I've mentioned it in other threads before, but I boxed up a Dist+/Scrambler combo that simply kicks ass hard enough to cause another butt-crack. I can't recommend it as a project highly enough.
One of the shortcomings of the stock Scrambler is that one can't adjust the sensitivity of the octave generation (or degeneration, as the case may sometimes be). You also can't adjust the output level. I found that by sticking a slightly modified simple diode clipper (with its own output level control) just ahead of the Scrambler, you can nail a substantially wider range of tones and levels and actually squeeze more personalities out of the Scrambler.
Note that the Blend control on the Scrambler pans between clean boosted/buffered and altered signal. If you rotate it fully to the clean side, then you can dial in whatever you precede the Scrambler with. If that preceding circuit has some gain and a level control, then you can achieve levels well above and well below what the Scrambler itself provides. The level control on the Dist+ also doubles as a sort of sensitivity control for the Scrambler, permitting you to get hint-of-octave sounds, robust octave sounds, and sounds that are "ebola" sick. Rotate Blend in the opposite direction and you can get the crunch of the Dist+ on its own. One of the nice things about a Dist+ front end, as well, is that the clipping can provide some toneshaping and some mild compression, pushing the Scrambler towards better octaving. Four pots, and away you go. Tons of tonal flexibility. There is probably a simpler way to achieve the same result, but this uses canned circuits, existing board layouts, and works fine.
On mine, I used the stock Scrambler circuit with 1N457 diodes. For the front end, I used a 100k gain pot for the Dist+, as well as a .22 cap to ground (rather than .047) for more bass, and 1N4148 diodes for a less distorted sound. A 47pf cap in the feedback loop of the Dist+ op-amp helps to clean the fizz and provide a better signal for the Scrambler. It's enough of a change that I would probably say it leans more in the direction of a DOD250.
The two circuits together take up a modest amount of room. I built them into a plastic box smaller than a 1590BB. Current consumption is modest. You could probably build in a second bypass switch to cut the Scrambler out and have the Dist+ alone, but with the Blend control I personally saw no need for anything other than a master bypass.