Sunday, 15 May 2016

Electro Harmonix Small Stone


16/11/2016 Layout Updated! Added cut next to LM324 pin 6.

32 comments:

  1. Now way.. Get outta here!


    YES!!!!!!!!

    ReplyDelete
  2. May God bless your name!

    ReplyDelete
  3. amazing job alex. been waiting for this for a long time. looking at the layout and the schematic i wonder if the color switch could be replaced with a pot to allow for more variation in "color." could probably add depth pot. not to mention adding s witch for univibe

    ReplyDelete
    Replies
    1. well it didn't take much digging, but......mods, mods, mods

      https://sites.google.com/site/flofxdiy/eh-small-stone-phase-shifter

      Delete
  4. i boxed four today another wigl vibe, proco rat,vox tonebendef , and a ross compressor with soft latch switching.i want to start this one ha ha.Whats a good sub for the LM324. i have tlo74 tlo64 tle074 and lf347 on hand

    ReplyDelete
  5. from what i can tell the tl064 would be my best sub on hand its low current but probably not as good as the lm324 but should be able to work

    ReplyDelete
  6. which schematic is this based off of?

    ReplyDelete
    Replies
    1. I've used this:
      http://s853.photobucket.com/user/bernardduur/media/Schematics/SmallTone.jpg.html

      Delete
  7. Does anyone had a look at the first Sovtek Small Stone? This will definetly be on my build list. I had the opportunity to buy the Sovtek Small Stone when it was new, but at the time really needed more a distortion so bought the Green Russian Muff (One that got me really started on the whole stompbox "madness")

    ReplyDelete
  8. I have built this layout and I am getting some distortion but mostly ambulance siren style oscillation.

    ReplyDelete
    Replies
    1. I swapped out the lm324 for other quad opamps and it stopped the siren but the effect became barely audible.

      Delete
    2. I've double checked again and it matches the schematic.
      The only thing missing between this version and the original is a 47R resistor between the transistor's Emitter and Collector.
      Can you try to add it?
      Can you measure your voltages?

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

      Delete
    4. Could you start a thread in the debugging forum with quality pictures? I would be happy to look at it maybe you missed something. I used a 47k at the input instead of the 100k for less volume drop. There are several mods for these on the tonepad site.If Alex double checked im sure you have a bad part or a bridge or a small mistake off by a hole or missed a cut. Alex is as sharp as a razor.I am going to make one but it will be several days before i can. Busy at the day job and have some troubleshooting to do on a couple of my mishaps ha ha.When I do make it ill post working voltages for sure if that will help

      Delete
    5. http://postimg.org/image/kxqmzwurl/
      http://postimg.org/image/6pwcxisox/
      http://postimg.org/image/460q3f54x/
      http://postimg.org/image/4hi6g6lkx/

      Delete
    6. What transistor did you use?
      Have you tried the 47R resistor?
      Can you measure your voltages?

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

      Delete
  9. few things beats a vero of a classic stomp, good job!
    gona build it ASAP and if it doesn't work... it's nobodys fault but mine :)

    ReplyDelete
  10. Is there any substitute for BC337?

    ReplyDelete
  11. I built a second one and it is good to go. I will say that it doesn't sound quite as deep as the small stone I own, but not bad.

    ReplyDelete
    Replies
    1. Cool! Thanks for verifying it!
      Some Small Stones were built with different ICs and that could make the difference.
      Did you try to add the 47R resistor between Emitter and Collector to see if it makes any difference?

      Delete
    2. i see what looks like at least 3 solder bridges on the back top left row four or five and 6 or seven a few holes from the right. take a knife and cut between every row you have a lot of bridges or near bridges and or resin . i know resin isnt supposed to conduct but several times i cur resin and my pedal worked after. there maybe micro bridges hiding under it . . also found a leg that was poorly soldered bottom inch from the rright second last row on leg is mostly not soldered. canr reallt troubleshoot much more unless you mark the cuts with a red or blue marker. i know it takes a few minutes to mark the top and bottom for cuts but it saves way more time placing parts and troubleshooting. they are food reference points.I drill my holes its just as fast and cleaner cuts. after i drill i use a scotch bright pad and clean away any stuff sticking up . you have some stuff sticking up it looks like .you definitley have some solder bridges knife every row . hit that partially soldered leg with some solder. even if you have built 500 pedals on tagboard marking the top and bottom saves time trouble and headaches.

      wires are good electrolytics look good. i noticed you used 12k for 11k that shouldnt matter to much. might make it less small stoney but should work.

      you should post the voltages for the working and non working one if scoring in between rows doesnt fix it. i wish i could see the cuts better if knifing isnt the fix then recheck the cuts. also saw some solder that might be bridging across a cut longwise in the top left area. i should have written it all down but there were lots of things that looked shaky its hard to tell from a 2d pic. go over it again hit your cuts agiain and knife it. that top left has several bridges it looks like. i just knife the entire board now . it doesnt hurt anything sometimes you get some fray just resolder and it melts. good job on verifying a difficult build on the second attempt.


      does it have the volume drop? if so you can change the 100k inout to a 47k it helps lesson the drop.

      Delete
  12. I've noticed that the older small stones use 6.8nf caps in the phase stages, this one uses 3.3. Try the bigger ones.

    ReplyDelete
  13. wow lots of typos in previous post sorry burning the midnight candle

    ReplyDelete
  14. Very impressed with this Alex. I started this a few times but the way I do layouts always ended up with it becoming too big for a 1590BB ad so I stopped before the end. Nice job matey

    ReplyDelete
  15. This comment has been removed by the author.

    ReplyDelete
  16. Is there a way to have an LED status light change with the rate? I'd like to build this with a mix level mod, but I'm also in love with the rate LED idea having seen it on the chorus projects.

    ReplyDelete
    Replies
    1. Not sure but try adding a CLR from 13700 pin 16 to LED+ and LED- to ground.

      Delete
  17. I posted this in the debugging forum and I'd be interested in some expertise:

    As I continue to troubleshoot this, I'm seeing something in the layout that doesn't make any sense as compared to the schematic. Reading left to right and top to bottom, there's a link in column 13 that links rows 17 to 21. Among other things, it links pin 2 of the LM324 to pin 6. However, these two pins are not linked in the schematic (OP1A- and OP1B-):

    http://s853.photobucket.com/user/bernardduur/media/Schematics/SmallTone.jpg.html

    It would seem to me that there is a missing cut in the layout - right above the one in the very bottom row. This would isolate pin 2 from pin 6. Pins 6&7 would be linked and connected to the 1k resistor which goes to the 3u3 cap and out. Pin 2 would then only be connected to the 15k and 18k resistors as in the schematic.

    Can someone take a look and verify? If I'm right, how would anyone have successfully built this?

    ReplyDelete
    Replies
    1. Just to close the loop, that cut was added and I verified this layout. Sounds really great! Still not sure what the trimmer does.

      Delete
  18. Finished this pedal today and I also have an ambulance siren emitting from it's output when turned on.
    Glad I checked back on this page before starting to troubleshoot!
    Will add the missing cut tomorrow and report back.

    ReplyDelete