Oscilloscope

[dipolar]

I am looking forward to buy an oscilloscope.Preferably USB type with pc interface.

My field of interest is as you all can guess, AMPs and loudspeakers.
with some SMPS messing around.

Advice me best option for the same.

Is it wise to go for USB type oscilloscopes?

and what range or features should I look for optimum satisfaction.

Thanks

 

[gmphadte]

Get yourself a good sound card.

 

[dipolar]

Thanks ,gmphadte.

I am afraid to say this but a sound card will not respond to spurious oscillation in my amps at 100khz .neither it may be able to reveal phase shift in my two way loudspeakers.

 

[benb]

That's a good point about the amp, but the typical USB scope may have 50MHz bandwidth but will only have 8 bit resolution and will be useless in measuring distortion. I might even suggest an older analog scope (used 15 to 20MHz bandwidth CRT scopes are cheap enough) for looking for oscillation or ringing (with maybe a 10kHz square wave input) and SMPS waveforms, but a "soundcard" sound interface with a bitdepth of 24 bits is necessary for distortion measurements. I don't see why measuring phase shift would be any better with an oscilloscope interface than with an audio interface either.

The short answer is neither will do everything you want, so you need both. No single (reasonably priced) instrument would cover the whole frequency range and bit depth of interest.

 

[dipolar]

DSO-2150 60MHz 2CH analog bandwidth, 150MS/s real-time sampling PC based DSO Rs 15990.00 Delivery: immediately
DSO-2250 100MHz 2CH analog bandwidth, 250MS/s real-time sampling PC Based DSO Rs 18990.00 Delivery: immediately

DSO-5200 200MHz 2CH analog bandwidth, 200MS/s real-time sampling PC Based DSO Rs 19990.00 Delivery: immediately
DSO-5200A 200MHz 2CH analog bandwidth, 250MS/s real-time sampling PC Based DSO Rs 23990.00 Delivery: immediately
Channel

2 Channels
Impedance
1MΩ 25pF
Coupling
AC/DC/GND
Vertical resolution
9 Bit
Gain range
10mV-10V, 10Steps
DC accuracy
±3%
Timebase range
2ns-1h, 39 Steps

Above is the offerings from one of the local dealers nearby my Place.Brand "HANTEK" Y

 

[dipolar]

As a rule of thumb, your scope's bandwidth should be at least five times higher than the fastest digital clock rate in your system under test. If your scope meets this criterion, it will capture up to the fifth harmonic with minimum signal attenuation. This component of the signal is very important in determining the overall shape of your digital signals. But if you need to make accurate measurements on high-speed edges, this simple formula does not take into account the actual highest-frequency components embedded in fast rising and falling edges.
Rule of thumb: fBW≤5 x fclk

Above is excerpts from a website regarding choosing right oscilloscope.

My confusion continues to annoy me concerning the pc sound card vs usb adaptor.

Gurus please help!

 

[FullMetalJudge]

Soundcard scopes are ok for a learning exercise or cheap audio work but lack real bandwidth and sensitivity.
Id say get a PicoScope USB oscilloscope as they have completely free software which is FULLY functional.
The following is lifted from their website:
If you buy a traditional oscilloscope, you get an oscilloscope. Buy a traditional spectrum analyzer, you get a spectrum analyzer. Buy a traditional waveform generator, you get a waveform generator. Buy a PicoScope USB Oscilloscope and – thanks to power of PicoScope – you can get an oscilloscope, spectrum analyzer and signal/waveform generator all in one. (With PicoScope’s ability to continuously stream data you can even use your oscilloscope for data acquisition.)

Free updates
You can’t usually upgrade traditional test equipment. If the device is upgradable it will often need a time–consuming and expensive trip back to the manufacturer. PicoScope software is regularly updated with feature extensions and improvements. These can be downloaded for free from our website and ensure that your oscilloscope will always have the latest features and enhancements. What other test equipment gets more powerful with age?

Easy to use
PicoScope 6 is powerful yet easy to operate. You benefit from the power of the PC, and the familiar Windows interface and controls, making the software easy to use. It has tooltips and help pages to explain all the features.

Unrivalled performance
PicoScope uses the latest Windows technologies to give you the performance you need. Fast capture rates make it easier for you to see fast–moving signals, while fast data processing ensures your PC is able to process even the most complex of waveforms.

All this and it’s free
PicoScope is free to download and use. Download your copy of PicoScope 6 today and experience the power and performance for yourself. (If you haven’t yet purchased your PicoScope Oscilloscope you can use the demo mode to test many of the features.)