Topographer Distortion: Finding My Way...

jeffwhitfield

Well-known member
I built this one a few weeks ago. By far one of the most original distortion boxes I've tried yet. At first, I wasn't sure if it was working right. The problem was that setting the gain up high causes it to clip with a gated effect. It's actually a pretty cool effect...but unexpected from a distortion pedal. The reason is due to how the transformer works. Push it hard enough and it clips really hard.

In terms of sound, it adds quite a bit of grit. By itself, it's a pretty good distortion box...but where it shines is when you stack something behind it. In this case, I stacked it with a Harmonic Perculator clone. Once I did that, holy cow, did it ever open up! Seems that pushing it with a Germanium-based boost or pre-amp really makes this one sing. And you don't have to turn up the gain much to get it there. For me, the sweet spot was around 10-11 o'clock...not quite halfway.

For the design, I used a flat black textured enclosure. Used AmplifyFun for the UV printing. Wanted something that sort of resembled the original IVP pre-amp that this particular circuit was based on. I found a really cool topographical graphic and added it to the bottom. It's funny cause it sort of has that Asteroids thing going with it. Still a damn cool effect for the pedal though. Pleased with how it turned out.

IMG_0327 (1).jpeg
IMG_0328 (1).jpeg
 
Your’s definitely looks better than mine. I think the gated clipping you are describing is what the pedal is supposed to sound like. It’s a kind of nasty, solid-state distortion, in a good way…
 
Your’s definitely looks better than mine. I think the gated clipping you are describing is what the pedal is supposed to sound like. It’s a kind of nasty, solid-state distortion, in a good way…
Yep! AionFX mentions this in their documentation of their IVP-based pedal. Absolutely normal. It’s just how the transformer works.
 
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Looks sweet!
I built the AionFx version, but haven't experienced what your talking about with the gain maxed. I think they also said it may self oscillate if the treble is turned up all the way, but I don't have this issue either. Hmm, I wonder what I did differently?
 
Looks sweet!
I built the AionFx version, but haven't experienced what your talking about with the gain maxed. I think they also said it may self oscillate if the treble is turned up all the way, but I don't have this issue either. Hmm, I wonder what I did differently?
My guess is that the gain on the transistors might be a little high. Could be they’re overloading the transformer a bit at higher drive settings. I’ll test this theory out soon.
 
Very cool!

What was the process like using Amplify Fun? I know the whole process with Tayda, but not them. Do they take Affinity files or just illustrator?
 
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