tube amp (or with output transformer in general) or solid state (or OTL - output transformer less):

1.Tube/OT - impedante must be the same for head and cabinet;
2.SS/OTL - the cabinet impedance must be same or higher than the head impedance.

Looking at the original schematic the 4th triode is (I don't know the correct word here... biased?) at the same way. 100k resistor on the cathode. maybe it's a coincidence...
My question is about the "anode" trimmers. is 20k enough? I've alway seen 100k trimmers on fet drain.

Now the real important thing. This build is awesome! The graphic gives a 3d look at the pedal.

I use the afterlife in my pedalboard as effect. It's compact ad do the job.

Very nice. I like the shocking pink.
I have a bike of this color.

So, 24*2.8=67.2. That's why I also bought a 48v zener diode.

The schematic attached should be fine. But I think I have to add a resistor on the red circle. right?

Thank you very much for helping me!

you're right!
my knowledge is regressing 
Are there some advantages using a full bridge rectifier?
like this:


Doubling the voltage the current is halved, right? the transformer is 0,5VA (2x0,25). so the current should be about 20mA?

some years ago I started to build a mic preamp with phantom power supply.
I bought a 2x15v transformer as main power and for the phantom a... 2x12v transformer.
What strange drugs did I take to get this idea? How can I get 48v from 2x12v transformer?

I bought also every component to build this project and there is no charge pump or something similar.
Only a 48v zener diode.

You could try these steps.
-Check the value of T1.
-Remove all chips except the charge pump, then check the voltage.
-If you can try another 1054.
-check solder join on the -15v trace.

this is what I was talking about:

and this is how it sounds:
https://www.youtube.com/watch?v=4_j0lhKfSz4
The switch is on C8, changes between 33n and 100n.

I don't like overdrive with blend, instead you could use a cap in series with the clipping diodes and a potentiometer as variable resistor.
In a tube screamer I used 47n cap and a 50kB pot.

Better for me is a SHO with hard clipping stage and same capacitor/pot solution. (and also a volume pot).