Even with the 7” and an SPU -A I could get the arm pod close enough to the plinth to align it. General guidelines here: http://vivaudiolab.com/Rigid_Float_files/置き位置目安.pdf
VIV Laboratory Rigid Float Tonearm, first experience.
- Thread starter shakti
- Start date
The mounting distance of the ViV tonearms is bigger than the inch-number of the arms
leads to believe. This is because of the underhang.
One time I had the opportunity to hear a ViVs in different legths. For me there was no
difference in sound. So my choice was to buy finally two 9" arms (they "look" more like
a 10,5" arm) because the offer a perfect view of my turntable installation.
leads to believe. This is because of the underhang.
One time I had the opportunity to hear a ViVs in different legths. For me there was no
difference in sound. So my choice was to buy finally two 9" arms (they "look" more like
a 10,5" arm) because the offer a perfect view of my turntable installation.
Hello RaceDoc, hello all,
Did you try a different head shell than the stock Nelson Hold with DS Audio cartridges, such as a Nasotec? I would be very interested to know as I am willing to buy a Rigid Float 9 aluminum to be used with a DS Audio 003 cartridge on a Technics SP 10 R. Many thanks in advance.
From the geometry, there is a clear relationship between the offset angle and the skating force. If the offset angle is zero, the skating force is also zero.
No, skating force is the result of overhang in pivoted arm designs. Offset angle has nothing to do with it. That's why any pivoted arm including the tangential ones require an anti-skating mechanism. Offset angle is primarily used for reducing tracking error/distortion not for anti-skating.
I am sorry to tell you that you have misunderstood something here. Overhang, offset angle, P2S, effective length and the position of the two points where the tracking error angle is zero are the parameters of the tonearm geometry. These are all directly related. I spent many hours studying these relationships when designing my tonearms. I always work on such topics by drawing. Through this approach, you get a deep understanding of the relationships, because you directly notice what consequences the change of a parameter has.
underhung tonearms only have one zero point, not two like overhang tonearms. due to the transverse position to the groove you have a faster response more dynamic. That sounds fantastic, but you have don't forget that depending on the length of the tone arm, you get up to 10% distortion towards the middle of the record.
There is no need to be sorry cause I didn’t misunderstand. I’m behind my words. VIV tonearm is a pivoted one and most definitely it needs anti-skating. besides that, omission of the offset angle is also increasing tracking error by reducing null points from two to one. these are the facts you can rest assure that. you said you’ve done your research, so did countless tonearm designers over the last 70 years. many pivoted tonearms are designed and almost all of them have overhang and offset angle. do you think all ended up using overhang and offset by coincidence or all of those designers couldn’t think of designing without overhang and offset if it would have been better?
overhang and offset are embedded in pivoted tonearms because of basic rules of geometry.
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The skating force of a ViV is present but VERY small.
I made some experiments using a flat LP without grooves.
The ViV is moving VERY slowly compared to a “normal”
tonearm at the end radius points of the usual music signal.
At the 0 point of the adjustment there is no movement.
At this point the direction of the movement changes.
I made some experiments using a flat LP without grooves.
The ViV is moving VERY slowly compared to a “normal”
tonearm at the end radius points of the usual music signal.
At the 0 point of the adjustment there is no movement.
At this point the direction of the movement changes.
If the zero point in the middle of the record the highest distortion must be at the beginning and end of the record.
Where does the 10% number come from?
Pivot to spindle distance 215mm 7"ridgid float the tracking error variates from positive to negative over the lp side.
in another forum has someone who is well versed in mathematics. created a formula for calculation. I think the tone arm is very good in terms of sound. those who only like numbers will be put off. The maximum underhang is 15 mm not 21mm must be corrected will probably result in a little less distortion than this calculation.
