Dear friends: I always said that each day is a learning day and if like me that from several years now think always " out of the box " many of you will find out great rewards that audio always has for us as an unexpected gifts.

Obviously that’s not easy to think " out of the box " because to do that we have to have a different kind of self attitude where between other things we must to forget for ever at least the 50% of all the information we learned through our audio life in the AHEE. With out that " forget " we just can’t do it.

This review is more than an usual audio item review for many reasons I will try to explain over the thread.

First I want to leave very clear my room/audio system main target: STAY TRUER TO THE RECORDING.

To achieve that we have to think that usually the recording microphones are positioned at very near field of the MUSIC sources even like in the 3 Blind Mice recordings: inside the instruments. Recording microphones are not " seated " at 20m-35m. from the source as usually we listen when attend to a live acoustical music event. So we have to have self experiences of live MUSIC seated at near field. If some of us do not have that kind experiences then is very dificult to understand what I’m talking about here and elsewhere.

OK, the ADC 26 cartridge is a vintage Induced Magnet invented motor design by Peter Pritchard ( that pass away. ), it’s not a MM or MI or MC kind of cartridge design. Here you can read about and on his patent and a little of his audio life history:

The cartridge under review is this:

that is part of the ADC 25, 26 and 27 cartridge family.

This is the ADC 25:

and this the ADC 27:

and here the ADC 26 specs ( please take note those 15° stylus tip mounted angle. ):

As you can see and read all seems very old and rudimentary with really humble cartridge specs ( nothing spectacular down there. ) where the elliptical stylus is: 0.03 x 0.07.

The ADC 25 red dot stylus ( exist the red blue 0.03 x 0.09 and the white dot. ) is similar to the 26 and the ADC 27 change is that is the same 26 stylus type but nude. I own all those models that comes with the same cartridge body but different color and where the cartridge motor in the 26 and 27 is similar and the cartridge differs only in the stylus and that the compliance instead 50 cu as in the 25 and 26 is " only " 40cu.

All these cartridges are my oldest ones ( comes from the 60’s. ) that I bougth years ago when started the very long MM Agon thread and I remember that I mentioned there the 25 and 26 but almost no one took cares about not even me because I really never gave it the enougth listening time to those cartridges and was only like a month ago that I really discovery this fenomenal, outstanding, astonishing and " perfect " performer.

When you listen it you are not listen as if was alike MM/MI/electrect cartridges but more as a live event/truer to the recording with some characteristics only shared for the best of the best LOMC cartridges.

I made my self developed evaluation proccess where I’m deep trained and is almost " bullet proof ".

The best MM/MI cartridge is with out doubt the AKG P100LE followed by Astatic MF-2500 and others as the JVC X1MK2 or the Technics EPC 100CMK4 but no one of them can even the quality performance levels of the ADC 26. The ADC is in a different league " the major league ".

I compared the 26/27 against the Colibri, Ortofon A95, Lyra Etna, My Sonic Labs Supereminent ( I think ? ? ) Dynavector XV-1s, Clearaudio Goldfinger and some other vintage top MC designs. No one of them beats overall the ADC 26.

The main 26 characteristics to beat belongs at both frequency extremes where if we want first rate quality performance there first condition is the transient response/attack of the music notes and develops of harmonics along the decay timing that’s where exist clear differences in between MC cartridges and all the other kind of designs. Nothing but the 26/27 compares with a top LOMC cartridges in those regards.

The transient response and fast timing decay in the low of the bass range is second to none and " mimic " what we can listen in a live event at nearfield position. With out this " sole " characteristic MUSIC as MUSIC just can’t exist and is here where belongs the MUSIC foundation.
At the other frequency extreme things are more of the bass range quality performance. In both frequency range it’s not only the rigthness of the transient response but the notes definition its very clear distinction in between and its harmonics. Exist no overhang or bold sound. At the high frequency range ( at the top. ) nothing can beats a Colibri 0.22mv output and the only contender for is precesily these ADC 26/27 ! !

As you can see the 26/27 specs says not very wide frequency range but when listen to it you can sware it goes from 5hz to over 100khz but the more important issue is the clear definition. When the timing in those frequency ranges are spot on then the overall MUSIC rythm is just spectacular and makes and moves all your feelings and body.

