Some advice on buying an oscilloscope
A reader asked what “[w]hat would be a good [oscilloscope] (hopefully economical) that would be able to handle your course and build my own headphone amplifier/preamp and “stomp boxes” for an electric guitar? What do I need to consider when purchasing a capable, reliable oscilloscope? Is there a particularly good place to purchase one?”
Here is my answer:
There is some information on oscilloscopes in the online chapter:
https://laoe.link/appendix/Appendix_F_Equipment.pdf
but ultimately it depends on your budget and needs. The audio devices you list do not require an expensive oscilloscope. Nor are they likely to require more than two channels (a few of the experiments in the book are easier to debug and understand with a four-channel scope). You can get a very inexpensive two-channel scope suitable for audio work for under $100 (some as low as $38 – https://www.amazon.com/FNIRSI-DSO-510-Oscilloscope-Generator-Automotive/dp/B0DJX6W58S/ – 10MHz is adequate for audio work):
https://www.amazon.com/s?k=oscilloscope
These are hand-held, with a small display but should be sufficient if your budget is limited. (I have no personal experience with them so I cannot recommend a particular unit.) Cheaper handheld scopes are usually limited in bandwidth and may be limited in sensitivity (the smallest voltage signal they can display) so it depends on if you want to look at something like the output of a guitar pickup (a very low voltage) or not.
Moving up, you probably want at a minimum a 100Mhz scope for the digital half of the book and to see the parasitic oscillations discussed in Chapter 9. I am familiar with Siglent scopes (I bought a dozen of the 2000 series for my lab at Harvard ). This 1000 series, 4-channel, 100MHz scope for $500 is a very capable scope that should get you through all the experiments in the book.
https://www.amazon.com/Siglent-SDS1104X-oscilloscope-channels-standard/dp/B0771N1ZF9/
You can also get a two-channel scope for less from other vendors, but I am unfamiliar with the brands or their products.
https://www.amazon.com/Hantek-DSO2D15-Digital-Storage-Oscilloscope/dp/B08MDSG839/ ($225 for 2 channels, 150Mhz)
https://www.amazon.com/FNIRSI-1014D-Dual-Channel-Oscilloscope-Generator-Bandwidth/dp/B097T5NRTZ/ ($180 for two channels, 100Mhz)
https://www.amazon.com/HANMATEK-Bandwidth-Oscilloscope-Channels-Professional/dp/B0833YFNKP ($170 for two channels; $240 for four channels, 100Mhz/110Mhz)
These include a built-in signal generator (which tend to be limited in amplitude but could be adequate for what you are doing).
All of these are incredibly powerful tools at prices an order of magnitude less than what was available when analog scopes ruled the earth.
I like Amazon because I have Prime so shipping is free and they are very generous with returns, but you may be able to find them elsewhere for less. You might want to make a decision soon because when stock runs out the next batch will probably cost more due to Trump’s tariffs on China (most likely all of the scopes listed above come from there).
Links and prices as of May 2025
Update 2025-05-16
The latest bonus edition of Elektor (free to download) has a review of one of the low-cost ($85 at Amazon) hand-held scopes on p22.