Formula
!/usr/bin/python3
# -*- coding: utf-8 -*-
import math
r1 = 60
r2 = 146
le = 194(215)
h = -21 # sign is "-" because of underhang(15mm)
for r in range(r1, r2 + 1):
lte = math.degrees(math.asin(
r/(2*le) + h*(2*le - h)/(2*le*r)
))
distortion = 44.4 * (lte / r)
print("R = {:3}mm, LTE = {: .2f}deg, distortion = {: .2f}%".format(
r, lte, distortion)
)
R = 60mm, LTE = -12.37deg, distortion = -9.16%
R = 61mm, LTE = -11.87deg, distortion = -8.64%
R = 62mm, LTE = -11.38deg, distortion = -8.15%
R = 63mm, LTE = -10.89deg, distortion = -7.68%
R = 64mm, LTE = -10.42deg, distortion = -7.23%
R = 65mm, LTE = -9.96deg, distortion = -6.81%
R = 66mm, LTE = -9.51deg, distortion = -6.40%
R = 67mm, LTE = -9.07deg, distortion = -6.01%
R = 68mm, LTE = -8.64deg, distortion = -5.64%
R = 69mm, LTE = -8.22deg, distortion = -5.29%
R = 70mm, LTE = -7.81deg, distortion = -4.95%
R = 71mm, LTE = -7.40deg, distortion = -4.63%
R = 72mm, LTE = -7.00deg, distortion = -4.32%
R = 73mm, LTE = -6.61deg, distortion = -4.02%
R = 74mm, LTE = -6.22deg, distortion = -3.73%
R = 75mm, LTE = -5.85deg, distortion = -3.46%
R = 76mm, LTE = -5.47deg, distortion = -3.20%
R = 77mm, LTE = -5.11deg, distortion = -2.95%
R = 78mm, LTE = -4.75deg, distortion = -2.70%
R = 79mm, LTE = -4.39deg, distortion = -2.47%
R = 80mm, LTE = -4.04deg, distortion = -2.24%
R = 81mm, LTE = -3.70deg, distortion = -2.03%
R = 82mm, LTE = -3.36deg, distortion = -1.82%
R = 83mm, LTE = -3.03deg, distortion = -1.62%
R = 84mm, LTE = -2.70deg, distortion = -1.43%
R = 85mm, LTE = -2.37deg, distortion = -1.24%
R = 86mm, LTE = -2.05deg, distortion = -1.06%
R = 87mm, LTE = -1.73deg, distortion = -0.88%
R = 88mm, LTE = -1.42deg, distortion = -0.72%
R = 89mm, LTE = -1.11deg, distortion = -0.55%
R = 90mm, LTE = -0.80deg, distortion = -0.40%
R = 91mm, LTE = -0.50deg, distortion = -0.24%
R = 92mm, LTE = -0.20deg, distortion = -0.10%
R = 93mm, LTE = 0.10deg, distortion = 0.05%
R = 94mm, LTE = 0.39deg, distortion = 0.18%
R = 95mm, LTE = 0.68deg, distortion = 0.32%
R = 96mm, LTE = 0.96deg, distortion = 0.45%
R = 97mm, LTE = 1.25deg, distortion = 0.57%
R = 98mm, LTE = 1.53deg, distortion = 0.69%
R = 99mm, LTE = 1.81deg, distortion = 0.81%
R = 100mm, LTE = 2.08deg, distortion = 0.93%
R = 101mm, LTE = 2.36deg, distortion = 1.04%
R = 102mm, LTE = 2.63deg, distortion = 1.14%
R = 103mm, LTE = 2.90deg, distortion = 1.25%
R = 104mm, LTE = 3.16deg, distortion = 1.35%
R = 105mm, LTE = 3.43deg, distortion = 1.45%
R = 106mm, LTE = 3.69deg, distortion = 1.55%
R = 107mm, LTE = 3.95deg, distortion = 1.64%
R = 108mm, LTE = 4.21deg, distortion = 1.73%
R = 109mm, LTE = 4.46deg, distortion = 1.82%
R = 110mm, LTE = 4.72deg, distortion = 1.90%
R = 111mm, LTE = 4.97deg, distortion = 1.99%
R = 112mm, LTE = 5.22deg, distortion = 2.07%
R = 113mm, LTE = 5.47deg, distortion = 2.15%
R = 114mm, LTE = 5.72deg, distortion = 2.23%
R = 115mm, LTE = 5.96deg, distortion = 2.30%
R = 116mm, LTE = 6.21deg, distortion = 2.38%
