Nux Horseman Huge beep sound

[Jun1001]

 I got a broken Nux Horseman from an acquaintance and it makes a very loud beep when I raise the gain. What could be the reason?
 And I also filmed this phenomenon as a video, Can I attach a YouTube link?

[GibsonGM]

Would be helpful if you could go find its schematic and post it here, and tell us - are you powering it from battery or wall wart?  It sounds like any of a few things, oscillation.  The more info you give, the more likely the answers for it will be correct   

Yes, you can post a link.

[Ice-9]

I have just googled the Nux Horseman and from the pictures I would take an educated guess it is a clone of the Klon Centaur. It should be quite easy to verify if it is the same as the klon if you can post some pictures of the Horesman PCB.

[Jun1001]

Hello, I used a 9v center minus constant voltage adapter and after receiving this stormbox I tried for a few days to find the outline right away, but I couldn't find it. Here's the video and a picture of the pcb.

https://youtube.com/shorts/zOiKzZ1_G-g?feature=share

https://youtube.com/shorts/1TY4xGHQd5s?feature=share

[GibsonGM]

Hi Jun, you must make your videos public on Youtube for us to see them!

Have you tried it using a 9 volt battery?

[Jun1001]

 Oh sorry, I switched the video to public.
 And maybe this stomp box is too small to support the battery 9v battery, but I didn't have the adapter as shown in the picture below, so I couldn't try it.

[FiveseveN]

If you don't have the means to whip up one of those adapters it's highly unlikely that you have the means to repair this pedal.
E.g. can you check for ripple on the charge pump's output (after trying it with a battery)?

[GibsonGM]

Yes (FiveSeven).   There are a few different causes for 'boop' noises in pedals. It's usually something oscillating.  In order to know if the innards are functioning properly, we'd need you to take voltage measurements and try a few different things.  And the ability to test components is needed, too. 

I wonder if someone didn't connect a power supply that had reversed polarity.  But can't tell from here!

[Jun1001]

Sorry for the delay, really if I need a battery adapter, I can buy it right away. And I connected the polarity of the adapter properly, but I remember the former owner of this pedal said that it failed after plugging in 12v power.

[FiveseveN]

it failed after plugging in 12v power.

Well that'll do it. Can't see what charge pump is in there because postimg is having a fit. But if it's the original MAX1044, its maximum input voltage is 10V.

[Jun1001]

I think this is the most important thing, but I'm sorry I said it too late.

[GibsonGM]

So, you would need to take some voltage measurements to see what they charge pump is outputting - do you have a DMM, and can you make some measurements?

[Jun1001]

So, you would need to take some voltage measurements to see what they charge pump is outputting - do you have a DMM, and can you make some measurements?

Yes, I have dmm, so should I measure the output of my 9v adapter?

[ElectricDruid]

No, you should test the output of the charge pump to make sure it's working and wasn't fried by the 12V input, which is quite possibly the fault the pedal has.

Here's a schematic for the circuit:

https://aionfx.com/app/files/docs/refractor_documentation.pdf

(Page 7 - Thanks Aion!)

The charge pump is that TC1044 at the bottom of the schematic. The points you need to test are the voltages it produces for the rest of the circuit. You should have 9V in at VA, -9V out at -VA, 18V at VB, and 4.5V at VR.
Where exactly those points are on the circuit on front of you is not easy for us to say. You'll have to trace it out from the TC1044.

HTH

[GibsonGM]

What Tom said. Be careful when doing this, take it slow and be careful not to cross IC pins and so on (causing a short)!   Clip the neg. lead of your meter to a known good ground and use the pos. lead to measure (sorry if you already know this)


Pin 8 of IC1 and IC2 ("upper right hand corner" of each IC on PCB image) might offer easy to get at locations to take a voltage reading, should be about 18V if the charge pump is working.  That would tell us a lot about the problem.   

[Jun1001]

I tried to take your advice and measure it with DMM right away, but I couldn't find tc1044 anywhere on pcb. I tried to measure it somewhere else, but I couldn't because I thought it would break more in this state.
I'll attach a picture of the other ic chips on the pcb.

[FiveseveN]

Wow, a uC is about the last thing I was expecting to see in there: https://www.st.com/en/microcontrollers-microprocessors/stm8s103f3.html
SGM3209 is your charge pump, which says can take up to 18V input. The plot thickens.