Wayne, thanks for the revaluation of how much greater WLL (and others could be).
I would like to tackle a few of these issues (not all can be resolved but some can be made lesser of an issue [and I am basing that on my Technics SL-M3 Linear tracking turntable])
SPECS:
From: Audio Database
Technics SL-M3
- ¥ 99,800 (around 1986)
Commentary
A full-auto player with linear tracking system.
It is equipped with a unique linear tracking arm that can make tracking error, which causes distortion during playback, and inside force, which causes channel imbalance, close to 0.
The tracking error angle is within ± 0.05 ° by detecting the arm deflection angle with an optical sensor and obtaining a high-precision detection signal.
The tone arm uses a unique dynamic balance system, and the arm bearing uses a 4-point support system gimbal suspension system.
In addition, the arm has a low mass design with an effective mass of 13g including the cartridge. (They fail to mention that it is made from titanium [EJ3])
Diameter 32.5 cm, Weight 2.5 kg, Inertial Mass 427 kg / cm2Large and heavy aluminum die-cast turntable has been adopted.
Continuously variable pitch adjustment within ± 6% is possible.
Equipped with an electronically controlled full auto mechanism.
Equipped with plug-in connector system MM type cartridge.
TNRC and high-density particle board are used for the cabinet.
Model Rating
Type | Quartz DD full auto player system |
<Turntable portion> | |
Drive system | Direct drive |
Control system | Quartz control |
Number of revolutions | 33 1/3, 45 rpm |
Wow flutter | 0.022%W.R.M.S(JIS C5521)
0.008% W. R. M. S (Rotating Part Only) |
Signal-to-noise ratio | 82 dB (DIN-B, IEC98A weighted) |
Cartridge Section | |
Type | Plug-in connector MM type stereo cartridge |
Exchange needle | EPS-P205ED4(¥15,000) |
<General> | |
Pwer | 100 VAC, 50Hz/60Hz (in my case 120/220 VAC, 50Hz/60Hz [EJ3]) |
Power consumption | 22W |
External dimensions | Width 526x Height 202x Depth 426 mm |
Weight | 13.5kg |
- tangential tracking error caused by a pivoting tone arm - masters are cut radially see this group :
https://www.facebook.com/groups/2116299488450938. Unlike the cutting head of a mastering lathe - which travels at a perfect 90d tangent to the groove - a stylus is constantly changing it addressing angle to the groove walls. So the modulations of the groove are not faithfully reproduced since the playback stylus is always moving at a non-perpendicular direction as to how it's cut.
Solution: (not perfect but minimizes the problem)
It is equipped with a unique linear tracking arm that can make tracking error, which causes distortion during playback, and inside force, which causes channel imbalance, close to 0.
The tracking error angle is within ± 0.05 ° by detecting the arm deflection angle with an optical sensor and obtaining a high-precision detection signal.
Pivotal tone arms also lead to:
- Skating. As a disc rotates it impinges forces on a contacting surface that cause it to be drawn to the center of the spinning disc. In the shop, we had blank records with no groove that we'd use to set the antiskate mechanisms (usually a spring or weights) that would try to counter act that force. Problem is under compensation causes the stylus to ride up on the side closest to the hub (the left channel) and proper compensation causes the groove closest to the outside (the right channel) to have to drag the stylus against the antiskating force, which causes the stylus to ride up on the outer wall of the groove. It's a real problem that's very hard to deal with.
Solution: (not perfect but minimizes the problem)
Same as 1st one
+ (on my APT/Holman Preamp): The right channel of each of the two phono inputs is internally adjustable ±2 dB for perfect channel balance
+ All outputs are non-inverting. Volume control rated to track left-right to within 1 dB over the entire range.
(Ken Rockwell says: I'm impressed: this is a very important parameter, and this is the only preamp I've ever seen which bothers to specify it).
The multiwiper 10 kΩ volume control has 32 clicks, or 31 intervals, at 10º per click, or room for 36 clicks in 360.º
The volume control uses individually trimmed thick-film resistors to ensure precise channel-to-channel tracking.
