Sunday, 24 June 2012

EHX Black Russian Big Muff V8








64 comments:

  1. lots of big muffs! now, wheres the plimsoul? :p

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  2. Rudeez: I bet it's coming. Build some muffs while you wait.

    Hmph. How was i supposed to compare this to original without building it. :)

    Can't really see myself doing five boards a day again anytime soon. But. Finished.

    I omitted the switch 'cause i wanted to get this as near to the original as possible. And when comparing them side by side (the original black russian and my clone), it's pretty darn close. I wouldn't call it 100%, but very, very close. My original has tiny, hardly noticeable amount of more bass than the clone, and i feel like the pots aren't linear. At least the volume seems more like a logarithmic than linear. Plus, i only had BC549Bs, so that might also do something to the overall sound. Anyway. It's fourth BMP i've built today, and as they all line up in my opinion:
    (first/second and third/fourth places are ties..)
    1. Green Russian
    1. Triangle 74
    3. 77 IC
    3. Black Russian
    5. Ram's Head

    But. That's just how it is for my ears. I bet that no one is going to list them like that :)

    Whoah. Could this be enough muffs for me, let's say for a month? I've built those five, a few skreddys and Ibanez 850 so i think i have enough BMP styled circuits for a while :)

    Thanks Mark!
    +m

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    1. Nice one mate, yes I think you may have enough muffs to last you a while now! :o)

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    2. Typoed that 74. it should be 66 :)

      One more thing. My clone seemed also a bit louder than the original. Which i find quite strange, as it has lower hfe B class transistors. Can't say anything about those russian transistors inside the original though - and i'm not going to desolder them :)

      If i was to rebuild any of these four as close to original as possible - that would mean to get the original value(s) for the mid caps - what would they be?
      +m

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    3. The V8 was from the late 90s so the components used were more modern values. The 3n9 is the cap used, again the switch just puts others in parallel with it.

      And the B transistors will probably be too low gain, you'd be better trying it with your BC550Cs which will be closer matches to the 547C and 549C.

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    4. So if i got it correctly, the other three also fall back to stock values, if the switch is snipped?

      I don't think i want to change the transistors, as the BC549Bs sound very good in it... :)
      +m

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    5. The caps in the switch are only working with the 3n9 to increase it's value. As the value of that cap increases, so does the mids. So if you wanted it absolutely stock you'd either leave the switch in the centre off position, or remove it.

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    6. So it is like i figured. I meant Ram's head, 66 Triangle and Green Russian with "the other three" :)
      +m

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  3. Finished box. Omitted the switch and it's 1:1 with my original, except for the vol/tone pots. MIne are lin and orignal has logs.
    http://mirosol.kapsi.fi/varasto/boxes/BlackV8Fuzz.jpeg
    +m

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  4. finished mine, works fine, excellent layout.. i used bc549, and the pinout is completely the other way round..

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    1. Yes the transistors in the layout should have been rotated 180 degrees. I just used the same transistor layout that I'd used for the Rams Head which I used as a template for this. So thanks for the heads up, I've rejigged the layout to suit.

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  5. Hey Mark- is the switch an on/off/on?

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  6. hey guys, bit of a noob at this, the sw1 is confusing me a bit, if I don't want the switch do I jump that straight to tone 3?

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    1. No. If you want to make it like the original, you can just omit the switch and its wires altogether. Do not connect the wires from sw1 to tone 3, as that will kill the tone stack completely.
      +m

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  7. also I replaced the 3n9 cap with a 3n3 as thats all i had, i realise this is probably the reason my circuit doesn't work

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    1. Nope. That can't be the reason. All 3n3 instead of 3n9 would do to this is to make mids even more scooped.

      Did you check for unwanted solder bridges?
      +m

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  8. yeah it must be a solder bridge somewhere then. I also have a log pot for volume but as some people have mentioned on here that seems to be whats on the original. will hunt for a solder bridge and double check my wiring.

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  9. Hi guys, I've just completed this circuit but mine dies after a few seconds, i.e. if I turn the effect on, it puts out a (normal) fuzzed guitar sound for a few seconds then fades to a buzzing tuned frequency with no guitar sound coming through. It won't go back to fuzzing (for only a few more seconds) unless I unplug the PSU and plug it back in.
    It sounds like the problem is with a capacitor somewhere in the power supply for the circuit, seeing as unplugging the PSU "resets" it, so I've tested with batteries and different PSUs and nothing changed.
    Anyone had this problem before and manage to solve it or anyone with any ideas?
    Thank you very much for any help with this.

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  10. By the way, I know the most common source for problems with Big Muff circuits is solder bridges, so I've triple checked for those, will check with a magnifier just in case, but I'm pretty sure that's not it....

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    1. Yes sounds like a cap to me too which unfortunately is going to mean testing and swapping to try to find the culprit. I'd start by removing the 100u filter cap and seeing if that makes a difference because that cap could be creating a short between the two power rows.

