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Bobtavia analysis
This is a quick look at how the Bobtavia works. The Bobtavia is uses the LM386 to amplify the input signal. In the default setup the LM386 has a gain of 20. The output of the LM386 runs through a 220µ C4 cap into a small audio transformer. The input appears at one output of […]
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Bobtavia by Bob Starr
Bobtavia is an old-school DIY octave fuzz. It’s a lot like the Roger Meyer Octavia but uses an LM386 instead of transistors. The Bobtavia uses a transformer like the original Octavia and the Maestro Brassmaster. What’s nice about the Bobtavia is its simplicity. The whole circuit is just a handful of parts. This was one of the first […]
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Titan boost analysis
Here is a closer look at the Titan Boost by John Hollis. The circuit uses an op-amp to boost and buffer the input signal. This is fed into an inductor that steps up the voltage at the output. The amplifier is built around a TL072 dual op-amp IC1_A and IC1_B. The first stage, IC1_A, is […]
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Titan Boost build
Here is a build of John Hollis’ Titan Boost. I built this a long time ago and liked the sound. There is also a mod to turn it into an octave up. John Hollis was involved with the early DIYStompbox community. He posted some amazing and original designs on his site. The site seems to have been […]
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Fake op-amps
I bought some op-amps from Aliexpress a few days ago. They seem to be working. I patted myself on the back for getting a such a deal, they were about $0.08 each! All of the parts seem to be working except fro the LM308 which didn’t work at all. After watching this video, I’m starting […]
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Timmy clone
Timmy is a boutique overdrive by Paul Cochrane. This pedal generated a lot of discussion over the ethics of cloning pedals. A couple companies were accused of cloning Timmy. Most of the most popular boutique pedals out today are clones of something. In the case of Timmy, Paul is a small manufacturer, who does all of […]
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New PCB day!
I have a few new PCB projects in the mail today. Flatline Compressor by John Hollis Titan Boost by John Hollis Tremolo-matic XXVIII from Stompboxology Distort-o-matic XI from Stompboxology Bobtavia by Bob Starr John Hollis John Hollis was one of the first people I ran into posting DIY designs on the internet. All of his […]
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Cheap parts from Aliexpress.com
I need some op-amps, usually I’m buying these from Tayda Electronics or StompboxParts.com. Tayda is the cheaper of the two but StompboxParts ships faster. In this case neither place had all of what I wanted in stock. I wasn’t in a hurry so I decided to experiment and order from Aliexpress.com. This place seems be […]
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The Crank by Mark Hammer
This is interesting variation on the Tube Screamer style diode clipping. Read more about it at Mark Hammers site here: https://hammer.ampage.org/files/The_Crank.gif In a nutshell the goal seems to be less distortion. More of a booster to overdrive effect. I’d say this circuit meets that goal. The sound is mostly clean with some gravel or grit […]
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Tremolo-matic X by stompboxology
This circuit is based on a type of tremolo that some Fender amp models. Its operation is very interesting. It splits the signal path into a low pass and high pass routes and alternates crossfading between each. It has a sweet subtle flavor of tremolo. I had built this circuit years ago making a PCB […]
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Experimenting with the mill
These are some experiments to render some patterns on the mill. I did a wave pattern on a powder-coated green box and two bare-metal boxes. I also did a pattern similar to the cover of Joy Division’s UnknownPleasures. The green boxes came out good but the lack of contrast makes the effect rather mild. The […]
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Tremolo-matic XXII v2
This project was originally from the Stompboxology newsletter. In a discussion about the circuit, the question came up about an extra op-amp used to create a second bias voltage buffer. This appears twice on the schematic as IC1B and IC2. IC2 seems redundant. I decided to test this out by making a second version of the […]