New Oscilloscope Day! (Now what?)

Discussion in 'Pickups & Electronics [BG]' started by tlite, May 18, 2020.

  1. tlite

    tlite Supporting Member

    Aug 18, 2016
    Saw a good deal on a used one of these and pulled the trigger- I am now the proud owner of this Hantek DSO5072P:


    Not sure what the most common uses are for this thing- any ideas for cool stuff to try in the music realm?

    Most oscilloscope threads I found here mostly relate to what to buy more than how to use them for bass and guitar stuff. Most videos/tutorials I've found aren't specific to guitar/effect usage so much as general oscilloscope tips.

    I am using an old iPad2 as a tone generator and am able to get the sine wave showing on the screen. Set the proble to 10X and have calibrated it per the manual.

    I'd like to start with using it as a tool to build and analyze effect pedal circuits. Is there a good process for doing this? Any common settings I should use?

    Maybe after I get comfy I'll try to diagnose faulty electronics, amps and stuff, but wanted to start with things that aren't going to potentially electrocute me...

    What do you all find you most frequently use an oscilloscope for?
  2. abarson


    Nov 6, 2003
    Santa Cruz
    Get a breadboard and a bunch of passive components. Start with simple tone circuits and explore how they work. This is the basis to all electronics: resistance, inductance, capacitance (RLC).

    Next get some transistors and build some really simple amplifiers with them. You can build different class amplifiers, cascade stages, etc. using simple, cheap devices.

    These two types of circuits are fundamental to electronics and have wide application in audio. If you get a good grasp of them you can take on more ambitious circuits.
    I'm certain that there are lots of online resources that can help you learn.
    Last edited: May 18, 2020
  3. skycruiser


    Jan 15, 2019
    Why did you get it? What aspect of electronics are you interested in?

    If you want to look at what pedals are doing to your signal, you could build break-out box, something like this:


    Blue rectangles are FX boxes and the breakout box. Green boxes are 1/4" audio cable jacks. Arrows are cables. Orange circles are some kind of test point you can clip your scope probes onto. Black lines are wiring inside the box (also wire the ground probe to the cable shield). (There may be an easier way to break out cable signals but I didnt' find anything after a quick search.)

    Put one scope probe on the "IN" signal and the other on the "OUT" signal. With this you can monitor how FX Pedal 2 changes the signal (waveform shape, magnitude, phase, etc.)

    As mentioned above, do some breadboarding with basic FX circuits. You could start with filters and then transistor circuits described above. Also a very simple op-amp fuzz circuit can be built with only a few parts. Usually there a gain stage and clipping stage with a pair of diodes in the op-amp feedback. The Build Your Own Clone site has a lot of schematics to help get you started.

    There is a free program made by Texas Instruments called TINA. It is a fairly easy to use circuit modeling program. I sketch my designs up in TINA, run a few simulations to confirm it is doing what it should, then implement with parts. Might be worth taking a look at that as well.
  4. tlite

    tlite Supporting Member

    Aug 18, 2016
    I've built a few circuits (and my wife can attest that I have breadboards, jumper wires and alligator clips all over our home office- yeah, it's kind of looking like a mad scientist lair right now). Mostly have built distortions, fuzzes, overdrives, a rangemaster, blend/split circuit, boosts, and a tremolo (using a GuitarPCB PCB for the tremolo). I guess I'm trying to learn what production pedals (or tones) I like are doing to the signal, and how I can design things to replicate those effects. Will an oscilloscope help with this?
    AudioTaper and skycruiser like this.
  5. tlite

    tlite Supporting Member

    Aug 18, 2016
    THANK YOU! This is exactly the kind of advice I'm looking for.
    skycruiser likes this.
  6. tlite

    tlite Supporting Member

    Aug 18, 2016
    Forgot to answer this as best I can...

    --> The short answer is, 'I dunno, seemed like a good idea at the time.' The long-winded answer is...

    I thought it would be a fun tool to learn to use, but I don't know much about them (obvee).

    I do know that geeky pedal videos I watch on YouTube sometimes use them to visualize clipping on a waveform at different frequencies. A goal is to understand how to get intelligently creative with circuits instead of just copying them. Same applies to the repair and/or modding of stuff.

    The oscilloscope came at a fair price and I'm willing to gamble that I'll find uses for it or sell it at an acceptable loss.

    One example of something I plan to try:

    I have a Fulltone CS-Ranger. I built a pedal off of Rangemaster-esque schematics that is designed to pretty much do the same thing, but they still sound a bit different from each other despite the same input cap values on a rotary switch (my pedal isn't bad, but Fulltone's sounds less hissy and just better.)

    I expect I could use the oscilloscope to compare clipping from each input cap on the same waveform to see if I can pinpoint how to get closer to what that pedal is doing- or at least visualize some differences. Also will compare the effects of the gain control and mod the circuit until I get a little closer to the Fulltone's sound and waveforms. Does that make sense?

