[neobop]

Interesting test reports - Ortofon Cadenza Blue, Bronze.  Notice the 2 amplitude graphs for each:
http://www.hi-fiworld.co.uk/index.php/vinyl-lp/25-cartridges/86-ortofon-cadenza-blue-a-bronze-mc.html?showall=1

This one is 7 MCs from 2012:
http://www.bm.rs/Micro%20Benz/Benz%20Micro%20Ace%20-%20HiFi%20News%20July%202012.pdf

neo

[dlaloum]

Hmm I look at those group test plots, and then I look at my own plot of the DV23RS, and something smells wrong.

My DV23RS measures flat as can be with a very minor rise starting at 18kHz... they are showing the 17D3 with an amplitude drop?!

Makes me wonder whether they are using the HFN test record pink noise track to test with? (it is flawed above 15kHz)

In fact all the cartridges are showing a similar high frequency drop of starting around 15kHz .... I suspect a systemic error in the testing!

The Cadenza plots are what I would expect...they are really nice right up to around 10kHz - very little midrange trough - do the magnetics are good with minimal losses drops around 1db very gradually from 1kHz to 6kHz before the resonance takes over and pulls things up.

Aluminium cantilevered Bronze seems to have marginally greater losses at 6kHz than the ruby cantilevered Blue ... more cantilever flex maybe? difference is small enough that it could be test error/variability.

Don't have specs for effective tip mass, and the plots don't extend further to check where the peak is... would need to get plots out to 30kHz (I doubt the peak would be above 30kHz)

[neobop]

I think you're right.  It's a little strange seeing all those MCs with no extension on HF response.  I remember a few years back Werner Ogiers EE posted that both the HFN and Analog Productions test records frequency sweeps were miscalibrated.   Must be the case here.
neo

[tonyptony]

Makes me wonder whether they are using the HFN test record pink noise track to test with? (it is flawed above 15kHz)

Hi dlaloum. This may have been mentioned earlier in the thread, but what test disk could be used for this if the HFN disk is flawed?

[dlaloum]

The old CBS test disks are excellent, also the test disks put out by Denon (even better but much rarer!)

There is rumour of Denon re-releasing some of their test disks - apparently they kept the masters... but I have yet to see them available anywhere...

The CBS disks come up all the time on ebay.

There is quite a range of test disks from both Denon and CBS (as well as others of course) - some of them are specialised with tests designed specifically for one aspect of performance. So you do need to check that the record has the tests you want.

A Square wave test record won't be much good for frequency response.

Some records have pink noise tracks, others use a swept sine, still others a series of spot frequencies - all are valid test methods for frequency respons, but they all required slightly different interpretation - Pink noise will include harmonic distortion as part of the measured signal, swept sine may do the same (depending on how you measure it) where spot frequencies are purer in terms of signal response, but require more work as you need to measure each of 20 (or more) spot frequencies to plot the chart....

Yosh in Japan maintains probably the most comprehensive data page on test records and associated data:
http://www7a.biglobe.ne.jp/~yosh/recspecs.htm

bye for now

David

[tonyptony]

Great info. Thanks! 

[neobop]

I still have the stylus on the Signet MR5.0ML  It sounds very good at 47K.  I got the 790 ohm spec from the database.  I checked the spec sheet for some of the other Signets.  I think it was the 5, 7Ea, and 7LCa were 800 ohms, 550mH.  My inductance meter won't go that low.  I wonder if this could be the same generator.  The database has all the MR series being the same - 790/490.

I'll have to try the stylus on the 440 and see if I can hear any difference.  This makes me want to get a 100E and compare.  I'll have to listen exclusively to the stylus for awhile to get a handle on it before I order a 100.  I wonder.....
neo   

[neobop]

Interesting calculator posted by J. Carr on Agon.
http://sim.okawa-denshi.jp/en/RLCtool.php

Electrical modeling including phase response?  I'll have to see if I can figure it out.

neo

[dlaloum]

If you are comfortable modelling in Microsoft excel, I have been using a cartridge model including phase originally built by LuckyDog and modified by me...

It is a tangled web of interrelated calculations across a series of worksheets - but can be very useful

No instructions though - other than what I can help you with online!

The downside of the calculations (which I do not believe will be any different to the link you just posted) is that they only include the electrical aspects, there is no model for cantilever behaviour - that aspect has to be measured! (and due to the difficulties with measuring phase, phase response has to be assumed based on principles... ie: that phase/amplitude behaviour in cantilevers is minimum phase and therefore symmetrical and equal to the same effect on the electrical side)

You are welcome to the model if you want it...

[neobop]

Hi David,
Taking a look at that calculator I'm not sure what I'd use it for.  Could come in handy if you're designing a cart.
I had a feeling you already had something similar. 

