Dear friends: I'm not on the TT design ( tonearm/cartridge is my priority. ) but this discussion could help to everyone in some way or other, at least to understand what is happening.
Some of you " speak " about specs and IMHO this subject could be very controversial for say the least.
Many of the " standard " specs/measures on audio items ( any ) can't explain per-se why we hear/heard what we hear/heard.
My opinion on the subject is try to define what/where/how to measure and its relationship with what we hear/heard or our targets about. IMHO not an easy task: whom will fix/decide those " true/new spec standards "?. Anyway a good " exercise ".
A second subject: stylus drag. During our tonearm/cartridge research/design I made several tests and still doing ( for different reasons that TT design. ), one of them was this:
I choose seven different cartridges ( different stylus/compliance/MM-MC design, VTF, etc. ) and five different LP's.
The test was over the same TT and same tonearm ( at the same time. ) where the " only " variable was the cartridge ( well more than one variable due that each cartridge has different parameters. ).
The test was a " home test " not a strict controled and scientific one but interesting.
What we want to measure was how the stylus drag ( well the tonearm/cartridge. ) could change with different cartridge in different LP in different velocity recorded tracks that I choose.
What we do?: we put " that " cartridge in the tracks ( each one at the same time ) I choose ( running the TT at 33 rpm. ) and suddenly switching-off the TT and measure how many seconds take the platter to stop. I choose three tracks on one side in the LP: one at the outer of the LP one at the middle and one at the inner of the LP.
The tools I used was a cronometer, eyes and very fast " brain reaction ".
Not an easy test, I have to train for several hours ( two days ) till I " show " good " constant " response ".
This test show us that that stylus drag " exist ", that its behavior is cartridge/stylus/VTF/position on the LP dependent, that is different on different tonearms and TTs, that a heavy platter ( 20 kg. ) in rotation has an influence on that stylus drag when you swtich-off, etc, etc .
I know that maybe this almost " hobby-test " does not help on the TT discussion due that the TT was/is switch-off and that was not made it in a scientific/tools way but the test opened my " eyes " for our self tonearm/cartridge design.
It is not to easy the desing/research on " mechanical " devices ( like tonearm/TT and the like . ) specially the tests of those devices because it is not only a subject to have the know-how what/which/where/how but to have the precise scientific tools to do it: we need a laboratory and we need a lot lot of money to have that laboratory.
This issue is/was one of the reasons that bring us ( on the tonearm design ) to find where to do it, finally we meet our friend at the University and even here is not easy because is something " new " where the " scientists " does not have many experiences: it is an easy task for them nothing difficult but " new ".
Like always, I say every single day is a learning one to anyone in different areas/topics on our day by day life. There are more knowledge to discover to experience that our self ( each one ) know-how.
Regards and enjoy the music.
Raul.
