Monday, 18 June 2012

Maxon OD808

Info from Maxon about the reissue:

Originally released in 1979, the Maxon OD808 was one of the first tube-amp overdrive simulators to hit the market. Its smooth, creamy crunch tone caught on quickly, and helped to launch a long line of predecessors as well as imitators. Today, the OD808 design is without a doubt the most used, most imitated and most lauded overdrive circuit of all time. The reason for this is simple ­ tone. Simply put, the OD808 provides the natural, mild overdrive of a tube amp without sacrificing your guitar's original tone. In addition, it can be used as a clean booster to provide increased gain without compromising the sound of your amplifier.

The secret behind the legendary "808 tone" lies in the amplifier section of its circuit. Rather than having an amplifier stage followed by a clipping stage, the Maxon OD808 uses a signal-distorting diode (Panasonic #MA150) that is located in the amplifier stage's negative feedback loop (which also contains the JRC4558 IC chip). Therefore, the Maxon OD808 distorts signal in the amplifier circuit itself which yields a smoother, milder, more natural sounding distortion than a separate clipping stage. This is also the reason that the IC type used in the circuit has such a large impact on the unit's tone. Maxon developed this unique design more than 20 years ago, and while it is commonplace nowadays, back then it was an industry first.

It should be noted that the Reissue Series OD808 uses different output resistors than the original version. After the unit's initial release it was discovered to have a high susceptibility to noise due to static electricity buildup. To improve performance, the positions of the output resistors on the reissue OD808 were reversed and their values increased in order to reduce noise levels. This circuit change has no audible affect on the sound of the unit, save for reducing the noise levels.

Whether it's used as an overdrive or a booster, the Maxon OD808 is the closest you can get to the classic sounds of 1970's rock guitar in a compact effect pedal.







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50 comments:

  1. Works. Tag it.

    It sounds nice. There's really nothing that would make me go wow! but it's still an ok overdrive. I sticked 1N914 diodes for clipping. Somehow i feel like this one should have had germaniums for more vintage-like tone, but it's not bad with silicon diodes either. Relatively easy build with no special components - it's good/nice OD for such a minimal effort.

    Just makes me wonder what it would sound like with 12V power...

    Anyway. Not that i really needed another overdrive as i have Klon, Red Snapper and Zen. Klon just replaced TS9 on my board today - Yes. It's really that good. Listening to new Turbonegro album made me swap TS9 for it.. Plus there are still like 8 more interesting projects waiting for me.

    But.This seemed like a fun project to slab together on a monday evening. And it was. Not sure if i'll box it anytime soon though...

    (fixed some typos etc.. Sorry for the crud in the beginning of comments :))
    +m

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  2. Ha ha, that could be the record for layout posted to verified. Thanks mate :o)

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  3. I built mine but breadboarded the diodes, tried quite a few options but settled on 1n60p's, a classic glassy sound, like tubes just at the point of break up. Yeah there are other overdrives out there (I've built plenty) but it can be very hard to dial in this kind of tone in most of them, if at all. Definitely a keeper for me, I love it. Thanks for another great layout. Any chance of a ROG English channel hint hint ;-)

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    1. Thanks for the info, and yes the English Channel is on the list. In fact all the ROG pedals are on the list but I'll do the EC first as it's been requested :o)

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    2. I wasn't implying that this isn't useful. It's good. And one can never have too many ODs.. I just personally like to the sharp, articulate and loud sound of the Klon at the moment.
      +m

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  4. @ mirosol. I wasn`t trying to contradict your review, i was adding to it. Yes this pedal has it`s limitations, in fact it`s very limited, but what it does do it does brilliantly. Anyone thinking of building this should watch the demo, what you see is what you get. Sorry for any confusion.

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    1. No. It's ok, don't worry :)

      I knew what i was getting in to :) This is good classic OD, but yesterday was the first time i got to play really, really, ear bleeding loud with my Klon (Tokai modded tele w/ S. Duncan Custom shop on bridge -> Klon -> JCM800 -> 4x12), and i think that's the main reason why this didn't impress me. On some another day i would probably have gone much easier on this little classic :)

      I might try those 1N60Ps on. I was eyeballing them when i chose the those 1N914s, but somehow just chose those. If 1N60Ps make it glassier, this might get in a box much sooner...
      +m

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  5. fantastic pedal! Sounds great. When will the drive breaker be ready?

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  6. In the year 77: http://mirosol.kapsi.fi/varasto/boxes/Vuonna77.jpeg

    It's Maxon 808 OD and '73 Ram's head muff in a single box. Instant J. Mascis sound :)
    +m

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  7. I just built this and I'm getting no sound out of it at all. Bypass signal is good then I switch it on and it's complete silence. No noise or anything. Any ideas what I may have done wrong?

    I tried plugging in my cables the other way around, tried flipping the op amps in all possible orientations, looked over my board, looked over my wiring, reflowed some solder joints.. Nothing. It's really frustrating

    I have pics but for some reason I can't paste my links into this box. Can I email them to somebody?

