For Those About to build Scramblers..

Started by Solidhex, December 31, 2007, 08:01:01 PM

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Solidhex

I recommend the Central Semi ( 610-2N5306 ) transistors at Mouser. I tried some of the Fairchild ones and found them to be harsh and indistinct. They tested almost identical gain wise but in the circuit the central Semi's were sweeter in the more "tame" side of the texture control and had a nice defined and animated Ring mod sound in the "crazy" side of the texture control. Tons of splat but still nice and dry. A tiny bit more expensive than the Fairchilds but still pretty cheap. They have the weird 2N5306 pinout. Sounds great in the GGG Scrambler board.

--Brad

tcobretti

More people should build scramblers; they kick ass.

Cardboard Tube Samurai

Such a quiet pedal though. If there was a way to make it louder without needing a booster built in with it, it would be amazing

oldrocker

OMG a quiet Scrambler?  Mine is a loud monster.  Scramblers I believe are generally high volume.  What transistors are you  using?

tcobretti

Yeah, mine isn't quiet.  I'd say it's just above unity.  Not enough to push the amp much, but enough that there is no drop in volume as you crank the blend.

I posted some sound clips awhile back with my scrambler's blend knob hooked up to an expression pedal.

Solidhex

Happy New Year!
  I've built about 4 or 5 Scramblers. They aren't high gain monsters but they are a lot of fun. There's a lot of cool stuff you can do by blending the crazy side with a distorted amp. I'm a big Cactus fan so I've been trying to get some of their tones for a while.

--Brad

oldrocker

Oops.  Your right I just got mine out and it's not super loud.  I guess I had my amp turned up when I used it last.  A little booster would maybe give it some volume.

Mark Hammer

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.

Solidhex

Neato

   I gotta try that!  Does anyone know the deal with the extra diodes in the GGG version? I've noticed the original schem only has 2.

--Brad

Mark Hammer

Plenty of times manufacturers will "overdesign" something, prepare the board for it, then realize that some parts are essentially superfluous and do little to improve circuit performance even though they add to production cost.  Since it also costs money to redesign the board without those components, they simply leave the boards as is, with parts legending intact.  From what I understand, those "missing diodes" are such parts.

Solidhex

Ah

  Yeah the schem I was looking at had the extra ones crossed out. The first one I built was using the layout on www.Ustomp.com . It doesn't include the extra 3 diodes and I think they sound fine without them. Nice layout too let's you use the 2n5306's without bending the legs around. Now that I've gotten a grip on Eaglecad I drew up my own layout but with just the two diodes. I'm going to experiment with some fuzz circuits before it.

--Brad

Solidhex

Yo

  draggin this thread back out. Having messed around a bit more with pedals in front and after the Scrambler I like the EH LPB-1 after. When the Scrambler's texture knob is set more to "crazy" louder signals and some distorted signals seem to make tone take longer to bloom into that signature Scrambler mess. I think the stock circuit wired with true bypass is pretty quiet too. Sticking the LPB-1 in there gets you tons of output and a larger range of saturation without changing the way the Scrambler reacts...

--Brad

rove

I added an LPB to my scrambler build as well and really love it.  this configuration has the added benefit of being  a simple clean boost with the blend knob all the way dry.  Unfortunately I no longer have mine, building another and may have to try the Dist + addition...

newfish

Happiness is a warm etchant bath.

AL

Quote from: newfish on June 27, 2008, 04:58:28 AM
...err, We Salute You?

:icon_lol:

:icon_lol:  I was waiting for that.

Thanks for the info - I may just have to get off my backside and build one.

QuoteI'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.

Now that is a ringing endorsement !! I'm off to buy new pants.


AL