Help with the Suhr Riot "Fixed" Schematic [Resolved]

[GarrettVD]

Edit August 2, 2015: Issue has been resolved; several problems along the way from defected capacitors, missing a jumper, to missing a ground from the circuit to stereo jack sleeve.

Hey all,

I'm trying to get my Suhr Riot clone to work, with little success.  In fact, this is my second attempt at the same board! I must be doing something terribly wrong here.  So, I'm following the Veroboard Suhr Riot Schematic created by |v|ark.  I'll list some notes in no particular order, that may give some insight to someone with greater knowledge on DIY pedals.

-I'm not 100% sure if the ground on the SLEEVE of the stero jacks need to be attached to the negative terminal of my 9V battery -- but when I do try to do that, NO SOUND comes out of my amp at all.

- I didn't have a 1uf non-polarized capacitor, so I swapped with a 1uf polarized electrolytic capacitor (with the negative terminal directed upwards, from the perspective of the Veroboard schematic)

- Ohmmeter test confirmed that the pots are functioning.  I didn't / nor could I find a 10K Reverse Log pot for the TONE control, so I'd swapped with a normal 10K Log Taper pot, and switched Tone lugs 1 + 2 with 2 + 3, and Tone 3 with 1 in the Veroboard schematic.  Yeah, not ideal, but should work in a pinch, and not inhibit functionality.

- Diodes D1->D4 are 1n34, D5 and D6 are 1n4148.  The schematic says "51V" but reading the comments on the blog I referenced earlier indicate that they could be 1n4148's.

- The LEDs do not light up at all, yet are all fully-functional.  Out of curiosity, I swapped with all red LEDs, but they similarily do not light up unless I test them individually with a continuity diode test + 1k resistor.

-I'm waiting on my DPDT ON/ON/ON switch to come in, so I did a red-neck workaround on my breadboard for the time being.  This might be where the problem is?? Have a look at the pictures attached below.

-When all wires are connected as described in the schematic, I only hear my guitar, with no effects.  In fact, even when removing the JRC4580 ICs, I can hear my guitar.  So the diodes are not clipping, that's for sure.

-Using a 9v battery, a fresh one.  Even connected a 5V DC 1.5A wall adapter.
-I used my multimeter to test the voltages of each of the pins on IC1 and IC2, and they resuled in the following:

IC#1:
PIN 1 / OUT 1: +3.99v
PIN 2 / -IN1:  +3.99v
PIN 3 / +IN1:  +3.98v
PIN 4 / -Vs: 0v
PIN 5 / +IN2: +2.096v
PIN 6 / -IN2: +7.1v
PIN 7 / OUT2: +7.48v
PIN 8 / +Vs:  + 7.94v

IC#2:
PIN 1 / OUT 1: +4.07v
PIN 2 / -IN1: +4.09v
PIN 3 / +IN1: +3.89v
PIN 4 / -Vs: 0v
PIN 5 / +IN2: +3.9v
PIN 6 / -IN2: +3.94v
PIN 7 / OUT2: +3.93v
PIN 8 / +Vs: +7.89v








Edit 1: Added |v|ark's schematic.

[dexxyy]

looks like you have at least 1 solder bridge, possibly 2 between rows 4 & 5 from the right of your photo ( back of the board) row 4 is connected to ground so if that may be grounding that section of row 5.

[dexxyy]

Sorry, I was looking at this on my iPad and had the orientation locked but the iPad turned, the suspect bridges are between rows 4 & 5 FROM THE BOTTOM on the left side near the cut on row 5.

[GarrettVD]

Thanks dexxyy, I'll take a look at that and report back.

[kirshman]

Welcome man.  I'd start by knifing all those gaps.  That one was sure, but it looks like you might have several bridges.

[GarrettVD]

Could be the case, yeah.  It looks clean, but I cant always trust this rosin core solder of mine, it likes to bridge here and there :p Something is broke, somewhere!

I replaced the 2u2 cap and now I at least have one LED working (D7 in the schematic)... I did test the voltage just before the LED on the anode side and saw it was only ~ 2v or so... hmmm....

Oh, and I labeled the underside diagram as well, if that helps.