We all hear through all our body not only through our ears. We hear through the skin, bones, skind hair and millions of nervous terminations in the body and when you are listening to the ADC 26/27 all those have a true meaning as never before.

What about soundstage, layering, inner detail and the like: just very first rate. Tonal balance is outstanding nothing at the broad wide frequency range tells you " hey: I’m here ", exist a true coherence in between all frequency ranges.

Yes, it’s a UNIQUE listen experience a NEW listen experience coming from a very older cartridge and YES is the best Pritchard design and if you think that you already own the best cartridge ever you need to experience the ADC 26/27. I compared against the best out there in the same system with the same tonearms and same everything.

Was not only me but some other audiophiles friends where at least one of them is a music player. This one is a drummer/batery player and when he was at my place I run ( between other LPs. ) the Sheffield D2D with Ron Tutt and Jim Keltner great drummers with out telling him which cartridge was playing and my friend that’s a true expert with those instruments and golden ear by nature was " jaws dropping " and it’s because is incredible the TRUE of that kind of sound coming from the ADC’s
. This recording specially is something to listen through the 26/27 at 95db SPL with peaks in the 100db neigborhood, you can touch the sound and cut it with a sizzers ! ! !. It’s amazing.
The ADC never lost its aplomb no matters at what SPL you are listening from 70db to over 95dbs .

Every single good recording " sings " as never before of all what I experienced in my system and several other top audio systems.

One of the best MUSIC LP for testing any audio item is the Telarc 1812 and not because the cannon shots but overall frequency ranges that’s always a challenge for any cartridge andd for any audio system in other frequency ranges than the bass range.
No one of the other top LOMC cartridges can even overall the ADC 26/27 quality performance levels in this LP recording in all the frequency range other than the very low bass where the ADC beats to all of them.

I running the ADC 26 at 1.1grs and due ot its very high compliance ( 50cu. ) and cartridge body design is a very low rider when the 27 is only a low rider.
As with other top LOMC cartridges the alignment set up is critical but with the ADC 26 we have to do it with the best accuracy we can and with the VTA/SRA tiny/sligthly up at the tonearm bearing. This VTA/SRA is critical and as always not only depends of the accuracy overall set up but room system dependent.

That explosiveness, power, dynamics, transient response, thightness, flow, true tonal balance agresiveness, natural brigthness, rythm that usually exist only in a live MUSIC event with the ADC 26/27 you can feel that never was in your home audio system as nearer as with these ADC cartridges.

Those audiophiles terms as: lush, organic, color, smothness, bold, and the like does not exist through these " truer to the recording " performers. Those audiophiles terms/characteristics of sound just does not exist in the nearfield MUSIC live events are only characteristics " invented by the AHEE and very far away from reality.

The ADC 26/27 as the very top LOMC cartridges are made it for true music lovers more than for " audiophiles ".

I think that in the 60’s the ADC 26/27 you can get fro no more than 80.00 and today can compete against 15K+ LOMC cartridges.

This all new experience through the ADC 26/27 bcartridges came in the best moment when I 'm more mature in all subjects with MUSIC and audio and when my room audio system is at its best with all the up-dates and up-grades I can afford bor the better.

As always your contributions in the thread all are welcomed and appreciated.

Regards and enjoy the MUSIC NOT DISTORTIONS,

Ag insider logo xs@2xrauliruegas
 Dear Raul, you and I both agree on the central importance of the tonearm in determining how a cartridge sounds. The tonearm and cartridge form a system of their own. So please tell me why you wrote that very long review without mentioning the actual tonearm in which you mounted the ADC 26. Better yet, please say what tonearm you are using. 
Dear @roberjerman : Please tell me why do you think that? , btw I clearly don't smoke but you have to have some reasons for what you posted and I'm interested about because maybe I'm missing some important parameters by my ignorance levels.

Regards and enjoy the MUSIC NOT DISTORTIONS,
Dear @lewm : As any other analog audio link the tonearm is important but the star always be the cartridge.

Anyway, I mounted all the cartridges in my self design tonearm and in a AT 1503 heaviliy up-dated. Results are almost the same and I said " almost " because in my tonearm design things are better but the characteristics through  the 1503 remain there.

The ADC 26/27 is truly unique, an incredible performer.


Post removed 
Dear @viridian : The ADC 26/27 are really old designs ( the 60's. ) and I don't think very easy to find out the cartridges in good operation conditions but if you can find out at any price is a must to listen it.

