Oscilloscope

[jayadev]

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.

[jayadev]

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.

[jayadev]

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

[jayadev]

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!