    Thanks
    -Travis

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    Replies
    1. Email them to the address linked in the header

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  8. Or could somebody post the guts of their working one?

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  9. Thanks Mark! I've just sent you an email

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  10. Turns out I just forgot to solder one of the IC socket lugs in. Now it sounds really nice!

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    1. I emailed you back to see if you had a track side picture, but glad you got it sorted.

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  11. This is the schematic for the OD808 Reissue! It will be interesting to have a vero of it!

    http://www.freestompboxes.org/download/file.php?id=249&mode=viewhttp://www.freestompboxes.org/download/file.php?id=248&mode=view

    I think you can use your actual layout and modify it partially

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    1. That's nothing like the original at all. Transistor instead of opamp buffers, and looking at it looks just like a TS9, or at least extremely close.

      I can do away with a lot of the circuit because the buffers and components at the top are for the switching circuit so I could omit much of that. So I'll do this one because it is a quicky but I reckon it is going to be so close to the TS9 that it will be indistinguishable.

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    2. Yes Mark I saw that is really close to the TS9, but when I tried the pedal compared to a TS808/TS9, this shit sounded really cool with the famous clean boost settings. I know that a lot of bands really prefer the maxon. I don't find video that make the comparison between the vintage and the reissue version.

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    3. http://medlem.spray.se/guitarmaniac/hpbimg/ts808.gif

      It seems to be the exactly the same, just different IC

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  12. What 1uf caps I should change to bi polar 1uf for better iriginal sound?
    Thanx!

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  13. hello, is this the correct OD-808 schematic? :)
    http://www.matsumin.net/diy/bunkai/od-808/OD-808_sch.BMP

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  14. I built this from a kit I got off bitsbox... just having one tiny issue with my build.
    My pedal only works when I turn up the balance all the way. I checked the polarity of the caps and that seems fine, the components seem to be in the correct places. I haven't thoroughly checked for shorts yet. Anyone have any idea why my pedal is behaving this way ? Any help would be appreciated. Thanks.

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  15. Hello, I have only electrolytic 1uF caps, can I use them anyway? How can I find out the right polarity?

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  16. I going to put one of these together tomorrow and if like to add a 3 way clipping switch (diodes attached to the switch), and I'm curious how I'd wire that up. Would I run one wire to overdrive 1 and the other to overdrive 2&3? Any help is always much appreciated.

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    1. If you remove D1 and D2, take the wires from the holes one of the diodes should have connected into up to the switch.

      Switch lugs are like this:

      1---4
      2---5
      3---6

      The wires will go to lugs 2 and 5 (doesn't matter which), one set of diodes is soldered between pins 1 and 4, and the other set are soldered between pins 3 and 6.

      If you use a 3 position toggle with centre off, that will also give you a diode lift setting which can be quite useful for a louder clean boost.

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  17. Ahhh. Makes more sense than what I was thinking. Thanks Mark. I've built about a dozen of your layouts and for what it's worth, this site is a invaluable source of info and tech help. Between between you and M all of my answers are here!

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  18. So this is a very n00b question. I have not tried reading circuit diagrams for a very long time and these are in a different format than what i barely grasped back in the day. can anyone clue me in with a ledger of some kind explaining some of these symbols meanings? the components are pretty self explanatory but things like "red square with red dot in the middle" and so on are baffling me. tried to look back at the older diagrams on this site and was able to understand them a lot better.

    Thanks,
    Chad

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    1. The red squares are cuts in the track which you can do easily by twisting a drill bit at the hole. The black lines are links between tracks, and the blue and white circles on the black lines are points where two links are soldered, so you have one link going up and one going down.

      Remember all the layouts show the top components side of the board. The copper tracks are on the reverse side and so if you turn the board over to make the track cuts you'll have to mirror the cut positions from left to right (I sometimes use the Mirror function in Paint Shop Pro, or Horizontal Flip in IrfanView when cutting the tracks to give me an easier point of reference).

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    2. I'd recommend reading through the Build Guide to give you a visual picture of how the layout is translated to the build. In fact all the guides in the top menu may be useful for you.

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  19. didn't see your reply until now >.< so i messed up on the orientation of things when i drilled it out this morning... so everything is flipped. i had to turn the transistors around and mount the IC on the bottom to get the proper pins where needed. oh well... wont happen with the next build now that i know.

    Thank you so much for your speedy reply and all the work you have put in to this site, keep up the good work! Should be playing through the finished product by tomorrow after work :D

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  20. what does that double link do, and why is it made like this and not into seperate holes?

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    1. The links I use are pretty thin, about the size of the Chinese 1/4W metal film resistor leads, and so you can easily fit two in the same hole without any struggle. So I often use double links in the same hole simply because I can, and there isn't too much reason not to. If I stuck to always using separate holes on the same row to carry on links then it would often mean having to add an additional column, and given the choice I'd prefer to use a double link every time. It actually makes the build slightly simpler too, it needs only one soldering operation instead of two :o)

      In this instance I didn't actually need the double link, I could have moved the cut next to the 510K resistor and put the link to pin 4 there, but I do the links first before I start placing the other components.

