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cart measurement vs quoted spec

Hi,
I'm a bit puzzled by some cart measurements performed with the ACOUSTECH test record, using HP oscilloscope and using (differential connection) through ML 326S phono-modules.

No loading (47k), measured on XLR pre-outputs. The following transpired:
Left vs. Right = *- 2dB* @ 1kHz 7cm/s lateral (mono track), *spec = <0,2dB!*
Left vs. Right = on 1kHz 7cm/s vertical out of phase track, clearly NOT EVEN CLOSE to out of phase!
1 kHz left channel only *- 16dB* leakage to right! *Spec = >28dB @ 1 kHz!*
1 kHz right channel only *-10dB* leakage to left! *Spec = >28dB @ 1 kHz!*

This seems a most disappointing showing indeed. Let me hasten to say that all variations with regards to anti-skate, VTA, VTF, Azimuth and Zenith, were attempted for any optimisation.

I shall not yet disclose the make, which is a VERY well known brand, and their TOP of the range offering.

Has any one got some explanation for how such a major variation can be the case?!

There might just be some folks out there trying there darntest by NEVER getting their apparent alignment problem fixed, please note the various threads, ---- and it might be a cart way out of quoted tolerance?

I have also noted that in this instance, MAJOR Azimuth (+/- 2 deg), VTA, VTF, changes had absolutely MINOR measured effects!
The 'biggest' in this case was 'Zenith' by some 0.5mm left turn to compensate for a 'minor' out of centre cantilever (~ 0.25mm off-set to the left).

Tonality and such is NOT really affected, BUT distortion with massed instruments/orchestra etc. i.e. as soon as things get 'busy' the problems start.

Greetings,
Axel
axelwahl
axelwahl OP
788 posts
 
Hi Al,

THAT particular cart actually has no such an issue, as for example a 'Dorian' would have BIG TIME!

But now we'd get close to a make disclosure, which I would not like to do at this point. I'm in touch with the manufacturer to see what they have to say.

I can EASILY use this cart with 47k due to it's damping arrangement, in fact it is rather happy with 1k. (NO MORE CLUE NOW). You might be aware that these days there some are actually some quite fine with 47K.
Next I also mentioned the testing with SUT, which is using as low as 13ohms loading on primary. Results were NOT AT ALL influenced (I'm not talking of scope's beam-width variations here!)

There has been a lengthy discussion on that SUT subject on some other thread, say no more...

If a resonance would influence the channel balance being out by a factor of 10 (compared to spec.) we would see this BIG TIME on the scope.
The only res. as mentioned (~100 Hz!)is VERY visible on the scope.

Axel
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rauliruegas
13,002 posts
 
Dear Axel: Well, it will be interesting the Winfeld ( I assume is this one ) manufacturer answer and how they validate its specs on each cartridge sample.

Of course that could be really useful and appreciated that other cartridge manufacturers can share with us their " thoughts " about.

Regards and enjoy the music.
Raul.
axelwahl OP
788 posts
 
Hi All,
well, I'll keep you posted on this one.
I’d love to know if some other folk could share some related example(s), good OR bad, just so as to learn something from it.

You can tweak-align you sweet hind off, and NEVER come right if that happens, distortion is programmed for you right in the cart.

Note: an e.g. relatively cheap cart, the DV 20X-L STILL includes a measurement diagram of the cart you bought --- WELL DONE I SAY!

Thanks,
Axel
commcat
79 posts
 
"...characteristic initials in gold, which decorate the sides of the cartridge housing, stand as a signal to the outside world that this technologically advanced cartridge is ******** the finest, most accurate and in our own opinion also best-sounding design."

The above is quoted from the manufacturers sales material which goes on to state;

"...with a newly developed, state-of-the-art, moving coil cartridge in the absolute high-end class. In terms of design technology, the ********** is of course based on many of the most important innovations and patents that ********* secured for ******** in the course of his work stretching back more than 30 years."

Apparently, the substantial cantilever offset is a technological achievement. Based on the manufacturers statements there should be no need to actually test the cartridge.
axelwahl OP
788 posts
 
:-) Wow Commcat,

maybe there is no need to test a Ferrari either.
Well, I guess we do know it's more fun to drive with correct wheel-alignment, handles the corners just a bit better.
That said, would they ever agree that an incorrect aligned one ever left their premises? Mistakes can happen on all sides --- as long as they are not too many and too often.

Axel
PS: But then also, who actually has the gear available to question a factory setting?
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