DIY Consolidated Mark III Pedal Unit

[s-fresh]

I've wanted to build one of these for a while and got a start today. All I need now are some resistors to wire up the LED indicators. I'm going to go against the Mesa convention and have off be off, and the LED will light up when the feature is activated. So if I see a light I know R2 is enabled or Lead is enabled. From left to right the switches are EQ, R2, Lead, Reverb. The LEDs are in the same order. The inputs are EQ/Reverb, Lead, R2. I should be able to finish it off tomorrow.

 

[Promethean]

Nice!

 

[Mat_P]

Very cool!
May I ask for awiring diagram?

 

[s-fresh]

I got it all finished up tonight. I had the lights switched originally but got it sorted it seems to work as expected.

May I ask for a wiring diagram?

I am no expert so you might want to look elsewhere, but here is what I did.

Basically, three-pole stomp switches. One pole for the LEDs, one pole to ground out each lead from the amp to disable/enable each feature, and one pole unused. Instead of using the power coming in from the amp for R2 and Lead I just used a 9-volt for all four indicators. You'll have to match a resistor for whatever LED you end up using. I am not 100% any of this is even correct, but it seems to be working fine after some quick tests.

 

[Mat_P]

Thanks much s-fresh, I'm sure that'll do it for me.

 

[jhreid]

Basically, three-pole stomp switches. One pole for the LEDs, one pole to ground out each lead from the amp to disable/enable each feature, and one pole unused. Instead of using the power coming in from the amp for R2 and Lead I just used a 9-volt for all four indicators. You'll have to match a resistor for whatever LED you end up using. I am not 100% any of this is even correct, but it seems to be working fine after some quick tests.

With these 3PDT switches you could use bi-colour LEDs and use the unused pole on the switch to light the other half.

 

[s-fresh]

With these 3PDT switches you could use bi-colour LEDs and use the unused pole on the switch to light the other half.

I'm going to build another one soon so I might give that a try. Thanks for the suggestion. Is there no "off" in that case? How do you prevent the battery from draining?

 

[jhreid]

Is there no "off" in that case? How do you prevent the battery from draining?

Use a switch jack for the cable connection - just like a regular effects pedal does.
Use wall wart power.
Add an on/off switch.
Remove the battery when not in use.

 

[IronSean]

Why is a battery needed? I thought the voltage that ran through the footswitch was usually just used to power the LEDs, so you get your power from the amp?

 

[jhreid]

Why is a battery needed? I thought the voltage that ran through the footswitch was usually just used to power the LEDs, so you get your power from the amp?

If you want to add other status LEDs then power is needed.

 

[s-fresh]

Why is a battery needed? I thought the voltage that ran through the footswitch was usually just used to power the LEDs, so you get your power from the amp?

I think this only works for R2 and Lead, but I could be wrong. The Mesa EQ/Reverb pedal doesn't have LEDs as far as I remember.

 

[IronSean]

I'd have to look at a schematic, but just because they didn't wire them up doesn't mean it's not a perfectly valid way to do it. If it's just a simple Yes/No as far as connecting voltage which enables the circuit paths for those features then you could add an LED to any of them.

Only if it was audio signal travelling to the switch would I think it wouldn't work, but that isn't a good way to design things, you introduce noise for the whole length of your cable.

 

[s-fresh]

Personally I didn't use the power from the amp because the voltages were not consistent between R2 and Lead, forget about EQ and Reverb. My stock Mesa pedals looked different and I didn't want to deal with finding the correct resisters to get all the LEDs at the same light level. I just wanted it consistent and the switches I had allowed for this easily. This is the same way other 3rd party consolidated pedals works as far as I know.

I can check the EQ and Reverb lines later. I know Mesa does have other dual switch pedals that DO have LEDs so I'm not sure why they would leave it off here unless there was a reason. Will let you know either way.

 

[IronSean]

Cool, yeah, not needing to measure and calculate resistors is as good a reason as any. It looks good either way!

 

[s-fresh]

Doh, I forgot the most obvious reason... with the amp power the LEDs are lit when the feature is OFF! That always bothered me.

 

[el34sg]

Nice work! Looks great!

 

[gts]

Wow s-fresh! Nice!

Not sure how I missed this thread back when it started but now glad I found it!