MXR Stereo Chorus - Can I Replace Cord with adapter?

[gluedtogether]

I picked up a three knob mxr stereo chorus a couple years ago. I wanted to start using it again. It has a three prong plug coming from the pedal, however I don't have a place to plug it in. The power for my board only has 9 or 18volt adapter plugs.
I checked the forum for info or past threads on how to do this, but didn't find anything.
Is there a way to remove the plug and install a dc adapter that will work with 9 or 18 volts. The schematic is on the web, but I wasn't able to read it to find any voltage information for the pedal.
I am still new to modding and welcome suggestions even if the suggestion is to avoid removing the plug.

Thanks

[ironman28]

The original MXR AC powered effects use a standard 3 terminal voltage regulator(7815). You can disconnect the AC power cord and replace it with a standard 2.1mm power connector. The nice thing it is easily reversed if you ever want to restore the pedal to vintage specs. The hole for the power cord bushing is a perfect fit for the new power plug. The basic process is:
Desolder the AC cord and remove the bushing
Disconnect CR7 and CR8. You can just unsolder the cathode ends of each ( the end with the band). The other end can stay attached. You may want to leave one attached for polarity protection in case the wrong PS is used.
Install the new power connector and attach the center pin to ground and the sleeve to the input of the regulator. This is for a standard center pin negative Boss style supply. Check your PS to be sure you have a center pin negative type.
Be sure to use a DC power supply of 18 volts or higher, up to 24v. Don't go over 24v as the first filter cap is 25V.
You may be able to use a lower voltage supply but you will loose the regulation on the 15V resulting in increased hum. If you use a 9vdc supply make sure it is regulated. The pedal may perform different with a lower voltage but it won't hurt anything.

good luck

[gluedtogether]

thanks for replying. it sound fairly simple and easy to reverse. i am definitely going to give this a shot. I am using a gator regulated power supply similar to the dunlop dc brick. it was 9 and 18 volt outputs. I will use the 18volt. A couple questions.

I am not quite sure about the parts you are referencing. there are two diodes near the power section. Are these CR7 and CR8? Would it hurt to leave both soldered?

I would then attach a boss style adapter where the wires for the plug attached. the 2nd ground is screwed to the base of the pedal and not the board. Another newbie question, is the regulator in the small yellow/metal box in the picture below?



here is a picture of the board. the diodes I mentioned above are far right of the board, halfway down.


thanks again for the reply

[ironman28]

can you take some shots of the component side?

The yellow/metal box is the transformer. I dont have a MXR chorus but I do have a Dist2 I can post some pics so you can get a better idea of what I am talking about.

[gluedtogether]

When I went back to take pics, I found the two diodes that I think you are talking about. You will see in the first picture, they are sitting above the transformer.

Then from what you were saying, I think I would desolder the Blue and Black wires near the transformer and wire in the boss style adapter.


Here are other pics of the board





Thanks again for your help

[dbell76]

Can you please measure voltages on the big RETICON chip?