#1
Ok, I'm in the process of replacing some old parts and that includes the input jacks. I'm not too fond of having to unplug my cord to switch jacks so while I'm at it, I figured it would be best to add a DPDT switch with just one jack. I think i have it figured out but I am kindly asking for some confirmation before I order the parts for this.

In the original schematic of the input jacks, it looks like they are both switched jacks that are grounded until a cord is plugged into them. When a cord is plugged into the Hi jack the ground disconnects and the signal travels through both of the 10K resistors. When a cord is plugged into the Lo jack, the ground disconnects and the signal travels through one of the 10K resistors and the other 10K resistor sends some of the signal to ground. Is this correct? If so, if my poor drawing correct? I realize that I made a mistake with the two 10K resistors for the Hi side. They should be wired in parallel if my understanding of the original schematic is correct.

Can anybody confirm any of this for me?
Attachments:
inputs.gif
input with switch.JPG
Guitar:
Dean Vendetta 3 - Dave Mustaine Livewires

Amplifier
Carvin X100B - Bias Mod - Tungsol 12AX7's - JJ KT77's

I have built the most badass 212 that puts all others to shame
#2
Quote by MeanwiththeDean
Ok, I'm in the process of replacing some old parts and that includes the input jacks. I'm not too fond of having to unplug my cord to switch jacks so while I'm at it, I figured it would be best to add a DPDT switch with just one jack. I think i have it figured out but I am kindly asking for some confirmation before I order the parts for this.

In the original schematic of the input jacks, it looks like they are both switched jacks that are grounded until a cord is plugged into them. When a cord is plugged into the Hi jack the ground disconnects and the signal travels through both of the 10K resistors. When a cord is plugged into the Lo jack, the ground disconnects and the signal travels through one of the 10K resistors and the other 10K resistor sends some of the signal to ground. Is this correct? If so, if my poor drawing correct? I realize that I made a mistake with the two 10K resistors for the Hi side. They should be wired in parallel if my understanding of the original schematic is correct.

Can anybody confirm any of this for me?
That's correct. All you need is a SPDT switch and two 10k resistors, not four.

1 - Connect the resistors in series.

2 - One end of the string goes to the tip of the input jack.

3 - The series link goes to the grid of the first tube.

4 - The other end of the string goes to the pole of the switch.

5 - One throw of the switch connects to ground (low input)

6 - The other throw of the switch connects to the tip. (high input)

7 - Be certain to connect the switch portion of the jack to ground, to prevent hum when you don't have anything plugged in.
Meadows
Quote by Jackal58
I release my inner liberal every morning when I take a shit.
Quote by SK8RDUDE411
I wont be like those jerks who dedicate their beliefs to logic and reaosn.
#3
Just to be sure I have it right, is the diagram I drew up correct?
Attachments:
switch mod.jpg
Guitar:
Dean Vendetta 3 - Dave Mustaine Livewires

Amplifier
Carvin X100B - Bias Mod - Tungsol 12AX7's - JJ KT77's

I have built the most badass 212 that puts all others to shame
#4
Perfect. You even drew it right side up.
When the lever is down, the upper throw is engaged connecting the end to ground for "low sensitivity".
Meadows
Quote by Jackal58
I release my inner liberal every morning when I take a shit.
Quote by SK8RDUDE411
I wont be like those jerks who dedicate their beliefs to logic and reaosn.
#5
Excellent. Thank you for your help SYK
Guitar:
Dean Vendetta 3 - Dave Mustaine Livewires

Amplifier
Carvin X100B - Bias Mod - Tungsol 12AX7's - JJ KT77's

I have built the most badass 212 that puts all others to shame