ROG Double D build report

Started by SuperGeo, May 19, 2006, 05:21:32 PM

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SuperGeo

Hello

First of all, I'm not very good about english.

I really liked the idea. Etched the board with the layout (the 2nd) soldered all the components, like any other build. And so when I first tested, it didn't work. The bouce gain hadn't that gain I heard in the sample clip, and both channels volume were very low. The 4049 that I had here was the buffered one and because of that I had to unsolder an unbuffered one from an bypass switching that didn't work.

I thought maybe I fried the chip, so today I bought a new one, but nothing changed. Looked twice and the values and board were ok, no misplaced component or solder bridge.

When I checked the voltage at the drain of the FET, it was 0.7volt, very below the 4.5 necessary. First I took off the Transistor and replaced with a new one, but it was the same 0.7 volt. Took off the 10k resistor and placed a new one, but it changed nothing. Finally I put an 10k pot that make me able to get 4.5v

And it worked :)

It is a very nice pedal, I'm very happy with it. I prefer the bounce channel. I noted that it hasn't a (how can I say) 'sharp' palm mute, like I'm used to, but that doesn't bother me at all. Another thing I thought the Jiggle channel a bit too hot for me. I'm planning adding an tone stack for each channel.

I used an Bf245 and an mpf102 for the fets. The only value change was an 56pF in the bounce channel in the place of the 47pF one, that I didn't had.

:: Forgot to say:  when measuring the 10k bias pot, ny dmm read 2k.  :icon_confused:  :icon_question: :icon_question: It's at least strange

JimRayden

2k is normal. The noted 10k value is the value for the trimpot (hmm, I wonder why the schematic shows a resistor), that means it's the maximum value you can select. It's quite usual that the actual bias resistance will be alot lower than that, so you're okay.

Congrats on the build. I at first built it with the buffered chip too but soon realized it's hopeless. The 4049 sure is a good sounding piece of silicon.

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Jimbo