On/off/on switch as On/Off

[rockaffe]

Hi everyone, I'm building a very simple attenuator for my vox ac30 and, unfortunately, instead of an on / off switch I was given an on / off / on switch.
Since I live in an area where the only solution to have components is to buy them online and above all that I don't want to wait any longer to finish the attenuator, I would like to ask you if you can still use the switch by adapting it to this scheme.
Thanks so much!

[antonis]

Of course you can use it..

Just ignore one side ON lugs..
(you'll have 2 position OFF..)

[rockaffe]

Of course you can use it..

Just ignore one side ON lugs..
(you'll have 2 position OFF..)

Thank you!
I've connected the switch like the image below and it kinda work... I mean, it have 2 on and 1 off. Problem is that when on OFF, it's completely OFF. No sound from the amp. How can I solve this?

[antonis]

Can't say till you post a complete wiring diagram..

[rockaffe]

Can't say till you post a complete wiring diagram..

My fault 

[PRR]

[rockaffe]

Doing this will eliminate one ON, but when on OFF there will be no sound from amp anyway, right?

[RickL]

What do you want it to do in the "off" position? If you want the signal to go through completely unattenuated, run the green and yellow wires from the pot to just lugs 3 and 6 (ground wire stays the same). Connect lugs 1 and 4 on the switch. Input and output still go to lugs 2 and 5. This will give full volume in the top position, no volume in the middle (off) position and attenuated volume in the bottom position.

Another way of looking at it is that you're just wiring it as a regular dpdt true bypass switch. In the middle position it will just be completely off. Or wire just lugs 1, 2 and 3 as a non-true bypass switch (input to lug 1 and the pot, output to lug 2, wiper of the pot to lug 3. Middle position will still be completely off.

Or completely ignore lugs 4, 5 and 6. Wire the red and green wires to lug 2 and the blue and yellow wires to 1 and 3. In the middle position you will get attenuation, set by the pot. In both other positions you will get (close to) full volume. The issue with doing it this way is that the lower the attenuator is set the lower the output impedance with be when bypassed. But none of the positions are completely silent (unless the pot is adjusted to attenuate the volume to zero). If you only wire the blue and yellow wires to lug 1, it will be attenuated in position 3 too.

[rockaffe]

What do you want it to do in the "off" position? If you want the signal to go through completely unattenuated, run the green and yellow wires from the pot to just lugs 3 and 6 (ground wire stays the same). Connect lugs 1 and 4 on the switch. Input and output still go to lugs 2 and 5. This will give full volume in the top position, no volume in the middle (off) position and attenuated volume in the bottom position.

Another way of looking at it is that you're just wiring it as a regular dpdt true bypass switch. In the middle position it will just be completely off. Or wire just lugs 1, 2 and 3 as a non-true bypass switch (input to lug 1 and the pot, output to lug 2, wiper of the pot to lug 3. Middle position will still be completely off.

Or completely ignore lugs 4, 5 and 6. Wire the red and green wires to lug 2 and the blue and yellow wires to 1 and 3. In the middle position you will get attenuation, set by the pot. In both other positions you will get (close to) full volume. The issue with doing it this way is that the lower the attenuator is set the lower the output impedance with be when bypassed. But none of the positions are completely silent (unless the pot is adjusted to attenuate the volume to zero). If you only wire the blue and yellow wires to lug 1, it will be attenuated in position 3 too.

Thanks for your answer RickL, my idea was to have attenuated sound on both the ON position and full volume on the OFF position.

[anotherjim]

If it's a tube amp you do not want a speaker off situation. It can harm the output transformer.

[rockaffe]

If it's a tube amp you do not want a speaker off situation. It can harm the output transformer.

It is, thats why I would like to have  attenuator (on) amp (off) attenuator (on)

[FiveseveN]

Isn't this thing supposed to go in the effects loop? Like an extra master volume? Ain't nobody said anything about speakers and such, that's a different kind of "attenuator".

[antonis]

my idea was to have attenuated sound on both the ON position and full volume on the OFF position.

Your idea was wrong from particular implementation point of view..
You need ON-ON switch (one ON for clean signal and the other one for attenuated..)

So, ignore OFF position and wire it as below:

[rockaffe]

my idea was to have attenuated sound on both the ON position and full volume on the OFF position.

Your idea was wrong from particular implementation point of view..
You need ON-ON switch (one ON for clean signal and the other one for attenuated..)

So, ignore OFF position and wire it as below:

Thank you!

[pacealot]

Since we don't want the speaker to be disconnected by mistakenly setting the switch to the middle position, how about if we reverse the idea and wire the attenuator in as a default, and then shunt across it in both "on" positions, wie so:




This reverses the function of the switch from what you stated you want (it's now attenuator off/on/off rather than on/off/on), but it does prevent damage to the amp.

[rockaffe]

my idea was to have attenuated sound on both the ON position and full volume on the OFF position.

Your idea was wrong from particular implementation point of view..
You need ON-ON switch (one ON for clean signal and the other one for attenuated..)

So, ignore OFF position and wire it as below:

So: in the end this solution did not work, we had the attenuator activated on all positions of the switch.
After a few tries however, I was able to get what I wanted, connecting the switch like this:


Thanks to everyone who took the time to make my request!