Regards and enjoy the MUSIC NOT DISTORTIONS,
A friend of mine has a lot ADC´s. 220x i think with different needles. A few of them sounds great, but every one has a problem with loud s-tones. I never heard the ADC 26.
99,  Do you refer to "sibilance"?
Thanks for your response, Raul.  I gather that the AT 1503 must be a low mass tonearm; is your own tonearm also low in effective mass?
I like probably a few others of us took a look on eBay for the ADC 26/27. No luck.
Yep as soon as Raul posted I scoured eBay, Agon, audiomart

No 25,26 or 27.

I am sure they may appear at odd intervals though.
Well, the best possible vintage tonearm is SME III w/ fluid damping, naturally.  I bought mine in 1987 and never lusted after other pivot arms and after listened to a couple of HQ MM carts that confirmed it all : )
Dear friends: I’m loading the 26/27 at 100k with 150pf and both tonearms are not low mas but medium mass and well damped.

These both ADC models let a few lessons to all the ones that experienced it. What lessons left to me?:

well, we have here not only a very old cartridge design but a cartridge with a fenomenal " motor " design with a humble plastic body ( no Titanium or the like as today top cartridge designs. ), with no boron or diamond cantilever but just a short aluminum cantilever, with not the Replicant 100 or VDH or Geyger double polished stylus shape but a humble elliptical one, with specs that are for " laughin "/ridicule vs today designs or even vintage ones, with a very very high compliance that can be a problem today, a cartridge that comes not with a " fresh " cartridge suspension but builded in the 60’s, with " ridicule " non-gold plated output pins, with no internal silver/gold wires. ! ! ! !  !

Then how could be possible that the ADC 26/27 can performs at those very high quality level perfomance to compete with today best of the best? Outstanding cartridge motor/transducer.

Obviously is out of my mind and obviously I have not answers about. Maybe only a cartridge designer with the ADC 26/27 experiences could chime about and obviously that @jcarr come to my mind to do it if he already had those ADC " fresh " experiences.

It’s not an easy cartridge to set up for shows at its best, maybe because its very high compliance or its stylus ti 15° angle or maybe because its age.
With my samples what I experienced was that as no other cartridge the precise VTF set up is critical, it has to be where the cartridge sample " likes " and it has almost only one VTF position !.

I know that @florence4 own it because he posted a few weeks ago in the MM thread, I hope he can share with us his experiences in his room/audio system.

Regards and enjoy the MUSIC NOT DISTORTIONS,

Your experience supports my side of my discussion with Chakster. The materials of which a cartridge is built and the shape of its stylus are not necessarily guidelines to excellence.  

. The materials of which a cartridge is built and the shape of its stylus are not necessarily guidelines to excellence. "

Well then please explain what the guidelines to excellence are pixie dust, glossy brochures, rave reviews by self-proclaimed experts?
Dear @lewm : """  are not necessarily guidelines to excellence.  """

agree. The key word in your statement is: necessarily.

Everything is important but for sometime now I supported and support that the most important and critical issue with the cartridge quality performance levels is the cartridge " motor drive design " and its excecution.

The Pritchard IM patent and its excecution in the ADC 26/27 is nothing less that formidable and with out doubt the best cartridge Pritchard's work, not even his latest Sonus Dimension 5 can even it, as a fact is away from with lower quality level performance.

But if we have a good cartridge motor design then the other cartridge parts comes to be important and critical. One of my latests first hand experience about was with my Lyra Clavis DC sample where I decided to change the stock Ceralloy cantilever build material for a new boron cantilever and this change changed for the better the overall Clavis DC quality level performance.


Raul has almost superhuman powers to make prices skyrocket. I wish he'd do that for my old car.
Dear @ninetynine : The series 220 is a different quality level ADC cartridge and is away from the very high quality 26/27 performance levels and I know because I owned along the 10E.

Now, that SSSHH that you named is something I listened with my ADC samples till the VTF was exactly where it belongs. Very delicated cartridge on the VTF regards.

Ok, another cartridge of the month? 
At leats something new, good to hear 

Maybe i am late with ADC, but i've bought ADC TRX-2 MI cartridge with Sapphire cantilever. Never tried TRX series before. As far as i know this cartridge was designed in Japan by Nakatsuka-San (ZYX) for ADC. 

