23 thoughts on “Request: Suhr Riot

  1. hi harald, there was new schematic for “original” suhr riot in freestomboxes.org (traced by MarkGor ). Can you update your layout based on that new schematic? Thanks

  2. Just an aside. This pedal sounded good after I built it but it was a bit dark tonally. I was reading through the comments at FSB to find something to mod the tone a bit. Someone named JYMaze came up with some mods to brighten it up a bit. I did these mods and it really opened the pedal up. One of my favorite pedals after the mods.

  3. Hi Fernando, the answer is yes and no. Some effects can run on +18v instead of +9v, but it usually comes down to the safe operating voltage requirements of the components. Some ICs and transistors can’t handle that high a voltage, or you might have voltage regulators expecting only +9v that would overheat if fed +18v. (You also have to make sure to use capacitors, and especially electrolytics, that are rated for the extra voltage). Some effects are also biased for a certain voltage and won’t sound right with something completely different.
    As for the Riot you’ll probably be OK feeidng it +18v, just make sure you use caps rated for 25v or higher.

  4. Nevermind. I replaced the blue LED today and now it works fine and I can hear a differance when flippin the switch. 🙂 I also replaced C9 with a 10nF (insted of 33) and now it sounds much better. Cheers

  5. Just built this one and it sounds great (although maybe too modern sounding for my taste). The switch doesn’t do much, the middle position sounds alittle different but position 1″ and 3″ sounds the same to me. The red Leds light up very strong while playing, especially D9 so I put that one outside. 🙂 However, as mentioned before it seems like the red leds and active no matter what position and the blue led does never light up while playing, but when I pull out the guitar cable from the input the blue led lights up very strong (if in 1″ position). How can that be?? I must have done something wrong… Any idea what the cause may be, or if it’s supposed to be like this? Anyway, thanks for the layout. I love your site

  6. After a close examination of Madbeans schematic i realize that there is nothing wrong with my build, the red leds are always in the path… the switch ads either the germanium diodes or the silicon/blue led network, which very subtle differences in sound.
    In my humble opinion it would be better to be abble to switch between just red leds, red leds/germanium or red leds/silicon-blue led network. This would give more obvious changes in sound, especially in silicon/blue led-mode.
    I will try and fix my build this way… if anyone´s interested 🙂

  7. Built this baby today and it works fine… thanks for a great job Harald!
    Have´nt boxed it yet, just tested direct on the floor… sounds good so far.
    One problem though, would like to hear if anyone else has experienced this and have some tips…
    When the red leds are installed there is absolutely no difference in sound in all three switch modes – and both leds light up in all modes.
    With the red leds detached the blue led lights up in one position, in the center position it does´nt and there is a slight difference in sound. In the third position it sounds exactly like the center position and the blue led does´nt light up.
    Any ideas, someone?

  8. Finally got this built after all this time. Quite pleased with it. It’s a nice high gain sound without being too “scooped” as some are at this level of gain. It almost reminds me of the Steve Lukather kind of sound on his recordings ( I’m not saying this nails the Lukather sound – just that it reminds me of that timbre ). At the highest gain, it doesn’t get that harsh fizzy top end – stays tight and focused.

    I agree with Matt L – the different diode combos are kind of subtle but there is a difference. I socketed all the diodes ( lot of work! ) and may experiment with some more combinations later. It is the best sounding high gain pedal that I have built so far and recommend it.

  9. Incidentally, I’m aware that diodes don’t always light up. Have you seen that seven does?

  10. Well, number one build failed, but today I finished attempt #2 and it appears to be fine. With the testing setup I have (it’s not in the box yet) it does appear that you’re correct, that is to say that in respect to diode 7 these colors don’t seem to matter much. I was able to open an actual Suhr Riot, but they put the board in components down, so you can’t see anything. The blue diode never seems to light up, whereas in different toggle settings sometimes one red, sometimes two, sometimes nothing (diode lift I suspect (?) but the pedal seems to sound pretty much like the real thing. As I’m sure most builders have noticed, switching diodes can be subtle at best based on other circumstances such as gain, level, and overall volume, i.e. how loud the amp is. I heard the difference in my test setup, though again subtle, which is what I expect. Anyway, after I get done prettying up the box and getting the guts in there, I look forward to lots of fun with this pedal. Thanks Harald!

  11. Alright, Matt. I’m thinking you’ll hear very little difference between a green and a blue LED, but it’ll be interesting to see what you come up with.

  12. Okay thanks Harald, maybe I’ll try a few types,as I have some diffused blue ones on the way. I’ll also check Wiki and see what’s what with headroom and try to get back with some info.

  13. From wikipedia it seems the blue has a slightly larger voltage drop than the green, i.e. a bit more headroom.

  14. Thanks Harald, and just one other thing, how does the blue fit in with the others…more or less headroom than the green?

  15. The IC prefix refers to the company and I believe the suffix indicates various additional properties like packaging type etc. They’re usually not relevant, but there are cases where you have to pay attention (EH Hot Tubes using the unbuffered 4049, suffix UBE, springs to mind).

    When you see different color LEDs used for clipping the main difference lies in the voltage drop of each color. These gives you different signal amplitude thresholds before clipping occurs. E.g. red LEDs are approx. 1.5V whereas green LEDs are approx. 2.2V (and your regular small signal diodes like 1N914/1N4148 are approx. 0.6V). The green LEDs would give you more “clean headroom”.

  16. Hey Harald, I’m interested in Tinkercreek’s question also – I’ve heard in some cases that all that’s really important would be the (for example) 4558 aspect and that the prefixes and suffixes are proprietary to the manufacturer, though I don’t know if that’s true, false, or sometimes true and sometimes not.

    But my main question is this: I can’t seem to source a blue LED. My understanding is that the color isn’t that important, but many of the layouts we see for vero as well as pre-fabbed designs simply list the color originally used. I also have been told that the ones that appear clear, or colorless, don’t work for clipping, since not every circuit results in the LED lighting up. I plan to use a 3mm green LED in its place, unless I hear that someone knows a place to source the blue, or that it actually matters! Hope all is well with you Harald, and all the other nice people who hang out at this site!

  17. Just looked over on Madbean’s site after I noticed that that was where you got the schematic. He actually links to the parts at Mouser for the 4580. Thanks.

  18. Harald

    Trying to source the IC for this pedal. I found the 4580 at Mouser but they have several with different prefixes and suffixes. Do you know what I would look for in the data sheet to confirm which one to buy? They’re not expensive so I could just get a couple of each and try them but I’m just trying to learn as i go. I’ve got some 4558s and 4559s that I could probably sub but I try to stay as close to your parts lists as possible.


  19. Verified also by me.This pedal will be forever on my pedalboard!Build it ASAP!Great range of tones in this little monster 😉

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