Friday, 7 July 2017

Spaceman Sputnik II

"Starting with the same germanium transistors as the much-loved original Sputnik, but with slightly different specs, we added a few slight tweaks to get very close to the sonic details of the original circuit. Many of the other parts in the Sputnik II are different but of same or similar value, including many vintage and rare parts.
While extremely similar to the original, the Sputnik II is a beast all its own. The Sputnik II takes everything we loved about the original, and adds in the things we dreamed of after its original release it:
• Full-size control knobs for every parameter
• Foot-switchable DRIFT mode, with its own status indicator
• Additional FILTER options for maximum tone-shaping
• Additional circuitry making it more friendly to active pickups, buffers, synths, pedals, etc
Within Sputnik II lies a plethora of fuzz tones. Smooth, gritty, vintage, modern, thick, thin, buzzy, bassy, splatty, sputtery, noisy, buttery, controlled or very much out-of-control. A truly endless cornucopia of fuzz."

Here is another pedal reverse-engineered by Dino (Digi2t).
He also added an extra diode reverse switch.
For all infos on how to build this pedal you can find Dino's original thread (with his own vero) and schematic on the DIY forum here.



16 comments:

  1. Wow, another beautiful looking loayout Alex. Well done!

    ReplyDelete
  2. Great work Alex. Your layouts really are masterpieces. Gonna have to buy some bits.

    ReplyDelete
  3. Nice! Can someone enlighten me on how this is pos 9v if the ge transistors are PNP? Thnx...

    ReplyDelete
    Replies
    1. PNP doesn't mean it needs positive ground. Take a look at fuzz factory or silicon fuzzmaster. It's always the question of how the transistors are wired.
      +m

      Delete
  4. man original here is loaded with some mojo!
    http://www.spacemaneffects.com/model/SputnikII/Sputnik2Guts.jpg

    ReplyDelete
  5. I should have a video of the clone out soon. I highly recommend the diode reversing switch, don't know how that one slipped by Spaceman's radar. 22K to SCAN 2 should be replaced with a 50K trimmer to tweak the diode voltage. I'll try to come up with some kind of adjustment guide for that. Depending on the diode used, "I think" the span is somewhere in the 15K to 30K range.

    ReplyDelete
    Replies
    1. Oh yeah... I used a Russian D9E diode. In a recent post by diy-tubes over at diysb, he demoed the curves of several Russian Ge and Si diodes. The D9E Vf is almost identical to the 1N34A, but with a much softer knee. The softer knee comes in handy when using DRIFT mode on the edge of the envelope. You can fire the oscillation with a sharp input strike, and it will give you a longer decaying oscillation, which is really cool. I tried a bunch of different diodes, 1N60, 1N270, 1N118, 1N58, 1N34A, some unknowns from pulls, even BAT41/8, and the D9E was the best one. A D9J MIGHT be better, it has an even softer knee, but the trade off is a slightly higher Vf. Worth trying though. As for the transistor voltages, +/-0.5 volts here or there is tolerable, you'll be in the wheelhouse sound-wise. Any low leakage transistors in the 70 to 85 range will get you there.

      Delete
  6. Call your layout verified Alex! Just built it over the weekend, what a fantastic fuzz machine. Used MP20Bs initially for GE trans but found them a bit noisy (their HFE was 88, 111 & 113) so tried IT308Bs (74, 85, 75) and sounds much nicer. Used D9E for GE diode and the rest as written. Dino, A massive thanks for the amazing work you put in to give us these beauties. Time to have some fuzz!

    ReplyDelete
    Replies
    1. This comment has been removed by the author.

      Delete
    2. This comment has been removed by the author.

      Delete
    3. Thanks Dino! I've added the extra 100n cap. Is it correct?
      Thanks also to Gavin for verifying the layout.

      Delete
    4. Belay last!!!!
      After further noodling, the cap wasn't the best idea. Yes, it helped control the oscillation to a degree, but the problem is that it also really darkens everything, so it becomes a game of diminishing returns. By the time you get to a value that starts to kick in, you've really darkened the original tone. Not good. BUT... I did discover that using a Ge diode with a low Vf does improve things. The D9E that I had in there measured in a 0.323, but sorting through my bag, I found one that came in at 0.272. I swapped it in, and the oscillation is better than before, meaning that it's a bit easier to tune in jumping octave notes, tuned motorboating (is that a thing?), and the like, while still retaining the top end of the original tone. At the end of the day, different transistors = different tones and settings than the original. That's just the nature of the beast, and I can live with that. So, scratch the diode cap... unless you want to experiment, but I'm going without. I'm sticking a fork in this sucker, it's DONE. Muchos gracias to Gavin and Alex. Takes a village to reverse a pedal... and still retain your sanity!! ;-)

      Delete
    5. Thanks again Dino!
      I've removed it.

      Delete
  7. What ferrite beads are you using in this build? It looks like a good one :)

    ReplyDelete
  8. I don't remember where I bought them from, but they came with preformed leads. The pitch is the same as a 1/4w resistor. Sorry that I don't have more info, but Google is your friend.

    ReplyDelete
    Replies
    1. Oh sure I Googled them already, most of the through hole style ones are rated by impedance, frequency range and ferrite grade. I found a few that I may just order A/B them. Thanks again for your hard work Dino :)

      Delete