Strain gauge vs Zyx 4D/Atmos

I am on a boat -typing is HARD HERE! GROUP DELAY was what I was trying to type -Peter

Raul et al,

Your argument on equalisation is irrelevant. Strain gauge cartridges have a non linear output and therefore require different "equalisation" to achieve a flat response. My understanding is that the output is close to the inverse of the riaa curve and the compensation required from the phono is not far from flat.
Nonwithstanding that, you actually need multiple phono preamplifiers to reproduce records properly as there are differences arising from the use of different cutterhead angles from label to label even for standard riaa. I have a colleague who has analysed the cutterhead angles across the various labels and recording studios, and has a built phono stage with adjusted riaa compensation for the various cutterhead angles. Records I have heard that supposedly conform to standard riaa, for which the riaa compensation has been adjusted for the cutterhead angle have been revelatory.

Possibly a better way to think about the SG is this: when RIAA is applied to a magnetic cutterhead, it reduces the low end,and boosts the highs. This is done for various reasons, but the result is basically a contant displacement groove modulation for a flat, swept input from 20 to 20K. Since the SG is sensitive to DISPLACEMENT ONLY, and not velocity, it reproduces a flat signal from a constant displacement groove calling it non-linear is not descriptive enough.

It is somewhat serendipitous that the RIAA curve evolved in such a manner as to cut a nearly flat displacement groove from a flat swept input signal.

As regards EQ; one has to realize that many records are mixed in such a way as to allow the engineer to EQ each instrument, not to mention the coloration for varied mics,not to mention the final EQ that ALWAYS gets done so the the losses incurred from the multi-step process in making records is compensated for, not to mention to two BAD resonant points well in the audio spectrum that cutterheads suffer badly from and are EQ'D out (mostly.....) and the list goes on and on.....So what we finally listen to can often bear little or no resemblance to the orignal EQ of the live instrument or performance.

I am always amazed that it goes so well most of the time.

What I can say is that when I cut a lacquer dub on one of my Neumann lathes, and play it back with MC or my MI carts, it is no contest when compared to the Strain Gauge. I am bringing a lacquer I cut at half speed (22) to be played at 45; those coming to RMAF can ask me to play it to hear the newest generation of Strain Gauge, compared even to the new Hyperion.- VERY revealing - This is a piano/bass duet.

Peter Ledermann/Soundsmith

Dear Dover: I respect your point of view but for me is relevant and not matters what the cutter-head angle been because this fact does not affect the RIAA eq. what we do on playback is to set the SRA according with that label recordings. Somewhere is a list where we can have that recording information for we can adjust/set that cartridge SRA according to.

About different recorded eq. cuve you already know that exist over 10+ of them other than the RIAA standard. Before RIAA standard curve almost each LP label recorded with its own eq. and that's why exist some phono stage designs with several inverse eq. curves additional to the RIAA even the ones that include the Neumann correction at high frequency.

I owned the Win and Panasonic sstrain gauge but these ones conformed according to the RIAA standard.

In the SS that is not happening this strain gauge gives its " natural response/curve " with almost no signal manipulation ( and that's why sounds and perform DIFFERENT " from any other magnetic cartridge. ) to make its response flat according to the RIAA standard and this is why shows a RIAA deviation around 2db when the RIAA deviation in a phono stage ( for magnetic cartridges. ) that deviation are around 0.2db to 0.1db as something normal ( the Atmasphere phono stage shows 0.07db and if I remember one of the Rowland's: 0.05db. ).

Now, in my case one of my main quality audio system performance level is to add and lose the less from the cartridge signal. Yes, I know that that SS 2db frequency response deviation could be maybe not so important when we can have 10+db frequency deviations on the speaker/room response but this is not my point: my target is add and lose the less from the cartridge signal.

I almost don't care what happened during the LP recording because I can't have any control about.
What I care is what is in my " hands " to preserve the cartridge signal integrity.

Now, Mr. Ledermann choosed that the ss signal instead to pass for an inverse RIAA eq. curve process ( as any magnetic cartridge signal. ) to shows its " natural response/curve " with that frequency response 2db deviation.

He made something that in his opinion could gives a better quality performance level.

As always in any audio choices/alternative exist trade-offs: he choosed what for him was and is his best trade-offs: to have that frequency deviation instead the ss signal pass through the RIAA. inverse eq. proccess.
In both cases the cartridge signal " suffer " a degradation in its " integrity " over what came in the recording.

Which is the best trade-off?, I think that this is up to any one of us.

I prefer that if the LPs I own were recorded using the RIAA standard eq. curve on playback the phono stage must apply the inverse RIAA eq. curve to achieve flat frequency response at this stage/link on the audio system chain. Other people could like a different approach and this different approach is what is the ss device.

Mosin posted something that could be the best of both " worlds " ( with almost no trade-offs. ): a strain gauge design that can performs the inverse RIAA eq. curve with out the necessity to pass to that proccess on playback and with out no frequency response deviation other that the normal 0.1db one. This could be just great! and I think that this idea could be a good challenge to Mr. Ledermann to work about because he has the knowledge.

I hope Mr.PL does not take this post as an " attack ".

Regards and enjoy the music,
R.

Hi Raul,

I must point out that the Win Labs never produced a flat frequency response-- please have a look at some magazine test reports.

I own(ed) the Panasonic, and in the Jeff Rowland strain gauge preamp for it, Jeff applied a very mild amount of mid-band EQ to make the output 'flat'. And it was. I owned the stock cartridge, but my favorite was the boron cantilever version with a vandenHul stylus.

And then there is the Soundsmith Strain Gauge-- it also employs a touch of midband EQ, and definitely measures flat in my experience.

Raul, can you please show us what information or test that you found to show this 2dB frequency-response irregularity please?

Everyone should know that the frequency response of any cartridge depends on the brand of test record used-- CBS, and JVC being the most common. There is quite a difference in their highs. Have a look at USA magazine tests from the 1970's to see the difference, as some publications used both test records.

Obviously both CBS's and JVC's top engineers believe they each produce a reference-standard test LP. Yet this means only that there is no ABSOLUTE standard for which to MEASURE any cartridges using a test LP.

However, there is a way to measure the response of a test disc itself without playing it, by looking at how each modulated groove reflects white light, as the sine-wave signal is slowly swept from 20 to 20k Hz. This is pictured and described in my 1978 copy of the Audio Cyclopedia. I do not remember the mathematics involved, but this was a very useful and accurate technique according to that text.

Of course, it helps that Peter at Soundsmith has his own disc cutting machine. I know he has created his own test records containing impulses and other test-signals not available on commercial test discs.

And why would an already-renowned cartridge designer create his flagship cartridge with such a frequency-response error, one which anyone would discover? Makes no sense.

Best regards,
Roy Johnson
Green Mountain Audio