cart measurement vs quoted spec

Hey Axel,

Do you have the Cardas Test Record and if so, can you guys try this approach? (It may be similar to what you are doing but I'm not sure, so here goes). I probe from the phono stage output to keep other unknowns to a minimum, but probing from the preamp out should work. Also, I don't use my o-scope. Instead I use a DMM with MAX feature and at least 3 decimal place accuracy.

There are two, 1kHz test tone tracks. One is for the left channel and one is for the right channel.

Play the track for the left channel and record the peak voltage at the left output. That is V1.

Play the track for the right channel and record the peak voltage at the LEFT channel output. That is V2.

And, naturally: dB = 20 * log(V2/V1)

Now reverse the process for the right channel measurements. I don't get the published -30dB specs, probably only about 1/2 of that, for my XV-1s but I'm sure cartridge manufacturers have a better way to measure all of this without putting stylus to vinyl. However, I do get 1.0 to 1.3 dB of crosstalk which is very close to the published 1 dB spec from Dynavector. IIRC, I was getting -15dB on the right and -14dB on the left. Or something like that, which doesn't sound far from your original numbers.

HTH

Howdy Dan_ed
ha, ha, :-)
>>> ... but I'm sure cartridge manufacturers have a better way to measure all of this without putting stylus to vinyl. <<<
As we say over here: "my foot in a fish can..."

I asked them about the value of the induction of that cart uH..., was busy with figuring out primary SUT loading and the right RC for resonance damping ---- they do not even measure it or know!
I think they make a well working lot of samples by hand and then run production, no measurements no more. How else can you get such variations to happen, correct me if I'm wrong.
Output's the name of the game, even for the more pricy stuff.
Next, I unfortunately have no "Cardas Test Record" and if I can find one it's quite expensive I guess. The one I used "The Ultimate Analog Test LP" we bought at the RMAF.
Next thing is, that this cart has now been recalled, so we'll see what 'non-vinyl measurements' they will quote --- my best guess is non. They'll rework it and send it back in 3 month time, that's how it's done. It's not my first issue with them, you see.

Now, we have planned to do some follow-up measurements (same method, same rig, getting scientific...:-) using a Lyra Dorian and maybe some other cart, I'll keep you posted.

The joke of today is (for me) that I picked up a Garrott (A&R) P-77, MM for NOTHING!
It sound better than that... well you know what. It's not funny actually 3500$ MC getting whacked by a 40 year old MM for nothing!
Words fail me, and Raul will giggle quietly, saying I told you so... :-)

Your XV-1s is some fine item, I heard it at the RMAF and my take was, it to be superior to, well you know what.

Now your: "I do get 1.0 to 1.3 dB of crosstalk.." doesn't compute with me, it should <-28 or -30dB compared to the opposite channel when ONLY the opposed channel has information i.e. either lateral or vertical as is done with that test record from Analog Productions.
Maybe you can help me to get a handle on how this cross-talk measurement of yours compares.

Greetings,
Axel

Yes, well I posted too quickly here at work. That is,of course, 1 dB of channel separation. ;-)

Anyway, your Ultimate Analog Test LP has the tracks I mention. Tracks 1 and 2 on side 1. They are used for az adjustment but work pretty well for this also.

I think we both need Dre on this one.

I also used the Ulti. Analog test LP.

With titan i, phantom 2, tw raven ac, tricon phono cable into Allnic phono. I played track 2 and 3 and measured the output of the phono with PAA3 meter. I also tried using the Einstein TT choice and results are not sig. diff..

Playing the L track: Recorded 1V output at L channel, 15-25mV ( fluctuating) R channel

PLaying the R track: Recorded 1.1V output at R channel, 15-25mV ( fluctuating) L channel

I took the average value of the crosstalk so approx. 20mV. I was told to take the lower value because the higher value indicated noise in the cart.. If my wife tried to annoy me and turn on the washer & dryer, the cart puts out additional random 5-10mV. For more accuracy, you can use a filter to get rid of noise. I should apply the output ratio to the crosstalk measurement to be more precise. I am just too lazy and want to get the azimuth in the ballpark.

Crosstalk: 20log 0.02/1= -33.9db for one channel;
20log 0.02/1.1= -35.6db

Channel matching 20 log 1.1V/1V = 0.82db

This is not that accurate because I assumed the gain of the phono stage is perfectly matched. I should reverse the channel on the phono to idenfy the gain mismatch in the phono. The tracks itself may not be perfectly matched too.

My math is crude and I am not an engineer. Please correct me as needed. Always love to learn.

What's surprising to me in this exercise, I can get the most channel separation on the Phantom, second on the triplanar, no azimuth adjustment on the Davinci. Both the triplanar and Davicni throws a wider soundstage than the Graham. When optimize, Graham arm sounds very focused like some SS gear.

I cannot contribute to using an oscilloscope. Have not used one since college.

I think -15db crosstalk at 1Khz is poor. Once you lose it, you are not getting it back. I would interested in how the numbers compare at 10Khz, 15Khz and 20Hz.

The window for the >25db azimuth is small, it is easy to jump right pass it. If I make big adjustment, it never went < 20db As the numbers improve, make smaller and smaller adjustments until your back, neck, eyes gives out or reached equal and minimized crosstalk.

With the my sonic lab ultraeminent on the davinci with no adjustment, I managed a -28 to 29db crosstalk on both channels. I was either lucky to have a near vertical stylus or QC is very good. Same goes for airtight and Lyra. I will check out the dynavector next week.

After this exercise, most will see that adjusting azimuth to minimize summed output amplitude of the L & R channel playing opposing phase recording do exactly just that. It compensate for channel mismatch anywhere along the sound reproduction chain: cart, phono, pre, amp, speaker, rm acoustics ( unequal dist. to speakers). It does nothing to put the needle in the middle of the groove.

Hi Dan_ed,
that's fine, now we could be on your page... B U T a 1dB channel separation (balance variance, left vs right) would still be nothing to right home about.
With your kind of cart (and mine for that matter) we are talking smaller then 0.2dB spec --- now have I a feeling we might still not speak about the same thing...

As I mentioned:
1) channel balance (L to R imbalance) spec smaller then 0.2dB, mine was a dismal 2dB.

2) cross-talk (L or R leaking its info into the opposed channel) spec better then -28dB or -30dB, again mine was another dismal -16dB leak to right and **-10dB** (even worse)leak to the left.

I'm trying to put your DMM measurements against this, if possible.

Greetings,
Axel