# Paragon Distortion Mode Not Working



## A2K (Aug 17, 2021)

I've built a Paragon, seems to be working well. The only thing throwing me off is Distortion setting on the DIP switches. The KOT website lists the following setting combinations:

both sides clean boost : off off off off
red side OD, yellow side Boost (factory setting) : ON off off off
red side clean boost, yellow side OD : off off ON off
both sides OD : ON off ON off
both sides DIST : off ON off ON

For either side on my build, if I put switch 1 (or 3) to off and switch 2 (or 4) to ON, as indicated above for Distortion mode, I am getting no sound just like a clicking noise. It seems to me that Distortion mode is engaged on the Paragon when switches 1 and 2 (or 3 and 4) are both switched to ON, albeit the it's not like it turns into super high gain mode or anything.

Is this normal behavior for the Paragon?


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## Barry (Aug 17, 2021)

No, pictures please


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## A2K (Aug 17, 2021)

Here's a picture of the top side of the board.









						20210817-203519
					

Image 20210817-203519 hosted in ImgBB




					ibb.co
				




I can take the board out and snap a picture of the bottom of the board if necessary (I hope it's not necessary! haha)


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## A2K (Aug 17, 2021)

Also, I used 1N4148s for the MA858s and 1N914s for the 1S1588s on both sides


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## A2K (Aug 18, 2021)

Here's a picture of the underside of the board. I unfortunately forgot to clean the joints with IPA, so it's not super clear. But here it is.









						20210818-185851
					

Image 20210818-185851 hosted in ImgBB




					ibb.co
				




I also noticed this - if I strum softly on the distortion mode, then this clicking / buzzing noise doesn't happen, but once I strum hard and go over a volume threshold, that's when the noise happens. Also this "threshold" gets higher relative to where the drive is set (i.e. I can strum harder before the noise occurs if the drive is set low).

I still don't understand why this doesn't happen if I engage both soft and hard clipping. It only happens when I engage hard clipping and turn off soft clipping. For both sides. Regardless of diode (I've tried a few kinds).


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## A2K (Aug 19, 2021)

Tried reflowing the solder in a few spots, including the DIP switch. No dice. 

Tried going through it with an audio probe too. When I turn on the Distortion mode of either side of the pedal, it seems to cause issues going back to C1 (probing here sounds like a slightly farty tremolo effect and it just gets worse from here).

The other thing I noticed was if I have the red side engaged (I think I had the clean boost mode when I tested) and then I turn on the yellow side set to Distortion mode, it works fine. As soon as I turn off the red side it's motorboat city.

Wtf is going on here?? Any ideas?


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## A2K (Aug 21, 2021)

This is a longshot, but this is the correct dip switch, right?









						DIP Switch - 4 Position
					

Top Quality Parts for Guitar Effects Pedals and DIY Music Devices. Knobs, Pots, Switches, Kits, LEDs, Enclosures, Jacks, Wire, Resistors, Capacitors, Semiconductors




					stompboxparts.com


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## Stickman393 (Aug 21, 2021)

Can you confirm that C10 and C11 are oriented correctly?  It's difficult to tell with the photo.

That is indeed the correct dip switch.

If you're having trouble at C1, my best guess is that you have one of the following:

Bad solder joint at input,
Bad PCB trace before C1,
Bad contact on the footswitch,
Tiny solder bridge to ground around C1

My suggestion would be to trace out the connections using an ohmmeter.  Go from your input jack to C1, make sure you have continuity.  If you don't, poke around that area, keep one lead on the input jack and work backwards on the board until you see continuity.  You should be able to figure out where the issue is this way.

Alternatively, if you do see continuity, check between input and ground.  Resistance should be VERY high.  If not, you likely have a solder bridge.

If both check out, work forward from C1 to IC2.1.

If all that is OK, take IC voltages and post.


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## A2K (Aug 21, 2021)

Stickman393 said:


> Can you confirm that C10 and C11 are oriented correctly?  It's difficult to tell with the photo.
> 
> That is indeed the correct dip switch.
> 
> ...


Thanks for the reply and suggestions. I'll test when I'm back home in a few days.

Just for clarity, the issue around C1 is only when the dip switch is set to hard clipping. I don't have issues at c1 (or seemingly elsewhere) in Boost or OD modes.

