1N5817 Schottky substitute? 2N5087 substitute?

[Ell]

I'm currently copying this SubClone of the OD-3 Overdrive, but I don't have access to all the necessary parts.
Is there anything else I can use instead of a Schottky diode? I've looked up their function, but I think I only have access to rectifier diodes and zener diodes. I basically have access to whatever Steren have.

Also, 2N5087 is a PNP transistor. Would I be able to substitute this for a 2N3906, a BC327-B, or a BC558-B?
Apologies for my ignorance. I don't think I understand the reason why they used this particular transistor, and the reasons why another one would make a suitable substitution or not.



I appreciate it that you read this far, thank you.

[Ell]

So I've tried comparing technical specs on the transistors, and it seems like of my options BC558 might be the closest. To be honest, I might just buy all of the options and stick them in and see how they sound.

I still can't figure out what to do with the Schottky diode. If it's absolutely essential I can get a 1N5819 (the circuit asks for 1N5817), but it's a whole operation where I have to get a train and call some guy and wait half an hour for him to arrive on a bicycle and everything, hours of my life for a diode haha.

[Chillums]

Yes a 5819 will work fine as a replacement.  You can also omit it entirely and replace with a wire link but you loose polarity protection in case someone plugs in a center + power supply, but you also gain .4v because you lose the diode drop.

You should have no problem replacing the 2N5087 with the BC558  but watch the pin out as 2N5087 is EBC  and the BC558 is CBE and so you would have to rotate it 180°

[Keppy]

Most of the time you can freely sub PNPs for one another (or NPNs for NPNs). I'm not very familiar with the BC series, but 2N3906 is usually fine in place of 2N5087. For pedal purposes, both of those transistors are usually chosen when the circuit needs a generic PNP and isn't looking for specific characteristics. I'm sure the others you listed are fine as well. Like the reply above says, adjust the pinout if you need to.

Schottkys are usually selected for their low voltage drop. That's why it's being used in the power supply, so your 9v is reverse polarity protected but you don't drop the voltage too much. You can use another diode no problem, but:

• Your overall power supply will be about .3v lower, which is usually no big deal for a distortion.
• If possible it should be a power diode like 1N4001 rather than a small signal diode like 1N4148.

For future questions, it's more helpful to post a schematic rather than a layout. A layout shows how to physically build a pedal, whereas a schematic shows how the circuit operates. The schematic is more helpful for advice on parts substitutions.

[Ell]

Thank you both Chillums and Keppy! I really appreciate your replies. I'm gonna go ahead based on both of your advice and hopefully find out how this sounds. Just for the record, here's an OD3 schematic, bare in mind that the layout above is a simplified version without the tone control or the buffers, maybe there are other small changes too.

[Ell]

If possible it should be a power diode like 1N4001 rather than a small signal diode like 1N4148.

I just noticed in the original schematic it's actually a 1N4001, so you're absolutely right haha, I can get a 1N4007, is that good enough?

[Chillums]

That'll work fine.  Go for it  .  Let us know how you make out.
For the record, the 5817 in your layout isn't on that schematic, they didn't use polarity protection.  The 4001's (D6 & D7 in schematic) are the clipping diodes.  Swap these to your hearts content for different flavors.    The 1N914's (D10 & D11) are also clipping diodes.  Sub away....

[Keppy]

I just noticed in the original schematic it's actually a 1N4001, so you're absolutely right haha, I can get a 1N4007, is that good enough?

A 4007 works great. Those can handle high voltage, so you see them more in tube amps than pedals, but it will work the same as a 4001 for this.

[Ell]

I didn't have a chance to buy parts today so I just tried it out using a 2N3906, and a 1N4148. It works, but if anyone else in the future tries this, there is a missing connection on the layout.

I run a wire from Gain 1 to G of Q4, that fixed the issue. Looking at the schematic Gain1 should go to Q4 but it doesn't.

That's a quote from Er cinese from a discussion here : https://tagboardeffects.blogspot.com/2013/08/boss-od-3-subclone.html

Anyway, it sounds okay, but is a bit weak compared to how I know it should sound. I'm going to try the other substitutions when I get a chance. Part of me is wondering if some of the missing components from the original OD-3 could be making a difference. The original Boss pedal has an opamp. When I ran a clean boost into the pedal the result was closer to the sound I think I should be getting. The tone of this pedal is quite nice too, lots of clarity and sparkle.

Honestly, this makes me just want to clone the full pedal now.

[duck_arse]

if you can get any of the BAT series schottkys, they will also replace the1N5817.