[dlaloum]

Griff,
Yep, 5.0mV, 490mH, 3.2Kohm.  Don't waste your time and money.  The following carts (and more),  have identical specs:
440, 120E, 125LC, 130E, 132EP, 140LC, 142LP, 152LP (ML), 155LC, 160ML, 450.  This was the go-to HO motor for many moons at AT.

The carts with ML preceding the number, ML150, ML170 are different - closer to the 150MLX body - 4mV, 2.5Kohm.  The 150MLX is slightly better with 2.3Kohm, 350mH, methinks.  Admittedly, there's almost no difference, except the cantilever.  I think you probably already have the best generators AT ever made which includes CA and the older 500/550 ohm models.
neo

There are a couple of things here...

1) mV output is also dependent on magnet material and size/weight (so not meaningful given each of these has different stylus...)
2) Some of these bodies are in fact identical eg: 120/440, but others have differing construction and/or materials, this means they will handle some of the more subtle vibrations differently... there is a logical reason for the current AT150ANV being titanium with internal damping - I assume that means Titanium body with potted interior - I wonder what they pot it with?
3) The differing compliances and differing body masses lead to quite different optimum matchings with different arms.

Following on with regards to inductance / impedance - have been doing some research on the physics and maths behind inductance and impedance - the relationship for a "perfect" inductor is relatively simple between impedance and inductance - I'll post it later.

But the point is we can calculate the theoretical impedance from the spec or measured inductance for any given frequency - when I did this I started seeing figures of 60kOhm + for impedance at 10kHz - which clearly shows why high inductance rolls off high frequencies!

Also eddy currents increase the resistance - these are "imperfections" - ie: aspects that differ from the theoretical perfect inductor...

With regards to the theoretically "best" MM body AT have made, might I suggest that the AT21/22/23/24/25 TK9/10 family are clearly a notch above anything except perhaps the AT150ANV.... that series had magnesium bodies with damping, and steel sylus holders which were screwed in. Full toroidal coils - which implies hand winding, and inductance of around 80mH.

Toroidal coils would be more efficient (lower losses) - and may add another factor into things - each of these factors is likely to be subtle of course - but in combination?

bye for now

David

[neobop]

David,
From a Frankencart point of view, if you consider the generators independently from other aspects such as stylus, body, etc, I don't think there's any difference between a 140LC, 155LC, and a 440ML.  Isn't it curious that the 440ML/MLa have identical specs with 1mV less output for MLa ?
I also don't think AT varied the mass of the magnets.  The 440ML magnets seem identical to the MLa (although I didn't weigh them), I think only the magnet type was changed. Admittedly, this could result in a small change in mass.

Thanks for pointing out my oversight of the TK10ML, TK9_, AT22 through 25.  These carts and their styli are mostly unobtainium, so I didn't consider  them.  550 ohm, 2.2mV, and 80mH !!  They don't make em like that any more. 

Looking forward to your analysis of perfect inductance value.  My guess would be a value where impedance remains closest to resistance value with increasing frequency.
neo

 

[dlaloum]

Came across a spec sheet for the AT95 "family"

Interestingly there are variations in body generator specs within the family! - there are two specs for the bodies (according to this spec sheet)

AT95/93
Impedance 2800ohm
resistance 410 ohm
Inductance 400mH

AT94/91/90
Impedance 2800ohm
Resistance 410 ohm
Inductance 480ohm

Note that although Impedance and Resistance are the same, inductance varies...

Formulae for the relationship between impedance, resistance, inductance in a "perfect theoretical" inductor coil...

Reactance (in ohm) = 2*pie*freq*Inductance (in H)
IMPEDANCE = SQRT(reactance*reactance + Resistance*resistance)


The "theoretical" impedance for the two body types is:

400mH - 2550ohm
480mH - 3050ohm

So one is doing better than theoretical and one is doing worse?!

In any case, based on the maths, low inductance = low impedance - which seems a positive thing in most cases.

