Multiple arms, multiple cartridges and geometry?

Dear Raul,
Oh oh.......you mean that when I set up a cartridge on one arm with, say.....Baerwald geometry......it doesn't mean that it will be correct if I change to another arm with a different pivot to spindle distance and overhang?
I somehow feared this might be the case.....and I can easily check it......but damn!!!!......as Stanwal then says.....I am forever going to drive myself mad by changing and checking geometry at every change of tonearm and cartridge?
Oh boy......what a disaster!!?

Dear Nikola,
Que??.........
Lew.......you're right about my ability to 'massage' the spindle to pivot distances for all my arms.
I'm thinking......and I may be wrong (need to check the Vinyl Engine formula)....... Whether I can adjust the P to S dimension of all the arms to have a uniform 'overhang' dimension?
Will that allow for a 'common' interchangeability?
Regards
Henry

Dover,

and the only changeover issues would be tracking weight and VTA.

That's what I thought and the principle I have been operating under?
However.....I fear that is not the case?
The effective lengths and overhangs being different for all my arms......means the arm geometry is not easily transferable?

Raul,
I agree that I need to accept the same geometrical alignment for all the arms I wish to use with detachable headshells......say Baerwald?
I can appreciate that I can adjust the P to S distance of each arm so that the 'Overhang' can be the same.......but I don't see how I can adjust the effective lengths between 222mm, 230mm or 295mm to be the same? :-(

Can you possible explain a bit more thoroughly?

Cheers
Henry

Yes Ecir and John,
I'd forgotten your earlier response on this subject John.......but reverse engineering seems to be the way to go?
I will try it and see if it works on all my arms with all my cartridges?
Thanks...and keep tuned :^)

Henry

Dear Nikola,

Thuchan and Raul will really understand your effort.

Now that you've pointed it out........I realise how in the minority I really am?!

But what is this....changing the geometry to match the record??!
When you are telling me that this is what YOU do.......then I might think about it?
On the other hand......no I won't :-)

But you once wrote a very telling post which I remember very well.........you said:-
If there are two 'null' points on every side of a vinyl record where the cartridge is in perfect geometrical alignment.......why don't we jump up and shout "Eureka" when we hear these two magical moments on each side?

And the answer is.............

Kind Regards

OK........have just spent the day checking my arms and cartridges :-(
Who said that "Analogue starts with anal"?
Apart from one of my ZYX Universe cartridges mounted in the DaVinci 12" Grandezza and one of my Empire 4000D/III Gold cartridges which is fixed into the Continuum Copperhead tonearm.........all my other cartridges are fixed into removable headshells which have been aligned using Dertonarm's UNI-Protractor with the Fidelity Research FR-66s template and arm mounted at 295mm S to P.

I inserted some random headshell/cartridge combinations into the Micro Seiki MA-505s mounted at the recommended 222mm S to P distance and checked the alignment against the UNI-Protractor with the MA-505 template inserted.
The alignments were almost perfect......but a correction to 223mm S to P distance.....DID make them perfect :-)

I next inserted some random headshell/cartridge combinations into the FR-64s tonearm mounted at the recommended 230mm S to P distance......and lo and behold.......perfect alignment :-)

Moving onto the SAEC-308N with a recommended 235mm S to P distance......I could not make any headshell/cartridge combination align with the correct point?! At the furthest headshell slot.....the stylus point was always 3-4mm too short. Four different headshells were tried with the same result?!
I remember this happening with my Grace 940G tonearm as well....with only one headshell able to stretch to the correct distance?
I then remember what Daniel had written to me about the 235mm distance when he sent me TWO templates for the SAEC-308N......one at the 235mm S to P distance...and another at 225mm S to P??

It is indeed, but it results in a rather "sub-optimal" overhang of 5 mm only.
The resulting tangential curve is catastrophe.
The overhang has to be prolonged.
My template (at 225mm) results in effective length 251.1 mm.

So I moved the armpod to give the alternate 225mm S to P dimension......but of course all my headshell/cartridge combinations did not work!?
The off-set angles and overhangs were totally wrong :-(
They required massive twisting of the cartridges in the headshells to be aligned correctly and only the Yamamoto wooden HS-1AS and Micro Seiki headshells allowed such extreme twisting?
So I selected about 4 or 5 MM cartridges in these headshells...and aligned them according to the UNI-Protractor with the 225mm template.

Ahhhh........the sound....the joy....the bliss!!

So the net result is this:-
I have two tonearms (the Copperhead and DaVinci) without interchangeable headshells.
I have three tonearms with interchangeable headshells which accept any of 20 of my cartridges pre-mounted in their individual headshells...with correct geometry.
I have one tonearm with interchangeable headshell capability (MA-505s).....which has five dedicated headshell/cartridge options ready for instant insertion.

I'm like a pig in mud.....only cleaner.

Dear Raul,
Why not align all tonearm designs at 225-227mm?
THE REASON
It ain't a pretty sight huh??.....and most arms should sound their best at their Manufacturers recommended specifications?
But apart from all that......I would then not be able to use cartridges with fixed headshells such as the FR-7f and the Technics EPC100Mk3?

Regards
H

Good questions Mapman and Peter......
In one way I agree with both of you. There really are too many choices BEFORE I even choose a record to play?!

On the other hand......for 30 years.....I listened to one turntable with one arm and one cartridge (although that cartridge might change every 2-3 years?).
And yes....it was very enjoyable.
But each time a new cartridge was inserted.....a different perspective was given to all my cherished records. Sometimes....this different perspective seemed a step backwards....or at least....gave less satisfaction?
Only when a new cartridge gave a keener insight into the listening experience.....did it stay for the course.
But the sheer fact that every cartridge DID sound differently should have raised some important questions.......is there a 'correct' sound to a cartridge?......ie-the ABSOLUTE sound?
The answer of course...as we all know....is NO.
That is why we all have different systems with different sounds....and I won't venture into the preferences for valves vs solid state, belt-drive vs DD, MCs vs MM, planars vs horns vs dynamic vs sealed vs ported??

If every cartridge offers a different perspective....and every arm and turntable likewise......aren't there some benefits to being able to instantly sample those perspectives on a daily basis?

And that's precisely what I do!
Sometimes I'm entranced with the sound of a particular cartridge on a particular arm I'm using....and will listen to records for day after day until suddenly.........I will hear something on a track that triggers a desire for a 'different' perspective?
This may entail the 'radical' shift to my other turntable with a totally different arm and cartridge 'type'?

Most audiophiles don't use 'tone-controls' or equalisers and need to change a component or cable to effect a change in sound to their set-up?
Imagine being able to do that every hour of the day...every day of the week?

Yes...my choices are now vast compared to most audiophiles....but the increase in my knowledge and listening experiences allows for a greater appreciation of the variations and diversities which make up this intriguing hobby?
Anyway....that's my story and I'm sticking to it?! :-)

Cheers
Henry

Dear Mapman,

Shouldn't the letter 'p' in your name....be a 'd' :-)