Has anyone tried them ?   

Dear chakster, The curious thing is that we somehow own the

same carts. Even more curious is the fact that I started this

hobby in the 70is while my first cart and arm were ADC 25 and

Pritchard. Back then I thought that nobody in the world could

compare with me. Later on I discovered that this Pritchard arm

was worthless as well any other tonearm meant for high compliance

carts. For some unknow reason cart producers competed with

each other who would achieve the highest possible compliance

but without any consideration of the question  if there are suitable

 tonearms for them.

As is in ''general'' known the cart producers never achieved any

standard whatever. 

In my opinion the only possible tonearms for those  carts are

the linear tracker which I, alas, never owned .

Well at present I own not one but two TRX 2. The later one

with ''improved'' beryllium cantilever. This ''ADC'' with quotation

marks is made by an Japanese as you already mentioned. My

quotation marks are ''caused'' by this fact. Well to me this TRX2

is , say, equal to other of our ''best ever'': AT 180, Signet TK 7cl,

JVC X1-mk 2 ,etc. Except ''of course''  your own and only

Glanz&Astatic 61 (grin).

Dear @tzh21y : Good luck with your hunting. The ADC 26/27 quality level performance is way different to other of the ADC/Sonus models so try not buy other ADC models.
As a fact and as I already said it the 26/27 performs different as any MM/MI/electrect vintage or today cartridges.

If you don't have the kind of money for the great Etna SL or the Colibri or any other top LOMC cartridge well the ADC is the answer to it.


Well at present I own not one but two TRX 2. The later one

with ''improved'' beryllium cantilever. This ''ADC'' with quotation

marks is made by an Japanese as you already mentioned. My

quotation marks are ''caused'' by this fact. Well to me this TRX2

is , say, equal to other of our ''best ever'': AT 180, Signet TK 7cl,

JVC X1-mk 2 ,etc. Except ''of course''  your own and only

Glanz&Astatic 61 (grin).

I know that you don't use any of them :) 

Astatic is not in my list, buddy 

But the AT-ML180 is hard to beat by any cartridge.

Well i will check the TRX-2 soon, we will see how good is your memory regarding the quality of that rare gem  


 ''Astatic is not in my list, buddy''.

Well the carts are made by Mitachy  Corp. in Japan for Glanz and

Astatic. If I remember well on your Glanz 61 there is also Astatic


Let’s make it clear:
There is no relations between Glanz 61 and any Astatic, except for the MF generator. 
There is no equal model in Astatic line and that’s why the 61 is so speacial. Other models like Glanz 31, 51, 71 are all almost equal to the Astatic MF100 and MF200 (yes, all made by Mitachi).

But the Glanz MFG-61 has it’s unique cantilever and stylus tip that you will never find on any Astatic models. In fact ALL Astatic comes with aluminum cantilevers like any other Galnz models, except for the 61 which has a Boron Cantilever and Paroc stylus tip. I think Glanz people are smarter than Astatic if they made such a great model with different cantilever and different stylus tip.

Anyway i have not used my Glanz 61 for a long time.

P.S. Ortofon MC2000 is what i’m using this month with Gold Note PH-10 high gain MC phono stage. Very impressed!

Dear friends: I'm still testing the ADC 26/27 and making comparisons against LOMC.

No two cartridge even from the same manufacturer sounds alike, each one sounds " different " and it's through those " different " performance what determines if one cartridge is better than other or is at the same overall level but with different music/sounds presentation.

Other that the LP tracks in my whole evaluation proccess I listened and am listening everykind of recorded music and the good recordings sounds really good and the very good ones performs excellent and nothing less.
The bad recordings performs in that way and you can know " for sure " the errors in the recording proccess-

In a top LOMC cartridges or these ADC 26/27 we can detect some weird " noises/buss/murmur " that were recorded but that are not part of the music it self as in a London FFSS recorded when Sir Georg Solti ( that pss away. ) was the Director of the Orchestra of the Royal Opera house and we can hear there the murmur of the subway.

Something similar happens with some of the Chesky recordings and in other recordings exist noises coming from the air conditioner or even we can hear how some one opened a door. All these kind of recorded noises are of very low level but we can detect it if the room/system has that kind of resolution. Ormally we need to have a pair of subs because those weird noises are from very low bass. Of course that other type of noises could comes from mistakes in the recording proccess.