Further reading on transformer cores provides information on various core/pole structures and materials which behave more efficiently with reduced losses (and/or as a result of reduced eddy currents)

1) Lamination (reduces eddy currents)
2) Ferrite (hybrid metal alloy/ceramic) - reduces losses - used in Technics TOTL MM's and many MC's
3) Air core (reduces output, but improves linearity - used in some of the better MC's)

Interesting further reading shows that there are now manufacturers creating laminated transformers using ferrite materials - combining the benefits of both methods - in the past it was not possible to make laminations using ferrite - so it was an either/or compromise.
I have not heard of any cartridge manufacturer leveraging the new tech to produce a sophisticated laminated ferrite core MM/MI

Further understanding will require purchasing an impedance meter with variable frequency....

bye for now

David

[neobop]

Reactance (in ohm) = 2*pie*freq*Inductance (in H)
IMPEDANCE = SQRT(reactance*reactance + Resistance*resistance)

The "theoretical" impedance for the two body types is:

400mH - 2550ohm
480mH - 3050ohm

So one is doing better than theoretical and one is doing worse?!

In any case, based on the maths, low inductance = low impedance - which seems a positive thing in most cases.

David

My AT-95 spec sheet is in total agreement.  What I don't understand is how the impedance numbers could be the same. 

How about carts like the AT12, 13, with very high inductance.  It seems like impedance should be much higher than 1200 ohms.  Think that's actually resistance and not impedance?

Also, how does the formula work if there is capacitance?

Thanks David,
neo

[dlaloum]

Strictly speaking the impedance formula is :
IMPEDANCE = SQRT(reactance(capacitive)*reactance(Capacitive)+reactance(inductive)*reactance(inductive) + Resistance*resistance)

But for an inductor (which is what a MM cartridge is of course!) - capacitance is usually negligible... so the previous formula is a good approximation.

The site where I got those also provided the formulae for calculating capacitive reactance - so I guess I should probably check to see whether it is in fact negligible! (I'll get around to it...)

With regards to the AT12 - my AT12Sa has R=448ohm, My AT13ea R=1214

So yes 1200ohm is the spec for DC resistance on the high inductance bodies

I just measured my Aurum Beta body, and the specs I can measure (R & Inductance) - come up as identical to the typical AT92 p-mount bodies 420ohm / 420mH (actually 414ohm, 426mH) - but I cannot measure impedance @ 1kHz....

Still assuming a perfect inductor the impedance should be circa 2700ohm... the 600ohm spec makes no sense! (I would expect imperfect reality to show higher resistance than theoretical perfection, not lower! - I remain in the "emperor has no clothes" camp at this point)

Looking at the AT150MLx, R=530ohm, L=450mH Impedance=2300ohm@1kHz - the calculated theoretical impedance would be 2876ohm - so the specs are lower than the theoretical, although in the right ballpark (but this is not 1/4 the expected impedance!)


An interesting often forgotten AT body is the early AT14S - 363mH / 465ohm - same body measurements as the AT150ea....

 

[Grbluen]

I'm not sure if this is of any interest..


 http://sound.westhost.com/articles/cartridge-loading.html

I may have a few sacrificial lambs that I might be willing to experiment with, in the interest of science.

Dongrb

[neobop]

David,
AT-150MLX is 350mH, not 450.

An interesting assertion in Elliott Sound Products link provided by DonGrb:

"Using an inductance meter to measure the cartridge's inductance won't work! The DC resistance is high compared to the inductive reactance, so the meter will lie, and indicate that inductance is much higher than it really is. In addition, the test frequency is determined by the meter, and is unlikely to be appropriate for the task. Most meters don't even tell you what frequency is in use, so you don't get the opportunity to decide if it's appropriate or not (most will satisfy the 'not' criterion). A pickup I measured showed 1.55H (1550mH), which is silly - no cartridge will have that much inductance, however, the actual inductance calculated to be 1.15H, which is still silly and makes the cartridge pretty much unusable for anything other than very casual listening."

