Build Your Own Clone Message Board

Hello, I built the Green Pony with the FET mod. It sounds pretty good but there are two issues. One is that at reasonable gain/volume levels, I get a lot of hiss--obviously more so when the treble is high, but even other wise. For comparison, I have built a Boss FET Preamp clone and its a little noisy at high gain, but not quite this bad. Second is that with gain low/zero volume has to be maxxed to get any kind of clean boost. Are these issues related to the FET mod or do you think there is something wrong?

If someone has IC and Q voltages for a working version w/FET mod, that'd be great. If not, I can post information or would be happy if you can let me know where I might look for a potential problem.

Thanks!

I haven't built the Green Pony, so I can't help with voltage readings.

General troubleshooting response:

1. Did you build it stock before trying the mods? If so, did it work as expected before the modification?

2. Please post some well-focused photos of your build, including both sides of the PCB and your offboard wiring. There are many things we can do to help once we see the photos, but not much we can do without them. (It's sometimes possible that those with good knowledge of how the circuit works could point you to particular components to check, but it's vastly easier to help if we can see your work.)

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Scott

My band, Austin Hollow

Thank you for the response! No I didn't build the stock version before trying the mod. I did socket the key components, except for the one capacitor.

I will post pics, just thought I'd see if there's something obvious to check first.

here's the photos

I can't tell for sure because it's a little out of focus, but it appears that your middle IC might be installed backwards. The dot or notch should be at the north end, closer to the jacks than the foot switch. Can you confirm orientation of that IC?

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Scott

My band, Austin Hollow

@scott you are right about the IC, when I was pulling it out of the box, I accidentally popped it out of the socket and must have reinstalled it backwards. But I think the orientation was right when I was playing it before I unboxed the PCB--otherwise I wouldn't have gotten any sound, right?

[Also sorry about the blurry photos, I had to downsample them because of the strict size limit for photo uploads]

IC1 is a dual op-amp. If you installed it backwards and applied power to the pedal it is very likely the op-amp is fried and needs to be replaced.

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"It’s your soldering."

I tried it after I fixed the orientation and it worked ok. And actually, outside of the box the clean boost was a little better--I just had to keep the volume at 70-ish% to get it to work . So that probably means it still works right? Wouldn't the pedal just cut out if the op amp was fried?

I am wondering if some of the problem might be that, in the box, the dual gang pot is pressed down against the PCB, so perhaps something is shorting? As you might see in the pic, I've got some electrical tape under that pot though I could not get it all the way under.

I don't know if this would cause your symptom or not, but it's a fair guess, and there's a pretty simple way to test it. You said you can't get tape all the way under there, but I bet you could slide in a piece of card stock easily enough. Or even cardboard, if you cut it to shape and bent it at 90°. Or craft foam, if you happen to have any. (That stuff is so useful!)

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Scott

My band, Austin Hollow

Keep in mind that the volume pot has an audio taper. Unity gain should be about at noon. It shouldn't start boosting till after noon. A lot of boost pedals will use a linear taper to make you think it has a huge amount of boost. If you pay attention, those pedals volume knobs won't do much of anything after noon. Audio taper is the correct taper for a volume pot because it allows you to adjust the volume evenly throughout the pots entire sweep.. If you want the boost to come on before noon, then you need to switch it out for a linear taper.

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*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Thanks everyone your advice was helpful. I managed to slip in a piece of tape under the dual gang pot and re-boxed it. It sounds good, thanks everyone!