Mutron 3 workalike doubt on parts and layout

[Trolorol]

Hello, I am thinking on building this pedal and I am ordering the things that I need to build it, but I came across some doubts on the layout.

The project that I am following is this one: http://www.geofex.com/PCB_layouts/Layouts/neutronpub.pdf

In the parts list is mentioned a rotary switch a 3PST 10WW033, this is not available on mouser, and besides that were in the layout is this going and alternatives I have ?

Regarding other issue, on caps the voltage rating is something to be worried about ? I have always been told to have a voltage rating above the value on the maximum expecting voltage on the circuit, but for this project I can´t find some caps on that precise 25v rating, so if I use 50 or more, is that gonna be a problem? Is there some audio mambo jambo about voltage ratings ?

Thanks in advance for all your advices

[mth5044]

Hola Trolorol,

For the rotary, use any rotary that has at least 3 throws. I'm sure there are a ton at Mouser, but you can use 1P12T rotary switches. There is a little washer that you can use to set the amount of throws available underneath the mounting nut so you can limit to only three turns. Same with a 2P6T, 3P4T, or even 4P3T. You only need the one pole plus at three throws.

For caps, you generally here people say 2x the voltage you are using in the pedal. Didn't look to hard at the schematic but did see a possible 18V voltage if there are any caps put accross the +9 and -9V. So the 16V caps probably won't work, 25V would be marginally safe. 50V is fine. 2000V is fine, but they get larger, so make sure you make room in your layout for larger caps the higher you go.

[Trolorol]

Hola Trolorol,

For the rotary, use any rotary that has at least 3 throws. I'm sure there are a ton at Mouser, but you can use 1P12T rotary switches. There is a little washer that you can use to set the amount of throws available underneath the mounting nut so you can limit to only three turns. Same with a 2P6T, 3P4T, or even 4P3T. You only need the one pole plus at three throws.

For caps, you generally here people say 2x the voltage you are using in the pedal. Didn't look to hard at the schematic but did see a possible 18V voltage if there are any caps put accross the +9 and -9V. So the 16V caps probably won't work, 25V would be marginally safe. 50V is fine. 2000V is fine, but they get larger, so make sure you make room in your layout for larger caps the higher you go.

If you look in the parts there are C4, C9, C10 and C11 and they are all 16V, should I change them ?

[Trolorol]

In the parts list is mentioned a rotary switch a 3PST 10WW033, this is not available on mouser, and besides that were in the layout is this going and alternatives I have ?

Ok forget it, I saw the light lol, I just misread the rotary switch on the diagram lol, now my doubt is which one should I buy, anyone got a mouser number from a previous project ? When I search at mouser it only return switches in the 30€/40€ range :s

[mth5044]

Here is one, but it has mounting pins instead of solder lugs.

http://www.mouser.com/ProductDetail/Alpha-Taiwan/SR2612F-0112-21R0B-D8-N/?qs=yA6kp8fx8Y7S2TB5GvzfgQ%3D%3D

Alpha-Taiwan are typical rotary switches found at Small Bear, Tayda, Mammoth, etc. You could probably do a little re-searching and find the ones that have lugs instead of pins. If you don't feel like, the pins work fine, just wrap the wire around the pin and solder.

If that caps are specified 16V at GEOFEX, then you're fine with 16V. I can't question RG, so go for what he says. Just know that higher voltage isn't going to hurt anything besides (sometimes) your layout.

[PRR]

R.G.s power supply shows + and - 9V.

While it is "possible" to get 18V from this, I do not see any parts which go rail-to-rail, only rail-to-ground.

You need caps good for 9V. 16V is plenty ample unless you expect zero repairs over 20+ years. If this must work for "a lifetime", and you are young, 25V may be a bit more long-term. But don't over-over-spec electrolytics.

[Trolorol]

Here is one, but it has mounting pins instead of solder lugs.

http://www.mouser.com/ProductDetail/Alpha-Taiwan/SR2612F-0112-21R0B-D8-N/?qs=yA6kp8fx8Y7S2TB5GvzfgQ%3D%3D

Alpha-Taiwan are typical rotary switches found at Small Bear, Tayda, Mammoth, etc. You could probably do a little re-searching and find the ones that have lugs instead of pins. If you don't feel like, the pins work fine, just wrap the wire around the pin and solder.

If that caps are specified 16V at GEOFEX, then you're fine with 16V. I can't question RG, so go for what he says. Just know that higher voltage isn't going to hurt anything besides (sometimes) your layout.

Ok thanks , I am a little confused with the rotary potentiometer, but I will wait until the material arrives to see if continue I to have any doubts.

[Trolorol]

R.G.s power supply shows + and - 9V.

While it is "possible" to get 18V from this, I do not see any parts which go rail-to-rail, only rail-to-ground.

You need caps good for 9V. 16V is plenty ample unless you expect zero repairs over 20+ years. If this must work for "a lifetime", and you are young, 25V may be a bit more long-term. But don't over-over-spec electrolytics.

Ok, thanks!! I did't put the order in the move yet, so maybe I will change the 16v to 25v, or maybe I will order both(free shipping yey ).

[nocentelli]

In the parts list is mentioned a rotary switch a 3PST 10WW033

If you cannot find a suitable rotary SP3T switch at a reasonable price, a DPDT on-on-on can be modified to act as an SP3T:

http://rickviola.com/images/FigH.jpg

Toggle switches tend to be cheaper than rotaries and take up a lot less space inside the box.

[Frildo]

https://www.rfparts.com/switches/switches-rotary/10ww033.html

https://www.mouser.com/catalog/specsheets/TW-700032.pdf

here ya go