Yeah, that's what I was thinking. Or to get closer to this version, maybe a 220r minimum and a 2k pot. Cool. Thanks J. This looks like a nice version. I may have to steal steal some of these simple mods to sweeten the Expandora I already built.
This is verified. Decided to give it a try since I hadn't built anything new in a bit. Sounds good. Especially liked the germanium diodes in this one. Thanks for the layout.
They look like this https://www.musikding.de/Germanium-Diode-D9K_1 Also, it doesn't always matter, but the stripes on these diodes usually mark the anode not the cathode.
Thanks for the great layout. I just finished this build and it sounds great in all modes, but for some reason the fuzz decay is very fast and aggressive — once the signal starts to drop, the drive just cuts out, on other cases the signal starts with a fast on-off gain, very weird behavior.
The Expandora is known for its gated fuzz-like mode. But you may be right. I do recall it being a little extra prone to gating in that setting. I moved on from this one quickly but I’ll check mine out later.
I tested the circuit and focused on the 47Ω resistor (L17–O17). From what I found online about the Expandora circuit, it seems to affect the gate sensitivity. I tried using a 5k variable resistor, but it only worked better at the lowest setting, so I ended up removing the 47Ω resistor and replacing it with a jumper.
The gate is still there, especially when the signal fades out, but the cutoff point is much more reasonable now.
Yeah, that was the first thing I looked at but it matches the schematic. For the most part it’s fairly stock. Sorry I haven’t had time to follow up. The gating is part of what’s cool about the Expandora but too much isn’t optimal either. Jumper sounds like a good call to me.
Can anyone think of a reason why the mode switch on an Expandora can’t be something like a 2K pot rather than using multiple switches?
ReplyDeleteOh but you can. :)
Deletehttps://aionfx.com/app/files/docs/dynamo_documentation.pdf
Yeah, that's what I was thinking. Or to get closer to this version, maybe a 220r minimum and a 2k pot. Cool. Thanks J. This looks like a nice version. I may have to steal steal some of these simple mods to sweeten the Expandora I already built.
DeleteThis is verified. Decided to give it a try since I hadn't built anything new in a bit. Sounds good. Especially liked the germanium diodes in this one. Thanks for the layout.
ReplyDeleteThanks Tom!
DeleteTagged.
What germanium diodes are recommended for this pedal? Or which do you guys prefer?
ReplyDeleteDrunk Beaver seems to prefer soviet diodes. I tend to like D9K's in just about everything. But in this case, I used 1N34A's.
DeleteThanks! I'll ebay some d9ks ASAP! Does the stripe colour matter that much when ordering?
DeleteThis comment has been removed by the author.
DeleteThey look like this https://www.musikding.de/Germanium-Diode-D9K_1 Also, it doesn't always matter, but the stripes on these diodes usually mark the anode not the cathode.
ReplyDeleteThanks for the great layout.
ReplyDeleteI just finished this build and it sounds great in all modes, but for some reason the fuzz decay is very fast and aggressive — once the signal starts to drop, the drive just cuts out, on other cases the signal starts with a fast on-off gain, very weird behavior.
Has anyone else experienced this?
The Expandora is known for its gated fuzz-like mode. But you may be right. I do recall it being a little extra prone to gating in that setting. I moved on from this one quickly but I’ll check mine out later.
DeleteThanks a lot, Tom.
DeleteI tested the circuit and focused on the 47Ω resistor (L17–O17). From what I found online about the Expandora circuit, it seems to affect the gate sensitivity.
I tried using a 5k variable resistor, but it only worked better at the lowest setting, so I ended up removing the 47Ω resistor and replacing it with a jumper.
The gate is still there, especially when the signal fades out, but the cutoff point is much more reasonable now.
Yeah, that was the first thing I looked at but it matches the schematic. For the most part it’s fairly stock. Sorry I haven’t had time to follow up. The gating is part of what’s cool about the Expandora but too much isn’t optimal either. Jumper sounds like a good call to me.
Delete