Tracking error distortion audibility

Thom @ Galibier,
WOW!
I'm sure any competent person would not make the errors you cite above as reasons to not deviate from manufacturers set-up, certainly not Brooks. I understood him to mean increasing effective arm length with slotted head shell models is a trick he uses with no downside. I assumed it was commonly used by experience turntable techs. I am sorry if I misunderstood but it seemed pretty clear to me what he meant. You might have understood something different but I don't recall you being present during our conversation although I might be mistaken as you indicate you heard it with great clarity "I'm sure he was arguing.....".
I am glad even happy that you like your protractor. What is your reference that verifies your protractor's set-up? What do you use to verify the stylus is perfectly aligned to the cantilever? Your protractor?

Hi Feathed,

I'm sure any competent person would not make the errors you cite above

Well, that leaves the other possibility - that they are misinformed. It's no crime, and I surely have a lot to learn as well as the next fellow. Frankly, this is one reason I post on this forum. No one can know everything, and collectively, we are all better for the exchange.

OK, I'll do some work for you and for Brooks. Based on the Ellison spreadsheet, here are the distortion numbers for 239mm and 243 effective lengths:

Effective length = 239mm:

at 57mm = 1.16%
at 146mm = .62%

Effective length = 243mm:

at 57mm = 1.14%
at 146mm = .61%

As far as references are concerned, I primarily use the two appendages on the side of my head along with all of the other individuals who,like myself thought that years of working with two point protractors yielded as good results as you could reasonably expect to achieve. I don't know of a single individual in my listening circle who still has this opinion.

I'm going to be in So. Cal in a couple of weeks' time, and had planned on visiting Brooks. This thread gives me one more topic of conversation. Brooks is someone I've admired for quite some time. If indeed your memory of your conversation with him is accurate, then I'll take the opportunity to set him straight.

Cheers,
Thom @ Galibier

Dear Feathed: +++++ " It's so simple I just assumed everyone did this. " +++++

everyone that wants to change the effective tonearm length.

+++++ " You get the exact equivalent of a longer effective length tonearm. " +++++++

and a " little " different performance.

IMHO the designer tonearm voicing was taking in count that spindle to pivot spec along the overhang and " original " effective length.

How do you know what the tonearm designer intented through its original specs? IMHO it is not only the geometry tonearm parameters what define the tonearm performance. Nothing is perfect and has trade-offs: how do you know which trade-offs choose the tonearm designer?.

You can change those parameters but like I told you the performance will be different.
So, IMHO that spindle to pivot spec is still useful and necessary.

There are times where is important to preserv/guard a little respect for the designers.

Regards and enjoy the music.
Raul.

Thom,
Your longer effective length calulations show lower distortion and there is NO downside. You just proved the point. You claim to respect Brooks and you don't know everything yet you will
"set him straight".

Raul,
Not mounting a cartridge exactly where a manufacturer's direction say is not disrespecting the designer at all. The arm manufacturer has to allow for inaccurate drilling of the mounting board and has to accommodate all possible cartridges. I bet all designers would applaud taking the effort to tweak the most performance out of their arm. I'm not insisting anyone has to do this. You, like the manufacturer may want to drill in the middle of the range in case of a slight error during the drilling or in case you later wish to sell the table to someone with a very odd cartridge. I very much doubt the increase in length will make a significant improvement but why not optimized all you can?