[neobop]

Come to think of it, the strain gauge is the ONLY type of cartridge where development can in fact continue unimpeded....

Standard magnetics have reached a dead end, and stepped back from their peak in the mid/late 80's. (exceptions: Dynavector Karat, Decca London ?)

At some point I need to fix up my SG phono stage (which I believe to be the cause of a channel imbalance in my Panasonic SG) - I do recall it sounding quite stunning - but I had only just got it going and listened to one or two records when the channel imbalance appeared - I have been hoping since that it is the phono stage - but it has been in storage waiting for me to get a "round tuit" since...

I have a feeling that although the SS SG has had further development since the panasonic effort (which SS was one of the few to service!) - the key to its achievement is in the phono stage that apparently does some proprietary EQ.... no details have been forthcoming in any of the reviews, nor have I seen any proper measurements of its performance ... which would be of great interest!

As a mad keen electrostatic speaker fan since the mid 80's - the Strain Gauge cartridges seem right down my alley.

bye for now

David

(currently in the process of getting toddler friendly 'stats' operational .... ie: a pair of vintage Stax headphones)

Agreed about further progress via magnetics.  All we seem to get is variations on a theme.  Titanium bodies are the latest craze - Ortofon, Lyra, AT which is really only vibration control.  But I don't see how Dynavector or Decca are doing anything new either.  Improvements are from refinements.

Look at Clearaudio, how many magnets can you stick under the top plate?  Put 2g of gold on there and it's $15K.   I haven't heard it, but most say it's nothing special.  I don't care.  It's ridiculous.  Not sour grapes or envy, it's absurd. 
The first cart they imported here (AFAIK) was Veritas, $1K in the '80s as was the Benz (one model).  Between those 2 you had a clear choice.  The Benz sounded like it was playing next door or from across the street.  The Clearaudio was so bright it gave people ear bleed.  They should have been made to put a warning label on the box.  So now they're much improved, but they do their R&D with the consumer's money.  Pricing is based on relative value (whatever you can get) and hype is the game. 
neo

[neobop]

What's the biggest factor that distinguishes the strain gauge from a magnetic cart, or an electrostatic spkr from a dynamic or magnetic planer?

I think it's transient response - the ability to start and stop quickly and accurately in response to the groove, or the amp output.
My preferred flavor has always been accuracy over "musicality".  Not right and wrong, to each his own, but the accurate variety is harder to live with, while mellow or forgiving limits resolution.  That could be part of the reason for collecting carts.  Back in the day phony tech types would make statements saying, there was no reason for faster transient response when playing a record.  Nothing on there that calls for it.  Obviously they were full of crap.

Reading the reviews of strain gauge, it seems evident that superior transient response is the most distinguishing feature.  My impression is the same, but I never lived with a SG.  I heard the Win a couple of times and it too seemed to have that distinguishing feature. 
If anyone bothered to read both reviews each made that clear in the beginning.  What bothers me is Fremer's main caveat.  Is he a moron or liar?

"That stop-and-start ability, that freedom from overhang that audiophiles often confuse with "warmth," are leapfroggings in performance over more usual cartridge designs—yet the SG-200's delivery was so fast and clean that there was little time for harmonic development to unfold before it was off to the next aural event. So while the attack was extraordinary, the sustain was somewhat stingy. The SG-200 could sound somewhat cool and lacking in physicality, and while its top was crystalline and airy and its bottom tight, deep, and well textured, the mids were less than fully fleshed out, making the overall sound somewhat cool and slightly recessed."

What terrible writing.  Doesn't he have weeks to write a review?  What's confused with warmth, overhang or freedom from overhang?  While this is obvious to many of us, it seems deliberately confusing.  It's wrong anyway.  Warmth doesn't come from poor overhang characteristics, it comes from rolled off amplitude response.  The invention of the word leapfroggings is a little comic relief to set-up his defense of vested interest* - "sustain was somewhat stingy", "cool and slightly recessed" 
Subjectivism with no explanation.  To substantiate this BS, take a look at the amplitude response graph and square wave photos at the end of the report.  They seem to be missing.  If a cart has superior transient ability, wouldn't it stop faster as well as start?  Wouldn't that make his "reference" magnetic carts the ones with excessive overhang and excessive sustain? 

