Laser VTA guided Tonearm - REED 3Q !

john195 -- Sun, 10/23/2011 - 03:27

Hi all.
If you think you seen it all, meet the top of the line REED 3Q series tonearm with laser VTA guided mechanism:
 
Reed 3Q tonearm working principle
 
Laser-adjusted tonearm operation is based on a level principle and helps to determine when tonearm mounting surface is parallel to the headshell (cartridge mounting) surface.
When using laser-adjusted tonearm, it is possible to adjust VTA and azimuth very quickly, comfortably and precisely after changing LP with different thickness or switching cartridges.
Laser beam a is adjusted so, that when it points to the point A on the scale c of the headshell b (Fig. 1, Fig. 2), the tonearm armwand is parallel to the tonearm mounting surface and a platter, i.e. VTA is adjusted to zero position.

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    Fig. 1. VTA adjustment using laser (scheme)

Fig. 1. VTA adjustment using laser (scheme)

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    Fig. 2. VTA adjustment using laser (photo)

Fig. 2. VTA adjustment using laser (photo)

If laser beam points above the point A (Fig. 3), tonearm must be lowered until the beam appears at the point A. If laser beam points below the point A (Fig. 4), tonearm must be raised until the beam appears at the point A.

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    Fig. 3. VTA adjustment using laser - tonearm too high (scheme)

Fig. 3. VTA adjustment using laser -
tonearm too high (scheme)

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    Fig. 4. VTA adjustment using laser - tonearm too low (scheme)

Fig. 4. VTA adjustment using laser -
tonearm too low (scheme)

Headshell (cartridge mounting) plane is parallel to tonearm mounting/platter plane if, after turning the tonearm, laser beam a points to the point B, (Fig. 5, Fig. 6). That means azimuth is adjusted to zero position.
If laser beam does not appear in point B, azimuth must be adjusted accordingly.

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    Fig. 5. Azimuth adjustment using laser (scheme)

Fig. 5. Azimuth adjustment using laser (scheme)

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    Fig. 6. Azimuth adjustment using laser (photo)

Fig. 6. Azimuth adjustment using laser (photo)

john195 -- Sun, 10/23/2011 - 03:30

For more information and photos click on this link; http://www.excelstereo.com/reed.htm

vade@att.net -- Sun, 10/23/2011 - 11:43

The problem with this approach is that the correct VTA setting has nothing to do with having the tonearm parallel to the record surface. Quite often, the arm will NOT be parallel to the record when VTA is correct. At least that's my experience.
 
Vade Forrester

brian -- Sun, 10/23/2011 - 21:12

You are correct, Vade.
 
The same is true of azimuth. In virtually every instance I have found the optimum azimuth angle to be something different from dead level, and to use a worn out audiophile expression, the difference is not subtle.

Brian Walsh
Essential Audio  ~  Chicago area ~ 773-809-HIFI (4434)

john195 -- Mon, 10/24/2011 - 00:42

You guys are correct and have very good point.
I also think the idea with the laser is to get a quick initial "standard text book setup" is a good one, but in the real world it will need "non-standard textbook adjustment\setup", good eyes and ears and other tools to get it spot-on. It all depends on the cartridge cantilever angle to the cartridge body ie: 20 deg, or if the cartridge cantilever azimuth is perpendicular to the cartridge body, also if the coils of left and right channel are the same ie: 6ohms left - 6ohms right.

john195 -- Sun, 10/23/2011 - 22:51

Like this tonearm or not, in this so called digital age and if you have deep pockets, you are spoit for choice in new inovations in tonearms.

john195 -- Mon, 10/24/2011 - 01:38

Now we got some controversy, lets look at why REED uses wood for the arm-tubes:
 
Wood vs. The Rest: Testing Armtube Material
 
There are lots of talks in the industry on the best armtube material, whether wood is better than Aluminum, or maybe Carbon fiber is the perfect material and so on.
To find out who's right and which material is perfect for hi-fi tonearm armtube, we decided to conduct a little research.
We hope that results of our investigation will help you understand armtube material impact to the tonearm's sound and help choosing tonearm in armtube material perspective.
The Background
Figure 1 shows, why tonearm's sound depends on armtube material (and why turntable sound quality depends on mat material).

Fig. 1. Acoustic vibration spreading through the sound system

Stylus, while moving in the vinyl's groove, not only produces the musical signal, but also oscillates the cartridge itself. The oscillation (shown in red arrows) can be transferred through the armtube, partially reflect from the counterweight, and through the tonearm bearings, tonearm support, chassis, platter bearings, platter, mat and vinyl return back to the stylus. On the other hand, stylus causes vinyl plate vibrations (blue arrows), which, through the mat, platter, platter bearings, chassis, tonearm support, tonearm bearings and armtube, return to the stylus again.
The interference of these two acoustic vibrations can slightly impact the sound quality. Armtube material can suppress these parasitic accoustic vibrations (and of course, tonearm's effective mass depends mainly on armtube material).
The Gear
To carry on with the research, we built the device shown in Figure 2 (you can see its picture in the top-right of the article).

