Ortofon A90 with Graham Phantom


Looking at the top of this cartridge there are 3 little tabs. One at the front and 2 at the back. The top of the cartridge does not make contact with the headshell on its entire surface. Also, with the Graham, the cartridge is further back in the slots for correct alignment making one of the tabs at the back not make contact at all with the headshell.

After aligning it with my Mint LP and securing the screws, viewing the cartridge from the front, i can see a small gap between the top of the cartridge and the headshell and the cartridge is "tilted" ever so slightly to one side because only 2 of the tabs are making contact with the headshell.

Are you experiencing the same?
Thanks
smoffatt
If I were experiencing this problem I would be tempted to place a small amount of Blutak between the top of the cartridge and the tonearm. This should both ensure a good bond and to a slight degree lessen the effect of arm resonances on the cartridge. I can recall receiving a small amount of a similar substance for this purpose from a manufacture back in the early 90s , I cannot recall whether I ever tried it. You could take a Dremel tool and remove the offending tabs but the first suggestion is the less intrusive. In a perfect world all cartridges would be easy to align and install, but in ours things like this happen occasionally.
I am not sure how anyone could give advise to grind away an integral part of a cartridge, let alone a 4k cartridge. And Stanwal is a dealer - oh my god.

Hi Smoffat.

I have a Phantom and A90 and I know the problem you are experiencing. I also use the mint tractor. The phantom is wide but not very deep, so it is impossible for all 3 ridges to be in contact with the headshell, only the front ridge.

Your alignment does not sound quite right. The back of the A90 should be parallel. Either both of the back ridges will be seated on the headshell or none will be. Otherwise your cartridge body will be twisted slightly left or right.
I would go through all parts of the alignment again to double check.

With my A90, both the back ridges do not touch the headshell, only the front ridge. My A90 with the phantom is now aligned similar to the jubilee which has only one ridge down the centre - you just need to tighten the screws slowly to ensure the cartridge is level horizontally.

You now have me thinking that my SRA will be off - even level headshell the actual cartridge will be slightly back down. damm

I know a couple of other folks with Phantom / A90's, so hopefully they will chime in as well.
" You now have me thinking that my SRA will be off - even level headshell the actual cartridge will be slightly back down. damm "

Brain fade gents - Doh

The back of cartridge will be slightly up - probably close to the 92% SRA that Fremer.
I say that if the cartridge doesn't fit as intended with the "bumps" positioned in the headshell, you are defeating its intended design by "making it fit". Those bumps I am sure are there for the same reason you put cones under your preamp. I would not choose that cartridge for that arm, unless it could fit properly.
05-20-10: Downunder
I have a Phantom and A90 and I know the problem you are experiencing. I also use the mint tractor. The phantom is wide but not very deep, so it is impossible for all 3 ridges to be in contact with the headshell, only the front ridge.

That's what I have found - the same was true of the Ortofon Jubilee in the Phantom (or the Graham 1.5T for that matter).

05-20-10: Downunder
Your alignment does not sound quite right. The back of the A90 should be parallel. Either both of the back ridges will be seated on the headshell or none will be. Otherwise your cartridge body will be twisted slightly left or right.
I would go through all parts of the alignment again to double check.

Not in my setup with the Phantom II armwand.
Like you say, the Phantom headshell is quite narrow from front to back (narrow oval shape) but at the left-hand rear (looking from the front) there is an asymmetrical extension that connects the headshell back to the wand.
Looking from the front of the cartridge the left rear 'ridge' of the A90 is under the headshell (the extended part that connects back to the wand) - while the right rear 'ridge' does not contact the headshell at all. The cartridge is mounted symmetrically in the headshell and aligned with the Mint protractor (though its in the same position with the Graham jig).
You can clearly see the right rear ridge outside the headshell in this photo

Despite this, the A90 is still by far the best sounding cartridge I've heard in my system. I suspect the rigidity of the cartridge/headshell interface and resonance control etc is still far superior to most other cartridge designs - due to the A90's rigid and highly damped one piece SLM body/spine.
Smoffatt,

If like Stringreen you 'worry' that the bumps are not all under the headshell there may be another option.
Assuming your Phantom has the SME base, you could slide the base a few mm rearwards and move the cartridge forward in the slots to compensate - allowing all the ridges to contact the headshell.

The only negative consequence of this would be that the Graham jig - which expects a fixed relationship - could no longer be used. Obviously any of the 3rd party alignment protractors, such as the Mint, would still work perfectly.