R = 117mm, LTE = 6.45deg, distortion = 2.45%
R = 118mm, LTE = 6.69deg, distortion = 2.52%
R = 119mm, LTE = 6.93deg, distortion = 2.59%
R = 120mm, LTE = 7.17deg, distortion = 2.65%
R = 121mm, LTE = 7.41deg, distortion = 2.72%
R = 122mm, LTE = 7.64deg, distortion = 2.78%
R = 123mm, LTE = 7.88deg, distortion = 2.84%
R = 124mm, LTE = 8.11deg, distortion = 2.90%
R = 125mm, LTE = 8.34deg, distortion = 2.96%
R = 126mm, LTE = 8.57deg, distortion = 3.02%
R = 127mm, LTE = 8.80deg, distortion = 3.08%
R = 128mm, LTE = 9.03deg, distortion = 3.13%
R = 129mm, LTE = 9.26deg, distortion = 3.19%
R = 130mm, LTE = 9.48deg, distortion = 3.24%
R = 131mm, LTE = 9.71deg, distortion = 3.29%
R = 132mm, LTE = 9.93deg, distortion = 3.34%
R = 133mm, LTE = 10.16deg, distortion = 3.39%
R = 134mm, LTE = 10.38deg, distortion = 3.44%
R = 135mm, LTE = 10.60deg, distortion = 3.49%
R = 136mm, LTE = 10.82deg, distortion = 3.53%
R = 137mm, LTE = 11.04deg, distortion = 3.58%
R = 138mm, LTE = 11.26deg, distortion = 3.62%
R = 139mm, LTE = 11.48deg, distortion = 3.67%
R = 140mm, LTE = 11.70deg, distortion = 3.71%
R = 141mm, LTE = 11.91deg, distortion = 3.75%
R = 142mm, LTE = 12.13deg, distortion = 3.79%
R = 143mm, LTE = 12.34deg, distortion = 3.83%
R = 144mm, LTE = 12.56deg, distortion = 3.87%
R = 145mm, LTE = 12.77deg, distortion = 3.91%
overhang tonearms variates arround 0.7 % distorsion over the lp side
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Exactly! I have this 7” arm. It’s stunning. Best arm I’ve heard. You can fuss about the numbers or listen. Wish I could use it with my current table.
| Lofgren A | Lofgren B | Stevenson | |
| maximum distortion % | 0.81 | 1.3 | 0.97 |
Those are the maximum numbers for a 194mm effective length, overhang- offset-pivoted tonearm. If we stick to P2S distance of 215mm than those numbers will get lower while VIV tonearm's maximum distortion is around 9.16% as shared by @DasguteOhr
The difference is huge. there are two main problems with VIV design:
1. Since it's a pivoted tonearm eventually it will have overhang or underhang and requires and anti-skating mechanism
2. It's zero offset angle simply increases the distortion figures.
The magnitude of the skating force will be higher with a traditional overhung tonearm with an offset angle when compared to an underhung tonearm with no offset. With an underhung tonearm, the rotation torque (skating force) is generated only by the tracking angle not been inline with the pivot point. When an underhung tonearm transitions from a negative tracking angle through the null point to a positive tracking angle so does the direction of the skating force (inner to outer).
I agree.
A traditional overhung tonearm will always have a positive (inner) skating force while an underhung arm will have a transition point where skating force changes from inner to outer. This is independent from offset angle and underhung tonearm will have less skating force but it will also have very high tracking error.