My charge pump was also from tayda, which can apparently be hit or miss with those. Someone else has suggested this could potentially be the problem, but I don't have another to test with at the moment.


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## Loxton (Aug 21, 2021)

That seems very strange. Can you please remove the 2 distortion clipping diodes and report. Engaging the distortion only adds the clipping via the diodes to VREF.


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## A2K (Aug 21, 2021)

Loxton said:


> That seems very strange. Can you please remove the 2 distortion clipping diodes and report. Engaging the distortion only adds the clipping via the diodes to VREF.


I'll double check when I'm home to be certain, but I'm pretty sure I did this before and nothing happened when engaging distortion mode with the distortion clipping diodes removed. It basically stayed in clean boost mode.

I've also tried switching diodes btw.


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## Stickman393 (Aug 22, 2021)

A2K said:


> Thanks for the reply and suggestions. I'll test when I'm back home in a few days.
> 
> Just for clarity, the issue around C1 is only when the dip switch is set to hard clipping. I don't have issues at c1 (or seemingly elsewhere) in Boost or OD modes.
> 
> My charge pump was also from tayda, which can apparently be hit or miss with those. Someone else has suggested this could potentially be the problem, but I don't have another to test with at the moment.


Hmmm.  Taking a look at the schematic here, it looks like all the hard clipping switch does is connect VREF to D5 and D6/D13 and D12.  So yeah, removing those diodes should cause nothing to change when dip sw2&4 are flipped, the pedal should stay in boost/OD mode.

Sorry, didn't totally digest that first post at first glance.  Forget that first bit, I think what we'll need is IC voltages.

Honestly, that's a head scratcher.  I wouldn't put a ton of weight in the charge pump idea at this point, because if the rest of the circuit is operating normally and the issue is only presenting itself when VREF is introduced at those points in the circuit...  

It kinda sounds like VREF is shorting to ground when those switches are flipped...but that would be an awfully big coincidence if both switches were doing that in the exact same way...color me skeptical on that idea.

Yeah, grab IC voltages.  This one's gonna need more data


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## giovanni (Aug 22, 2021)

Not familiar with the Paragon, is the red side first in the chain or second?


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## A2K (Aug 22, 2021)

Stickman393 said:


> Hmmm.  Taking a look at the schematic here, it looks like all the hard clipping switch does is connect VREF to D5 and D6/D13 and D12.  So yeah, removing those diodes should cause nothing to change when dip sw2&4 are flipped, the pedal should stay in boost/OD mode.
> 
> Sorry, didn't totally digest that first post at first glance.  Forget that first bit, I think what we'll need is IC voltages.
> 
> ...


Well, I guess it's all a moot point now, as one of the tantalum caps apparently blew up on me last time I used this pedal. 

On the fence about trying to cut out the burned-out parts and trying to get it working, vs just building a new one from scratch.


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## Stickman393 (Aug 22, 2021)

Huh.

Which one?  Either a bad cap, or reverse polarity.  Tants fail closed, make for a good poof.


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## A2K (Aug 22, 2021)

Stickman393 said:


> Huh.
> 
> Which one?  Either a bad cap, or reverse polarity.  Tants fail closed, make for a good poof.


C10.

My Truetone CS12 power supply is also broken apparently (at least the 100 ma outputs). Either the tantalum in the Paragon blew and in turn broke my CS12, or vice versa. Can't be a coincidence both happened at the same time.

It's possible I got a bad batch of tantalum from Tayda too. I had a tantalum from the same batch blow up on me in the Super64 Overdrive, although that happened within seconds of powering the pedal up. I had tested this paragon multiple times before c10 blew up. I was 90% sure I had oriented the tantalum correctly in the Super64, but I'm 100% sure I had it oriented correctly in this paragon build.


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## waarp (Jul 23, 2022)

Just wondering if this was ever figured out. having this exact same issue on 1 of the 3 paragon builds I did.


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## A2K (Jul 28, 2022)

waarp said:


> Just wondering if this was ever figured out. having this exact same issue on 1 of the 3 paragon builds I did.


It never got figured out because the cap blew up on me. I replaced all the tantalum caps and it's working. If you got your caps from Tayda, that could be the problem.


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## waarp (Jul 29, 2022)

replaced the caps with nichicon and we are solid! thank you! it was one of the 10u caps btw.

spoke too soon, it lets audio through now but still clicking. guess ill continue to troubleshoot.


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