Unlike taking a dremel to your $4K cartridge - this could be completely reversed, should you wish to use the Graham jig in the future.

To be honest, I doubt you'd hear any sonic difference whether all the ridges are under the headshell or not (so long as alignment and azimuth is correctly adjusted for both circumstances).
Paul, that explains the difference.

Smoffat and yourself have Phantom II's. I have mark1 and the left side of the headshell is symetrical with the right, hence their being a gap on both back ridges with mine.

Nice thought re the SME mount. I have the SME mount, so I might try moving thebase back a few mm's. I can then tell you if there is any sonic difference.

I am hoping Bob Graham is reading this thread, as he may have a simple fix - I am guessing a headshell spacer - however since the Phantom headshell is so thick, it is hard to find screws long enough to fit.

cheers
I was trying to be factious with the grinding off, if your tabs offend you, cast them away etc. I myself would not obsess about all three touching at the same time but then I don't spend hours aligning cartridges. I have been setting up tables since 1962 and somehow seem to get them to work. I was serious about the Blutak, it is certainly an easily reversible option. There seems to be a conflict between fastening a cartridge to the arm as tight as possible and some of the coupling devices now on the market. Mapleshade has one but I haven't seen it, there are several others. I use a Graham arm myself and have had no problems, but then I don't use a $4K cartridge. I am a relic of another age when components were suppose to be capable of being used with most other things on the market. Naive of me to expect a $4K cartridge and a $5K arm to work together.
05-20-10: Downunder
Paul, that explains the difference.

Smoffat and yourself have Phantom II's. I have mark1 and the left side of the headshell is symetrical with the right, hence their being a gap on both back ridges with mine.

Yes Shane, I thought that would be the case.
I too have the SME base - so could adjust the base and cartridge position so the ridges contacted. I can't really be bothered going through the realignment process for what I suspect will be zero change sonically. At the moment 2 ridges are contacting and the third contact is with the cartridge top rather than the other ridge - no big deal IMO (as long as azimuth is compensated).
However, if you decide to experiment and find some dramatic improvement - do report it here!

05-20-10: Stanwal
I was trying to be factious with the grinding off, if your tabs offend you, cast them away etc. I myself would not obsess about all three touching at the same time but then I don't spend hours aligning cartridges. I have been setting up tables since 1962 and somehow seem to get them to work. I was serious about the Blutak,

No worries Stan.
Regarding the blutak - that's not something I'd employ with a high performance cartridge like the A90. That would seem to be the exact opposite of what is being sought with the ridges, ie a coherent rigid coupling for extraneous vibrations. Then again, things like the Cartridge Man Isolator works for some people, so who knows.
05-20-10: Stanwal
.......Naive of me to expect a $4K cartridge and a $5K arm to work together.

BTW Stan, just to be clear, the A90 and the Phantom work beautifully together. I didn't think twice about the positioning of the 3rd ridge when hooking up - but then I'd seen this before with the Ortofon Jubilee.
Those that are bothered by this detail can adjust the base and cartridge position - no big deal IMO.
Thanks for all the responses and tips. I have installed 2 little brass washers between the A90 and the headshell and tighten it down. I will give it a listen.

The cartridge is now perfectly level as none of the 3 tabs are touching now.
I do not have the SME base unfortunately. I do have a cartridge man isolator actually but i may not have enough VTA play at the back to bring the arm parrallel with the record surface. I will try this approach as well.
I am not about to take a dremmel to a $4K cartridge.

Thanks again guys......
05-21-10: Smoffatt
Thanks for all the responses and tips. I have installed 2 little brass washers between the A90 and the headshell and tighten it down. I will give it a listen.

The cartridge is now perfectly level as none of the 3 tabs are touching now.

I think that's a good solution - though exact levelness with the head-shell is hardly an issue with the Phantoms azimuth adjustment.
I'm sure it will sound great.
The solution is easy.
use a 2.5 mm square spacer which supports the three tabs at the A90. ofcourse the VTA needs to compensate for the 2.5 mm thickness.
you may use aluminum, brass, or ebony.
the downside is one of those materials will sound best in your situation so you have yet another parameter to tune.
the three tabs on the A90 just fit fine with the Airline, but not much space left here either.

very tempting to comment on the dremel tool 'advise'..
Tuboo, the only issue with that is the headshell is all ready thick on the phantom - adding another 2.5mm makes it difficult to find screws long enough.

