Rotary switch for tone

[Colas LeGrippa]

In my last build I would like to hook up a rotary
 switch to act as a tone pot. It is a 6 position switch. I would leave the 6th one unconnected to have access to the original tone  of the amp.
What would be the best way to achieve that ?


Thanx
Colas
 

[sluckey]

Without seeing a schematic it's hard to understand exactly what you want. But, take a look at page 2 of this pdf. Might give you some ideas...

     http://sluckeyamps.com/VAC15/Vox_AC15.pdf

[kagliostro]

There is also a different approach, option b instead of option a (Pot instead of Rotary Switch)



Franco

[Colas LeGrippa]

Very interesting indeed.  No signal is sent to gnd in the vox nor in Kagliostro circuits.Now would this mod be more effective early in the circuit rather than late ? I have an idea in mind: since that rotary switch  is stereo, placing it between the PI and the output tubes would improve or disminuish it s effectiveness ? The schem I don't have, but the preamp section is copied from the Marshall 2204 model, without the tone stack. It is my second 2204 since january. The first one is a bit less bright and more pleasant tonically, though the trannies are the same ( but the power tranny on this particular one which is a toroidal type from Avel Lindberg but with same voltages) this is why I d like to add a tone switch to adjust the brightness. I removed the 1000p cap accross the volume pot to give it a try but it changed the overall tone , though less bright. I put it back in place after. Same with the 470k bypass cap (470p).


Thanx buddies.


Colas

[pdf64]

The circuits below provide varying degrees of bass cut; sounds like  your goal is variable treble cut?

[shooter]

instead of PI to PA, might be better as part of your NFB, like a rotary presence control   

[Colas LeGrippa]

Yes, treble cut

[Colas LeGrippa]

Shooter  good idea, ( if there was a NFB  )

[kagliostro]

You can implement one NFB with values that can affect tone and not the general function of the amp

(I think  )

Franco


p.s.: .... Treble Cut ......    ......

EDIT: I remembered !

[nihonlabtiger]

when I finally get to the point of building my own amp, I'm thinking of doing something similar with a pushbutton and rotary control.

Check out the schematic for the Selmer Zodiac tone control. 

[kagliostro]

..... with a pushbutton and rotary control

Or Rotary Switch + Rotary Control





other Selmer with Rotary Control



Franco

[shooter]

just build this and be happy 

[jjasilli]

Can't find it right now, but I could swear that Ted Weber's site had a schematic for a rotary SW for different tone caps, to match values for F, M & V tonestack values.

[Colas LeGrippa]

ended up with the easiest one, 1m pot between the k and right after the first coupling cap. A bit more subtle that what I was expecting but it does the job right. Thanx Franco, you're my man !

[kagliostro]

De Nada 

Franco

[Colas LeGrippa]

Hey Shooter, I d sure be happy I am certain that EQ would be awesome , I might build it one of these days !
Thanx for sharing it

[shooter]

 

I got it from Franco couple years back 

I'm not good enough to pull it off, but I keep lookin 

[kagliostro]

Ciao Colas

I was talking with a friend of a different thing, and a council for you exit out

is a thing only to have a try, but may be you can be happy with it

instead of the 1M pot give a try to a 2.2M - 3M - 5M

reverse log, but you can try with a no reverse one and if happy, you can obtain the reverse log with the trick of the paralleled resistors, if you are not able to find a commercial one

http://www.geofex.com/article_folders/potsecrets/potscret.htm



Franco