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    2. OK I'm almost ashamed to admit this: it was the power plug.
      For some reason, the plug I was using to plug batteries and PSU's into the pedal was acting up. After going through the circuit once again checking for shorts, and removing the 100uF as you suggested with little effect, I started fiddling with the plug (I remembered it made some squeaky noise whenever I tilted the barrel), and after another round of absolute silent despair (the pedal, in "ON" mode, just hummed like a lightsaber - cool but not what I was after...) and an "anything goes" plug-swapping, everything is back to normal.

      Lesson learned: always make sure your plugs and jacks are working stable and fit snugly.

      THANK YOU VERY MUCH! This site and this project in particular restored my confidence in messing around with analog electronics =)

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  11. Sorry to be such a noob, but I think blew this one by flipping the positive/negative leads while testing the circuit, 'cause now that I've reversed them to the correct positions the whole thing sounds... well like a dying audio circuit would.
    Any thoughts on which components to start replacing? I'm guessing resistors and non-polarized caps should have survived it unharmed (right?), so I'm tending towards the diodes, transistors and the 100uF electrolytic.
    Or should I just scrap the whole thing and start anew?

    Thanks for any help.
    John

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    Replies
    1. There is polarity protection cap before the 9V rail, so if you used that - then it can't be broken with reversed polarity.

      Check the usual suspects first - Transistor pinout is good place to start, as Muffs work but sound just wrong with the pins misplaced.
      +m

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    2. Yes, this one has a series protection diode so under reverse polarity no current would pass to the circuit. Check what voltage you're getting between the bottom lead of the Dx diode and ground.

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  14. Thank you very much for the replies, guys.
    I see, I didn't mention it because I wasn't sure, but I remember reading somewhere that that's the sorta thing the 100uF and 1N5187 are for...

    But the weird thing is, the circuit was working fine before, I just soldered the wires the wrong way around on the plug and when I tested it in the box there was (obviously) no sound. I then flipped the wires back to their supposed position and the only thing that came out was this very faint, sorta fried up guitar sound. Turning the Sustain and Tone knobs up produces two kinds of tunable whistles, Volume only increases hum and background noise a lot.

    I think that because I wired the plug the wrong way around, the 9V flowing in from the GND track may have been grounded to somewhere else, like a pot or input/output, bypassing the diode and cap, and thus damaging components... Does this seem at all plausible?
    I believe I must stress this point: the circuit was working absolutely fine, already in the box, before I soldered the wires onto the plug the wrong way around.

    I have already removed the board from the box and replaced the transistors with sockets (which I intended to do anyway), and I'm gonna redo the wiring to the pots, in/out and power/ground just to make sure everything is wired nice and neatly, 'cause I mostly went with scrap wires I had lying around, some of which are unbelievably short.

    Still, I'm baffled.

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  15. hey guys, heres a vid of my build, (well one of my builds of this circuit) for a friend. btw it seems the layout has changed? what was altered?

    http://www.youtube.com/watch?v=bwWj3et0R1E

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    1. Sounds great, thanks for posting the video Thom

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    2. And yes I altered around 10 EHX and Skreddy Muff layouts to include a ground link so the board doesn't require 2 ground connections. Everything else remains the same, I just added a column and shifted the cuts around a bit.

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  16. collected entirely on Soviet detail and compared with the black.
    Everything is perfect!
    In the original, by the way transistors КТ3102Б
    If anyone interested, happy to be shared.
    1N4148 diode as in the original.

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    1. Thanks for that info! Only one guy selling those in ebay (from ukraine) - and only in lots of 12 :(
      +m

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    2. 12 is a lot?
      I would like to change it to unusual JFET (or some other interesting things) if someone would be interested in

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    3. No that's not a lot. The "lot" in this case is the amount he's selling at once. Which isn't too good deal in my opinion.

      You have those in larger quantities? You use facebook? Friend me! (https://www.facebook.com/mirosol) I'd be interested in trading these and maybe some other russian parts :)
      +m

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    4. I live in Russia and can get any regional componet.
      Added U FB.

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  17. can anyone confirme me what are the functions of the toggle switch in each position (up - middle - down)?

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    1. It says it pretty clearly on the layout. Down position is flat, middle is scooped (original) and up is boosted mids.
      +m

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  18. So I'm attempting this as my first vero build, and I've wired everything up, made sure there was no jumps between traces, etc, etc, but I'm getting nothing but hum when I plug it in (ground hum). All the pots seem to alter the hum as they should, ie: volume increases and decreases hum, tone makes the hum more treble-y, etc. But I'm getting a connection to ground on the tip of the output jack, which can't be right. But looking at the layout, pin 1 of the volume pot is tied to ground, and so therefore pin 2 of the volume pot (output) would also therefore be connected to ground, correct? Sorry for the awful questions. I've modded many a pedal before, and troubleshot and fixed many issues in the past, but I'm on day three of this build and feel like I'm probably just missing something stupid, and my searches have all come up empty. Thanks in advance!