I have a carbon fibre spacer from Thomas at TW, however none of the screws are long enough - where would you get loooong screws from??

personally I don't think it is that big a deal. the A90 is very rigid as is whether it be on the tabs or not.

yea I believe Stanwal is coming out with a DVD and book on how to care for your expensive cartridges with a dremel tool :-) sign me up - not
Downunder,
there are several screw lenghts supplied with the A90 package, but seeing the Phantom headshell thickness the 2.5mm extra spacer could be too large indeed.
the screws are metric 2.5 millimeter or M2.5 although they are easily obtainable in EU that might not be the case in USA.
but for sure you will find a supplier of metric nuts&bolts online who could send out those screws to you.
i can give you dimensions on the spacer to fabricate one yourself. the 2.5mm thickness is a suggestion, that could be 2mm but no less due to resonance. be sure to use non magnetic screws like rustfree steel, aluminium or brass.
I came across this on another forum and i think it could potentially help some Phantom users here. From the look of it I think it can be used as pure spacer or add a few inserts to decouple the cartridge from the headshell.
I have a Phantom II with Micro RX 5000 and i might try this later when i get my A90.

Midas Touch

Midas Touch
Jaspert, where do you get this spacer and do you know how thick it is.

Thanks
I have found a set of screws that will alloow me to fit the carbon fibre spacer and A90 onto the Phantom. This will allow all three feet of the A90 to be securely grounded.

Of course I found the screws after I moved the A90 to the Exclusive P3. So it will stay there for a while.

the carbon fibre headshell seems to be doing a very good job with my dyna XV-1. I think it sounds better balanced than just using the Phantom only. Might be somthing to think about for XV-1/Phantom users
The Ortofon Cadenza line has the same three nubs. I've been dissuaded from buying one, or the A90, for my Phantom II for this reason.

I ran across this carbon fiber spacer product from MusicDirect. It's rather expensive but might do the trick. Comes with a selection of long screws, too.

http://www.musicdirect.com/product/84232

Can't tell whether the three points will fit on the spacers, though, and the dimensions aren't published. Can any of you A90 owners guess at a glance whether these spacers might work?
Please excuse if I'm wrong, since I am speaking from experience with a MC Jubilee and a Graham 2.2, but I can see in that setup the very same visual discrepancy you describe with the A90/Phantom.

On the Jubilee there are three bumps at the top of the cartridge where it interfaces to the headshell. According to the Jubilee owners manual the purpose of these features are to provide approximately 2 degrees of azimuth adjustment.

What may not be clear is that the center ridge, that is the longer raised surface that runs partly down the middle from the cartridge front, is slightly higher in elevation than are the two raised bumps to the rear.

What this means is that the cartridge is intended to carry full contact, against the headshell, against the center ridge while it being optional as to which rear bump makes contact..... That means that Ortofon doesn't mind if one of those two rear bumps is not against the headshell.

As I take a close examination on my setup in use, it appears that, even though the Jubilee has two points of contact against the Graham headshell, the gaps seen between the low areas of the cartridge top surface and the headshell surface appear close to being uniform all over.

Fortunately with unipivots, azimuth adjustment isn't any kind of a problem. As to sra/vta, that's adjustable on the fly and none of us should have a problem dialing in that parameter even if your cartridge body isn't exactly parallel to the headshell....

I guess what I'm saying is; it probably wouldn't matter even if you did have enough headshell surface area to cover the three bumps, because the cartridge is going to be pressing its center ridge against the headshell and tipping ever so slightly to one side or the other.

-STeve
Wm57.

Those millenium headshells are the same as mine carbon fibre one, except that I only have one as it was given to me. From listening to it with the dyna XV-1, it sounds excellent as well.

Those carbon fibre headshell will fit no problems, in fact any headshell will fit on the A90 onto the Phantom.


I don't believe it is any problem using an ortofon cartridge with the Phantom as mentionbed by a few here.

I fould the A90 sounds superb with the Phantom as is, so IMO it is of no big concern. I will try the carbon fibre headshell with the A90 thou, but a bit later.
I spoke with Ortofon regarding the A90 and Phantom II and they assured me there are no issues what so ever.....it also was mentioned Bob Graham uses the A90 with his arms.

Dealer for Graham & Ortofon
Downunder, thanks for the info. I think I see an A90 in my future :)
Agree wth Downunder about the Ortofon working fine on the Phantom.

And the aluminium spacer with holes for screw in inserts is being made by a member of Lenco heaven.I'd asked him about it and i think it's about 2.35mm thick.