Help with 3-way Mini DPDT

kinski · Post by **kinski** » 03 Dec 2010, 07:46

I just built a Bazz Fuss. Awesome!

I'd like to add two 3-way mini dpdt switches. One to select 3 different input caps, and another to select 3 different transistors.

Problem is...I don't know how to wire the mini switches up. The switches have 6 lugs. Won't I need all 6 lugs just for the "legs" of the caps or transistors?

Any help would be greatly appreciated. Thanks!

IvIark · Post by **IvIark** » 03 Dec 2010, 08:27

If you look at this layout for the Vorpal Fuzz, that shows how you'd do with with the caps (even though they're resistors in that layout).

You need to connect the wires to the centre two lugs which are the switch commons. If you then also put a cap between those two lugs then that will be always in circuit. Then put two caps between the other lugs on either side as shown in the layout.

Bear in mind that you can't switch between 3 cap values, the centre one will always be in circuit. So then adding the caps on each side in parallel with the main cap adds the values. So if you had a 10nF in the centre position, another 10nF on one side and 47nF on the other, you'd get the equivalent of 10nF in the centre off position, 20nF in one position and 57nF in the other.

You would only be able to switch between two transistors, just take a wire from the emitter and collector positions on the board and take them to the centre two lugs. Then attached the emitters and collectors of the two transistors to the appropriate side of the switch. The bases are just commoned together and connected to the base pad on the board.

kinski · Post by **kinski** » 03 Dec 2010, 16:59

Hey, thanks a lot. This is the exact info I needed. I know what I'll do with the caps.

But, the transistors....basically, if I only use 2 transistors on the switch, the middle switch will have no transistor, right? I'd prefer to not have one position with no transistor. I have a pedal built by someone else, and it allow for 3 different transistor to be selected, and its on a 3 way switch...is there a different switch that i should be using to do this?

YuGi · Post by **YuGi** » 03 Dec 2010, 17:10

kinski wrote:Hey, thanks a lot. This is the exact info I needed. I know what I'll do with the caps.

But, the transistors....basically, if I only use 2 transistors on the switch, the middle switch will have no transistor, right? I'd prefer to not have one position with no transistor. I have a pedal built by someone else, and it allow for 3 different transistor to be selected, and its on a 3 way switch...is there a different switch that i should be using to do this?

Yea you can use a on-on-on toggle switch or a rotary switch.

kinski · Post by **kinski** » 03 Dec 2010, 17:28

yeah, i have a on-on-on switch. sorry if i was unclear.

its an on-on-on switch with 6 lugs.....what do you think?

YuGi · Post by **YuGi** » 03 Dec 2010, 17:34

I mean on-on-on with 4 lugs (or 8 if double).
Like this http://www.musikding.de/product_info.ph ... -DP3T.html or a rotary like thishttp://www.musikding.de/product_info.ph ... d-pcb.html

kinski · Post by **kinski** » 03 Dec 2010, 17:41

ok...so this won't work:

http://www.ioffer.com/img/item/167/351/851/8oJu.jpg

YuGi · Post by **YuGi** » 03 Dec 2010, 18:34

kinski wrote:ok...so this won't work:
http://www.ioffer.com/img/item/167/351/851/8oJu.jpg

IvIark have well explained what you can obtain with this kind of switch (that probably is an on-off-on).

kinski · Post by **kinski** » 03 Dec 2010, 18:53

What I have is an ON-ON-ON. It says so on the side. Yugi mentioned I could do what I'm trying to do with an ON ON ON switch...but how would I wire this? Is the layout he posted an ON ON ON, or something else?

lietuvis · Post by **lietuvis** » 03 Dec 2010, 18:54

kinski wrote:ok...so this won't work:

http://www.ioffer.com/img/item/167/351/851/8oJu.jpg

for this kind switch on on on look at bartolini preamp wiring diagram, midrange frequency selection.from there you might figure out possible ways for wiring.

lietuvis · Post by **lietuvis** » 03 Dec 2010, 19:31

see if this help you with cap wiring, swapping transistors will not work with this switch.

kinski · Post by **kinski** » 03 Dec 2010, 19:34

hmmm...okay...so, is there a toggle switch that will allow me to do this?

lietuvis · Post by **lietuvis** » 03 Dec 2010, 19:47

kinski wrote:hmmm...okay...so, is there a toggle switch that will allow me to do this?

yes you can do it with ON ON switch and toggle between 2 transistors, to toggle 3 I have not seen that kind of switch to be toggle,rotary(bigger)-yes.

Hides-His-Eyes · Post by **Hides-His-Eyes** » 03 Dec 2010, 20:45

Liet that one's for a Z switch isn't it?

lietuvis · Post by **lietuvis** » 04 Dec 2010, 07:27

Hides-His-Eyes wrote:Liet that one's for a Z switch isn't it?

Z switch ? I don't know what Z switch is. I Just tried to help with on/on/on toggle switch,to which recently I was wiring to my unsuccessfull copy of bartolini ntmb preamp (where I believe that schematic floating on net is incorrect,I had chance to take some measurements from working unit and they did not matched schematic values)

kinski · Post by **kinski** » 04 Dec 2010, 07:36

Okay, thanks everyone for your replies.

I'll give up on the 3-way transistor selector. I like the one i have in there now anyway.

however, I would like to do the 2-way input cap selector.

Please bear with me here. I'm totally new at building pedals...

1. How would I wire up a 2-way toggle switch (ON-ON, right?) to choose between 2 different input caps.
2. I really like the stock cap of 4.7uf. I'd like another cap that would cut the bass. Would 2.2 be a good value, or does anyone else have a suggestion for a 2nd cap option?

Thanks again for your patience and help!

YuGi · Post by **YuGi** » 04 Dec 2010, 09:33

Yea try 2.2 for bass cut first, anyway you can try other values if you don't like it.

kinski · Post by **kinski** » 04 Dec 2010, 17:51

Awesome! That's what I needed. This forum is incredibly helpful. Much appreciated, everyone.

kinski · Post by **kinski** » 04 Dec 2010, 22:01

Okay, I wired the switch up. Easy enough. The thing is...I can't hear ANY difference between the 4.7uf and the 2.2uf or even a 1uf. What's the deal? I check the - and + and everything looks fine. Eh?

YuGi · Post by **YuGi** » 04 Dec 2010, 22:37

What is the schematic?
Anyway maybe you have to decrease even more the capacitor to hear the difference.