* vested interest - a personal reason for wanting something to be done or happen

http://www.stereophile.com/content/soundsmith-strain-gauge-sg-200-phono-cartridge-system

neoboposaurus   

[*Scotty*]

It should be mentioned that you cannot listen to the Sound Smith strain gauge cartridge without also hearing the companion phono-preamp. The two are an inseparable system. Perhaps there aspects to the partnering preamp circuitry that maybe truncating reverberation times. Without hearing the analogue master tape there may be no way to know if this is the case or if the strain gauge presentation is more faithful to the source than the other magnetic cartridge designs.
 I have heard the Sound Smith strain gauge cartridge in an admittedly unfamiliar system, but I don't recall thinking that it sounded dry or lacking a proper sustain to reverberant information.
Scotty

[neobop]

The preamp Cordesman used was a full function preamp with dedicated phono stage.  Fremer used the newer phono stage only.  They also supply power for the cartridge which works on displacement rather than velocity.  No RIAA compensation necessary, which is a gigantic plus.  Ledermann developed a system to compensate for a minor discrepancy (1dB?)  in RIAA curve.  I think this is the EQ to which David was referring.  I'm not sure of all the details with this, and Ledermann's circuits are proprietary.   This discrepancy would be interesting to investigate.

To answer my question in last post, I don't think Fremer is a moron or a liar.  He may not be the brightest Christmas light on the string, but I wouldn't say moron imbecile or cretin.  I do think he's a lousy writer or deliberately confuses, maybe both.  All reviewers have a vested and invested interest in the industry and personal equipment.  In the old days of Stereofool the company whose products were being reviewed often gave the sample to the reviewer (nice incentive?), and bizarre of all bizarre, some reported it openly.  We can only imagine what goes on that's not reported.  People in the industry become friends with reviewers and the inevitable happens, reviewers are biased.  How can they not be?

I wasn't trying to deify Cordesman.  He's an intelligent guy, but he's out of his area of expertise.  When he wrote for Stereofool it was obvious to me, I just enjoyed reading his stuff and his apparent lack of agenda was refreshing.   

Today any dilettante can be a reviewer.  Look at Tone Audio.  Experience in online marketing is what it takes, it doesn't much matter what you say it's how many hits you get.  Money for nothin and the chicks are free.  What's that Hawaiian..... 
neosky

[dlaloum]

The SG's are naturally (serendipitously?) close to RIAA without additional EQ.

But when you chart the F/R you note that it is not in fact flat...

It is a while since I measured my EPC451C straing gauge - but I dug up this F/R plot....




Below 5kHz it is pretty close (within 1db) - but above that the variance can be 7db - which is quite substantial.

SS's version of a strain gauge may be more linear than the older technics/panasonic design - but I doubt it.

Much as they reverse engineered the B&O cartridges to create their own SS cartridge range (with B&O's blessing) - it seems likely that something similar went on with the strain gauge cartridge. Peter was one of the few people worldwide servicing those cartridges....and he clearly used the experience gained there in designing his own SG.

My gut feeling is that the phono stage corrects for the high frequency hump as well as possibly adjusting the slight low frequency discrepancy to RIAA....

But we ain't gonna find out (how linear it is) unless someone measures it!

bye for now

David

P.S. I like Cordesman's articles, his approach and attitude...., Tone audio articles on the other hand are an example of the blind leading the blind - I expect a journalist to do his/her homework a heck of a lot better than they do!!!

[neobop]

Thanks David,
That explains it a little.  Have you seen this?
http://www.diyaudio.com/forums/analogue-source/211081-strain-gauge-jfet-pre-amp.html

http://audioinvestigations.blogspot.com/2012/04/equalizing-strain-gauge.html

Could something like this be useful?
http://www.weighingreview.com/2013/06/mantracourt-launches-new-design-strain.html

neo

note: #3 - I was thinking maybe you could eliminate the preamp altogether and correct in the digital domain which seems to have advantages with EQ.  It should be relatively easy to make a battery supply for the cart. You would need a real-time output from the converter and I didn't even read the entire description.  Seems like it would solve some problems if it's feasible.