I have preferences for the female voices over the male singers and when you have these top kind of cartridge performers things are never be the same again. The ones that I will name are very well knows female singers and I'm really satisfied as ever with these experiences because I'm listened to it:

Dido, D.Krall, E.Fitzgerald, B.Holiday, J.Ian, R.Spektor, N.Jones, J.Warnes, C.Wilson, A.Franklin, L.Williams, Sade, D.Reeves, D Shuur, M.Caballe.

Other recordings that I'm listened with and follow  doing are: A.Delmoni ( Water Lily label. ), Center Stage ( Wilson Audio. ), Hyperion Knigth: Pictures at an exibition ( Wilson Audio. ), John Lill with Shuman piano compositions ( Green Pro. ), Kabi Laretei: Nocturne Chopin and Beethoven Sonata in D ( Propprius. ), The Royal Opera House Orchestra with Ernest Ansermet: The Royal Ballet ( RCA. ), Lorin Maazel and the Cleveland Orchestra: Respighi: Feste Romane ( UHQR MF.), the Bach Toccata & Fugue ( M&K. ).

Other are:  Elio Villafranca with CH.Flores: 16 eyes records label.
Demostration Reference Disc: top Music Int/Delos International labels.
Jheena Lodwick ( All my loving. ): The Music Lab label.
Mary Stallings ( Fine and Mellow ).: Clarity recordings label.
Hugh Masekela ( Hope. ): Analog Productions label.
Keit Jarret ( Köln Concert).: ECM Records.
Chie Ayado ( Prayer ).: East House Records
Youn Sun Nah ( Same Girl ).: Act Music.
Cristine Collister ( Love. ).: Rega Research Limited
He Xun Tian ( Paramita ).: WindMusic label.
Tsuyoshi Yamamoto ( autumn in Seatle. ).: First Impresion Music.
Dafos ( Reference Recordings. ).

From these two of them needs a special attention: Paramita and Dafos.  The recorded music comes from not usual instruments that have not usual sounds but with disonants characteristics. Not easy for any room/system to handle those sounds at 95dbs SPL at 3m. ( peaks over 100dbs. ) seat position but through the best of the best LOMC cartridge and the ADC under review the experiences on it are just superlative.

Other magnificent experiences you can have when listen to: 
The Power and the Majesty by MoFi and as you know it's a non music recording The recording it self is a must to own.

I have to say that some of those recordings if not all are a true evaluation test for any room/audio system and with cartridges of those values it's the GLORY ! and I mean it.

Regards and enjoy the MUSIC NOT DISTORTIONS,

BTW I know that there persons who search for their identity

while I am convinced that each individual in the known universe

has his own unique identity such that there are no two identical

persons in the mentioned universe. However ''Herr Freud'' invented

this theory according to which there are 3 of us in each of us: ego,

super ego and ''it''. Our moderators obviously believe this theory

so I got one additional identity from them called Nandric 3. This

Nandric made only 154 contributions in this forum while , probably

the ''super one '' made more then 3000 . So my dear co-members

you got an new member.

@chakster , I know that you know everything better but my

former self participated in the old Glanz thread. We all thought

back then that Glanz and Astatic where different animals.

Till we discovered  that both were importers who ordered their

carts by Mitachi corp. in Japan the inventor of ''magnetic flux''

technology. The only difference was the fact that that Glanz

ordered also elliptical styli for their  top range carts. Lucky me

I already wrote about identity. As you pointed out I mentioned

Vienna, Wien, Wenen and Bec 51 times.  Those are different names

but with the same reference. So regarding the question ''who

made those carts''? there is no question about: Not Glanz nor

Astatic but Mitachi. If you look at your extraordinary Glanz MFG

61 you will see on the ''nose'' of the stylus holder Astatic logo.

It is a sign like  A-- with a leg . I thought then that even Mitachi

was confused reg. the question for whom they made this 61.

I checked my Glanz and Astatic samples and can state that

Glanz has not its own logo while Astatic has. This logo you

can see on your MFG 61.

@nandric No, there is no Astatic logo on my Glanz and no "A with a legs" anywhere on the cartridge. There is a "HAH" letters on the inner side of the stylus replacement. The Glanz Logo is on the front side of the cartridge and also on the stylus protector mounted to the cartridge body. The cartridge generator is silver and the stylus replacement is purple on 61 model.

