Dharmonic Percolator

[irmcdermott]

Been a while since I've posted a build report. This was a fun one for a friend of mine. He wanted to fill it with as many LOST references as we could. So that's what we did.

I went with OA126 diodes for D4, D5. I may switch those out. There is a significant volume drop in that position. Has anyone else who has used those had the issues? They sound good, but I really need to crank it to get it where it needs to be. Any thoughts would be awesome.

Here are the pics

[midwayfair]

There definitely should not be a volume drop when switching to the OA126. They have almost three times the Fv of the 1N695 (.65 vs. .25), so it should be quite a bit louder. Are you sure it's not the other way around? Or make sure the diodes aren't damaged.

[irmcdermott]

Thanks Jon. It's definitely in the OA126 position that I get the volume drop. I've tried 4 different ones too. The bands on them are like any other diode, correct? There's not a chance I have them in backwards is there?

I'll try a few more and leave the leads longer to get in my socket to make sure it's not broken.

[midwayfair]

Thanks Jon. It's definitely in the OA126 position that I get the volume drop. I've tried 4 different ones too. The bands on them are like any other diode, correct? There's not a chance I have them in backwards is there?

I'll try a few more and leave the leads longer to get in my socket to make sure it's not broken.

Well, there is no backwards -- they're back to back. As long as you have them facing opposite directions.

Try a pair of silicon diodes in that position -- they should have a similar Fv. Also try just pulling them out, see if it gets louder. If it doesn't get MUCH louder when you've pulled the diodes, there could be something weird going on.

[irmcdermott]

Will do. Thanks Jon.

[jprizz]

I love the Lost theme. Great show, great pedal.

[Bret608]

Ha, I love the theme! There's been a void in my life since Lost went off the air.

I'll be curious what's going on here with the volume drop. So far I've done an Albini-specs version of this. I used 1n914 for the D4/D5 positions. It's definitely louder than the 1n695 positions (but not as much as the diode lift position). Also, it sounds really good. I'm just about to do a stock-specs version and am unsure what to try out for D4/D5.

[irmcdermott]

Hey guys,

It's working and sounds great. I think it was a diode, I swapped out and it is loud and seems to be working just fine.

[midwayfair]

I think it was a diode

The black glass ones break so easily. It's unbelievable how many I've damaged even with stress relief.

[irmcdermott]

I think this is normal from the videos that I have watched. But is the output on this kind of low in general unless it's cranked? I feel like all of the videos they have both controls past 1:00 if not more.

[midwayfair]

I think this is normal from the videos that I have watched. But is the output on this kind of low in general unless it's cranked? I feel like all of the videos they have both controls past 1:00 if not more.

The signal's not that huge at the output -- keep in mind that you're stricted to a mere .65v peak-to-peak even with those OA126s in there. That's pretty loud overall, but it's not like a booster.