While the final assertion itself may be a little silly, the info about a meter measuring inductance is not.  BTW, Elliott makes a phono stage kit or design, said to be nice:
http://sound.westhost.com/project06.htm

I fear we'll lose some of our audience with this discussion, but excellence comes with a price.

neo

[neobop]

Over the past couple of years we've briefly discussed carts other than AT/Clearaudio. 
A couple of favorites from the Agon thread are the Acutex M320III STR and the Astatic MF-2500.  I have no experience whatsoever with either of these and if anyone out there does, please feel free to discuss or just say what you think.  Others which I'm a little more familiar include Empire (4000) and Grace F9 Ruby, Shure V15V.

David and I have Stanton 980, and Pickering 7500 (same) LOMM.  This is an interesting cart and quite different from the 881.  Beside the LO, the 980 seems neutral, uncolored, and the 881 is slightly warm.  The 681 is a high inductance cart and sounds hopelessly compromised to me.  It has a loyal following though, and I would think these people have an overly bright system or maybe just like a "mellow" sound.

The cart of the month is the Talisman Alchemist III HOMC.  This is a nice cart with good resolution and a slight rise on the extreme high end, if I remember correctly.  Back then (mid '80s) many preferred the Talisman S LOMC.  I think the S was very listenable.  It had a big following, bigger than the Alchemist III, methinks.  I never owned either, but my impression is that the III was slightly faster, believe it or not, but this impression could be due to a more aggressive sound.  The III had a sapphire tube cantilever.  I think the S was a sapphire pipe. 

What do you like, or not?
neo

[dlaloum]

I have never heard the Talisman Alchemists, however there was an interesting comment in one of the period reviews... apparently the LOMC Alchemist (S I think?) is capacitance sensitive - the article did not explain why but did show measurements of differences with differing capacitances as I recall....

My personal stable of operational favourites (as opposed to the many many stylusless bodies I have!) include:

Audio Technica families:

Signet TK9  With ATN22
Audio Technica AT20ss (actually SLa body with SS stylus)
AT440MLa
Signet TK6 with ATN152LP
AT12Sa
AT14S
AT150ea with ATN152LP (I think I prefer the TK6 with this needle)

Shure

V15V-SAS
V15RS (V15VxHE) (unlistened to)
V15RS-SAS (V15VxSAS)
1000E-SAS
Ultra400 (preliminary listening only)
V15HRP

Dynavector Karat 23RS

Empire / Benz MC1 (HOMC)

Sony XL-MC104P

Pickering
XLZ7500
XSP3000 with D7500

Ortofon
OM with 300SE stylus
OM20
VMS30
X5-MC (unlistened to)
540 (unlistened to)
530 (unlistened to)

ADC
Various bodies & SuperXLM stylus
(Integra 420 & 490mH, 1/2" 230 / 260 / 350 / 500 / 600 mH)

I have been using the SXLM with 260mH body, but am due to experiment with the different bodies to determine what the optimum for the stylus is...

Panasonic
EPC451 (strain gauge - but the SG preamp is playing up - needs some TLC)

Exceptional cartridges that stand out in the above:
AT20ss
TK9
TK6-ATN152LP (effectively an AT152LP)
Shure SAS "family" (I still need to give the RS and the Ultra a fair go)
ADC SuperXLM
Dynavector Karat 23RS (dynamic, clean, wow)
EPC451 Strain Gauge (yes quite special - similar in some ways to the Karat)
Sony XL-104P (very sweet sound - far from the best but very appealing sound - this one with a top notch cantilever might be a killer cartridge.... they used to have an exotic XL9MC but it goes for silly money)

bye for now

David

[griffithds]

Hi Neo,

Maybe 15 +/- years ago, I had a SOTA Sapphire turntable with a Alphason HR100S arm. They are both items that I have stupidly sold over the years.  I ran a Talisman Virtuoso S and absolutely loved it.  I woke up one morning and went downstairs to play some records only to discover the cantilever had snapped off.  No ideal how it happened. VHd wanted $400 to replace it and Sumiko recommended I buy the piece of s**t Blue Point Special.  Instead I bought a Sigma Genesis 2000, which was another one of my stupid mistakes in selling.  The Sigma was head and shoulders above that well loved Talisman S.