I think Glanz people ordered some special cartridge from Mitachi and they got 61 as the best model, while the Astatic never ordered anything like that. Two different companies in different countries, one OEM in Japan. Astatic is Canadian brand?

Mr. Masataka Hamada who was the developer of “GLANZ” at Mitachi Acoustics, has resurrected “GLANZ” within his own company, Hamada Electric.

Glanz now making tonearms:
New address and contact info:
GLANZ 788-5 O-oka Numazu City
Shizuoka, 410-0022, JAPAN
TEL +81 55-963-8712
FAX +81 55-963-8758
Post removed 
Dear friends: Yesterday an audio friend that's owner of the ZYX Universe came to my place with his cartridge and we were listening for a few hours and we made comparisons against the ADC 26/27.

All my audio friends know very well the quality performance level of my room/audio system because they were here many times.
Well this ZYX owner was really surprised on what he listening from the ADC and after aa while he confessed that he prefers the ADC.

I have to say that along the A95 the Universe are the ones where  quality levels differences  are a little higher for the better in the ADC  26/27.

.I still follow and will follow listening it and making some cartridge fine tunning. I think that that ADC 26/27 cartridge suspension conitune settle down, we have to remember that was manufactured over 50+ years ago.
It's performance continue improving a little through that fine tunning. As a fact I'm trying to " know " the cartridge overall performance its " behavior ".

I hope some of you can find out a sample of it.

Regards and enjoy the MUSIC NOT DISTORTIONS,
 Since I doubt that I will ever find and buy an ADC 26 or 27 cartridge, I am focusing my attention on the eternal debate between chakster  and nAndric over the true origins of the glanZ MFG 61 phono cartridge. Surely, that is the most important issue of our day, not the collapse of democracy and liberalism in Europe and the US. 
One would think, if a product was, "the best of" anything, according to enough opinions, someone would have noticed and kept it(or something equivalent) in production.
Dear @lewm : You already gave up pretty soon. Maybe because you are not really interested. Don't give up yet.


Der @rodman99999  : ""   kept it(or something equivalent) in production. """

well I think that the equivalent is already  in production with all those top LOMC cartridges as the ones I named here. Yes at a price point for that kind of high quality performance levels.

I wonder how will performs the ADC 26/27/25 with a boron cantilever and/or Shibata stylus?..

Due that I own more than one original I will try something like that but I'm not to sure about because in stock condition are very good performers, I will think again about in the future. For now I'm too busy listening MUSIC.

Regards and enjoy the MUSIC NOT DISTORDIONS,

I am focusing my attention on the eternal debate between chakster and nAndric over the true origins of the glanZ MFG 61 phono cartridge. Surely, that is the most important issue of our day, not the collapse of democracy and liberalism in Europe and the US.

The world situation is rated X, it’s been said back in the 70’s and this is my favorite song for today’s situation. The song was unreleased for 40 years untill now, sounds like it was written yesterday. Pure soul music with the message.
My post was an attempt at humor, more than anything else, and I apologize if I changed the subject to something irrelevant.
I answered Lewm’s post — "Surely, that is the most important issue of our day, not the collapse of democracy and liberalism in Europe and the US" — immediately with: "It is because of that collapse that we’re focusing on trivia" — and it posted.

Now it’s gone. Was it removed? Don’t they usually leave a little note saying "post removed"?

Yet Lewm’s original statement remains; why wasn’t it removed? Maybe because it mentioned cartridges, in passing? And why must Lewm apologize?

Are serious things forbidden on AG? Why is "the world situation rated X", as Chakster ’explains’? I can understand disputes of a political nature being discouraged, they can become vitriolic and ad hominem (of course that never happens when discussing audio) — but there’s no dispute here.

A bit confused...

Well I think that the ''creator'' of the MM thread want to start this

thread once more to begin with the oldest (possible) carts. He

owns if I remember  wel +100 sampls so we will probably return to

the so called ''carts of the month''.

Bimasta, I don’t think we want to talk politics here. Nor are we allowed to by the rules, I think. That is why I apologized for my post. I think there is a whole separate forum for arguing about the state of the world. I am too frustrated and convinced of my own powerlessness to bother. Meantime, I still have not found an ADC26 or 27 for sale.

