Build Your Own Clone Message Board

Built my first OD2 and i have an issue. The boost works fine. Both Led work. The OD makes a high pitch squeal when i turn the drive knob past 8 o-clock, not very useful. I have tried adjusting the timpots and am able to get a little more drive maybe to 12 o-clock if i turn all pots to full counterclockwise. Using a multimeter i found that the min trimpot can only go as high a 37.9 KOhm, not near the 51Kohm recommended setting. Checked the op-amp and am getting ~9 volts out of pin 8.

The squeal also gets worse when i change pickups from center to neck or center to bridge. Center pickup seems to have less squeal. I dont believe this is how the OD2 should function I should be able to use full range of the drive knob. The boost and OD knob seem to have no affect on the squeal.

I looked over my connections and component placements and dont see anything wrong. I am having trouble putting pics but will soon. Any help in the mean time would be great.

Please get the photos posted ASAP. Otherwise, we're just guessing.

Here are a few photos.

http://imageshack.us/photo/my-images/824/airplaneride001z.jpg/

http://imageshack.us/photo/my-images/703/backpcb004.jpg/

http://imageshack.us/photo/my-images/220/backpcb003.jpg/

http://imageshack.us/photo/my-images/821/airplaneride005.jpg/

looks pretty darn good for a first build! too bad it's not working right...

Thanks, I'm no stranger to solder.

I did some more trouble shooting today. Tried swapping out op-amps with no differences. Still sqeals when drive is turned up. I am using a gibson les paul and noticed on brigde or neck pickup selection the squeal comes in sooner upon turning up the drive then when i am in center switch selection. This is getting very frustrating. I am going to try and re-flow the solder and see if that does anything.

Also i investigated the trimpots. At max clockwise turn the min trimpot only reads 37Kohm and at max counterclockwise it reads 87 Ohm. How am i to be able to get 51Kohm as instuction state. Could this trimpot be no good. The Louder trimpot at max clockwise turn is 37.2Kohm and at max counterclockwise reads 5.1Ohm. The Max trimpot at max clockwise turn is 8.2 Ohm and 9.7 kohm at max counterclockwise turn. Seem backwards to the other two. Are the trimpots suppose to increase resistance on couterclockwise turning.

The boost sounds great no problems, if that counts for anything.

If you try and measure the trimmers while they are soldered in and connected to other components you will not see their actual value.
Almost sounds to me like this is good old fashioned feedback and not a fault of the pedal.
If you put enough gain in the chain some electric guitars will produce feedback squeals even at low volume. You may find you are just too close to the amp. Try separating the guitar from the amp by say at least 10 feet.

The issue has been fixed. I re flowed solder in any suspect areas and the pedal works good now. Full use of the Drive knob with the trimpots set to specs on the build instructions. Rock N Out Now.