Here's a couple of cool links for the Accuphase AC1 and AC3.  Check out the cantilever/tip design at the bottom:
http://www.accuphase.com/cat/ac-1en.pdf

http://www.accuphase.com/cat/ac-3en.pdf

Here's the AC2 from the same site:
http://www.accuphase.com/cat/ac-2en.pdf

That completes the original Accuphase carts designed by Nakatsuka.  They were released from the late '70s to 1982 I believe.  The Monster carts were from the mid '80s to early '90s.  Accuphase now has a new cart designed by someone else.  It weighs 11.5g and max VTF is 2.5g.  It has a solid boron cantilever and a microridge. 
neo

[J-Pak]

About a month ago I bought a Panasonic 451 which was having some tracking issues. I replaced all the electrolytics in the phono box with Nichicon and Panasonic caps. It's now playing with a completely black background, there used to be a slight amount of hum audible when the stylus was in the lead in and lead out grooves. I let the suspension break in for 20 hours on a clean thrift LP. Still having the tracking issues, it won't pass the last band on side 2 of the Hifi News+ test record. Sound quality wise I can hear some promise, it's a "clean" sounding cartridge. Sort of reminds me of when I upgraded from a Denon DL-103 to a Zyx R50, more vivid tonal color (not as grey) and a reduction in groove noise.

My tonearm is a Nottingham Ace Space, which should be around 11g effective.

dlaloum do you still have your strain gauge to see how it tracks?

[dlaloum]

Hi J-Pak,

yes I do, but I cannot help you as my phono stage for it needs a good working over....
Which is why I put it away pending "getting a round tuit".

My recollection is that it is not a tracking champion but it was OK (but not great) for tracking....

I may have recorded the tracking results from the HFN record - need to search my records.

I'll have a look and see if I can find it

bye for now

David

[J-Pak]

Thanks David.

Anyone know who makes the sylii for LP Gear: http://www.lpgear.com/product/PAS451QD.html

I could not find a line contact or Shibata replacement stylus on the Jico website, so it seems unlikely that it's made by them.

[neobop]

Vivid line is made by another Japanese company.  Gear won't say who.  I think it's Nagaoka, but I really don't know.  People seem to get good results.

If you want a shibata made by Astatic:
http://www.turntableneedles.com/Needle-672-DQ-copy_p_1278.html

neo

[neobop]

Ever notice that the outer part of a record sounds brighter than the inner grooves?

Sometimes it's more noticeable than others, especially when an album starts out with a bang (lots of high frequency info).  Check out the graphs at the bottom of this test report:

http://www.hi-fiworld.co.uk/index.php/vinyl-lp/25-cartridges/86-ortofon-cadenza-blue-a-bronze-mc.html?showall=1

neo

[dlaloum]

It think we are hearing a bit of misunderstanding there!

It tells us more about the chosen manner of testing frequency response...

As the tracing gets worse, and the needle starts to marginally mistrack - we start seeing more distortion artifacts creeping into the sound.

If the F/R is tested with spot tones, the distortion is excluded from the measurement, but if the measurement is taken with a single sweep and averaging methods, or with pink noise tracks, then we would expect to see exactly what is shown by those charts - an increase in the high frequency content driven by increased distortion as tracking worsens.

There is an interesting thread on IGD currently on AK...

The tip mass is unchanged so it is not related to the cantilever/tip mass resonance - the only thing that changes is the density of the signal, which makes tracking harder.... the difference in F/R between outside and inner grooves might be an interesting measure of cartridge tracking ability! That had not occurred to me before... but one would need a test record with identical test tracks on the outside and inside tracks.... I don't believe I own such a beast.

bye for now

David

[neobop]

As the tracing gets worse, and the needle starts to marginally mistrack - we start seeing more distortion artifacts creeping into the sound.

If the F/R is tested with spot tones, the distortion is excluded from the measurement, but if the measurement is taken with a single sweep and averaging methods, or with pink noise tracks, then we would expect to see exactly what is shown by those charts - an increase in the high frequency content driven by increased distortion as tracking worsens.

But there was a decrease in high frequency content further into the record.  I don't think this has anything to do with inner groove distortion which seems completely related to density and groove width (pinch effect etc.).  Temperature could be a factor.  I seem to notice it more with a cold cart on the first record of a session.  I've been hearing this for years only never seen it in a test report before.
neo

[dlaloum]

You're right I was reversing the plots, the rising top end is the outer grooves...

I do know that many (most?) records were mastered with reduced HF content on the inner grooves (to reduce IGD) .... but this should not be the case for a test record...

Assuming the needle is tracking correctly (and most test tracks are recorded at -20db so there should not be a problem in theory) why would there be a difference?

[neobop]

J. Carr mentioned it on the MM thread.  In fact he posted the link.  He said it as if it was fact - temperature effects amplitude response and the outer grooves vs inner thing. 

I was about to pursue it when Nandric started up with some nonsense.   Maybe I'll see if I can get some more details from Carr.  Groove width might have something to do with it?
neo

[neobop]

Yes, it's groove radius and temperature.  Check out Jcarr post 8/11/14
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1200430667&openflup&11348&4#11348

neo