[dlaloum]

there was also a lengthy strain gauge preamp design thread on VE....

However at the time I decided to wait, as Lou Dorren (of quad CD4 design fame) was designing and planning to bring to market a CD4 decoder with onboard SG capability. He was a big proponent of the panasonic SG's.

The idea of a new and modern SG preamp designed by a highly respected (legendary in quad circles) designer was very appealing....

He was however doing it in his spare time, and he is not spring chicken either - he has had several bad spells recently and was off sick for quite a while - prototype was built and tested... but actual production has never eventuated....

Thread is here: http://www.quadraphonicquad.com/forums/showthread.php?9035-Lou-Dorren-A-new-CD-4-Demodulator!!!&highlight=lou+dorren+demodulator

Prototype was completed in 2007.... I think I joined the waiting list for the demodulator/phono stage in 2009....

I'm just not game to do an entire circuit myself... may try my hand at fixing my original panasonic stage though..

[neobop]

I took a closer look at that strain gauge/USB device.  It can take multiple inputs and supply power to the SG. They also sell boards and other models.
It could be a great analysis tool.  I suspect that different models of SG carts have different EQ requirements and one size might not fit all.

I don't know what they cost or even if usable.
neo

[neobop]

On page 30 we were talking about voicing, compromise vs. deliberate, possibly both.

This is the link to the 205C forum discussion:
http://www.hifisentralen.no/forumet/vennetra-der-hifimerker/66200-technics-matsushita-electric-trading-co-ltd.html

Post #8 has some interesting info:






As tip mass increases, resonant frequency decreases while amplitude of peak increases.  That's why a boron/ML tames a 440.  A beryllium/ML tames it a little better IMO.  Beryllium is lighter and a little more flexible, so it's slightly warmer or less exacting, also with less tip mass. 
neo

[dlaloum]

Yep - the same data (some of it in colour!) is in the Technics cartridge brochures....

I was going to attach some files here - but although this site allows images, it seems not to have a means of attaching a PDF...

They are all up on VE in any case...

The 1986 review shows that there is a slight (1.5db) trough starting at around 3kHz and ending at around 20kHz - probably the eddy current losses - starting to be offset right at the top end by the gentle rise to the resonance. (this was for an EPC205cmk4)

(alternative theory for the trough is cantilever flex.... but Ortofon blurbs on the "super" OM seems to indicate that this is where Eddy current would become visible, and switching a stantering D7500 from a HO XSP3003 body to a LO XLZ body shows a marked reduction in the trough - which seems to indicate magnetic effects are the culprit)

[neobop]

The 1986 review shows that there is a slight (1.5db) trough starting at around 3kHz and ending at around 20kHz - probably the eddy current losses - starting to be offset right at the top end by the gentle rise to the resonance. (this was for an EPC205cmk4)

(alternative theory for the trough is cantilever flex.... but Ortofon blurbs on the "super" OM seems to indicate that this is where Eddy current would become visible, and switching a stantering D7500 from a HO XSP3003 body to a LO XLZ body shows a marked reduction in the trough - which seems to indicate magnetic effects are the culprit)

This bears repeating.  For those unfamiliar with the nomenclature, Stantering D7500 is the Pickering 7500 which is the same as Stanton 980LZS.  The XSP3000 (3003?) = 980HZS.  D__ indicates a stylus designation often common to equivalent models. 

This sheds some light on rising high end.  We already knew that tip mass and high freq resonance have a direct relationship.  [David, what's that spreadsheet - calculator?]  The question I have is why does Atlas/Kleos have HFR @ 20KHz with boron cantilevers? 
They have a "healthy" output so high moving mass?
Unique damping system lowers HFR ? 
All of the above by design?  I think so.  You don't have to hear these carts to know something about them, if you can find a test report.  There's the rub, Macduff. 

