Tools, Tones and Toys for Guitarists
The RTO (or Robin Trower Overdrive) from Fulltone is a modified Tube Screamer circuit. The input buffer is removed and the soft clipping stage has an interesting mix of diodes. For a drilling template, use the Cmat Mods Signa.
I laid out the original 1977 Hot Cake a while back, but never got around to doing the modern one that came out in 2003. So here’s the newer one. I ignored the original relay bypass switch and the polarity protection diode could be replaced with a 1N4001 or similar. The original 1N5238 is an … Read more
Stumbled across the schematic for this recently. It’s takes inspiration from the Sparkle Drive with the clean blend function but uses a different drive section. I thought it was interesting and drew up a layout with board mounted pots and it’ll be an easy fit in a 1590B.
I can’t remember how many times I’ve been asked to do this one. I started laying it out ages ago, but got frustrated or interrupted and never went back to it. But here it is now, better late than never. The layout is for board mounted pots and it will fit in a 125B enclosure. … Read more
To my ears, this is an overlooked gem. Update! Built it myself and yes it sounds as great as i remembered. However. I do recommend going stright for C10K pot on the drive control. And it doesn’t hurt to up the “12K*” to 22K. This way the output level goes up to “modern sufficient”.
The Durham Sex Drive is a pretty versatile Tube Screamer variation. It can go from clean boost to medium overdrive. The traditional input and output buffers have been removed and there’s a toggle switch (SPDT on/off/on) to select between different clipping options–hard, off, and soft. Pots are board mounted and it’ll fit snuggly in a … Read more
For Fuzz Friday here’s the Bellows from Earthquaker. I picked up one of these late last year and was able to trace it. It’s fairly simple but sounds really good. It’s really similar to an Electra circuit, but with a JFET going between the base and collector of the transistor. Here’s the schematic for reference. … Read more
Alright, back to the normal layouts. Here’s a really unique overdrive pedal from Hudson Electronics in the UK. It features an onboard charge pump to take 9 volts up to 24, so be sure to use appropriately rated capacitors (min 35v for electros). The transformer (the big yellow thing on the board) can be found … Read more
The Joyo Ultimate Drive is a cool little pedal based on the Fulltone OCD. In fact, the circuit looks a lot like a V3-4 OCD. But what we’re looking at today is how to take a cheap, $35 pedal and turn it into something awesome. We’re going to be changing the gain pot so it … Read more
Happy New Year everyone! I thought I’d kick off the New Year with something different. Lately I’ve been doing a lot of work in Eagle CAD for some non-blog related projects and thought I’d do a few single sided layouts with it. For your perf guys, don’t worry, this isn’t going to be a super … Read more