Input 1 & 2 Footswitch for an Original Mark 1

[Boogiebabies]

If you short input 2, the entire preamp signal stops. It needs to be on all the time. Shorting Input 1 is basically completing the second circuit. So basically, Input 2 needs to be on all the time and input 1 needs to have a circuit breaker to pull it in and out of the circuit. So your Com would be wired to Input 2 normally and always on and your output to Input 1 would be the circuit breaker to engage/disengage the Input 1 circuit.

 

[kdove]

If you short input 2, the entire preamp signal stops.

Exactly ... :idea:

So my questions:
- Is the easiest way to deal with this ... buy the Mesa pedal?
- Does the Mesa pedal avoid grounding input 2 ?
- Any schematics of that pedal available anywhere?

I would hate to order the Mesa pedal and have it do the exact same thing as the Boss LS-2.

 

[Boogiebabies]

Ken,

Wire the com input directly to the first output, or the output for input 2. On the second output, just use a spdt between the tip and sleeve to get the circuit make/break. It's basically com straight to the # 2 input and and a single button footswitch to complete the input 1 circuit via the shorting/contact of the cable in the jack. To check this out, run your guitar into input 2 and stick a shorted 1/4 inch jack into input 1. If it works, all you really need is a single button shorting footswitch.

 

[kdove]

When you say "com" you mean both tip and ground?

I think I understand ... apologize for being a bit dense. :?



On the SPDT 1st switch setting:
- Tip and ground pass through to input 2

TIP GRND (In From Guitar)
.\/.........\/
TIP GRND (Signal Out To Input 2)>>>>>>>AMP INPUT-2

open open

TIP GRND (No Signal Out To Input 1)

Then the Signal is going to Input 2 Only





On the SPDT 2nd switch setting:
- Tip and ground pass through to input 2
- When switch thrown both tip and ground are connected

TIP GRND (In From Guitar)
.\/.........\/
TIP GRND (Signal Out To Input 2)>>>>>>>AMP INPUT-2
.\/.........\/
closed closed
.\/.........\/
TIP GRND (Signal Out To Input 1)>>>>>>>AMP INPUT-1

Then a signal is going to BOTH input 1 & 2

 

[Boogiebabies]

To check this out, run your guitar into input 2 and stick a shorted 1/4 inch jack into input 1. If it works, all you really need is a single button shorting footswitch. This will prove that the COM or common input is simply straight wired and the A output and that B is a simple shorting switch.

 

[kdove]

It does ... from an earlier post of mine:

"I have a set of those planet waves cables that you can touch a button and short the circuit. If I run through INPUT-1 and insert the cord in INPUT-2, it still works but as soon as I close the circuit on the cord on INPUT-2 ... INPUT-1 goes silent. I think the Mesa pedal must NOT ground INPUT-2 when it's not in use. Possible?"

 

[kdove]

Well ... I guess I figured it out. BUT I was hoping to leave the TS9/Input2 going and switch between the NORMAL Input-1 setup with one click. So I think the TS9 would always be in the mix unless I turn it off too.

Might just stick with the "no pedals" setup I've been using for a quarter of a century. Except for a tuner. :?

But the LS-2 would make a great two amp ... even three amp switch if I ever want to mix it up that way. Also, the LS-2 has a really good cut/boost volume setup that doesn't change the tone. I wasjust trying to do it all in one amp with one click ... probably not possible. But the TS9 through the Input-2 is an interesting sound.

Thanks anyway for the help guys.

 

[JOEY B.]

Sent you a PM.

 

[kdove]

Anybody got a schematic of the original Mark 1 Channel 1/2 footswitch? It was a simple footswitch but wired a bit different than a regular A/B switch.

I think they still sell them but I'm thinking about this old project again.

 

[igfraso]

Why don't you try and use the switchable "Gain Boost" instead of an A/B box?

 

[kdove]

I want to run a clean gain boost on the 2nd channel, but need the switcher to set it up. Like this:

guitar >>>>>>>>>>>>>>>>> Input 1 (All gain stacks)

OR

guitar >>> clean boost >>> Input 2 (minus the first gain stack)

Reopening this project from last year ... my thought was: Use the initial foot pedal designed back in the 70s to set it up and insert the clean boost as a replacement for the first boogie gain stage. This will level out the two signals which was the problem initially with this design.

I have a Boss LS2 A/B switcher but it doesn't work on the boogie because there is a ground issue when you plug both the A/B channels into inputs 1/2. Both channels don't function when both channels have connectors inserted.

I want to study the wiring of the switch if I can get the schematic. I think I might be able to figure out a way to do this if I can see how they did it originally. Somebody's got to have one of these schematics somewhere.

 

[drunkdolphin]

I know im late to the party but the EH Nano switchblade will do switch between input 1 and 2 no problem.
its cheaper than the mesa switch too.
dd

 

[kdove]

I know im late to the party but the EH Nano switchblade will do switch between input 1 and 2 no problem.
its cheaper than the mesa switch too.
dd

Will it do it with the original Mark 1 though? A regular A/B switch (like my Boss LS2) does not work. I got the LS2 thinking a regular A/B switch would do the job. I can easily build what I need ... if I can just get a look at the schematic.

I might be able to adjust the auto ground tab that I think is on the input 2. I think they put that in there to disable input 1 when input two has a jack in it ... to reduce input 1 noise. But I'd like to study the original switch to be sure. Might be as simple as replacing one of the input jacks on the boogie and use the LS2 that I have.

 

[drunkdolphin]

yes,
the inputs are almost, if not identical on the ri and the original.
i picked one of the Eh pedals up for 35.00 and it worked fine.

 

[kdove]

yes,
the inputs are almost, if not identical on the ri and the original.
i picked one of the Eh pedals up for 35.00 and it worked fine.

I looked at it on the website and it's described as an A OR B switch. I have an A OR B that just doesn't work with my model. I think the original Mesa switch may have been an A OR A+B switch. I think if I bought this one, I'd have two that don't work. I may try to find one in a store and take the amp with me.