Click title to read one, or click date to read all below it.
02-08-11
It is relatively easy to machine and is inexpensive. however ... Schipo
02-08-11
Maybe because it's non-magnetic and so won't suck the magnet ... Viridian
02-08-11
I would think copper would be good. especially an alloy tha ... Elizabeth
02-08-11
I was under the impression the weight of the platter was mor ... Has2be
02-08-11
The name of the plastic is delrin, a dupont trade name for p ... Viridian
02-09-11
The idea of "big" or extremely heavy platters is m ... Jtinn
02-09-11
Just look at the platter of the relatively inexpensive ($2k) ... Inna
02-09-11
Viridian thanks for the trademark education but michell p ... Has2be
02-09-11
"belt drives...in terms of speed accuracy, are clearly ... Wntrmute2
02-09-11
Nothing cogs like a dd. the mass of the platter has nothing ... Dan_ed
02-09-11
I just know in direct comparisons in the same system between ... Philb7777
02-09-11
Let me restate that. ;-) the mass is not there for inertia. ... Dan_ed
02-09-11
02-09-11: wntrmute2 wrote: "belt drives...in terms of s ... Chayro
02-09-11
Has2be, i wasn't speaking about michell at all, simply about ... Viridian
02-09-11
I think the key to an aluminum tt platter is to properly dam ... Peterayer
02-09-11
Aluminum is used for several reasons. the first is that it i ... Atmasphere
02-09-11
And this is why you as a consumer payed so much for the gold ... Schipo
02-09-11
i think the reason why direct drive tables tend to have ligh ... Paperw8
02-09-11
I am in the process of building a turntable made entirely of ... Manitunc
02-09-11
you're talking about half hertz at 33rpm. that frequency e ... Hiho
02-09-11
When vpi's harry was asked that question he said it was all ... Buconero117
02-09-11: Paperw8
02-09-11: Hiho
You're talking about half Hertz at 33rpm. That frequency exists in ALL turntables. Direct-drive is as quiet as anything. Unless the bearing is bad quality, there is very little or no noise in DD, just like belt-drive. I would say it's even quieter than belt-drive. The motor turns at 33rpm, the same amount of rotations as the platter of a belt-drive or idler-drive, WITHOUT the fast spinning motor in a BD or ID that sometimes spins at 1800rpm, and that's 30Hz! Now, the DD platter is spinning at 33rpm by magnetic force and please tell me where the stereotype DD motor noise is coming from?
you can't hear 2Hz so obviously i was not referring to any 2Hz rumble. in the real world, nothing is machined to perfect balance, so when it rotates there will be some vibration. if you can hear sound from a drive motor, then obviously the frequency is within the audible range. a cartridge can pick that up and if it does, it is likely going to be in the part of the frequncy range that is amplified in a phono stage.
as to the magnetic drive to which you refer, a rotating magnetic force field (which is what you need to turn the platter) doesn't just happen by magic: there has to be some motor that turns a rotor (e.g. an induction motor) that creates the time varying magnetic field that could turn a platter by lorentz force. there will be *some* vibration in that motor. if it is a reasonably well made turntable you probably won't be able to hear it, especially if you use a large signal cartridge.
Paperw8 (Threads | Answers | This Thread)
02-09-11
the rotor is part of the motor, propelled by the stator coi ... Hiho
02-09-11
No viridian it was not missed at all. as usual your need to ... Has2be
02-09-11
Aluminum (or aluminum alloy) were chosen many decades ago fo ... Johnnyb53
02-09-11
As a former club dj and as current employee for one of the w ... Nick_sr
02-09-11
things have probably changed quite a bit since the days when ... Paperw8
02-09-11
"in the '70s, a 4-to-5 lb. platter was considered a hea ... Robob
02-09-11
In my experience aluminum is not the best platter material. ... Teres
02-09-11
i used to have a dual turntable, which was a fairly popular, ... Paperw8
02-10-11
i was a dealer at an audiophile store in 1975 when the sl120 ... Johnnyb53
02-10-11
"i find that paper based phenolic, like garolite xx, ma ... Livemusic
02-10-11
If you use enough aluminum, it can get pretty heavy. it is a ... T_bone
02-10-11
T_bone, very good post. this dd sub-topic came about after s ... Dan_ed
02-10-11
Livemusic, yes cocobolo is still the best platter material i ... Teres
02-10-11
I had a technics sl-1100. i think it had the distinction of ... Atmasphere
02-10-11
"but compared to other 200-300 turntables of 1975, the ... Robob
02-10-11
Chris/teres, my understanding of the technical term for cogg ... T_bone
02-10-11
Copper is the best for platter top! Ebm
02-10-11
Cogging is measured as torque ripple. it is the amount of va ... Teres
02-10-11
Chris, i was wondering what physical phenomenon generates th ... T_bone
02-11-11
there are problems with any metal for being the top of a pl ... Atmasphere
02-11-11
I wonder if cocobolo is such a good sounding wood if one can ... Mechans
|
|