Regards,
Don

[neobop]

Hi Neo,

Maybe 15 +/- years ago, I had a SOTA Sapphire turntable with a Alphason HR100S arm. They are both items that I have stupidly sold over the years.  I ran a Talisman Virtuoso S and absolutely loved it.  I woke up one morning and went downstairs to play some records only to discover the cantilever had snapped off.  No ideal how it happened. VHd wanted $400 to replace it and Sumiko recommended I buy the piece of s**t Blue Point Special.  Instead I bought a Sigma Genesis 2000, which was another one of my stupid mistakes in selling.  The Sigma was head and shoulders above that well loved Talisman S.

Regards,
Don

Hi Griff,
The one I regret selling was a Signet TK-10ML II. 

15 + years ago I had a Goldmund Studietto with a Zeta arm and Alpha Genesis 1000.  I had a bit of bad luck and needed cash so I traded the Goldmund for a Sota Sapphire, Alphason 100S, Genesis 1000 and some cash.  I knew I'd regret selling the table.  It was my all-time favorite.  I still have the Sota.  It's in pieces to make a custom table, but still functional if assembled.  The Versus rim drive motor that I want to use costs $1800.  I'm reluctant to spend the money.  I'm thinking of selling the Sota and keeping the arm - nice arm. 

The Genesis 1000 now has a Soundsmith micro tip on the original boron tube cantilever.  Back in the '80s, first I had a Genesis 500, then the 1000 when that came out.  The 1000 was changed slightly in '88 - response extended past 100K (was 80K), but I couldn't tell the difference.  The 2000 came out in '89.  It has gold coils but was otherwise identical to the 1000.  I liked the 1000 because it was faster.  The 2000 was smoother/sweeter.  Those names were from Monster Cable and the number was the price.  A brief encounter with a ZYX _100 didn't seem any better than the 1000 maybe not as good.  Now they have one with a diamond cantilever for $6K.

My ex partner had a Goldmund Reference with a VDH Grasshopper.  The VDH was a nice cart, just a touch more romantic than a Genesis but not like a Koetsu or Kisiki.  I heard the VDH a lot.  I used to help set VTA/SRA.  Best belt drive I ever heard.

That Dynavector 23RS David has is a great cart too.  I also liked the Miyabi although not quite as exact, but I didn't own either one.  Regarding the Agon thread, I think Raul is losing credibility.  He never had it as far as I'm concerned.   How hard is it to go through every old TOTL cart and pick favorites?  He has tried a lot of them though and you have to give him credit for that. 
neo

[griffithds]

Hi Neo,

I still have my Signet TK-10ML MK II.  I consider it an equal to my AT ML180 occ.
You've had and still have some mighty fine equipment. Reading you various post, I have come to realise that your knowledge is rather extensive when it comes to all things related to Audio.  Your discussions with Dlaloum is like class room discussions in College.
 Flieb's comments to Raul (on his forum), put a smile on my face.
Have you noticed that Raul bumps up the cap. to go along with his 100K setting.  Sort of like a dog that
is chasing his own tail if you ask me!
Sometimes when I think back at some of the things that I have sold, I wonder 'WHY'?  I'm beginning to  think that perhaps it was
because of all  that 'B/S' reading I was doing with all the Audio magazines. What a waste of money.   
Your mention of the Mayabi also made me smile.  I am looking for one of them.  After spending some time listening to what it can
do, you kind of find it hard to forget it and spend your time mentally comparing it to everything else you hear.  A must have in my opinion.
Man, a Goldmund Reference!  Your partner had expensive taste! The problem with being around that level of equipment, it makes it hard to come back to your own!
In regards to our SOTA table and Alphson arms.  There was just something special going on when you mounted a Alphson on a SOTA.  They were a great match and I miss then both, but I don't miss the pain in the ass cartridge mounting method you had to use with it.   Your SOTA project sounds rather interesting.  Do you have a time frame as to when it will be complete. I would appreciate you keeping us/me posted as to how it progresses.  Sounds like it could be a major upgrade to an already great table.
Regards,
Don

[neobop]

Hi Griff,
What kind of table(s) are you using now?