My apologies for the negative posts on subjective reviews.  I think it needed to be said.  Matter of fact it isn't subjective, it's observational reporting according to Fremer.  See what I mean?  I don't want to get started again, but without objective information we're lost in the woods without a paddle?  That makes as much sense as subjective reviewing without test data.  Like a blind clown leading a parade.....
neo

[dlaloum]

Honestly, a resonance at 20kHz is pretty good...


Typical aluminium cantilevers tend to be around 16kHz - with some a LOT lower (6kHz, 8kHz, heavily damped...)

The Ortofon OM30 is around 19.5kHz (same cantilever on the OM20 & OM40)

But, I would be looking for something more like 28kHz out of a current top flight exotic cantilever... and it is apparent that J.Carr has intentionally increased the mass to lower the resonance - which would of course raise the high end.

If there is a magnetic loss issue causing a trough, bringing down the resonance will tend to "fill out" the trough, as the loss from the magnetics overlaps the gain from the resonance....

In any case the formula for calculating effective tip mass based on resonance is:

(cut and pasted from excel)
1/([@[Res f (meas) kHz]]*1000*2*3.14159)^2)/(0.000000000116343)

Where [Res f (meas) kHz] is the resonant frequency measured in kHz

And the result of the formula is in mg

I have tested this formula with all the older Ortofon cartridges I could get hold of (those where Ortofon had published ETM...) - and it has been very very consistent - I got the formula from a white paper on ETM from the late 60's, but it had a constant that was missing in the formula - using the Ortofon data, I then derived the constant.
There are a bunch of assumptions in that method, but the fact that it remains consistent with all the Ortofon cartridges tested seems to imply that I must have done something right....

On the other hand the Pickering XLZ7500S which is claimed to be 0.2mg ( the best Stantering ever put out purportedly) - measures out using this method at 0.32mg.

According to the white paper I based things on, the constant is related to the "give" of the vinyl compound in use - if the vinyl compound is different, then the constant would be different.... and the ETM calculated would then also be different!! (like I said there are some assumptions in there...)

There was never a "standard" for testing ETM... so quoted figures may well be apples to oranges when compared between differing manufacturers!

In any case my approach makes Ortofon the reference point - and based on that, the Stantering designs are optimistic on their quoted ETM. (Which actually makes sense, as they never moved to exotic materials and stuck with aluminium - they are in the same ballpark as the very good OM20/30/40)

It does make one wonder what a Stantering might achieve with a ruby cantilever in place?

Interesting to note also that Len Gregory (Musicmaker cartridges) is currently preparing to launch a ruby cantilevered variant of the Grado prestige/signature family....

[dlaloum]

P.S. the Ortofon MC200 which was considered a benchmark at the time, has a tip mass of 0.5mg (spec) - even though it has a boron cantilever ... making it heavier than the then current OM40 - the MM equivalent from the Ortofon range.... (Res F 20.9kHz)

[neobop]

Thanks for the formula.  Fill in the missing factor - nice.

P.S. the Ortofon MC200 which was considered a benchmark at the time, has a tip mass of 0.5mg (spec) - even though it has a boron cantilever ... making it heavier than the then current OM40 - the MM equivalent from the Ortofon range.... (Res F 20.9kHz)

No, you have it mixed up with another model?   Check the phase article/graphs again.  HFR is clearly just shy of 30KHz.   This is almost an exact quote from the PDF:

Typically, the undamped moving coil cartridge has an amplitude response which begins to rise in the 5 to 6KHz region, climbs to about + 8dB at 20KHz and peaks at about 15 to 18dB at 25 to 28KHz, with up to 180o phase shift centered around the resonant frequency.

But this would also tend to support your theory about amplitude response having more affect on imaging, than phase integrity.  I think J. Carr knows exactly what he's doing, and this describes aspects of his "flavor".  Kleos and Atlas have nearly identical amplitude response and there seems to be lots of love for these.  Response @ 20K is similar to an "unlistenable" and undamped MC200 ?    An asymmetrically machined titanium body defeats the resonances that mess up perception of aforementioned 20K response ?  What about Kleos?  Maybe Ortofon was wrong in '82 about listener perception of undamped MC200, or other factors...?   The mostly older folks who can afford these, can't hear above 8K anyway?
neo

[dlaloum]

Just quoting the etm from the mc200 spec sheet.... And translating it into an estimated res f...