TZ, earlier on I asked Raul to specify what tone arms he was using with his ADC 26. He responded by saying he is using either one of two tone arms that he characterizes as medium mass. I assume this means the effective mass is at least 10 or 11 g. But you are correct in your inference that cartridges with such high compliance as that of the ADC 26, in theory should be used with very low mass tonearms. In fact, so far as I know, there were only one or two tone arms ever made that would be perfectly matched to the ADC 26, so high is its  compliance. But Raul’s success illustrates the fact that one need not necessarily be obsessed with that equation for resonant frequency.
Has anyone tried Denon DA-401 tonearm for high compliance MM cartridges? The headshell is removabale, but unique type, so it's impossible to use any other headshells, except for the Denon shell designed for this tonearm. But the arm must be great for a High Compliance carts like those ADC, Sonus, Grace, Stanton ... 
Dear @downunder : Yes that XLM III is an average performer as you stated but even that the cartridge is an IM patent Pritchard design  he was not involved any more with ADC because  in 1976 that was when came the XLM III was BSR the ADC owner not Pritchard.

Anyway, both cartridges has no quality performance alike in between.  Totally different.

Post removed 
Dear @tzh21y  @lewm : Not necessarily a low mass tonearm as lewm posted:

"  success illustrates the fact that one need not necessarily be obsessed with that equation for resonant frequency "

Everything the same: is it important to match the cartridge/tonearm to the " ideal " resonance frequency range?

As always in audio: yes in theory it's important but not at the level we could think or the level we learned somewhere.

The important issue is that the tonearm be a well damped design.

In the old times B.Pisha ( Audio magazyne. ) reviewed the LOMC cartridge Ortofon MC2000 and he found out in his real time review measurements that the compliance of that cartridge was at around 32cu and with a weigth of 10+grsm.
He mounted during the review with a Technics tonearm and the measured resonance frequency was at around 5hz ! and he reported that that cartridge/tonearm combination were abble to play with out any tracking trouble all those cannon shots in the Telarc 1812 !.

Those facts goes against the thery about but I confirmed and confirm those kind of results sveral times with other tonearm/cartridge combinations.

The main reason why the MC2000/Technics tonearm did not shows any trouble was the great damping mechanism in the tonearm and obviously the huge tracking abilities of that Ortofon cartridge.

So, the best is to try and listen.

The people in the 60's made comments that only the Infinity blackwidow or the Pritchard tonearm design were almost the ony tonearms to make the job but we learn that's not that way.

Regards and enjoy the MUSIC NOT DISTORTIONS,

The people in the 60's made comments that only the Infinity blackwidow or the Pritchard tonearm design were almost the ony tonearms to make the job but we learn that's not that way.
Raul, I think you are a bit confused. Infinity didn't even exist in the '60s, and the Black Widow arm wasn't made until the late '70s.
^ Exactly, furthermore Black Widow´s arm wand is kinda flimsy to be taken too seriously for "the best cartridge ever" : )
Luxman TA-1 (made by Micro Seiki) is a much better alternative to Black Widow, perfect for high compliance carts. 
Dear @cleeds  @harold-not-the-barrel : As a fact I read the comments somewhere with out taking in count the date of those comments, but that's not the real issue. Thank's for both of you posts.

The main issue is that we don't need necessarily a low mass tonearm to enjoy the 26/27/25 cartridges.

...nothing new for me and my visitors. I wrote this around ten years ago on my website in "Die Liste" :

ADC 25,26,27= - *)> With the second generation of the ADC 10E, Peter Pritchard has already created in the 60’s the perfect system. The space reproduction combines the accuracy of a holographic Grace F9, with the depth of a dimension 5. The bass is deep rumbling and extremely precise. The high frequency resolution very fine and nuanced, the midrange presence so good that you look scared when the turns / singers / in gets going if you are not alone in the room. The ADC 25 is a complete set with 3 different needle cuts. only the sharp elliptical version 27, are identical at 26, the stand-alone of 25, and the slightly harder needle of the rated here. Light arms are required. OK, just with CU50 to the AR arms of dual, for the 27er is ideal with CU40. Attention 15 ° system, the VTA and the AK is extremely critical in this State of The Art System. *) It therefore runs in this list out of competition without scoring.
Dont forget to switch the language to english on the top left. Its possibly the largest info site about Pritchard and his carts in the www.