[tabbycat]

hey garrett, welcome to gfx. i hope you'll get plenty of kicks here.

underneath as has been pointed out, it is a bit blobby and i would recommend (carefully) running a blade (stanley knife, exacto, etc) between the copper strips just to break any accidental bridges. be gentle as if you put too much pressure on the board it might crack.

as to the top view of the board a few random things:

is the 1u cap oriented in line with the current, i.e. the negative side (the stripe) should be on the ground side of the circuit.

there's a jumper missing under the 1m resistor next to the ic.

can't see d6, may be hidden?

is the 2u2 cap oriented properly, stripe facing down?

next to that 2u2 the resistors are missing or misplaced. things have def gone a bit wrong around there.

just below the 47u cap things looking a bit untidy. you might want to pull up and rearrange a couple of the components so they are not tangled. as a general rule it's good to keep resistors as flat on the board as possible, with the least excess wire exposed that could cause a short.

maybe hit those few things...

don't mean to sound negative. not at all. 90% of the top view of the board looks fine to me at a quick glance. that's a good start. but as trouble shooting is about spotting potential mistakes i've picked out what i could see.

trouble shooting is just about combing through again and again until you've caught things you missed first time. it's as much a part of building as building.

good luck with it and report back with more photos when you've nailed everything you think you can.

[motterpaul]

I went thru proverbial hell with my Suhr riot, too, and even when I finally got it all working I didn't love it ( not that much gain there, and kind if dark).

One thing I would check is the continuity on all your switches - your LEDs not working tells me they are not getting juice, and they are switch dependent.


EDIT: I see you "recreated" the on/on/on switch - so you are fine.

Make sure all other switch connections are going where you wanted as well. I know the schematic is a little hard to follow.

The way the circuit works is that different LEDs lite up on different switch settings.

If I have time I will check my IC power v. ratings - just woke up.

EDIT: also - when subbing a reverse log pot, I highly recommend you use a linear, not  log, because the taper is now backwards from what you want making it very hard to dial in.

[GarrettVD]

@tabbycat Thanks for the super detailed post! The note about the jumper saved the day!  Owe you an e-beer.   Not sure how I missed that one, as I soldered the jumpers and made the appropriate cuts before any other components went on the board.  C'est la vie.  Yeah, things went a tad awry around the 47u cap.  Not my finest moment, especially the two resistors on parallel for my 11K3 resistor, as well as the two caps that make up my 33p one…

Now I'm getting some distortion sound, but definitely not the trademark Suhr Riot distortion we know and love -- this sounds really crackly and inconsistent with lots of tone-suck going on… Like a super overdriving transistor or something.   Hm. Now thats a head scratcher… any tips for troubleshooting that w/ a multimeter?

@motterpaul I got the LEDs to work, just a matter of replacing the 2u2 cap in the top-left of the schematic.  And thanks for the tip re: subbing the linear instead of a log pot, I have a few kicking around I can make use of.

[tabbycat]

GarrettVD wrote

@tabbycat Thanks for the super detailed post! The note about the jumper saved the day!  Owe you an e-beer.   Not sure how I missed that one, as I soldered the jumpers and made the appropriate cuts before any other components went on the board.  C'est la vie.  Yeah, things went a tad awry around the 47u cap.  Not my finest moment, especially the two resistors on parallel for my 11K3 resistor, as well as the two caps that make up my 33p one…

Now I'm getting some distortion sound, but definitely not the trademark Suhr Riot distortion we know and love -- this sounds really crackly and inconsistent with lots of tone-suck going on… Like a super overdriving transistor or something.   Hm. Now thats a head scratcher… any tips for troubleshooting that w/ a multimeter?

@motterpaul I got the LEDs to work, just a matter of replacing the 2u2 cap in the top-left of the schematic.  And thanks for the tip re: subbing the linear instead of a log pot, I have a few kicking around I can make use of.

hey garrett, you're welcome. it was a team effort but i just happened to be up for indulging the 'compare and contrast' quest on this occasion.

am glad you are getting sound. did you run between the tracks with a knife? definitely worth a try. that or misplaced-missing components usually make up 90% of trouble-shooting woes, especially early on.

re your compound resisitor (11k3?) and compound cap (33p) that could be an issue. can you explain how you made up those two values? cap maths in particular can quickly get tricky. worth double checking the maths on both just to be clear.

pics would be good as soon as you have knifed between the tracks. we can go from there.
if you are non-uk and on weird foreign time i may be sleeping by the time you get the pics up, but the death star is manned around the clock so hopefully someone will pick up the threads.

congrats on sticking with it.

