Simple Oscilloscope Question

[GobbleStoo]

Hi.

I need to buy an inexpensive oscilloscope to measure the output signal/voltage from my turntable cartridge from each channel so I can set Azimuth and be sure that the left and right channel are outputting the same level.

I know nothing about these things but I see prices betwen 40 bucks to thousands. Can I get away with a cheap one for this purpose?

https://www.amazon.com/HANMATEK-HO1...-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1

Thanks,
Stu

 

[Audio1Man]

Hi Stu
I would look for a 2 channel scope. By inverting a channel and sum you can see the true balance.

 

[GobbleStoo]

Cool, maybe something like this?
https://www.amazon.com/FNIRSI-Oscil...-2-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1

 

[rayma]

After verifying your phono preamp channel gains are matched, just use the RIAA outputs and your DVM.
The setting of your volume control could also affect the channel balance.

 

[GobbleStoo]

Rayma but I want to set the Azimuth angle in the cartridge, I'm not trying to match channel gains on my phono pre-amp there are none.

 

[rayma]

No, you first just verify that the phono preamp gains are matched between channels, and then use it normally and measure the outputs. Measuring a few mV directly from the cartridge is not trivial. The phono stage outputs will be 50x to 100x larger at 1kHz
than the inputs.

 

[GobbleStoo]

When I do this I typically measure from the output of the phono cable with the preamp not even connected.

 

[tomchr]

You'll want a scope with a pretty sensitive front-end. A typical cartridge only puts out a few mV. Much less for a moving coil cartridge.

I'd measure at the output of the phono stage as suggested above. It'll be a more reliable measurement.

Tom

 

[lcsaszar]

Distortion has better correlation with azimuth than channel balance.

 

[Mark Tillotson]

A scope without good bandwidth limiting simply isn't suitable, 100MHz of noise is 100 times the amplitude of 10kHz worth of noise, all else being equal.

Checking azimuth requires a test disc with separate left and right channel tracks, tune for minimum crosstalk, don't expect better than -40dB crosstalk from vinyl, but the ear doesn't really care below -30dB anyway.
Measure after the phono preamp or you might be injecting more signal than you measure!

Equalizing the output levels involves having some gain/balance adjusting circuit - the balance control on an integrated amp for instance.

Azimuth is about keeping left and right separate, not matching levels.