EQD Bows

Here's Jamie's take on the classic Rangemaster circuit, with a NPN germanium transistor. There's an added toggle to switch between full range and treble input caps. Probably a tight a squeeze in a 1590A but should be doable. There is also a 1590A specific PCB with board mounted pot and switch in the store now (link below).

   

EFFECTS LAYOUTS BEAUREGARD

ThroBak Strange Master

Essentially a Rangemaster with a switch selecting the input cap (Hi/Lo) and another switch (Ge/Si) selecting between a germanium or silicon transistor. The bias pot helps to fine tune the bias (imagine that lol) differences between germanium and silicon modes. Other transistors can be used other than what's specified. Something in the 100-120 hFE range for the germanium and something around 250 hFE for the silicon. Schematic here.

Run Off Groove Omega

Here's a nice little boost from ROG that originated from trying to design a FET-based Rangemaster treble booster. I've laid it out for a 1590a with board mounted 9mm pots. More info, schematic and sound clips can be found here.

Smallsound/Bigsound Sparkle Motion

Stumbled across this one on the old Smallsound/Bigsound blog. The Sparkle Motion is based on the classic Rangemaster treble boost, but with a lot of extra controls. Schematic and more info can be found here.

Run Off Groove May Queen

Here's another "Brian May in a box" circuits, this time from Run Off Groove. The May Queen is a treble booster/overdrive that should get you pretty close to those classic Queen tones. The cap between 9v and the drain of Q3 in the layout below is optional. It's a high end filter, so the larger the values will cut more treble frequencies (2.2n is just a good starting point–adjust to taste). I've added polarity protection, power filtering, and a pull down resistor at the input. You might be able to cram it into a 1590a. For the schematic, transistor voltages, and sound samples, check out RunOffGroove.com.

Vox Treble Booster

The Vox Treble Booster was a simple silicon treble boost effect that plugged straight into an amp's input jack. It allowed the user a boost in high frequencies for lead work. I laid this one out to use as a built in effect on a guitar (hence the lack of a power filtering cap and polarity protection). Note that the 10uF cap is on its side to reduce the height of the populated board. It should easily fit in a 1590A. If you want a volume control use a 100k pot with the Out pad going to lug 3. Lug 2 becomes the Out and lug 1 goes to ground. I found that I really didn't need a volume pot though, as the effect level was right around unity.

Range Blaster

From Fuzz Central, this is a modified Dallas Rangemaster treble booster. Uses an NPN germanium transistor so you can daisy chain it with other pedals that run off a positive 9 volt supply.