Two "Redstone" pedals

[zippofan]

I appreciate how hard it is to come up with a good name for a pedal, and I'm working on two with the same name. Back in the winter I found Nucleon FX and picked up a couple PCB's, including their original EQ/boost circuit called Redstone. Then about a month ago, DeadEnd FX released a clone of the spaceman Mercury IV boost. As a boost nut I had to pick it up, and I really like their boards.

Some progress:




And just finished buttoning up the EQ:



Cool circuit, just been playing with it through my little ZT lunchbox Jr and it provides a lot of flexibility over the three bands, and good amount of boost. The circuit uses a charge pump, a pair of TL072's, and an optical switching setup.

Hope to finish the Mercury IV "Redstone" tomorrow.

 

[zippofan]

Finished up the Mercury IV Boost today, a little more involved than the Redstone EQ. There is no provision for biasing JFETs in the circuit, so the only way to get it right is to sub in different devices. I have a stash of JFETs, but if you don't then it might not be the best circuit to build.
Once I got the biasing within 10% of the measured values on the schematic I fired it up, and it's a doozy! A metric ton of boost, lots of harmonics, and a lot of tone shaping with the boost/cut switches. The Harmonics control is subtle, a thickening of tone as it's turned up.
The circuit uses a germanium PNP transistor (I used a NOS RCA 2N404), (2) J201's, an MPF102, (2) 2N5457's, and (2) 2N5484 JFETs and BS170, BS250 MOSFET's, plus a TLE2426 virtual ground. Based on the gutshots I saw, there are two electrolytics on power supply rails, all others are film caps.
Dead End recommends a big box for it, so I used a 1590BBH.

Some pics:


If you haven't checked out DeadEnd FX, you should. The guys that run it are always on the stompbox boards and Tagboard effects. They make a lot of wild circuits, most of which are long gone (like Lovetone stuff). In many cases they have posted Vero versions of the circuits they've done too. No affiliation, I just really enjoyed the three boards I've made from them.

Z