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.



19 comments:

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

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

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

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    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

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

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  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.

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    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.

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  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!

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

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    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!! ;-)

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

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

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  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.

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    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 :)

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  9. More build info. This is from the Laika Fuzz build, but applicable nonetheless;

    Supply voltage = 8.98v. All controls at zero, filter switches in middle position, diode switch down (normal mode), no input.

    For the germs I used (measured with a Peak DCA55 / 22 deg. C.);

    - Q1 = MP42B - gain 56, leakage 0.04mA
    - Q2 = MP16B = gain 84, leakage 0.06mA
    - Q3 = 1T308B = gain 84, leakage 0.00mA

    Voltages - Q1 and Q3 collectors are adjusted via trimmers 1 and 2, original Spaceman unit values in parenthesis;

    - Q1 - E - 8.98 (8.98)
    B - 8.77 (8.86)
    C - 5.66 (5.66) adjusted

    - Q2 - E - 8.32 (8.41)
    B - 8.19 (8.19)
    C - 6.59 (6.45)

    - Q3 - E - 8.68 (8.71)
    B - 8.46 (8.50)
    C - 6.20 (6.20) adjusted

    As you can see, the Laika's voltages are pretty dang close to the original.

    Important note; For D3 (the diode that feed Q2 emitter), I ended up using a 1N965. It was a diode that I pulled from an old Farfisa organ board, it had a groovy old school look to it. I measured it on my DMM at 0.556vF, so I plunked it in there. I had no idea that it's a 15v Zener, but it works just the same. Actually, Q2 voltages seem to be even closer between the Laika and the original, than what I got on the vero unit using a 1N4148 equivalent. Might be the diode, might be the transistor. Happy accident? Sure, why not.

    The germ diode is another Farfisa pluck. Came in at 0.332vF. No idea what the knee looks like on this sucker, but it works AMAZING!!

    The 24nF cap, I had some 20nF caps (which you'll need for the PLL build), and I tried a 4.7nF cap in parallel with it. My cap meter said that it was 24.3nF, so given the tolerances, pretty darned close. You can do the same with a 22nF, and a 2.2nF. The 5nF, I just bought some off Ebay, but again, a 4.7nF is really close, or a 3.9nF with a 1nF parallel, even better.

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  10. I'm pretty new at this so please correct me if I'm wrong, I'm trying to learn as I go, but it seems like are some errors in this layout. Unless I'm mistaken here;

    Switch 3 (DPDT) is actually drift and switch 5 (3PDT) is bypass.
    Connections for Ground and LED2- on the 3PDT should be reversed to put the ground to pin 8 and the LED cathode to pin 7. This would keep the Source on the 2SK30 connected to ground and connect the LED cathode to ground only when engaging the effect.

    Does this sound right?

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  11. Nope, the drift is 3pdt and bypass is dpdt. You can use a 3pdt for the bypass but you'll have a redundant pole.
    Remember that this layout has been verified so it should work as above.

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