Mod your Deluxe Electric Mistress Reissue for True Bypass and a status LED

[Reaganomics!]

Ok, so I recently took apart my reissue DEM to replace an op amp (RC4558) with a lower noise version (TL072) to try to get it to be less noisy. That mod worked fairly well, but when I looked inside I saw this:

 

 

For whatever reason they are using a 3DPT switch, but not using it for true bypass or an LED like it is commonly used for, which is strange because it is much more expensive than a DPDT or SPDT switch they could've used.

 

a look at the board:

 

 

I studied the wiring and the PCB, as well as old diagrams of SPDT wiring and figured out what wires went where.

 

DISCLAIMER - my pedal is from the early-mid 2000's. I can't guarantee that the wires are the same colors (or the pcb even being in the same layout) in everyone's ri DEM!

 

I made an easier to see illustration of how this is wired:

 

 

1.) As you can see, the circuit path goes like this. A white wire comes from the sleeve of the input jack (another wire goes directly from that input sleeve to the direct out "Direct Out" but that is not relevant to us) and it connects to the PCB, so it is the Board Input wire.

 

2.) A black wire nearby is connected by a trace on the PCB to that white wire and it goes from the PCB to the switch. Since it is basically an extension of the white wire we can remove it (DISCLAIMER - There is another black wire next to this one on the board, it goes to the ring tip of the output jack. It is the ground, do not remove this. Only the black wire that goes from the board to the footswitch is removed)

 

3.) A yellow wire goes from the switch to the board, This is the Board Output wire.

 

4.) A Brown wire goes from the switch to the sleeve of the Flanged Out cable.

 

To do this mod you need to

1.) carefully desolder all of the wires from the footswitch

2.) Desolder the white wire from the sleeve of the input jack. Leave the other end attached to the board.

3.) Desolder the black wire that was connected to the footswitch from the board. It should no longer be connected to anything. You can get rid of it as it is not needed

4.) Connect a new wire to the sleeve of the input jack, make sure it is long enough to reach the footswitch.

 

So now you should have these wires

1) Input jack wire (let's call it "blue")

2) Board input wire (white)

3) Board output wire (yellow)

4) Output jack wire (brown)

 

Wire them up to the footswitch like so:

 

 

(you can use other 3dpt wire schemes if you like, but I like this one)

 

It should now look like this:

 

 

To add an LED connect the negative end to the remaining lug of the footswitch (top left corner lug) and connect the positive end to the sleeve of the DC jack make sure there is a resistor about 15k or higher between the DC jack and the positive leg of the LED or else it will burn out.

 

I tried using the free lug on the DC jack that is usually used by battery snaps, but it didn't work for me. I then connected it to the other lug that was also powering the board (There should be a red wire connected there).

 

To drill the hole, I put some masking tape on the spot I wanted, and drilled a 1/4" hole. That was the perfect size for the little plastic LED holder and 5mm LED. I secured it with some hot glue, just like EHX does for other big box pedals.

 

Results:

 

 

 

Enjoy!

[TheMistressGuy]

Hello Reaganomics!,

 

 

For whatever reason they are using a 3DPT switch, but not using it for true bypass or an LED like it is commonly used for, which is strange because it is much more expensive than a DPDT or SPDT switch they could've used.

 

 

1. You can buy 3DPT at large numbers nowadays cheaper than SPDT. The first version of the reissue used SPDT and they shifted to 3DPT mid-2000s. Probably to reduce production cost and not to increase them.

 

2. The Deluxe Electric Mistress version you own is intended to be a reissue of the vintage late 70s/early 80s version. The vintage version had no LED, so the reissue has none, too. (I modded my Deluxe reissue with a LED, too. I can't understand why EHX didn't add that feature sometimes in the 80s to the vintage ones when LEDs became cheap. This pedal is so uncomfortable to use if you don't know whether it is active or not.)

 

3. This pedal has a buffered bypass. Some people even think buffered bypass is superior to true bypass. I don't think there is a need to mod the Deluxe to true bypass.

 

Best wishes

 

Ralf

[badsbb]

Hi!

Great details on the mod! Enough details to make me order parts, and start.:-) I have a nearly brand new one ordered late 2012, and it looks just like it, inside.

But I don't see why you define the stock version not to be true bypass? The white wire is connected to the board, and it goes via a small direct strip strait out to the black wire connected to the 3DPT, and when in bypass that goes straight to the output. It's like you described that the black wire is just an extension of the white wire. Since current always follow the least resistant path, there will not flow any juice through the board in bypass, and certainly not through any buffer. It looks like true bypass in stock version. Is it the risk of some capacitance effect of having the board attached that make's you wanna remove it completely?

Another question: Why do you connect the ground to the input in bypass in your version? Don't you make some kind of shortcut between + and - on the board? Why can't the input of the board just have nothing as it's signal in bypass?

I just wonder:-)

 

The mod for the LED is great.

But one question here as well:

Why do you need over 15K of resistor in series with the LED? Even with a LED with forward voltage of 4,5V it should be enough with 1K Ohm's .

Is it just to reduce the overall power consumption of the pedal?

 

Thanks a lot

BR

BADSBB

[Urinate Forever]

year old post, reaganomics might have left tho