Can you elaborate a bit? I'd love to learn what to measure and how to interpret it. Phono setup can be fiddly, I need all the help I can get.
Nothing concrete, like Scott thinking aloud, just without his experience to stop me saying something daft. But I think a significant amount of the measurement could be automated.
And bear in mind I'm yet to actually try measuring azimuth on my turntable.
But still thinking aloud I 'athink' there are 3 parameters that interact
Azimuth
antiskate
cartridge balance
azimuth and antiskate are about finding minima, once those are found balance should be a measurement. BUT can you infer both at once,or do you need to optimise one after the other. I guess that's measurement time.
Or I could be completely hatstand.
And bear in mind I'm yet to actually try measuring azimuth on my turntable.
But still thinking aloud I 'athink' there are 3 parameters that interact
Azimuth
antiskate
cartridge balance
azimuth and antiskate are about finding minima, once those are found balance should be a measurement. BUT can you infer both at once,or do you need to optimise one after the other. I guess that's measurement time.
Or I could be completely hatstand.
Bill, getting back to the original topic. I buy a lot of old, filthy records (none of the obscene) for cheap. Here is what I use to clean them, and it works better than anything I've ever tried.
Vinyl Record Cleaner & Washer | Spin Clean
I've had discs that look like they'd been thru a dust storm in the Outback and then left to mold in jungle - come out shiny and pretty as you please. Doesn't do anything for scratches, of course. It's low tech and manual, but certainly works well. I don't do as many cleanings per refill as suggested, because I'm starting out with such filth and the water gets dirty fast.
Vinyl Record Cleaner & Washer | Spin Clean
Vinyl Record Cleaner & Washer | Spin Clean
I've had discs that look like they'd been thru a dust storm in the Outback and then left to mold in jungle - come out shiny and pretty as you please. Doesn't do anything for scratches, of course. It's low tech and manual, but certainly works well. I don't do as many cleanings per refill as suggested, because I'm starting out with such filth and the water gets dirty fast.
Vinyl Record Cleaner & Washer | Spin Clean
Yeah, I was being seduced by the ultrasonic cleaner too, but the cost just wasn't justified for the old records I buy. The spin-clean works remarkable well. I use microfiber towels to pat the disc dry, then air dry the rest of the way. They dry very fast.
Spinning the records by hand in the cleaner - there is a bit of drag - fast gives you an appreciation of vinyl thickness and how the edge is finished. E.G., must Decca are heavy with a smooth edge.
Spinning the records by hand in the cleaner - there is a bit of drag - fast gives you an appreciation of vinyl thickness and how the edge is finished. E.G., must Decca are heavy with a smooth edge.
Who said I would only clean records in it? Next you'll be telling me car parts should never be put in a dishwasher
Back on the azimuth etc and having had a first read of the B&K links you could use a piezo device to do setup without the vagaries of a test record. Would still need a test record for the impulse response test. Just depends what is available off the shelf that isn't big $$$ or needs mega cal.
Anyone got any candidates?
Back on the azimuth etc and having had a first read of the B&K links you could use a piezo device to do setup without the vagaries of a test record. Would still need a test record for the impulse response test. Just depends what is available off the shelf that isn't big $$$ or needs mega cal.
Anyone got any candidates?
Here's something that might warp fragile minds, and I suspect you've probably not heard before, Bill, and bang on topic.......
The best way to set stylus azimuth is to measure friction, eg as per the Pardee paper in the OP. Most of the audible effects arising from incorrect stylus azimuth, including mistracking, are due to variation of friction with exact alignment of the stylus. The only exception is channel separation, which is determined by coil azimuth alignment. Everything else is influenced by friction, which varies with the exact angle presented by the stylus to the groove. The finer the contact radius, the more sensitive to exact alignment.
Same is true of VTA, and also zenith (cartridge tracking angle).
There is also a noise minima at optimal azimuth and VTA, and zenith, this is the best method for setting them, IMO.
Setting azimuth for optimal channel separation aligns the coils, but not necessarily the stylus. If the stylus is not set accurately in the cantilever, as can often be the case IME, best overall results might not arise from most of the accepted methods which align coils...............
