Any Scrambler mods? I have one hole left

[Bernardduur]

Hey all!

I love my new build Scrambler on bass for that gritty sound. I already modded it a bit with a LPB-1 on the end so I can push the output a bit. Now I use this enclosure I used for another pedals and it just fits this build precise; now I have two additional holes in it. One will be used for a switch to change the input cap (0.01 to 0.1 uF) for better bass response, but what should I use for the other hole. I checked, and there are not that many Scrambler mods available..............

Some ideas?

[Cardboard Tube Samurai]

I am a massive fan of my scrambler and will watch this topic closely!

[Bernardduur]

Small bump

[Bernardduur]

Ah, I filled my holes

OK; here are the mods I've done. I've done this to make my Scrambler clone sound better on guitar, but even more better on bass.

As for the start, I used the schematic available everywhere. I fixed the small error of the reversed cap.
I installed all diodes except for the one on the emitter of Q2.

The mods:
- I used a high gain darlington transistor for Q2 (KSP14) for some more treble response (a must on bass)
- I added a switch to bypass the octave section; fuzz only is fat and gritty /w already a hint of upper octave. Output is much bigger this way so I added a small trimpot wired as a volume control
- I added a second switch to replace the 470k resistor between the collector and base of Q2 with a orange LED for some serious FUZZ (a la Bazz Fuss)
- I added a LPB-1 on the end of the Scrambler so I can boost the output a lot. Great for clean boosts (/w blend set at clean) or a hint of coloration

Hope you like the mods!

[Mark Hammer]

Interesting to see this topic pop up.

Having obtained a nice big supply of phone jacks by buying a 2nd hand patch bay, I've been gradually completing a lot of 95% populated boards that have been sitting around jackless and ignored because of that.  Last night was the Scrambler's turn.

At first, all I got was decent signal with the Blend pot panned to full-clean, and nary but crackle noise as the Blend pot got rotated to full fuzz.  Naturally, the Texture control wouldn't do anything.  Changed pots, checked over the solder joints, verified the PCB (Tonepad Revolcador), but no improvement.  Took out Q3 and Q4 to check them, but they checked out okay.  Then, yesterday I realized that I was using a 2SC1815 for Q2 and that, lo and behold, I had treated it as if it had an E-B-C pinout (1815s are E-C-B).  This was a bit like having a man and woman back to back wondering why "the romance" wasn't living up to their expectations!   Flipped the 1815 around the right way, re-installed the two pulled Darlingtons, and the Scrambling began.

I had made one before and found it sort of aggressive for my tastes, but this one was a bit more demure than what I recalled from before.  If anything, it sounded more like a mis-set, mis-used Jawari (see Tom Escobedo's "Circuit Snippets") than the snarling Tasmanian devil of a fuzz I remembered.  Plugging in a 4049-CMOS overdrive ahead of it, though, and boosting the input signal, brought out the finer qualities in the Scrambler, including the super-squished attack andnice octave-ey sound higher up on the neck.

As luck would have it, my Scrambler was etched on a larger board that included several other overdives.  After the others were cut away, what remains is a reasonable-sized board that has a Tonepad "Mas Distortion" (Dist+) snuggled up against the Scrambler.  So, I'm going to install it in a chassis with the two circuits in one so I can overdrive the Scrambler's input with a slightly modified Dist+.  I don't really need the Dist+ to serve as one, so instead of having a bypass switch, I'll leave it in circuit, use Si diodes for less clipping and a larger cap (instead of the .047uf unit) for a little less bass loss, and deploy the Dist+ for a hotter input with some useful coloration.

Still, though, a stock Scrambler ought to sound nasty on its own, right?  With a Darlington on the input, I'm puzzled as to why that isn't happening.  Is it a matter of reducing the emitter-to-ground resistor value to squeeze a little more "push" from Q1 on the front end of the circuit?

[Bernardduur]

I dunno; have tried to get that "same" push but all gave me unsatisfied sounds........

The LPB on the end really helps me. I want my clean blend (as I use it on a bass) + the slight fuzz blend to be amplified a bit to be used. And right now, it works great for me!

Still, more mods I need

[orgaqualia]

I'm starting a scrambler build this weekend and Im wondering....

Why leave out the diode on the Q2 emitter?
I guess that I should be able to figure out which cap to reverse (assuming that you were using the schem from GGG).
I was considering using a mosfet boost in front of it in the box...bad or good?
thanks,
-db-

[Joe Kramer]

Hi Bernardduur!

I liked the following tweaks for the Scrambler:

--Internal 50K trimmer to set the distortion output volume (stock is too loud!)

--2SC1583 dual-matched xstr for the differential pair (gives more intense octave)

--Three 1N34 diodes in series instead of the 1N456 diodes

The last mod gives a softer distortion, better touch sensitivity, and more sustain on the octave sound.    You could add a toggle switch that allows two different diode options.

Regards,
Joe

[Bernardduur]

Thanks Joe;

I have some volume issues with mine (and want to use it as a clean boost) so the LPB on the end works great!
The diode-mod is great; I must say that I lose some volume this way, but the sound is on some points more usuable. This one is a keeper.

@ orgaqualia: I removed the diode at Q2 because when I switched off the octave section this diode would give me some artefacts

[Austin73]

Hey Bernard, ben looking at this thread every now and again. Tempted now to build one (for guitar) just interested in how you switch the octave.

I was going to use the layout suggested on here (I think its dragonfly's or torchy's)

Cheers

Aus

[Mark Hammer]

Hi Bernardduur!
I liked the following tweaks for the Scrambler:
--Internal 50K trimmer to set the distortion output volume (stock is too loud!)
--2SC1583 dual-matched xstr for the differential pair (gives more intense octave)
--Three 1N34 diodes in series instead of the 1N456 diodes
The last mod gives a softer distortion, better touch sensitivity, and more sustain on the octave sound.    You could add a toggle switch that allows two different diode options.
Regards,
Joe

Wait.  Let me get this straight.  You have access to 2SC1583s that you can simply "throw away" on fuzzboxes?  Aye caramba!!  Where do you get them?
The other thing I wonder about is how a circuit that seems to want Darlingtons can be happy with regular (but matched) NPNs.

As for matching to achieve better octave production, I'm wondering if a balance trimpot arrangement similar to that found on the differential pair in the Superfuzz would be appropriate.

[Joe Kramer]

Hi Friends,

Hey Bernard: Glad you like the 1N34 mod.  I found it helpful to mix and match the diodes so that each trio had close to the same voltage drop, within a few mV.  Again, more intense octave.  To cure volume drop, you might want to go for four in series if you can afford the 1N34s.   

Hey Mark: As for "throwing away" the 1853's I know what you mean, but I scored a bunch from a place that was blowing them out a while ago.  I also figured on trying them in a Ross/Dynacomp clone to see if the control signal would be improved any.  The only thing I can figure about displacing the darlington's with regular bipolars is that maybe the higher input impedance of the darlington's is irrelevant at that point in the circuit.   I don't know of any other reason why they would really need to be darlington's otherwise.  A matching trimmer would probably do the trick, but the way mine works, the tone/fuzz control actually has a "null point" at about 2 o'clock.  At the null point, there's a slight gating effect where very soft signals don't leak through from the input.  The octave effect is fairly strong on the null point too, but I prefer to go a little past that for some sustain.  Since I haven't used a real Scrambler before, I'm curious if they all do that or anybody else's clones do that?

Regards,
Joe