    What aspect of electronics are you interested in?
    Mostly just as relates to musical instruments- gear, amps, pedals, effects for now. That's more the 'stuff I want to work on' answer than perhaps than a particular aspect of electronics as an academic pursuit, but that's all I've got for now.
  7. Cutter8

    Cutter8 Supporting Member

    Feb 4, 2018
    Skycruiser and abarson are great examples of why you gotta love TB! No matter what you need to know, or how broad or narrow your questions, someone who knows what they’re doing will take the time to school you, and the rest of us get to learn right along with you!
    Thanks to all of you who are so generous about sharing your knowledge and advice. :thumbsup:
    That works for me! It’s actually my “go to” answer for at least half of the stuff I buy, if not more. ;)
  8. Killing Floor

    Killing Floor Supporting Member

    Feb 7, 2020
    Austin, TX
    HG1180, tlite and sing-modulator like this.
  9. I bought that exact same scope when I was rebuilding some vintage tube amps. I don't use it often but when I do need it, it's great to have one around. There is a hack where you can turn it into the much more expensive one (higher bandwidth) since all the components are the same, you just need to trick it into accepting the firmware for the higher end model. But I'm only using it for audio so it has much higher bandwidth than I'll ever use already.

    How much did you pay for it? Looks like it still has the protective plastic film over the screen.

    Oh ... a heads up for you. The ground on the probe is a real ground - meaning it goes to earth ground if you have the scope plugged into a grounded 3 prong power cord. So be careful (i.e. don't put the probe ground clip on the output of bridged power amplifier)
    Last edited: May 18, 2020
  10. Wasnex


    Dec 25, 2011
    @tlite ,
    The warning about the ground is very important.

    It's also important to learn about the voltage limits of the probes and what sort of probes you have. Basic probes are usually 1:1 or maybe 10:1. This sort of probe cannot handle the working voltages in big tubes amp.

    The last shop I worked in had only one 100:1 probe, which was shared by several technicians. We had a pretty rough couple of weeks when someone had an accident that destroyed the probe.

    So my advice is look for and read tutorials on using oscilloscopes and probes. It may seem like overkill, but this level of knowledge will reduce the chances that you do something stupid that may wind up damaging or destroying your equipment.
  11. glocke1

    glocke1 Supporting Member

    Apr 30, 2002

    Neat...I've been wanting one recently so I can wrap my head around things in the synth world better.
  12. 4001

    4001 Inactive

    Sep 29, 2004
    Lake County, IL
    Just because....

  13. tlite

    tlite Supporting Member

    Aug 18, 2016
    Truth! Thanks so much.
  14. tlite

    tlite Supporting Member

    Aug 18, 2016
    Great find. Duly saved to my hard drive for day job procrastination reading material!
  15. skycruiser


    Jan 15, 2019
    Sounds like you're a bit past the beginner stage so the scope is probably a good fit for what you're doing. I feel totally blind working on circuits without an oscilloscope. Great for troubleshooting as well. If you review the manual referenced elsewhere in the thread, pay attention to instructions on triggering. Assuming you will be looking at some sort of regular waveforms (audio signal with some fundamental frequency), you will be using the triggering function all the time. It can be tricky to set the right trigger point sometimes. Often using the cleanest waveform to trigger is the best way to go.
    DrummerwStrings and tlite like this.
  16. tlite

    tlite Supporting Member

    Aug 18, 2016
    10-4 and thank you! This scope has selectable 1X/10X probes. I'm not opposed to reading and tutorials at all- though admittedly I will default to hands-on learning when possible. I'm Googling this stuff, but any sites or tutorials you recommend?
  17. tlite

    tlite Supporting Member

    Aug 18, 2016
    Thank you. Please note that the 'Make a Mushroom Using Sound' video @Killing Floor posted was 1,000 times less painful to watch than this. Rush videos... blecch.
    RoketRdr, 4001 and Killing Floor like this.
  18. AudioTaper


    Sep 23, 2018
    Cool scope! It's awesome so many members on here are into this aspect of music (developing electronics)

    I use mine for testing the power output of an amp (see photo below). Years ago before the big boutique pedal boom, I developed some mods fo a Fuzz Face that were fantastic. The scope really helped 'visualize' what was going on in the circuit.

    Heres my setup. The analog BK tracks better when measuring the power amp. I also have a digital Tektronix that is great for small signal and is a lot easier to work around. Signal generator is a BK, I also have a Wavetek. The dummy load is a 4 Ohm 600W Vishay on a heatsink (and it really needs a fan on it....) I have a power meter (on top of the scope) but I cant get it to work properly.
  19. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Troubleshooting and measuring pretty much everything, and testing every new DIY build. A big part of that is looking at out-of-band performance, i.e. parasitic oscillation and general behavior at higher frequencies than we can hear. This often translates to stability, and not blowing stuff up is always a bonus.

    I have a 90s vintage digital Tek 4 channel scope that I was given, which needs a substantial rebuild due to the infamous "bad caps" syndrome. I will probably never get around to that and would consider giving it away to someone with the requisite experience to replace 85 or so SMD parts, and the willingness to pay shipping cost or come pick it up. It's a big nasty job and it may easily still not work after that since it's been sitting for so long. If anyone feels brave enough to take this on they can PM me. I'd hate to take it to Staples for destructive recycling, but that's the other most likely outcome. My 35 year old analog Hitachi scope still does what I need it to do and I just have way too many other rabbit holes going on at the moment.
    DrummerwStrings, AudioTaper and tlite like this.