[GarrettVD]

tabbycat wrote

hey garrett, you're welcome. it was a team effort but i just happened to be up for indulging the 'compare and contrast' quest on this occasion.

For sure, seems like an active community of custom pedal DIYers here!

tabbycat wrote

am glad you are getting sound. did you run between the tracks with a knife? definitely worth a try. that or misplaced-missing components usually make up 90% of trouble-shooting woes, especially early on.

Yeah, I went track-by-track with my high-precision wire cutters, carefully scraping away any extra solder.  Only removed a bit, but I'd found the culprit... It was that brand-new 2u2 capacitor I'd put in... It was a tad loose.  Easy fix, thankfully.

tabbycat wrote

re your compound resisitor (11k3?) and compound cap (33p) that could be an issue. can you explain how you made up those two values? cap maths in particular can quickly get tricky. worth double checking the maths on both just to be clear.

Compound cap is a 220pf in series with a 39pf, resulting in 33.13pf.  I do have a varicap kicking around, so I may swap that.  I cannot find a 33pf capacitor available -- short of ordering it online, of course.  The compound resistor is a 12k in parallel with a 220k, resulting in 11.38k.  I have a few varistors as well, but it seems to work OK for now.  Confirmed with Ohmmeter.

Suffice to say, things are coming along nicely!

...However... only the Gain pot (100k Linear) seems to work at the moment, meaning I can hear a definite increase in crunch when turning the pot clockwise.  But the Tone pot (which is now a 10K Lin wired backwards) and Volume pot do not have any effect.  I'm currently making a "To-Do List" of items to double-check in order to narrow-in on why this is.  I feel the best place to start would be at IC1 pins 5, 6 and 7... right near my best friend 2u2.

Fortunately, my DPDT on-on-on switch arrived this afternoon, so perhaps things will sort themselves out when this is added.  I'll make sure to follow up with the results either in a couple hours, or tomorrow morning.

tabbycat wrote

pics would be good as soon as you have knifed between the tracks. we can go from there.
if you are non-uk and on weird foreign time i may be sleeping by the time you get the pics up, but the death star is manned around the clock so hopefully someone will pick up the threads.

congrats on sticking with it.

I am across the pond in Ontario, Canada, so I believe GMT is five hours ahead.  Thanks for the help thus far, I'm determined to get this thing working.  If I can build a beer-brewing robot, I know I should be able to make a custom effect pedal!

[GarrettVD]

Following up to say that I finally got this working.  The biggest problem was (among other things) that the negative terminal of the battery was not grounded to the sleeve of the stereo jack.  Also the red LEDs were suspect so I swapped them and used smaller 3mm ones.  Works fine now.

[tabbycat]

hey garrett, am glad to hear you finally nailed that sucker. was a test of patience and determination i bet.

grounding is a classic. i've messed it up so many times that now when i trouble shoot the very first thing i do is take a spare lead from the power ground and just tap it on (or clip it if i use a croc clip) all the key ground points around the circuit as a sort of double check that all key grounds are being made. you can work through all the important grounds in less than a minute.
if you tap on a ground point and the thing suddenly leaps into life you know what you've missed. i put something on my mp3 player playing into the input, attach the output to some cheapo mp3 speakers, and tap my way around like a water diviner looking for inspiration. making a little audio probe is another cheap and cheeky trick for quick trouble shooting of basic things.

so, high on success (and armed with the knowledge, experience and confidence you earned from seeing this project through) what's next?

[GarrettVD]

That sounds like a nifty trick.  I generally use my multi-meter's continuity tester, but it had seemingly failed me this time around.

Also, before I forget to mention it -- regarding cleaning or otherwise removing any unintended solder bridges between strip-board tracks, I found that using a fine-tooth miniature hack-saw blade worked well.

As for what's next... hmm... great question! Klon Klone? But looks like Electro-Harmonix already got to that first.

Thanks again for the help,

-G.