cart measurement vs quoted spec

[b]There is a resonant peak ~ 12dB --- can you believe it, at between 80Hz - 120 Hz!
But it does not translate into hearing it... The main issue it that whacked out channel balance. [/b]

Are you saying that a measured 12dB peak at 80-120hz is inaudible?

dave

Hi all,

Dave,
that res. ~ 100Hz showed a 'lift' of 2.25 times signal level compared to the rest of the measured band level.
I would NOT think it is a faulty test record... And as I stated, it is not audible with normal listening.
Why? I have no idea, other than at ~ 40Hz I have some 'room lift/lock' --- and it might just all fit together. Who knows.

Dre_j,
in being proper and decently scientific what you suggest aught to be done. Alas I have not another cart of same make and build to do this. THEREFORE, in all fairness my measurements are not 'valid' according to scientific method. What is valid is that I get distortion at high vinyl levels with massed instruments / orchestra / fortissimo, and it *seems* to tie in with the channel imbalance. At medium level, and less complex music it can not be easily noted, if at all.

Larryi,
it sounds contradictory and you noted that correctly.
Yet --- if I compared the two carts, not factoring in the problem area of the one, it is my finding. Since at the time of comparing I was still assuming that 'some' as yet un-detected alignment issue was causing this distortion with massed instruments, fortissimo, etc. It is NOT affecting tonality, detail, and such at more normal levels. So, the 'assumed to be defective' cart still sounded a good second to what I had listened to. The Orpheus is yet more detailed, yet a bit clearer, yet a bit more balanced, simply better. I incidentally also had the lesser "Transfiguration AXIA" in my system and of course given taste and all such it was not my preference, with a type of slightly more refined Dorian sound i.e. it has a slight edge on a Dorian - AND if you like that sound presentation. It is VERY open sounding and a bit tilted towards the top i.e. not at all as neutral as the Orpheus.

The point is, that the cart under question is NOT breaking up all over the place!! It might just be yet so much better if it were in spec. --- an assumption of course.

Part of this enquiry was to get some feedback on similar 'encounters' AND NOT to categorically insist on a scope beams width measurement finding.

There is e.g. one track that puts left to right channel out of phase so as to cancel them. All being at it's best next to nothing should be heard during play-back.
I instead get 1kHz 'screaming' at me. A pretty clear indication that the preceding measurements of channel leakage and imbalance found were correct.

Greetings,
Axel

Hi Dave,
some dB correction.
I just veryfied the 100Hz res. level. It was 2.5 times signal level. BUT that makes it ~ 7dB and NOT 12dB. Sorry, for this misstatement.

It appears to fill in the upper bass 'floor bounce' related dip in that area of the speaker, and is therefore not actually noticable.

Axel

I meaured channel match + crosstalk on PC1, ultraeminent and titan I. All performed to spec. L & R less 1db difference (assuming phono stage gain is matched). Titan I was best in channel separation with 34db crosstalk on both channels tested with Analogue test LP (track 2 and 3) while mounted on the Phantom. On the Davinci with no Azimuth adjustment, still a manageble 29-30db. The azimuth sweet zone is tiny and easy to jump thru.

I did not measure the frequency response of the cartridge.

Thanks Glai,
just the sort of feedback, type=good, I hoped for.

Now,+++ The azimuth sweet zone is tiny and easy to jump thru. +++

On a 3 point cart mount i.e. not flat-top mounting, and in a fixed Azimuth arm like a SME V, I come to think the ~ 2 deg. stated Azimuth-test-tilt, might be a bit out-of-whack.
So let's say it's more like +/- 1 deg. at best.
Suffice to say I NEVER ever would tilt it that much, that the cart-body outer rim touch the head-shell, the max. that was tested.
A perceivable air-gap would always be still there i.e. left and right top between cart main body top and head-shell bottom.
In your experience could an Azimuth-tilt, as actually in use, of between ~ 1/4 to 1/2 deg account for a 10 times! greater channel mismatch, AND a 12dB(L)to 18dB(R) out of spec cross-talk?! I have a hard time to figure that to be so.

My suspicion is further, that the gummy / suspension settled (funny enough, always to the left in these type carts) creating this 10 thou out-of-centre cantilever.

In your experience, would such 'smallish' cantilever off-set be able to create these out of spec. measurements?

Again, I find this hard to swallow, since cantilever off-set is a 'fact of life' even with some more pricy carts --- according to what I hear.

+++ (assuming phono stage gain is matched) +++ this point HAD to come up, which is good.

On the oscilloscope measurement the amplitude mismatch was perfectly replicated by swapping channels left to right.
Next argument could be some out-of-balance cable connection. Again, no measurable difference in resistance could be noted, BUT about 0.1 ohm difference in DC cart-coil resistance between left and right!
Could this explain the (10x higher then spec) 2dB left-to-right mismatch (spec= >0.2dB)?
And also the *different* L/R cross-talk of 12dB and 18db?

But surely NOT the 12/18dB *higher* crosstalk of -16dB and -10dB vs. spec. = >-28dB!

I'd really appreciate your take on this.
Thanks,
Axel