"I still have my Signet TK-10ML MK II.  I consider it an equal to my AT ML180 occ."   That's interesting.  Seems like you have AT nailed.  I never had a ML180, but I would have guessed the 10ML would edge it out.  Too close to call, or one does some things better than the other, and visa versa?
Still using the ATN440MLa on the CA?  How does that fit in?

Yes, David adds an invaluable dimension to this Circle.  We couldn't have made the progress we have, without his input.  There's another long thread about phase you might find interesting.  Ever hear about using a dummy cart to cancel inductance?  Discussion also gets into hearing perception, imaging, reverberation time of concert halls etc, etc.  A fun time was had by all.

Wild story about Dan Fanny and his Reference.  Maybe next time.  I just want to say, it was no problem going home and listening to my Studietto after hanging out at his house.  Different system, another context - we listen within the framework of our system and it wasn't good or bad, more like good and better. 
neo

[griffithds]

Hi Neo,

Currently I have 2 turntables. One is the VPI Extended Aries with the outboard flywheel and a Graham 2.2 arm.  The other is a Victor (JVC) TT-81 with a JVC 7045 arm.  Both are run from a BAT VK10SE with the (what is referred to as ), 'depth charges'.  I'm a little embarrassed to say but I'm pushing 60 cartridges.
The TK10 and the AT180 sound so similar, that I would could consider them twins.  Another one that is also so similar that perhaps what I have is triplets, it the Technics U205C MK4.  The CA Maestro/440MLa is a great sounding cartridge, but (isn't there always a 'but'), it just is not at that level.  There is a delicate refinement with the previous mentioned 3 that just doesn't present itself with the FrankenMaestro. Still, it does stick its head above the crowd of many of the cartridge of the month also rans. I sure you do know which forum I referring too! (grin)
I have not heard about using a cartridge as a dummy load?  Where can I find this thread about phase and this dummy load?  Sounds like something I definitely would be interested in.
BTW:  I like your 'more like good and better' comment. I need to remember that!
Regards,
Don

[neobop]

Hi Neo,

Currently I have 2 turntables. One is the VPI Extended Aries with the outboard flywheel and a Graham 2.2 arm.  The other is a Victor (JVC) TT-81 with a JVC 7045 arm.  Both are run from a BAT VK10SE with the (what is referred to as ), 'depth charges'.  I'm a little embarrassed to say but I'm pushing 60 cartridges.
The TK10 and the AT180 sound so similar, that I would could consider them twins.  Another one that is also so similar that perhaps what I have is triplets, it the Technics U205C MK4.  The CA Maestro/440MLa is a great sounding cartridge, but (isn't there always a 'but'), it just is not at that level.  There is a delicate refinement with the previous mentioned 3 that just doesn't present itself with the FrankenMaestro. Still, it does stick its head above the crowd of many of the cartridge of the month also rans. I sure you do know which forum I referring too! (grin)
I have not heard about using a cartridge as a dummy load?  Where can I find this thread about phase and this dummy load?  Sounds like something I definitely would be interested in.
BTW:  I like your 'more like good and better' comment. I need to remember that!
Regards,
Don

Dang Griff, you got it going on man.  Not too shabby, no indeed.  I wonder how that Maestro or Virtuoso would sound with a beryllium/ML.  You know, the Virtuoso might outperform the Maestro with an exotic stylus.  Might be a hair overdamped on Maestro.  My guess is that beryllium would be better on both, but boron would be better on the Virtuoso.  I think you're in pretty good shape the way it is though.

