cart measurement vs quoted spec

I'd rather stay in my corner. With the extra bass loading it really rocks in here! Also, it makes it easy for your slings and arrows to find me. ;-)

Glad things are sounding better. :-)

Hi All,
as promised some more measurements information.

First the good news:
A well used Lyra Dorian that did perform much better than that first measured cart (PW) showed the following:

Loading with 1k, AND 10nF capacitance, measured on XLR pre-outputs:
Left vs. Right = -0.6dB @ 1kHz 7cm/s lateral (mono track), spec = <1dB (So that was a pass)

Left vs. Right = on 1kHz 7cm/s vertical out of phase track, pretty CLOSE to out of phase, (about 12dB better on listening then PW, pretty good)

1 kHz left channel -28.5dB leakage to right! Spec = >30dB @ 1 kHz! (Only marginally less then spec. and can be attributed to it's aging, or measurement variation(s)...)

1 kHz right channel -28.5dB also, leakage to left! Spec = >30dB @ 1 kHz! (comment as above)

Cart roll-off @ 20kHz -3db (much better then PW rolling off at -6dB)

Resonance at 29Hz at -20dB, high Q for about 3sec. during the sweep track.

The measurements confirmed that the set-up is pretty much OK.

Now, what was NOT OK, was my consultants 'R.O.T.' initial db conversion on some PW dB results. Still the figures show a big problem yet.

Here the revised figures:
No loading i.e. 47k:

Left vs. Right = -1.6dB @ 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! (no change as done by listening)

1 kHz left channel only -18dB leakage to right! Spec = >28dB @ 1 kHz! (only a smallish convertion error of 2 dB)

1 kHz right channel only -27dB leakage to left! Spec = >28dB @ 1 kHz! (now this was pretty way out, not in voltage measurement but in the dB conversion! :-(

The end-result is still bad enough though.

There are plenty more measurements on this test record, which where done, but those above tell most of the story.

Track ten for example should produce a clean sine-wave and in the case of the Dorian it does, the PW looked rather distorted leaning to one side and dented in, plus more of such, all supporting that something is not right.

So there you have it...

Next up will be a Transfiguration Orpheus, I'll keep you posted and hope it will not be getting too boring.

As Doug would have it, if its 'broken' why bother to measure it :-) Both the Dorian and Orpheus are not 'broken' so I guess we may have his blessing :-)

Greetings,
Axel

Look numb nuts,

Dear Sir, you must READ my statements properly and sink them in. I AM USING A SCOPE! This multi-meter measurement stuff sux, period.
On a scope you can see what going on, like noise etc. but not every one has one to play with as I mentioned also.

If you saw the damn noise why didn't you and your buddy think to filter that out? This is all mildly interesting to me because I do need to learn better measurement techniques. But for you this all seems to be just a "hey look at me".

Comments like this are exactly why I just knew coming back to your thread was going to bite me in the ass. I know you are using your friends scope. I own a scope myself but I chose not to use the scope for several reasons. There is NO benefit to doing this with an o-scope. Now, a spectrum analyzer would be much different.

I took a chance and it didn't pay off. I'm done here.

Hey Dan_ed,

man, not "LOOK AT ME" ...look at these measurements. I have no noise to take care of as I explained, so ARE you reading what I put there? I NEED NO FILTER neither my buddy, somehow it feels you are busy with some other contributor. No need to get tizzy with each other, please...

You say:
>>> Now, a spectrum analyzer would be much different. <<< Well yes, I guess we can agree on this. But hey, now we are really talking $$$. Just to check a cart, well maybe, but not in my budget, sorry.

So let's agree you go use your DMM, and I wish for you it's a FLUKE of sorts, else any error will be very likely further aggravated.

Please lets just be nice, and I will say it next time more pretty like e.g.: measuring with a DMM, compared with a O'scope appears to me of a little lesser result related quality. Also no filter seems needed, given of course the particular circumstances. (I think of hiring a typist, all that for simply "sux" :-)

Love you all,
Axel

LOL :)