What's the + and - of the 12" Tonearms

Issue 51 of HI FI+ features a comparison of three 12"arms the Vpi 12.7,Kuzuma stogi 313 and the Schroeder reference.Roy Gregory talks about the theory longer arm lower tracing error and the bad things higher cost,higher effective mass and inertia and turntable compatibility [not mountable to most closed sprung chassis tables designed for 9" arms]His summing statement is that he could live happily with any of the test arms and based on the evidence a good 12" will always beat a good 9" and that they have an ease and natural sense of musical progression and they help remove the system itself from that process,Issue 50 tested a SME20/12 and 52 a project p9 carbon 12"arm and the Brinkmann.Its worth a read.