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In Reply to: RE: SAS available again posted by flood2 on July 24, 2016 at 02:57:47
> The 500 hours is not the time to failure but the time for the distortion level due to wear to exceed 3% at 15kHz
In addition to frequency, the modulation level of the groove is also important because distortion increases with modulation level. Therefore, you need to specify either groove amplitude or groove velocity in conjunction with the 15-kHz frequency. Another approach might be to simply specify the particular test record being used for the 15-kHz distortion test.
Best regards,
John Elison
Follow Ups:
I think we would both agree that the number of hours is a meaningless metric. It is rather like comparing the range of a vehicle with respect to fuel economy. Without specifying the average modulation level and the number of different records used, tracking distortion characteristics, antiskate level, cleanliness of the groove, tip alignment, diamond purity, tip polish, VTF, compliance etc.
If the test used the same record and played that over and over to determine wear rate, one would find the rate of wear to be higher than playing a wide variety of different records.
However, with the SAS/MicroLine, I think there needs to be some guidance on what to listen for given that they will fail catastrophically if taken right to the limits of the ridge "height". The patent implies that the limit to the scanning radius dimension is that which doesn't break off....
Regards Anthony
"Beauty is Truth, Truth Beauty.." Keats
I'm not sure what you're arguing about or why. Your original statement about evaluating stylus wear by measuring 3% harmonic distortion at 15-kHz is incomplete without also specifying the groove velocity of the test tone being measured. In lieu of that you could specify a particular test record instead. I'm not talking about using a worn out test record. That would be pretty stupid, wouldn't it?
I'm not sure why you assume that everyone is arguing with you. You should get over yourself and learn to be a little less defensive.
Who said anything about a worn out test disc? You obviously didn't read what I wrote clearly, in which case, read it again. This time with both eyes.
If you have an issue with the information take it up with JICO who supplied it!
Regards Anthony
"Beauty is Truth, Truth Beauty.." Keats
Sorry! I guess I shouldn't have responded because I really don't understand what you're talking about. I keyed in on the statement about 3% distortion at 15-kHz, which is basically meaningless without further qualification.
Sorry!
John Elison
...has test tones (20,18,16,14,10 and 5kHz) at -15dB ref 0dB, 5cm/s RMS for L and R channels at the inner and outer grooves for determining scanning loss/wear. I am not aware of any current test discs that have similar test tones, although any test disc with spot frequencies could be used. A cartridge manufacturer could specify the "life" based on any arbitrary frequency they chose and choose any distortion level that gave them favourable numbers.
Regards Anthony
"Beauty is Truth, Truth Beauty.." Keats
No worries! Just to reassure you for future interactions, I'm not given to attacking on the forum (unless provoked!) and least of all with people I respect. In fact, I was agreeing with you. The ill defined test conditions of the distortion level at 15kHz notwithstanding...my point was that quoting a specific lifetime is itself meaningless given the number of factors involved in determining wear. For a given tip, say a MicroLine in a PTGII tracking at 2g, you must get a higher wear rate than for the same tip in a V15VxMR tracking at 1g. Quoting 1000 hours as the life may give an indicative figure, but is clearly not going to be accurate.
The other point I was making about the wear rate was that if you play one record (not a test disc!), say, over and over, you will wear the tip at a greater rate than randomising the playback over a significantly larger sample of discs. Presumably this will be due to the wider variation in modulation level plus if you play back one single record, the particulate buildup in the grooves (shed from the tip) will accelerate the wear.
Regards Anthony
"Beauty is Truth, Truth Beauty.." Keats
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