# Oscilloscope Recommendations



## Sixtusv (Jan 4, 2015)

I'm just getting into this hobby, and every day I learn something new. Not afraid to sound like a NOOB 'cause I BE ONE! :nerd: just picked up the MAKE: Electronics book and parts kit, so I can start testing and building some basic circuits soon.

I've been looking at used (Tektronix and others) Oscilloscopes Ebay has a bunch) to help me understand input/output from amps, other audio equipment. I wonder what specifications I should be focusing on: # of Channels? Frequency (150 Mhz or higher?) Analog or Digital? Portable or Bench?

Is there a particular Model(s) I should look for or stay away from?

First I want to test and understand what my current Audio equipment is and how it works...At some point this year I plan to tackle DIY speakers, active crossovers and amps. Scopes seem to have come down in price significantly, I wonder if it makes sense to have one in the shop to just tinker and learn more. :sweat:


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## chashint (Jan 12, 2011)

An oscilloscope is not all that hard to use. For audio applications pretty much any one will do.
Might as well get a digital one with a USB port for saving data.

If its available to you maybe check out the local Jr college or high school and see if anything electronic related is offered as continuing adult education.
Its usually very inexpensive and maybe you can pickup some basic electricity /electronics.
After that you can decide if its worth really learning about electronics. 

I wouldn't have been able to self teach myself electronics by just reading books.
But that doesn't mean you can't learn it on your own.


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## Sixtusv (Jan 4, 2015)

Thanks Charlie, that's a great idea about the local Jr. College. I think the Digital 'scope recommendation is also sound advice, (they do cost more!) since I have read that older, analogue scopes with frequencies under 100 Mhz might not be as good at accurately capturing the lower spectrum of audio frequencies. 

Are 2 channels enough? Do I need 4 channels to measure stereo signal inputs and outputs?
I'm currently watching several Tektronix TDS420 150MHz, 4Ch, 100MS/s which I think might meet the criteria, but there are also 2-channel versions that are generally less expensive.

Six - Minneapolis.


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## chashint (Jan 12, 2011)

This is difficult for me.
I do not want to discourage you from trying but having said that buying an oscilloscope without having any understanding of the instrument does not seem like a good place to put your money.

Oscopes measure voltage vs time.
Frequency is derived from the time but an oscope is not a frequency device.

What price range are you looking at?

Download the user manual of any Tektronix and start reading it.
Other manufacturers may be good too but I am reasonably familiar wit the Tek products and the manuals describe measurements and setups.

100MHz bandwidth instruments are more than adequate to use on audio circuits.


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## Sixtusv (Jan 4, 2015)

No worries Charlie (from my end anyway) I appreciate the advice! (sometimes I get a little Toy-Crazy). The scopes I'm looking at are in a range under $200, and I'm sure I could put that money to work in more rewarding ways at this stage of my learning than a scope. On the other hand, if a bargain comes along (Say under $100) that may be worth scooping up a scope that may gather dust for a few months, just so I don't have to wait when I do decide I want one. I'm mostly trying to leverage the forum's knowledge to make more informed decisions.
Thanks again! - Six- Minneapolis.


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## lcaillo (May 2, 2006)

I have a couple of scopes and have not used them since I was doing repairs. If you are not tracing signals, not needed much. A good calibrated mic, mic preamp, and SPL meter are much more useful.


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## Sixtusv (Jan 4, 2015)

*Re: Oscilloscope Recommendations?*



lcaillo said:


> I have a couple of scopes and have not used them since I was doing repairs. If you are not tracing signals, not needed much. A good calibrated mic, mic preamp, and SPL meter are much more useful.


Hello Leonard, thanks for the note! I have the mic, and REW setup ready for testing some new components... 

I just purchased two different tweeters and two different mid/woofers to start testing what works, why, and how. I will be using a Behringer CX3400 crossover to test them, and I think I will also need one or two 20-50 watt PCB amps since my goal is to go active throughout my system. (I already have the plate amp for the woofer) 

I first started to think about using a Scope when I noticed the voltmeter readings across my existing speaker terminals held steady when using tone generators, but fluctuated quite a bit when listening to music. I have subsequently read more about the potential for distortion and clipping, especially when going with an active setup and bi-amping or tri-amping. 

As you may have guessed, I'm quite a ways off from needing a scope, and even when I get to that point, I also realize it may be of limited use, but I hope it can be a useful tool to help me figure out things as I test/play with different components. (and stay away from distortion and potential driver failure when cranking it up!)

Finally, it may be obvious to some, but I thought if I share the WHY behind my questions, it may help others who want to do similar things. I am doing this for a few reasons. I like good music, and get frustrated by the limitations of my current audio setup (so I'm looking to upgrade my gear). I also like to tinker and try new things, (so I must have the DYI gene in me somehow) and I don't have an unlimited pocketbook (so I look for ways to make things that are unique and valuable to me both as an experience, and as an end-result.)

Thanks again, Six - from Minneapolis.


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## chashint (Jan 12, 2011)

I for one appreciate the explaination.
I was actually unaware that a new oscope could be purchased for $200-$300.
I guess I am spoiled with the Tektroniz 7104C I have been using for the past few years at work.
If I were inclined to do what you have sescribed an oscope would be very handy to have around.
The low cost oscopes should be plenty for looking at the signals you are interested in.
If they will accept a real current probe that would also be very handy.

As long as none of this breaks the bank go for it.


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