I have yet to measure one...

[neobop]

Just quoting the etm from the mc200 spec sheet.... And translating it into an estimated res f...

I have yet to measure one...

That's unsettling.   I wonder if the tip mass/resonance formula is incomplete.   The graphs and description in the article were explicit.
neo

[dlaloum]

Formula worked for.the disappointingly heavy ortofon X5MC at 0.7mg... Will get an mc200 measured soon...

[neobop]

This brings to mind Kiddman on Agon:
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1392385752&openfrom&1&4#1

"Come on, nearly all of these manufacturers make up the specs. Measuring lots and lots of high end analog, I've found the specs are dreams and wishes. MC's that show flat but have a rise of 8db by 14khz. Turntables that quote .01% wow + flutter but are really .3%.

Before you argue with me, buy some test gear and prove it for yourself. Measurrments mean a lot. But manufacturer quoted measurements, in this industry with no accountability, are meaningless."


"What are you using to verify inductance and resistance repeatedly?

I've measured, using state of the art equipoment (with AC test signal, the only way to do it right) 30% differences in impedance with some brands. Yes, "mass produced" ones, if you can call the bigger premium MC makers "mass produced".

A few manufacturers are quite consistent, and very consistent in sound. And with many manufacturers, I've never heard 2 sound close to identical, tested one right after the other."

neo

[J-Pak]

Come to think of it, the strain gauge is the ONLY type of cartridge where development can in fact continue unimpeded....

Standard magnetics have reached a dead end, and stepped back from their peak in the mid/late 80's. (exceptions: Dynavector Karat, Decca London ?)

At some point I need to fix up my SG phono stage (which I believe to be the cause of a channel imbalance in my Panasonic SG) - I do recall it sounding quite stunning - but I had only just got it going and listened to one or two records when the channel imbalance appeared - I have been hoping since that it is the phono stage - but it has been in storage waiting for me to get a "round tuit" since...

I have a feeling that although the SS SG has had further development since the panasonic effort (which SS was one of the few to service!) - the key to its achievement is in the phono stage that apparently does some proprietary EQ.... no details have been forthcoming in any of the reviews, nor have I seen any proper measurements of its performance ... which would be of great interest!

As a mad keen electrostatic speaker fan since the mid 80's - the Strain Gauge cartridges seem right down my alley.

bye for now

David

(currently in the process of getting toddler friendly 'stats' operational .... ie: a pair of vintage Stax headphones)

How is the tracking on your Panasonic SG, have you ever tried it on a test record?

IMO personally I believe Peter Lederman when he says there is no EQ in his SG's phono box. To me he is not one of the BS'ers and designs his cartridges around some objective criteria like measured channel separation. There was a video on Vimeo of one of his talks at an audio show, but I can't seem to find it. I have two of his moving iron cartridges and along with a Shure V15 it is the only one capable of tracking band 3 on the Hifi News+ test record (I had a Zyx and Lyra that couldn't even track band 1), which IME translates to real world performance with really pain in the butt loud cut records.

[dlaloum]

The SG has been packed away for a few years  - I had only just started using it when it developed a channel imbalance - I have a feeling that the problem is in the phono stage but I have not gotten back to it since....

It seemed to track fine, given that I always check the tracking when setting up a cartridge, I am quite sure I tested it - but I don't recall the results.... I am sure it wasn't a poor tracker (otherwise it would have stuck in my mind) - but how good I just don't remember.
I consider a reasonable tracker to be one that manages the third track - and a good tracker manages the fourth track on the HFN test record. Doing only the first track is a poor tracker... fail - managing the second track is a scrape through pass.

Like I said I would love to get some measurements done on the SS SG.... Given that the native behaviour of SG's has a rising top end, I would love to know how he tames that - or whether he just lets it through?