Tonearm without off-set

Johnbrown

"but don't expect me to support your ill-fated dream."

None was asked for. It is just a bloody arm that we are discussing. I do not understand why you are so worked up about this. You want to kick my dog or something?

And regarding "math (sic)" logic, so how come some highly regarded contributors here removed their anti skate devise on their ET tone arm and not use them? There is no maths in that.

Some of us actually use our ears to determine what Maths can't explain.

Also if we are so dogmatic about perfect tangential alignment, we should never ever use any pivoted arm - off set or not. How much distortion is acceptable or discernible? Choosing by numbers is a worry when it comes to sound.

And in your opinion, it seems that the only criteria for a tone arm to sound good is to have perfect tangential alignment. There are other factors that can make a tone arm great sounding. And if you do not know already, all tone arms sound different regardless of perfect geometry or not.

Anyway, I respect your opinion and let's just say that you do not agree with me on this topic and perhaps many more.

Nice talking to you.

What Doug and Raul said ...

Look up the numbers on John Ellison's gift to analog-kind - his Baerwaald / Loefgren spreadsheet on the "Free Stuff" section of the Enjoy the Music website. This is Frank Schroeder's and my bible.

If you have trouble finding it, go to my Support Page, where I maintain a link to that section of the Enjoy the Music site.

Cheers,
Thom @ Galibier

Hi William62,

One more thing ...

Removing the offset angle still leaves you with the decision as to whether to create overhang, underhang, or neither. You still need to arrive at an alignment strategy that minimizes tracing distortion for your chosen path (e.g. offset angle = 0).

While skating forces are very real, they are secondary to minimizing tracing distortion, and this is the genesis of the posts advising you to go by the numbers.

The math developed by Baerwaald, Loefgren, Stevenson, et. al. were all exercises in optimizing tracing distortion over various parts of the LP.

I have to admit that I've played only minimally with Loefgren, but my experiments with the Baerwaald Mint LP protractor (after being a two point protractor user for eons) was a revelation to me, Doug and countless others.

Now, strictly speaking, slapping a cartridge on a tonearm and randomly mounting it is an "alignment" and we can give it a name if we choose ("Joe the alignment").

After hearing the difference between "almost Baerwaald" (as in attempting it with a two point protractor) and an accurate Baerwaald (Mint LP arc protractor), I've gained more respect for the math developed by him.

Having said that, knock your socks off and have some fun. Why don't you make concentric, crescent shaped slots in your headshell that will allow pivot the cartridge from 0 degrees offset to the Baerwaald recommended number for your effective length? Then, you can prove this to your own satisfaction and report your findings.

Enjoy the journey,
Thom @ Galibier

Cheers,
Thom @ Galibier

Thanks Thom. I really enjoyed reading all your posts in AG.

Over the years I have owned or still own: Grace 707, Lenco, LE1, PU2, Alphason HRS100, Rega RB250, Well Tempered, PU3 and Aro. So I am not new to pivoted off-set arms or has anything against them.

You are absolutely right that tangential alignment accuracy is very important. I can hear the difference you mentioned. I even slotted my Aro head shell which only had two holes so that I get it perfect.

The thing that most interest me in trying non off-set straight arm (which is only one of the 3 arms that I am intending to use in my system), is the fact that the cantilever will not be subjected to inward force (or even stress) created by off-set arms. What I am interested to know is how much more we can gain from a cartridge when there is no inward force caused by off-set arms.

Perfect tangential alignment aside, there must be benefits from having a "less" stressed cantilever.

I am now almost certain to have a 12inch arm with both off-set and non off-set straight arm wands. Both will be exactly the same except for the head-shell geometry. (So Johnbrown, I do actually listen to other people's opinion.) I will report my findings if there is any interest on this topic.

It really surprised me that I did not get any response from people who have tried or taken this path before. I was really hoping to hear from someone with actual listening experience of a non off-set arms. They have been manufactured before and I am sure there are some still in service out there.

The RSA-1 has somewhat of a cult following for those who do not mind fiddly toys. This arm has no offset and the tangential alignment is way off, but it is acknowledged by some to be a great tracker with very low distortion (soundwise). I will also be getting one of this to see what the buzz is all about.

Don't know if what I am intending to do will be any good, but I am certainly going to enjoy the experience.

Later.

Dear William62: +++++ " Don't know if what I am intending to do will be any good, but I am certainly going to enjoy the experience. " +++++

any audio experience is a learning one and certainy could be fun.

Now, why exist a tonearm?, IMHO ( like the TT ) is a tool that the cartridge needs to recovery the information that was/were recorded on each groove on each LP tracks.

Which is de " ideal " way for the cartridge can/could recovery that recorded information?, IMHO that is through a linear tracking tonearm that in theory has no tracking error ( angle ) over the LP.

Well, the main subject/target on that tool name it " tonearm " is to help the cartridge to recover the recorded info with no tracking error ( of course, between other important things ).

IS there other form/way to help to the whole cartridge job different than a linear tracking tonearm?, yes, one of that forms/ways is a pivot/ed tonearm.

will it be any trade-offs using a pivot tonearm against a linear tracking one?, yes, any other tonearm form/design means tracking angle error against cero traking angle error on the linear tracking tonearms.

So, what to do if we want a different/pivot tonearm?, well some people like Baerwald, Loefgren, Stevenson and others made scientific studies to achieve/optimize how to put at minimum that tracking angle error for the cartridge really can to take out the recorded information with almost no ears perception distortions trying to even the linear tracking ( in theory ) cero distortions.

And this was the main subject on those " tonearm projects and was from them that the terms " effective length, overhang and offset " comes out.

Today normally we align the tonearm/cartridge through Baerwald or Loefgren ( where Baerwald has a slightly higher distortion over the LP but the inner grooves against the Loefgren ) trying to have the lowest distortions and the highest quality performance.

Any one of us ( including you, according with what yu posted ) knows that very small deviations on/out that " ideal " alignment alternatives makes a difference in the quality performance and almost always for the worst.

Now, you don't want to make a " small/slightly " change but a " big " one with the non offset tonearm, this fact makes that what you hear will be a far far away " sound " of what is in real in the recording with a lot of distortions, no doubt about because is a totally wrong " road, if you like it or not ( what you are hearing ) it is another matter and does not change the fact that is wrong: you can't change the geometry rules, well at least I think ( with all respect ) you are not a " new " whole geometry proposal scientist man.

If we analize all the different parameters on the tonearm/cartridge alignment/set-up like: VTA/SRA/VTF/overhang/Azymuth/anti-skate/etc, probably the less/least important is the anti-skate and you want to make a " huge/great " trade-off changing the main tonearm target for the " less " important one!!!!!

Have fun.

Regards and enjoy the music.
Raul.