Saturday 20 July 2019

Spaceman Effects Sputnik II






18 comments:

  1. Making this, got the fuzz section to work. The calibrate and low eq do what they're supposed to. The high eq only changes the tone on one setting, it sounds like. Did you add the correction from Dead Ends Laika?
    Also... it seems quirky, the Range (supposedly the gain knob?) only works on the middle/off-position of the low sw. Is that how it's supposed to work?

    The oscillation/drift section I can't get to work. Working on it

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    1. It will take a couple of weeks until I will take a look at it since I have a break from this obsession/hobby at the moment.

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  2. Okay.. have tried just about everything. The fuzz works, but sounds nothing like the original. Way thinner, almost garagy. Recognize a bit of the velcro-y texture when the Calibrate is fully open, but it lacks a lot of gain. Could it be my transistors? They're in the noted range -70-90 but medium leaky.

    Also cant get the oscillation to work. When I close the Scan knob fully, all the leds go out and it hums, the Scan pot starts smelling burnt and gets hot.

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    1. I'll take a look at this tonight.:-/

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    2. Thanks so much, man! I hope it's just my fault - then I can take it to a forum and get some help troubleshooting and hopefully verify this (I'm surprised not more people have undertaken this - one of the best boutique fuzzes in recent years). I did notice Dead End has made new Laika boards and updated the schematic since this layout was published, dunno if it plays into this layout.

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    3. Ok, I checked the updated schematic and it appears that 62k resistor/High Sw 5 should connect to the Calibrate 1/24nF junction. Try to solder wire between Calibrate 1 and High Sw 5.

      Can't find any issues at the Scan control at the moment. How is your 50k trimpot set?. If it is turned fully to the right and the Scan pot is is turn CCW there is a risk for a short since there is no resistanse between 9v and ground.

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    4. Thanks for checking! It makes sense with the scan control. I think that is/was the issue. I did already.

      How about the Range knob? On the schematic, lug 2 of the Range knob goes to lug2 of the Low-switch, but here it's lug 3. I have an issue where the range pot only works when the LOw switch is the off-position, whereas the gain is maxed (the Range knob doesn't do anything) when it's switched up or down.

      Otherwise the fuzz does work as intended, though it's much lower gain, and a more grainy, less pleasing timbre than the original. It's gotta be my germanium transistors.. Gonna order some low leakage ones in the values specified. Do you recommend buying unopened boxes of soviet germaniums? I fear I'll end up buying ones with correct HFE, but high leakage, if I buy pre-tested germs.

      In the Drift section, the only transistor that has any voltage is Q7 (D: 7,9v / G: 0,06 / S: 5,50) and Q6 (G: 0,06, otherwise 0v). Doesn't seem right, right? If so, where should they get their power from? I don't get the power supply in that section at all..

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    5. I'll take another look tonisght.
      So, wh´hich transistors are you using for the germaniums? Have you checked the pinout? Also, are you using a 2SK30 for the FET in the Drift section?

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  3. Thanks you so much. I know I must be a royal PITA to be such an inquiring commenter. You're really not obligated to, but I appreciate it and hope I can verify it for others.

    I'm using AC125's, 60-80 HFE (same HFE as Dead End), but with medium leakage as stated. Pinout is correct, I triple-checked.
    And yes, I'm using 2SK30. That transistor works, as I can hear it amplying the signal when I audio probe it. But the signal stops dead at Q6, the BS170.

    One thing I wonder: One of the pins of the 50k trimmer is unconnected on the layout. On the schematic, pin1 is connected to pin 2. Could it make a difference?

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    1. Ah, don't worry, this is one of the coolest fuzz designs out there and I really would like to have this one working...

      Been over it again but found no mistakes. Have you soldered the LEDs yet? LED 1 looks like an integral part for the FET transistors....?

      As for the trimpot, in this case one leg can be left out, it will function the same way. Oriented it as is because tight board space...

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  4. OK, OK.. the fuzz works properly! I scored the lines separating the tracks, probably a burr of copper.
    The "Range" pot is still funky in the sense that it only works when the "Low" switch is in the middle, "off" position.

    Now to troubleshoot the oscillation circuit. Disregard my trimmer comment. It definitely flows from 9v through the trimmer to the scan pot and through the 10k resistor. Q6 has a drain voltage of 0,24 on my current trimmer+Scan setting

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    1. For the Range control and Low switch: move link connection from G3 to F3 (so it connects to 15nF).

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    3. It's alive! It works! Moving the link up one row also fixed the Range pot issue. Tag it - perhaps with the High-Calibrate and the Range 2-Low2 fixes:)

      The damnedest thing.. was working on it around the troubling part, not sure what exactly worked. But it oscillates nicely!

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    4. Awesome!. Glad you got it working. Got to order some parts and build it myself...

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  5. ...now on to the Spaceman Gemini, haha

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  6. The 4 of course! The bigger, the better right? *nervous laughter*

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