Jen Harmon Booster

Here's a really unique overdrive from the Italian manufacturer Jen from the late 70s. Think Tube Screamer meets Big Muff. It sort of reminds me of a DBA design (only more stable and not as over the top) with a whole mess of transistor stages pushing a BMP style tone stack. Originals used BC318c transistors, but others in the 400-500 hfe range can be used. Here's the schematic for reference.

Jen Fuzz

Jen was an Italian manufacturer in the 60s and 70s that produced their own line of effects in addition to OEM stuff for other brands like Gretsch and Vox. This fuzz effect is essentially a Fuzz Face with an emitter follower up front and clipping diodes on the output. It produces a treble-heavy fuzz with a good bit of volume. Original transistors were BC238B for Q1-2 and a BC239C for Q3. Some schematics floating around call for 2N5088s, but shoot for transistors in the 200hFE range (2N2222, 2N3904, etc). This layout should fit in a 1590A, and if you drill the enclosure right, you could board-mount the pots using long-leg right angle PCB pots (mounted from the component side).

Jen HF Modulator

Jen was an Italian electronics company that produced a lot of OEM stuff for other companies (Vox, Gretsch, etc.) as well as marketing their own line of effects. For instance, the HF Modulator was the same effect as the Gretsch Playboy.

This effect is a ring modulator and sounds fantastic with a fuzz pushing it. The original unit used 2N5172 transistors (which have BCE pinout), but I've laid this out for more common 2N3904 or 2N5088 transistors (that have CBE pinout). I've also added pulldown resistors, polarity protection, and power filtering.

Here's the schematic if anyone needs it. Most of the ones online have the tone section wrong.