A great sounding and flexible 2-band baxandall eq booster that can get quite gritty depending how you set the internal gain trimpot. The Mid control is not actually an active mid band control, it is a passive variable resistor that changes the overall mid slope.
Note that this seem to be an earlier version, the current version got a small revision with an external gain control and fixed mids. More info on that at Blackhawk Amplifiers.
Here is a heavy dirty booster that will melt your Orange, Green or Sunn amp head. And your one knob fuzz will love it.😈. The gain range goes from a fairly clean boost to a hairy and fuzzy overdrive. "Transparent" it is not...
It is a fairly simple circuit that boost the whole sound spectrum and relies on op amp clipping. The most common chip used seens to be the olde LM741 which works great for this application. LM308 and CA3130EZ is used as well, the former sounding pretty close to LM741 while the latter is more high gain and has more high end distortion qualities. Note that LM308 and CA3130EZ requires an external compensation cap (read the notes below the layout).
It has two internal trimpots, one for Gain and one for Tone. The Tone trimpot is quite subtle while the Gain trimpot is worth having as an external potentiometer IMHO.
This one is traced by evilarsen, thank you!
More info on the circuit at Blackhawk Amplifiers.
Another overdrive from Nobels which shares a similar topology as ODR-1. But this one appears to a have a bit more gain on tap and a more flexible eq section. The mid control is powered by a transistor gyrator while the Lo and Hi controls are Bandaxall. And the hard clipping diodes are germaniums so you can choose your "magic fairytale" diodes in that spot.;-)
Schematic is avaiable HERE.
A quite simple old japanese compressor by Univox. For part substitutions (since stock parts is long gone obsolete...) the transistor were a low gain NPN silicon so PN2222 or 2N3903 should work. MD234 were silicon signal diodes so 1N4148s is a near enough sub. The spec of the original vactrol remains unknown so socketing a LED/LDR combo seems to be a wise decision.
Schematic, gutshots and info at FSB.
A Rat variant with some added features; a Fat control and a variable diode control called Comp.
Schematic avaiable at PedalPCB.
Note that this layout is sligtly modified. The buffer bypass switching is subbed for normal true bypass.
An old german overdrive that has become almost a cult item. It has a very well designed circuit with lots of sensible filtering and a higly tweaked gyrator powered tone control called "Spectrum". Some "bouteek" pedal companies has started making their own variants of this circuit, the most noticable ones are Wampler Belle and Rockett The Dude.
I've included the Bass control found in the Aion Fx Andromeda project.
Factory schematic is avaiable HERE and Aion Andromeda project files is avaiable HERE.
A cool little pre amp circuit from an old german reverb unit. It is fairly clean on its own, it adds some volume, lows and sparkles to your sound. When being puched hard, it clips in a very pleasant way. It also works great for pushing a tube amp. And of course it can be used as a studio tool for drums and keys.
The stock transistors were TFK OC603s. After some experimitation I found out that low leakage transistors wih Hfe between 70 and 120 sounded best (....at least to my damaged eardrums) so transistors spec'd for Rangemasters or USSR germaniums works really good.
Just is a variation of a russian big muff. The base eq of the circuit is preserved i. e. dark, bassy and heavy but there is much more gain and volume on tap. There is also an old school inductor based Mid Boost circuit at the recovery stage that boost and saturate frequencies at 800Hz.
Per request.
Note that he relay bypass switch circuit is omitted. Based on schematic from Dead End Fx.
Uh oh. Post number 1000. I think I have a problem. :-p.
Here is a great sounding simple fuzz from a most excellent builder. It is loosely based on Os Mutantes Fuzz, an aggressive, buzzy and squelchy 60s style fuzz. The most noticable addons are the tone control which are big muff based but it seem to have much wider range. There is also an added recovery stage. The original had 2SC1815 (BCE pinout) transistors which easily can be replaced with 2N2222, MPSA06 or 2N3904.
The schematic is avaiable at FSB.
Per request. The switch can be replaced with a tone control. Just omit 100k resistor at column 17 and replace the switch connections with the lugs of the 100k tone control.
This was a request. It is an old multieffect that includes wah, two noise generator settings, a volume pedal setting and a "Siren" switch which is an oscillator.
Now this is some crazy stuff! How about a wah / ringmodulator with vibrato tails???
The schematic is avaiable at DeadEnd Fx.
Note that the Wah/Cosmo Select switch is the stock 2P6T rotary for this layout.
Another old japanese obscurity. There is a hand drawn factory schematic floating on the web but I decided to clean it up in order to build a clone. It looked like slimmed down Ibanez Standard Fuzz with a tone control. and a "Howl Adjust" control which dials in the upper octave.
And built the fuzz section only...and it wasn't any good...at all. Lacking in gain, output volume and the tone control was useless. So I had to mod it without tinkering too much Added a "gain cap" across the source of the input FET transistor and ground and subbed the ge diodes for silicon. For the tonestack I simply moved the 3,9nF cap from bass side to the treble side and the 33nF from treble side to the bass side. It now behaves like the tonestack in Foxx Tone Machine but it is not as scooped. Volume control was increased to 250k and the 2SK30 input FET was just not cutting it so I replaced it with a 2SK117 for much more gain on tap.
Much better! But still not as good as a regular Superfuzz or Standard Fuzz IMHO. But it was fun to tinker and "improve"old forgotten stuff.:-)
Fuzz section with suggested mods.
The Royal line of effects was made in Tokyo, Japan in the early 70s by Thunder Electronics. Not much is known about the company but they had some own designs in their portifolio along with the casual Shin Ei superfuzz clone.
Royal RC-1 Effect Machine was an inductorless wah which topology was based on fuzz face and a twin notch filter. It is not the most powerful or vocal wah but it does a decent job after a superfuzz just like in Royal RFC-1 Double Effect Machine.
The layout and schematic is verified.
The last mojo layout for a while. This one isn't one of the classics, quite the opposite. It isne of the rarest vintage fuzzes out there and for the longest time noone knew what the circuit was like until Deadend Fx managed to trace it a couple of years ago. It is a quite heavy affair, especially when the larger input caps is selected. Fairly low gain NPN silicon transistors is recommended, in the 100-150 Hfe range.
Compact layout avaiable HERE.
It is all about the MOJO! Got a comission to build a bunch of the larger classic fuzz circuits using "mojo" parts, more preciely 1/2w carbon composition resistors and axial electrolyctics/tantalums. It may not be a huge difference soundwise but it is quite fun to build and it looks cool.:-p.
Power filter caps remains radial as well as the film caps but for true MOJO, tropical fish or mustard caps should be used:-). But I will probably end up with Greenies or ceramics. Also, all transistor pinouts will be CBE but if I manage to source some of the harder to find transistors with BCE pinouts, I will do some leg twisting. Note that none of these layouts is verified at the moment and I will start building most of the stuff in a couple of weeks but if anyone fancy building it now...here you go!
First up....Fender Blender.
Compact layout avaiable HERE.
A simple but heavy germanium fuzz using PNP transistors with normal power supply. What not to like?
The original used fairly high gain OC76 cans but others with less gain will work as well. Just keep the leakage reasonable low when selecting the transistors.
Two layout for this, one normal compact and one MOJO with 0,5w carbon comp resistors and axial electrolyctics.
Schematic avaiable at PedalPCB.
Did one tiny mod; replaced the drain resistor of Q4 (20k) with a trimpot for easier biasing.