That thread is another long one:  http://www.audiocircle.com/index.php?topic=92138.0

So, I was a turntable guy in a high end supermarket in the late '80s, and I met Dan Fanny there.  He used to bring in customers and be a sort of consultant for them.  Danny was a tube god and modified high end preamps mostly.  Things like ARC, Levinson etc.  He also built stuff from scratch, the best stuff you ever heard.  I was familiar with most of the best components at that time.  What we didn't have, we took in trade and I used to take preamps home to try, but that's another story. 

Before I met Dan he had a Goldmund Studio.  He designed a set-up jig for the linear arm.  He had a customer with a Reference.  Dan heard his Reference and bet him that he could get his Studio to sound better.  The bet was for the table. 




neo

[dlaloum]

Yep that picture reminds me of that turntable....

At Kostas Metaxas' Melbourne audio Salon - played through his own electronics and esl speakers....
It think the Aussie market was too small for him, he moved to Europe where most of his business is in Greece and Germany I believe....

I presume that he won the bet and got to keep the TT?

[dlaloum]

Don,
 
the "Capacifier" (capacitance pacifier) thread is on VE at http://www.vinylengine.com/turntable_forum/viewtopic.php?f=19&t=33929

The method works very well for those situations where reducing capacitance to the desirable range is well nigh impossible (due to constraints of TT, cables and/or phono stage).

Still a low capacitance setup is simpler and to be preferred, but if like many of us you have lots of spare cartridge bodies lying around, and are not afraid of soldering and putting together a circuit - this can be a good alternative.

bye for now

David

[dlaloum]

Don,

you mention the U205mk4 - I have the MK3 body, and have been seeking a stylus for it for a couple of years now (broken would be OK so I can retip, but without the stylus holder the body is just a piece of metal junk!!)

You wouldn't happen to have a worn out or broken stylus with your U205?

Interesting that you find it so close to the ML180 and TK10 - theoretically the closer to objective perfection (neutrality) a cartridge get the more it sounds like other cartridges that get close to the ideal!

I have several AT22/23/24/25/TK9/10 bodies, but only 1 working stylus (ATN22) at the moment - I have a plan of at some stage getting a retip/recantilever for some of the others....

I have considered mounting the TK9E on the Revox - but cartridge mounting is a pain on that TT, and I now have it set up with a p-mount adapter fully aligned and adjusted.... if I could get the U205 working that would be perfect.... (currently running Shure V15V-SAS)

I also recently paid too much for a broken (transformer blown) Sony PSX600 Biotracer table - a complement for my JVC Ql-Y5F, the JVC being solidly mid mass arm, the Sony low mass - now I need to source the parts to fix it - that should be a perfect platform for the TK9E....
(I am also inherently inclined to the high compliance school of thought, as I believe low damping and high compliance are theoretically better..... )


bye for now

David

[neobop]

David,
Yes, that's how Danny got his Reference.

I think you said your PS-X600 is 120V ?   I have a PS-X50 parts table with a good transformer.  If it will work in your 600, you're welcome to it.  It's a pretty big transformer (for a table), but I don't have a service manual and don't know the secondary voltage.  I can copy the numbers on the tranny if that would help figure it out.

Thanks for the link to the Capacifier.  I saw it mentioned on the loading thread.
neo

[jmowbray]

Don,

Interesting that you find it so close to the ML180 and TK10 - theoretically the closer to objective perfection (neutrality) a cartridge get the more it sounds like other cartridges that get close to the ideal!

I have several AT22/23/24/25/TK9/10 bodies, but only 1 working stylus (ATN22) at the moment - I have a plan of at some stage getting a retip/recantilever for some of the others....

bye for now

David

Hi David - I'm interested in the fact that you chose to install your ATN-22 on a TK9 body rather than a TK10. I have a NOS ATN-22 mounted to one of my TK10 bodies and it sounds great (though not quite as nice as the SS LC retipped boron TK10 I have). Was there something special about the TK9?

Jack