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    1. pin 2 (volume) is to the output not to ground

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    2. Sorry, I should've been more clear. I have pin 2 volume going to output jack tip, not to ground.

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    3. Nevermind. I had the transistors in backwards, ie: as the diagram above shows. Can we update this layout so idiots like me don't make the same mistake in the future?! Thanks for the help, and the build though! I look forward to making some noise with this now!

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    4. What transistors did you use? Those images match BC547 and BC49. 2N5088 for example, has reverse pinout.
      +m

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  19. Ahh, now I see! I used 2N5089's so that explains it!

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  20. Is there any reason not to use ceramic caps for the 100n? I have a ton of them but nothing to use them on.

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    1. Those will add some unnatural noise to the signal, but as for big muff, that might be a good thing. I've built some with ceramics and they tend so sound more like vintage circuits with ceramics on. You should probably try them.
      +m

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  21. So, what's the point of the cut on the bottom-right? I don't see anything to the right of it, so the cut doesn't seem to do anything.

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    1. That small section of row has the 9V supply linked to it for the filter cap and I often do that with the a supply row because I've got it in my head that it may minimise noise, particularly when other components are crossing it. It probably makes no difference at all, but I still do it sometimes.

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    2. Ah. That's a bit subtle, but that makes sense. Thanks! And also, thanks for all the layouts! I love the site.

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  22. i was building this last night and noticed that the resistor from sustain 1 to ground is labeled 10k but it should be 1k.

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  23. Hi Mark,
    I built this and hooked it up to test box 2.0 (very nice idea), but nothing comes out (except true bypass), the effect didn`t work. So for this it was (the first) time to go some steps deeper and use the audio probe to find where the signal stops. I checked the signal path from input up to Q3 and from there to tone pot (both ways over sw1 with switch and tone3) and from tone pot back to the board. I don`t understand why the signal from tone pot is quieter than on some stages before (e.g. Q2 or Q3), but the signal is still there after tone pot. So from tone2 it goes in the last stage to the 100n cap, but after the cap and so in Q4 too the signal is gone. After the 100n cap it`s very very quiet, but in Q4 I can’t here anything.
    So I decided to change the cap, but he worked fine, with the new one the problem is still the same. (Because I didn’t have a 2K7 resistor I took two (3,3K and 18K i think) in parallel, but I can`t imagine that’s the problem.)
    Do you or someone else have any idea what could be wrong here and can solve the problem? I would be very happy about any suggestions. Thanks a lot.

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    1. Got the problem solved, the resistor to ground at Q4 was 100R insteed of 100K.

      I tried the noise reduction mode from http://www.freestompboxes.org/viewtopic.php?f=28&t=23085 (socketed the diodes; soldered a 1N34a diode to the lugs of the 1N914 at D4) and swapped the 10K resistor from sustain 1 to ground with 1K like it is on the schamtic from Kit Rae (http://www.bigmuffpage.com/Big_Muff_Pi_versions_schematics_part3.html). Sounds great! Thanks for the great work on this site!

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  25. Hey guys.
    Love the site and have made a heap of layouts.

    I have had a good look around and there is heaps of information on boosting big muff mids, although I can't find a clear answer..

    If I was to wire up the mid boost cap to a footswitch, how would I wire up a pot between the two to control the level of mid boost?

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    1. hmmm. to be honest the way the layout is done the switch has the ability to control the mids, and you can make it either flat, mid bump, or boosted. if you look at the switch the mids are controlled by switching between different caps for the tonestack, rather then a mids pot.

      what i would use a DPDT stomp switch, and have one cap between the top two lugs for one setting, another cap across the bottom two lugs, and run the middle two to the board like you see the switch is run now. this would allow you to have 2 different mids settings on a stomp that you could change on the fly.

      if you want to make it a pot, take a look at the AMZ Presence Control,

      http://www.muzique.com/lab/tone3.htm

      this is how you would add a mid pot. you'd have replace the mids switch with a single cap, and change the resistor in series with it to a pot. i just think that doing what you want would be easier with 2 settings using caps on a stomp instead.

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    2. Sweet!

      Thanks for the quick reply and the info.

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    3. anytime buddy. i hadn't thought about doing something like that. it's a really neat idea, and really can be fairly useful in certain situation. rock on man....

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  26. Hi! Thanks so much for posting this, it's one of my favorite pedals.

    Just built it and for the most part it works great. The only issue I'm having is the tone pot doesn't seem to be working properly, it's basically functioning as a volume control. I've double checked all the component values and I'm pretty sure they're correct, as well as the off board wiring. The mid boost switch works properly. Any idea where I may have gone wrong?

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    1. Found a cut that hadn't been completely separated, this fixed the tone pot problem. I also reversed the connections to 1 and 3 on the Sustain pot and it's working normally as well. Is the reverse travel of the sustain pot something that was on the original or is the layout incorrect? In any case, works perfectly now and sounds great!

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