Carlson's Super Probe




About: Hi, i'm electronic technician but it's my hobby too. I like to do and try many projects just for fun :)

Intro: Carlson's Super Probe

Hi everyone, recently i made the "Carlson Super Probe" and i'd like to share with you how to do this!

First of all, listen Paul's video. You will see why you should build this probe, how sensitive that is. Also if you like electronic you should see Mr Carlson patreon page here: and maybe support him.

So let's begins!

Step 1: Schematics

Here are the schematics. Those are exactly the same you saw in the Mr Carlson's lab video. Except for the amplifier. I added some diodes to lower the voltage, if you are using alkaline batteries instead rechargeable. Alkaline batterie are 1.5v. Nica or nimh are 1.2 only. The amp chip 4871 need a MAX of 5.5V. So add diode lower the voltage by 0,6v each.

Step 2: ​Doing the Probe

For the probe shell, i used copper. Go to hardware store and buy those pieces. The pipe size is 4/3 inches.

Step 3: Electronics Parts

You will need some specific part. This is the digikey part number.

The little switch:

CKN9559-ND OS102011MA1QN1


Pot 100k

CT6EX104-ND CT6EX104


capacitor 1206 22uf



capacitor 4.7uf 0603



capacitor 360pf 0603






Transistor 3904 sot23



Light bulb (optional) to put on supply vr. See Video 42:00 min



Amplifier chip



And for the resistor all are 0805 resistor.

Step 4: Probe PCB

To do the pcb, just print and etch the carlson probe.pdf. Refer to the component location to solder the part. You do not need to etch a double side pcb. The bottom side is ground, except for swtich, led and one pin of the pot. Refer to the probe bottom picture.

Step 5: Make Encavure

Make an encavure and solder the pcb right in the middle. Try and adjust the size of pcb to fit in the pipe.

Step 6: Install Wire

Here i'm using a mouse cable. You can use a headphone or mic cable if you like. Keep in mind that the probe will move very often. So use an appropriate cable.

Step 7: Put the Probe in a Shell

For now i used black tape. But i'l probably put a little machine screw or a bit of solder.

Step 8: Probe Amplifier.

The pcb is single side. No jumper at all.

Step 9: Amplifier in a Box Plus Holder

Choose an appropriate box. I took an old power supply box and some paint.

Step 10: Conclusion

This is the whole project at the end. The speaker is where the psu fan was. The probe itself is very sensitive and a must to have it. I hope you will enjoy the project. See you!

Step 11: Gerber File.

In addition, this are gerber file. You can upload those files to a pcb manufacturer. You can see the future result here: by uploading the .rar gerber file.



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    13 Discussions


    Question 3 months ago on Introduction

    Where should the ground wire for the audio and 5V be attached?

    The only points I see are for +5V and Audio on one end of the probe pcb
    and a connection for the signal on the other end. So I'm left wondering
    where to attach the outer shield for all of these others.

    I've built the amp and probe and I'm in the process of testing it. I used
    your gerbers to order pcbs and the only issue at the moment are these
    ground connections.

    Also, I assume that there needs to be a ground connection between the
    probe circuit board and the copper tube housing the probe, right?

    It's pretty clear that getting these grounding points right is critical to
    proper operation and I really need some guidance.

    One more thing...I'm using a shielded XLR cable to supply 5V and
    the audio connection with the shield providing the ground return.

    Thanks in advance for your help.

    P.S. I really like your design using copper pipe and fittings for the
    probe shell and will be using that idea more in the future.

    1 more answer

    Reply 3 months ago

    I'm using only one point of attachement. +5 et GND. Mr Carlson is doing the same thing. Look on the pcb, you will see GND. Solder the ground to this point. For the probe gnd, if you look well. You will see that the back of the board is a whole gnd. And this one is soldered to the inner copper tube as well. At the end, i suggest to put a shield on the nutshell if you want. On my side, had an accident, the probe did a short circuit because of the copper nutshell. keep going!!


    3 months ago

    Hi, could you please add a component sheet that corresponds with the values in the gerber files ?


    4 months ago

    Thanks for help with diodes :)

    I found the 2k potentiometer with switch (audio gain) ... but can not find the 4.7k with 3 pin + 2 on the back, which is for the probe gain, right? I've never seen this kind of potentiometer

    (I have only seen now that before I used to "ask a question" instead of "post comment")

    1 reply

    Reply 4 months ago

    Sorry for delay, yYou can use regular pot and add a switch beside. So 2 regular pot, one on/off switch


    Question 4 months ago

    Hi, the .01 and .1 capacitors are 0603? And how many ohms is the resistor on red led in the ampli pcb? And what are the specifics of the 2 diodes for alkaline batteries?

    I have some difficult to find the appropriate yours they have both switches?

    Many Thanks. :)

    1 more answer

    Answer 4 months ago

    Hi, capacitor are 0805. led resistor is 1k. I have only one pot with a switch. If you dont find that, no big deal, you can use a switch aside and use a regular pot :) For diode, package is sod-123. I'm using 1n914 on my side i just install one


    hey Yannick, Thanks for putting up the Gerber files. I just made this today! Unfortunately when i powered up the amplifier I blew C2 the 22uf Tantalum cap smoked and burned up instantly. Any ideas what ive done wrong? the polarity was correct. Maybe it was shorted as i installed it?

    1 reply

    Reply 5 months ago

    Hi, Tantalum capacitor have polarity. Did you put the cap up side down. Normally the line is the +++


    9 months ago

    great job looks fantastic, gotta love Mr. Carlson's Lab :)

    1 reply

    Reply 9 months ago

    It's an sensitive noise amplifier probe. It can catch wire noise without touch the wire itself. Look at the video for more detail and exemple :)