Runoffgroove Umble

 Schematic and writeup is avaiable HERE.

 

Runoffgroove Azabache

 Schematic and writup is avaiable HERE.

 

Runoffgroove Thor

 Schematic and writeup is avaiable HERE.

 

Runoffgroove Eighteen

 Schematic and writeup is avaiable HERE.

 

Mesa Boogie Mk. 1 Preamp

 A verified layout by Sebastian, thanks mate!

In his own words...

 

I forgot about this layout I did ages ago, built up (it works), and never got around to boxing up: a Mesa Boogie Mk.1 preamp. I'm personally partial to pre-gain tone stacks (e.g. '60s Fenders, Orange Graphic MkII), so I was disappointed with the Runoffgroove Uno having its gain control before the tone stack instead of after. So I knocked together the schematic below, which is basically a straight JFET emulation of the actual Mk.1 preamp if you plugged into Input 1 (i.e. the input with the extra gain stage). This gives the user both pre- and post-tone stack gain controls. I added a Marshall-style "treble peaker" bright cap between the input and 2nd gain stages, just for some extra clang, which can be engaged or disengaged with the "TP" switch. After the master volume control, there's a mu-amp output stage to mimic the push-pull amplification of the Boogie's phase inverter.

I used BF245A JFETs just because that's what I have the most of, but I tested it with PN4393s and J201s, and it worked just as well. The gain boost can be either a toggle or stomp switch; as the original boost was operated by footswitch, I opted for that in my build.

This thing's pretty fun. Like actual Boogies, it takes a bit to dial in a great tone—it's absolutely packed with bad tones, LOL—but it can do everything from crystaline Fender cleans to Weezer "blue album" growl to thrash grind. I hope other folks enjoy it!

 

 

 

 

Marshall 1959 Pedal

Schematic is avaiable HERE.

 

 

 

Marshall JMC900 Pedal

 Schematic is avaiable HERE.

 

Marshall JMC800 Pedal

 Schematic is avaiable HERE.

 

PedalPCB / Chuck D. Bones Thunderzone

 Schematic is avaiable HERE.

Madbean Dinky Drive

Schematic can be downloaded HERE.

Based on the pre amp section of a Bad Cat Mini II which is supposed to bring some "Voxy" tones.

Jok3rx Blacker Forest - Bogner Ubershall Emulator

 Schematic is avaiable HERE.

GoosoniqueWorks Seventh Heaven - Bogner Ectasy Red Ch. Emulator

 Schematic is avaiable HERE.

Soldano SLO Pedal

 Schematic is avaiable HERE.

Runoffgroove Britannia

 Per request.

Schematic is avaiable HERE.

Sovtek MIG 100H

 Another generous contribution by Sebastian, this time a Sovtek MIG 100H amp emulator!

The Acorn MIGFET post inspired me to whip up this layout for a version of the MiG 100H, which is more like a hot-rodded JCM800 than the pseudo-Plexi MiG 50. An interesting variation in its own right.

I've not built this myself yet, since I'm out of 100k trimmers and A1M pots, so due diligence is encouraged. I've attached the amp schematic for scrutiny. The layout follows the circuit pretty much 1-to-1 until the phase inverter. One half of the phase inverter is used, then the output stage is pilfered from the Menatone Foxy Brown (I've found it great in various AIAB builds, so it should do the trick here too). The master volume is moved to the end of the circuit.

Like the JCM800, the MiG 100H has two channels with separate inputs, the lower-gain of which skips the first stage of the preamp. This layout has a footswitch to toggle between the two channels for (hopefully) added utility.

 

 

 

 

 

Acorn Amplifiers MIGFET 50p Preamp

 A big thanks to Chris Stelloh for the schematic!

 

 

 

 

Jackson Audio 1484 Twin Twelve

 Another guest appearance by Sebastian. Thanks a lot!

Schematic is avaiable HERE.

Miles Platting In-A-Box

 Time for a a guest appearance. Sebastian sent me some interesting layouts that might interest some of you. Here is what Sebastiam says about it.

The best-sounding amp I ever played through was a friend's Miles Platting 100W head (made by Wilsic Sound during the 1970s in Doncaster, England), which was basically a Bassman preamp going into a Marshall power section. So I did a JFET translation of the preamp and grabbed the "power section" of the model feT and voilà, a Miles Platting-in-a-box.

 

 

 

 

GuitarPCB 69 Stones Drive 2022

 ...and a another request!

Schematic is avaiable HERE.

God City N.E.W. The Thing That Should Not Be Preamp

An op amp emulator of Mesa Boogie Mark II C+ which was used by Metallica for Master of Puppets. There is also a an eq board (which is huge!) so that one is for another post.

Schematic is avaiable HERE.