Oscilloscope for cartridge setup - what to look for?

[elrod]

I'm looking into picking up an inexpensive oscilloscope for setting up my cartridge. I'm inexperienced with setting up a turntable and using an oscilloscope, but I can learn.

What should I be looking for in an O-scope - two channel, triggered sweep, etc...

Any input or scope recommendation will be appreciated!

 

[ConradH]

I can't imagine any modern scope that wouldn't be suitable as they'll all have at least two channels and triggered sweep. Only ancient service scopes lack the latter. Cartridge signals are small and unequalized, so you'll be looking at the preamp output or beyond so you can see something useful. You could also use various programs that give you a scope display from a sound card on the PC. The nature of the waveforms is such that a digital scope or software has an advantage. All that said, and especially if you're inexperienced both with a scope and setting up turntables, I'd start with the usual templates. In more than 40 years of doing this and owning half a dozen (OK, only five) scopes, I've never felt it necessary to use a scope to align a cartridge. I do anti-skating by equal onset if breakup with a test record (use headphones), and everything else with templates.

 

[MRL_Audio]

Agree with Conrad. No need for a scope to get a proper cartridge setup. Overkill.

 

[elrod]

Sounds like good advice.

If i did want to play around with a digital scope (maybe I can learn a few things) would a Hantek6000BE Series be a good choice?

 

[jancumps]

Sounds like good advice.

If i did want to play around with a digital scope (maybe I can learn a few things) would a Hantek6000BE Series be a good choice?

I checked the specs. They don't say the maximum input voltage - manual only available after logon.
I read a review on Amazon that says 300V at 1:10 probe

These specs are certainly good enough for audio.
You have to decide for yourself if you want to work with a USB scope with user interface on computer. That's a personal preference.

For cartridge setup it's definitely overkill. But for learning electronics, it's a great enabler.

 

[TerryS]

I'm not sure what is needed for aligning a cartridge, but any computer with a sound card can become an o'scope with the addition of some software like this:

https://www.zeitnitz.eu/scope_en

I wouldn't recommend it for use as a general purpose o'scope, but for this application it seems perfect.

Of course I agree with the advice Conrad gave. I've had an oscilloscope (or several) for many years and it never occurred to be to use it for cartridge alignment. What do you look for? Phase balance between L & R channels?

Terry

 

[Catcher10]

You can download an O-scope program, most only have minimal functions unless you buy the program, but can't see doing that as you don't need it for anything else.

You need a test record that has the 1khz tone. I have one that has 3 tracks, a L track only, R track only and a L&R track (mono). The deadhead vinyl setup gurus will tell you to play each channel and write down the measurements and adjust till the difference is minimal...Too much work. I used the L&R track (mono) and then use the L+R setting on the O-scope and adjusted till the difference was minimal and pretty much in phase number wise. Since I did not buy the program the details of the wave are not good enough to use that so the digital number output is the way to go, the program would not allow me to over lap each channel wave, only side by side....useless.

I did find it helped quite a lot to my vinyl playback, and my former method was the mirror, magnifier and listening with cans process.

But I would never buy an o-scope.

 

[shelly_d]

What is the turntable and cartridge? Sometimes it is dirt simple to set up correctly and sometimes a real pita. My Thorens TD150 needs a good ruler and a good eye. Perhaps a bubble level could help if your eye isn't great at seeing if the top of the headshell is parallel with the record surface. I have run 4 or 5 different cartridges through it with just the instructions in the manual and a ruler. They worked every time.

Shelly_D

 

[jancumps]

A protractor works better than an oscilloscope. Setting up is a matter of geometry.
It's fairly easy to spot misalignment on a protractor.

When you spot distortion on an oscilloscope, your cartridge is already way off.

 

[for_p1]

Oscilloscope can be useful. Main mode will be X/Y, rather than regular Y/T. Analog scope will work better. If you want digital one - choose scope with very high refresh rate, which excludes cheap or older models.

 

[jancumps]

How will that help you align a cartridge?

 

[for_p1]

It will allow to see phase difference between channels. You will need LP with test tones for that too.

 

[jancumps]

Phase difference shouldn't occur at the cartride, no?
That's not a product of cartridge misalignment.

 

[Gooch]

How will that help you align a cartridge?

It's for azimuth adjustment but not all arms have that. To limit the amount of crosstalk between channels. You could use a good Digital Multi Meter and a test record to measure the output voltage at the amp then you have to convert that to db

 

[jancumps]

I have a hard time seeing a scope as the solution.

Alignment -> Protractor
Azimuth -> bubble level

The first is a thing you can print for free,
the second costs a few $

An oscilloscope is an expensive piece of measurement equipment that can reveal many things, but it won't reveal the two issues reported here any better than the protractor and the level.

 

[ConradH]

There's a thing called a Fozgometer that lets you set azimuth (and other things?) using a test record. I think it works by channel cross-talk and you could probably do the same thing with a scope.

 

[for_p1]

There's a thing called a Fozgometer that lets you set azimuth (and other things?) using a test record. I think it works by channel cross-talk and you could probably do the same thing with a scope.

If one already has a scope, there is no reason get a dedicated device. Both azymuth and tracking angle affect phase. Though later one is only important for linear tracking arms (where tracking error is extremely small). Generally azymuth is better aligned using test tracks with only one channel active and high quality RMS meter.

 

[jancumps]

On a turntable, where everything before the cartridge's coil is a mechanical device, I'm a big fan of using mechanical/ geometrical tools to judge the setup. Measure mechanical settings with mechanical tools.

Once the audio is picked up by the coil, electronic test equipment is the way to go. It's an electronic issue from then on.

 

[for_p1]

I have a hard time seeing a scope as the solution.

Alignment -> Protractor
Azimuth -> bubble level

The first is a thing you can print for free,
the second costs a few $

An oscilloscope is an expensive piece of measurement equipment that can reveal many things, but it won't reveal the two issues reported here any better than the protractor and the level.

Mechanical tools are only good for preliminary adjustment. Since there is no ideal cartridges, small correction is always needed. It can be done with test LP and metering tools. Actually oscilloscope is the cheapest tool to be used. You also need high resolution spectrum analyzer.

Of cause here we are talking about arms and cartridges which are at least comparable with mentioned measurement tools in price. If you are working with $100 cartridge and $200 table, you probably won't find any difference befroe and after adjustment (if that can be even possible).

 

[elrod]

I'm kinda like the dog who chases and catches the bus - don't know what to do once you've gotten it. Only prior experiece with turntable setup was back in the 70's when you slapped a cart on you run of the mill TT, level, and hit the switch.

Well I "caught that bus now". I've rebuilt a TD-124, got a Tri-Planer VII arm with Clearaudio Maestro cart. Doing research you hear everything from "it's way overkill" to "for best audio you need to do all of this"

Being I'll have the ability to adjust the azimuth, I'd like to do that the best I can. I'm under the impression that crosstalk can be minimized also. I don't mind doing "overkill" because I figure I can learn something in the process.

I'm leaning towards the soundcard/PC approach but if I can find a scope good enough and cheap enough I might try that also - I like to tinker

So any input is welcomed and thanks for the input so far!