Skate force compensation is just a hopeless cause. See Barlow's footnote in the Pardee paper, how measurement of even steady state or average friction can vary over the surface of the record by a factor of 3..........furthermore friction varies from moment to moment in a flicker law, perhaps by a factor of +/- 4 from moment to moment - see my earlier posts on this thread.
Then applying a constant antiskate force doesn't do much good in the grand scheme of things. It's just surrogate VTF, so might as well press up VTF by 10% and omit the antiskate mechanism IMO. Less things to rattle around.......
That will set coil azimuth. See my post immediately above for why this might not be overall optimal..........
Yes. One is looking for the minima of the friction noise floor. The process can be meticulous and slow, patience is needed. But one doesn't do it often, with a bit of luck. Needs to use a silient or 'blank' groove on a test record. I've never tried with a run-out groove, but often they aren't silent, the headshell is always in motion, and the groove there isn't necessarily cut with care - plus need to avoid the lock-jump which obviously isn't silent......
You mean not optimal for things like distortion? Setting the az to where xtalk in both directions is equal does implicitly assume that the tip is aligned perfectly wrt the coils, isn't it? That may not be a correct assumption.
Jan
Yes. Near perfect axis alignment of the stylus is not typically a safe assumption, and indeed varies widely IME. It does seem to be one of those aspects which correlates with price, unfortunately....... Friction is the factor behind the general 'fussiness' of fine contact radius stylus as to alignment versus performance in the broadest sense.
Here's another blast from the past: attached is an old plot of mine from a few years back of how coil azimuth affects channel separation in principle. You can see that setting for the optimal separation is very critical, and results in a very specific setting for the coils. This setting might not be optimal for the stylus axis, if it isn't set near perfectly in the cantilever.
Whereas, if one say compromises channel separation to a limit of say 20dB or lower, a much broader range of stylus axis alignment is permitted. And there may be friction related performance gains which more than offset the compromise in separation..........
Whereas, if one say compromises channel separation to a limit of say 20dB or lower, a much broader range of stylus axis alignment is permitted. And there may be friction related performance gains which more than offset the compromise in separation..........
Attachments
Thinking aloud here. The average MM has a noise floor anywhere from -70 to -80dB so a good phono stage into a decent pc sound card should be good enough for this. But I assume you would be better off with unequalised gain ? what is the noise spectrum we are talking about here?
VTA I can adjust whilst playing. azimuth I can't. In fact on the SME its a gert pain. Don't suppose anyone knows how to actually adjust the cartridge rather than the tonearm?
I think there is defiantly something we can do here to help the DIY community. With Fozgometers running $300 for a meter in a box.
VTA I can adjust whilst playing. azimuth I can't. In fact on the SME its a gert pain. Don't suppose anyone knows how to actually adjust the cartridge rather than the tonearm?
I think there is defiantly something we can do here to help the DIY community. With Fozgometers running $300 for a meter in a box.
The absolute figure doesn't matter, and in any event depends on the test record and the specific stylus/cartridge - what matters is finding the noise minimum. Noise spectrum is formed from random pulse events of various short duration, as such it is pretty much white.
I really think this is strictly one for the vinyl Jedi. It's difficult to measure, requires interpretation, and depends on specific configurations as to whether it is observable at all.......billsurv said:
Really I mention it as a matter of principle, to help understanding of what is really going on with friction in vinyl playback. The most overlooked factor in playback performance for decades, IMO.
I'm not so sure. People are in many cases being more careful with vinyl setup now than in the past as the information and technology is available that was $$$ in the past. Look at the number of USB microscopes for setting VTA and the sales of the feikert test record. Everyone has a PC that has the sort of processing power we could only dream of in the 80s.
But for now some fun learning for me
But for now some fun learning for me
Re VTA issue, see VTA
Re skate compensation issue, skating force=coefficient of friction*stylus pressure*sinus of tracking angle. No advanced antiskating mechanism can compensate for the dynamic change of coefficient of friction
http://www7a.biglobe.ne.jp/~yosh/bias%20devices.xls
George
Re skate compensation issue, skating force=coefficient of friction*stylus pressure*sinus of tracking angle. No advanced antiskating mechanism can compensate for the dynamic change of coefficient of friction
http://www7a.biglobe.ne.jp/~yosh/bias%20devices.xls
George
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.