Fig. 2. Armtube testing device scheme

It consists of two acoustic dampers, holding the armtube; at the point A a broadband acoustic signal is fed; at the point B, it is registered using the broadband acoustic receiver and then passed to the spectrum analyzer.
The Wood
We acoustically tested following armtube materials:

  • Western redcedar,
  • Ebony Macassar,
  • Cocobolo,
  • Pernambucco,
  • Pao Ferro,
  • Panzerholtz (Tankwood)
  • Zirocote
  • Wenge.

Also for comparison we carried the same test to Carbon fiber, Fiberglass and Aluminum arms.

 
The Result
As you can see from the graphs on the right side of an article, woods with closest-to-perfect characteristics are Redcedar, Pernambucco and Panzerholz. They don't have clearly expressed resonant frequencies, and their sound damping characteristics are close to exponential function.
Results of our test are basically same to some audiophile opinion, that tonearms with Redcedar and Pernambucco wands produce very clean, transparent and deep sound. Meanwhile, even if tests show Panzerholtz being nearly perfect material for the arm, audiophile opinions on it are different.
 

 

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    Tool for testing armtube sound properties

Tool for testing armtube sound properties

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    Acoustic characteristics in Perfect conditions

Acoustic characteristics in Perfect conditions
 

 

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    Cocobolo (Dalbergia retusa) arm

Cocobolo (Dalbergia retusa) arm

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    Acoustic characteristics of Cocobolo arm

Acoustic characteristics of Cocobolo arm
 

 

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    Brazilwood (Caesalpinia echinata), also known as Pernambuco, arm

Brazilwood (Caesalpinia echinata), also known as Pernambuco, arm

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    Acoustic characteristics of Pernambuco arm

Acoustic characteristics of Pernambuco arm
 

 

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    Wenge (Millettia laurentii) arm

Wenge (Millettia laurentii) arm

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    Acoustic characteristics of Wenge arm

Acoustic characteristics of Wenge arm
 

 

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    Zirocote (Cordia dodecandra) arm

Zirocote (Cordia dodecandra) arm

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    Acoustic characteristics of Zirocote arm

Acoustic characteristics of Zirocote arm
 

 

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    Western redcedar (Thuja plicata) arm

Western redcedar (Thuja plicata) arm

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    Acoustic charakteristics of Western Red Cedar arm

Acoustic Charakteristics of Western Red Cedar arm
 

Approximate effective mass of Reed tonearm in grams

Armwand
Azimuth adjuster
Effective lenght

9,5"
10,5"
12"

Cocobolo
Yes
14
17
22

No
12
14
17

Pernambucco
Yes
14
17
22

No
12
14
17

Wenge
Yes
12
14
17

No
10
12
14

Zirocote
Yes
14
17
22

No
12
14
17

Western Red Cedar
Yes
10
12
14

No
8
10
12

vade@att.net -- Mon, 10/24/2011 - 10:02

It would be useful if the axes were labeled to show frequency and amplitude units. Also if there were measurements of non-wood materials as claimed in the text. For example, how does carbon fiber perform?
 
I would love to have an easy and reliable way to set up VTA other than by listening to music. It seems to me that there must be a way to use a computer playing, say, a test record to get this measurement right.
 
Vade Forrester
 
Vade Forrester

john195 -- Mon, 10/24/2011 - 19:34

Vade, I could not find the measurements of non-wood armtube materials, on REEDS website, I find this is odd BTW.
http://www.reed.lt/

john195 -- Thu, 10/27/2011 - 08:58

More tonearm tube information from Excel website: cabon fiber, fiberglass &aluminium
Acoustic characteristics of Carbon fiber arm
Acoustic characteristics of Carbon fiber arm

 
Acoustic characteristics of Fiberglass arm
Acoustic characteristics of Fiberglass arm

 
Acoustic characteristics of Aluminium arm

vade@att.net -- Thu, 10/27/2011 - 09:58

It's hard to tell that the woods have significant differences from the other materials. I'm not sure that all aluminum arms would show the same resonant signatures-seems like it would depend on the thickness of the arm tube wall and the construction method used. For example, a typical extruded aluminum tube might have a different resonant signature than a cast aluminum tube or a welded tube.
Does anyone make a fiberglass arm?
 
Vade Forrester

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