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    2. thanks for the response! Great build!

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  21. Hey IvIark,

    First time poster here so first off thanks so much for all the wonderful info you are sharing here man, it's really awesome stuff. Thanks!

    I am quite new to the scene but enjoying this new hobby immensely. I can see that I will need to stock up on more beer though. :)

    I have three (much simpler) builds under the belt. I got this working 100% with true bypass, LED and boxed in a 1590B so this is my first decent build (*flex*). Not by a mile as neat and good looking as the other stuff I see around here but getting there. :)

    I would however greatly appreciate some advice if you (or the community) would be as kind:

    1) I am getting the pops when I switch on the pedal via the 3PDT. Read here and Google'd some so I did temporarily disconnect the LED, try another switch and attempted to discharge possible static buildup by switching it on and off a gazillion times. None of these helped. Further reading mentions leaking caps and pull down resistors bit this yielded mixed reactions so, together with my still limited knowledge, I am left unsure. For what it is worth I followed the build exactly barring that I used Tantalum caps for the two 220nF caps (which I read was used originally) and 914/4148 diodes (could not get the Panasonic ones) which to my understanding should could not be the culprit here? Anything a brother can try? Could it be a faulty cap (which one)? Anyone else experiencing this with this build?

    2) Although I am new to the DIY scene, I have a decent ear for gear. I chose this build as I was looking for a more "brown" sounding OD that my TS9 RI (stock, I don't want to mod it - my motivation for the new hobby is that now I can build various sounding things to use for various applications). I also wanted to compare it to my TS808 RI to experience what the plethora of Maxon 808 believers experience. However, my build transpired to what (to my ears) actually sounds a bit more harsh and fizzy than than my TS9 (blasphemy, I know), which should not be the case...? I am thus thinking there might be something wrong with my build or, alternatively, is there something I can try to calm the harshness a bit?

    Thanks again for everything and keep up the great work man.

    Cheers!

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    1. Never mind - you can delete first comment if you like. Solved both issues with replacing one cap. Sound great - exactly what I wanted. Much better than my TS9 RI, still A/B comparing with my TS808 RI will most probably only be able to compare 100% on full volume tomorrow \m/. Sooooo stoked I got this one working 100%.

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    2. Next up OpAmp Big Muff. \m/

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  22. Just my two cents: This pedal comes to life using the orginal MC1458 opamps. This is the only double opamp that I never consider swappin' as let's say, is an "speciall" IC, more noisy (in all senses).
    In envelope filter effects, is a must in many circuits, if you don't use it, the effect won't work. But for what I've seen until now, in the noise circuits where it was originally used, is a must too, as you can see on this very effect, the IC Big Muff and many others.

    J.

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    1. I just won a cheap lot of 29 of these from eBay. Good to know they'll be useful :o)

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    2. MC1458 my favorite IC in dirty pedal :)

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  23. built this and it works great! Thanks for the layout! Only issue is that it pops when turned on; I've built a couple other OD's from your layouts that have the 1M pulldown, how would I go about adding that to this one? Thanks in advance!

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    1. See if you can squeeze a 1M resistor from where the input wire connects to the second from bottom row. You may be able to squeeze the top lead in under the 510K resistor before the cut

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  24. Ok Thanks! I'll try that. (So the same row as input lead, right before the cut under the 510K down to the second from bottom row correct?)

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  25. I haven't had a chance to try adding the 1M yet; does this already have a buffer? If not I was going to add the klon buffer to it...

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  26. sorry for the noob questions, I'm good at "coloring by numbers" with these, I just don't know how all the technical stuff works yet haha

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  27. Hi all! So, I just finish this one and it is not working. I just hear a hiss. What are the expected voltages in the IC pins? Thanks!

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    1. Triple check over all the connections, cuts, and any offboard wiring too. You likely have a simple error or cold solder joint somewhere. A signal probe can be handy too - you can find out where your audio signal stops - use the original schematic and refer to your layout to work it out.

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    2. Found the issue with the probe! One miss solder resistor! Thanks!
      I think I should stop soldering after 1am :)

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    3. Hahah yeah, always unsafe to do stuff at nite. I just get angry.

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  28. Hi Guys, I have minor issue with Tone Control, unless it is normal behaviour.
    Generally I have muddy tone at 90% of entire Tone knob control range. Tone knob starts to brighten up the sound after 4-5 o'clock. Is it normal behaviour of this pedal? I confirm I have 20K Log pot. Maybe I should use Lin instead?

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    1. I have built the reissue and have the exact same problem. Although I tried a lot of different pots (B20k, A20k, B100k, A100k) I did not see any difference, tone control for the most part is too dark. Can someone help us spot the tone circuit on the vero so that changing some values would work? Thanks.

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