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THAT's the tune you pick to demo it??? 

I don't know any blues licks...

[Texture]

I've been exporing analog octave circuits lately and nothing sounds quite like the Green Ringer to my ears, but it generally needs help to sound its best. Grawlix is a Green Ringer with some quality-of-life features added.



I repurposed an old enclosure as the original occupant had been superseded by a newer design.



The first half of the circuit is the classic Green Ringer topology with modernized and streamlined values. The bias network is a little eccentric, but it gets the necessary voltage at the base of Q2 to maximize the headroom and octave effect. Instead of a fixed gain, Q1 can now be adjusted. This lets you set the level that hits the rectifier section for the most prominent octave. It can also be cranked up to some serious fuzz. The Texture control pans between metallic fuzz and full octave up. The further clockwise, the more prominent the octave will be. This also makes diode matching less critical, as the Texture control can be adjusted until the octave pops. Q3 buffers the output—I tried to ditch this, but the rectifier is very picky about what comes after it!



The octave section is followed by clipping diodes. These have a similar effect to placing an overdirve after a Green Ringer; they act as a crude form of compression to keep down the crazy transients the octave can produce. With the Gain control low, they don't do anything. After about half way, they start to color the signal.

Tone is a tilt EQ with a mid bump around 800Hz. Clockwise, it cuts the thump of strong transients that can be created with the Gain set low. Counterclockwise, it cuts the fizz and treble without getting too dark. In the middle, it gives you a throaty midrange, similar to running a Tube Screamer after your octave.

Last is a make-up gain stage to ensure a good amount of boost is available at all times.



This circuit definitely does the Green Ringer thing, but I think it's also a reasonable substitute for a Moonrock or a Superfuzz. It can fuzz, but it's more open and dynamic than most octave fuzzes.

Here's a demo:

As always, I have extra PCBs. If you're interested, DM me!

Thanks! It's definitely easier to control the gain with my foot.

Sounds like someone is trying to reinvent the mixing console.

This all started with Jessenator giving me the bullying me for building in 125B instead of 1590B. I threatened to put a mosfet boost in a 1590XX just to spite him. That's not where I ended up, but the idea for this circuit did come to me while contemplating mosfets and revenge.



Polyphemus is a one-knob overdrive/distortion with internal voicing options that allow it to be tailored to a variety of rigs and use cases. The idea was, to do all the dialing in up front, then screw the thing shut and just rock! As it's built around a Super Hard On of sorts, it only seemed appropriate to name it after the original one-eyed monster!



The circuit consists of three gain/eq stages. The first stage is a high shelf filter that boosts everything above a set frequency by 20dB. Everything below that frequency stays at unity gain. The second stage is a simple mosfet boost, which is pushed by the first stage into clipping. The final stage is a low shelf, set at a similar frequency to the first. This flattens out the eq again. This makes for a "transparent" overdrive that emphasizes harmonics and retains clarity, since higher frequencies are saturated more and sooner. It also greatly lowers the noise floor!



Switches 1 and 2 set the capacitance/cut-off frequency in the HPF stage. Switches 3 and 4 set the capacitance/cut-off frequency in the LPF stage. HPF and LPF interact to shape the character of the gain, as well as the frequency response. Flat, transparent overdrive, various kinds of mid boost or treble boost, mid scoop, even distortion/fuzz is achievable. Heat sets the range of the Gain control. This is so that the headroom can be adjusted to suit your pickups and maximize the range of the Gain Control. Output is a volume control. With Heat dialed in, there is a moderate change in volume from the lowest to the highest Gain setting (maybe 6dB). I like to set Output so that the lowest Gain setting is about unity with bypass, but you could attenuate or boost to taste.


Here's a demo:

There's a little dedication to Jessenator on the PCB. 😘 I built mine in a 125B, as is my preference, but it'll fit into a 1590B with top mount jacks. Side jacks are possible, but you'd have to push the Gain knob up to accommodate them. And, of course, it's in green, Jessenator's preferred solder mask color.


As always, I have extra PCBs. If you want one, DM me.

Nah. Just slap a BS170 in the stock circuit and see what it does. You might have to change R12 if the bias is way off, but it probably won't be.

What about using a mosfet for Q3?

The AE tremolo produces a sine wave, or very close to one. I'm using that drive a two-stage optical phaser. It's producing vibrato. It doesn't go very slow, but that's not necessary in my use case. If you want a really slow sign wave, you might consider using a micronctoller. Maybe on of Electric Druid's TAPLFO chips?

*It's designed to fit in a 1590B with top mount jacks.

Autocorrect did me dirty.

Lol that file name. So 1590F is it? 

Jokes aside, nice work!

I'll print something kinder on the actual PCB 😘. The board is designed to fit in a 1590A with too mount jacks (of your into that).

Our repartee got me thinking about the SHO and the Speaker Cranker and how much I enjoy the sound and simplicity of operation. This circuit sandwiches the SHO between a pre-emphasis and de-emphasis stage to create an overdrive while retaining clarity. Gain staging and filter cut-offs can be set internally, then it's all rock and roll!

I couldn't bring myself to do SMD, but I was inspired to make a one knob, mosfet overdive!

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I noticed that you changed Q2 from Ge to Si, did you try both?

I didn't test a Germanium transistor; I generally avoid them as they are both more expensive and less reliable than silicon. The mosfet boost at the front softens things in a similar fashion anyway.

But I'll use all SMD inside. 😈

One of these days I'm gonna put a moseft boost in a 1590XX just to spite you! 

[Lows]

This is my highly tweakable take on the Harmonic Percolator. I've added a modified Push-Me-Pull-You in series for octave fuzz goodness.



Water slide decal on bare aluminum for the graphics. I wanted the metallic look of a Moka Pot.



I used my standard I/O and bypass layout.



A mosfet boost feeds the fuzz section to allow for more saturation. This is especially important as I decided to leave out clipping diodes. They just seemed to mask the character of the fuzz. The Lows control is pre-fuzz. From fully clockwise to noon, it tightens up the fuzz response. Below noon it noticeably attenuates low-end content. The Gain control is just a volume control for the boost output, which feeds the Harmonic Percolator section. I arrived at the values here after much experimentation, trying to get as much tonal variation as possible. The Highs control uses negative feedback to attenuate treble in the Q2 gain stage. Placing it here effectively cuts high-end content without masking the character of the fuzz. Clang sets the bias of Q3 (which in turn effects the bias of Q2). This goes from smooth saturation when counterclockwise (think Albini values), up through the spitty ripping-velcro type sounds the percolator is known for, and into farty misbiased octave down sounds as you move clockwise. Lastly, Octave blends in a separate octave up circuit, which is based on Tim Escobedo's Push Me Pull You, and is optimized to compliment the fuzz. As this sub-circuit comes after the boost and percolator sections, it is sensitive to the other controls.

I'm pleased wth this design. It gets all the sounds I'd want from a Harmonic Percolator while remaining farily ugly proof (for a fuzz).

Here's a demo:

As always, I have extra PCBs. If anyone is interested in building one, DM me.