- low frequency modulation caused by the slight warpage - causes the woofers of a system (or the panels in planar speaker like an Acoustat or Magnepans) to modulate signals above it. You can see it on a Lissajous display on an oscilloscope. it cause the center dot on a blank groove to bounce. You can also see it in larger woofers moving at super low freq (~1-10Hz).
Solution: (not perfect but minimizes the problem)
20 - 20,000 Hz ±0.5 dB, with ultrasonic and ultrasonic filters active.
Selectable 15 Hz Infrasonic filter (rear panel switch)
Within 0.5 dB at 20 Hz, -3 dB at 15 Hz and > -30 dB at 5 Hz.
Group delay 4 mS at 50 Hz.
If the filter isn't selected, the -3 dB point is 8 Hz.
Interchannel delay: < 0.5 µS. (the limit of audibility is 10 µS.)
When the tone controls are defeated, the -3 dB point is 150 kHz.
- mismatched RIAA equalization curves - this is the reason you hear about how records sound "warm". That warmth is a mismatch between the RIAA curve that was used to cut the master, and the inverse one used in the consumer's gear. See Larry Boden's book. The RIAA curve was developed to increase the play time on an album side. So during cutting it rolls the bass off and increases the treble. On playback, the consumers reproduction system is supposed do the opposite - increase the bass and roll the treble off. Unfortunately, getting two filters to do a perfect inverse is impossible. Just won't happen. See this
https://en.wikipedia.org/wiki/RIAA_equalization
Solution: (not perfect but minimizes the problem)
20 - 20,000 Hz ±0.5 dB, with ultrasonic and ultrasonic filters active.
RIAA EQ ±0.5 dB 30 - 15,000 Hz.
- Reduced elasticity of the groove walls on subsequent passes of a stylus. You see, records are made with polyvinyl materials that have plasticizers mixed in. The problem becomes that as the tiny radius of the stylus impinges on the groove wall, it compresses it. That can be an issue if enough time has not elapsed on subsequent plays of the same section of the groove. That can lead to fracturing of the groove wall, since it's already compressed.
Solution: (not perfect but minimizes the problem)
Do not play any side of any record more than once per day, allowing time for the groove to recover from being compressed.
- Asperities in the surface of the vinyl. These cause the noise heard. It's because there's no way to make a perfectly uniform material, so slight variations in the surface are unavoidable.
Solution: none known to me.
- Limited channel separation - a few issues lead to this - one the aforementioned skating forces in addition to the limitations of the groove geometry. An groove with stereo information that is in-phase and monophonic swings the stylus left to right. Channel information is realized by a 45 d up pitch of the stylus movement - which is limited so it limits the separation of the left/right signals.
Solution (not perfect [&, in fact, not that great) Channel Separation: 25dB @1kHz 20dB @10kHz
This helps, though:
It is equipped with a unique linear tracking arm that can make tracking error, which causes distortion during playback, and inside force, which causes channel imbalance, close to 0.
The tracking error angle is within ± 0.05 ° by detecting the arm deflection angle with an optical sensor and obtaining a high-precision detection signal.
But what's really bad is left and right channel signals that are out-of-phase. This causes the cutter head to move vertically. If significant low frequency information is out-of-phase in the audio signal it can cause lift out of the groove path which leads to skips in the groove.
Solution This is sort of an IF AND BY HOW MUCH thing that cannot be controlled at all by the end user of the vinyl..
- Decreasing circumference as the groove goes toward the center of the record. This is obvious as the record is spinning at a constant RPM (revolutions per minute) so that means less material is available for groove modulation.
Solution None that is known to me, as it is a property of the physics involved.
So, while not as objectively good as DIGITAL, the right vinyl setup can be much better than typical vinyl set ups.
And I proved that you can't make what one does to vinyl as good as it is possible to make digital (which I think that (at least from a measurable perspective) we all know. But there are many psychoacoustic and plain old psychological reasons for peoples preferences.
I want to transfer all my albums to digital (many of which cannot be obtained on CD or are not being streamed [& I wouldn't expect them to be]).
This has been a great confirmation for me of my need to digitize (but my audio budget will not allow me to until next year).