Dual Rectifier in a Box (Dr Boogey) Build Report

September 23rd, 2007 Chris Brown Posted in Diy Stompboxes, Guitar, Guitar Gear, Live Music, Music |

My latest guitar fx project is the Dr. Boogey. (photos at bottom) This design was originally created by electrictabs and it has been extensively reworked by gaussmarkov and the DIY community.. the updates were discussed in detail here at this thread.

I based my layout on the gaussmarkov layout… this is supposed to be quieter and solve some of the noise issues that previous layouts have had.

I have not built this box previously so I can not compare the noise level to other layouts, however, I will say that this is a noisy build and I can see by moving the wires around that it would be even noisier if it wasn’t layed out as it is.

Day 1: I started out by making a layout for perfboard from the gaussmarkov layout and comments here at this thread. I also found an old box meant for switching one keyboard between two computers. Nice and big.

Day 2: I went ahead and populated the perfboard and soldered it all together.

Day3: I completed the build by soldering all the wires, pots, switches, the led, and the jacks. It was easy to bias the jfet drains to 4.5v.

Night 3: I added the build to my pedal board and went to the gig…

This thing was extremely noisy!!! Waterfall sound like crazy, I guess that’s white or pink noise… I should do my homework about the names of noise eh?

Anyway… I still used it, but even with the guitar volume at zero it made so much noise that it was obvious to everyone on the stage. We’re a rock cover band that also does jam music jazz, fusion, and blues… we play loud.. for others to be able to hear my the noise it had to be extreme.

I came home from the gig knowing that the hundred or so posts that I had read about quieting the Dr. Boogey would pay off.

Day 4: I went back through the forum posts that I had bookmarked and got some ideas about lowering the noise. The first thing I did was changed Q1 from J201 to MPF102…. This helped substantially and left so much gain that I still probably won’t set the gain knob to full. While I was in there I added a 100pf cap parallel with the 20pf cap…this slightly tamed some of the highs… there was just a little too much high end crunch for me before.

When I went to re-bias the build I realized how much trimmer noise I was getting. I set Q1 to about 4.8v and the rest at 4.55ish and tested it one last time… sounded great, still a lot of waterfall sound…

I bit the bullet and replaced the trim pots with fixed resistors….WOW WOW.

Taking out the trim pots took away 85% of the annoying waterfall sound…

I brought home my Twin Reverb and my fx board and tried it out with my normal rig at stage volume…

Now my Dr. Boogey is only slightly noisier than my fulldrive2. It’s about as noisy as a fuzz face or something.

AWESOME!!

Big thanks to the DIY community for making fx building information available to the world!!

Photos:

Parts and Board