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Anyone try the replica B-60 Fidelity Research VTA?

My sammle moved not only up an down but also sidewards.
The reason as far as I can judge is the pin on the screw
which connect the inner and the outer collar. The inner collar
slides along this pin up and down but if there is
any play between this pin and the notch of the inner collar
the tonearm will move also sidewards. This means that the
'replica' is not as 'exact' as claimed by the producer.
I assume that this screw is better made by the orginal B-60 .
128x128nandric
lewm
13,101 posts
 
ct0517, The answer to your question will vary according to how the tonearm is installed into the B60.  If, for example, the lowest adjust point on the B60 places the tonearm parallel to the LP surface, then the highest adjust will raise the rear end of the tonearm with respect to the LP surface and will therefore slightly increase VTF.  And you can see how the result will change, for example, if the lowest adjust point on the B60 places the tonearm either raised or lowered, at its pivot point.  So, yes, there will always be a change in VTF associated with changing VTA, but there is no rule you can derive from the experiment you asked us to do, unless you know how each responder positioned the tonearm to begin with.
ct0517's avatar
ct0517
2,041 posts
 
chakster
@ct0517 May i ask why you are concerned about it ? It can be verified with any tonearm, in reality there is a minor difference in VTF if any.


Chakster. I did not say concern, I said curiosity. I am curious and asked for information from someone reading on this thread with a B60. Surely with a slick accessory like the B60 it's what, a 3-4 minute exercise, to give me a number.

i.e. If when the B60 is set at the low point, and your cart weight is say 2.2 gms. How much then is the cart weight when you move the B60 to the highest point in the range - for that persons specific setup.

That's the number I asked for

************************

Lewm
ct0517, The answer to your question will vary according to how the tonearm is installed into the B60. If, for example, the lowest adjust point on the B60 places the tonearm parallel to the LP surface, then the highest adjust will raise the rear end of the tonearm with respect to the LP surface and will therefore slightly increase VTF. And you can see how the result will change, for example, if the lowest adjust point on the B60 places the tonearm either raised or lowered, at its pivot point. So, yes, there will always be a change in VTF associated with changing VTA, but there is no rule you can derive from the experiment you asked us to do, unless you know how each responder positioned the tonearm to begin with.


Thank you Lewm. As I assumed. Still curious what the VTF range is for your B60 setup. btw - raising VTA lowers VTF and vice versa.

IMO if this B60 raises and lowers the arm consistently and smoothly each time, as expected, it is a good accessory - as long as one remembers to re-adjust for VTF after. For this same reason the B60 does not make the tonearm VTA/SRA on the fly. Some carts are very sensitive to VTF changes. The changes in sounds we hear when changing the VTA /SRA could also be influenced by the higher or lower VTF. Just sayin....

Now if this B60 did this movement well, and at the same time kept VTF intact, (the same) - that's playing in a different league. I would call it an excellent accessory at this point ....even genius.

********************

Nandric (Nikola)
Regarding VTA versus SRA.
It may be a different "focused" area of measurement. But the target is the same. Relative angle of the stylus to the groove.

In this hobby - and lets face it - to spend this much time discussing this one aspect - it is a hobby, the objective if possible is to try to duplicate as much as possible the actual cutters stylus angle. The included cut angle that is in the record.   
All of things that cause variations to these angles, both on the cutters side and the reproductive end (playing the record), are well documented.

This means these adjustments we are making need to be done by ear because we have no idea who cut the record that day and at what angle.  Again just saying....

Happy VTA'ing SRA'ing

nandric's avatar
nandric OP
4,086 posts
 

The question is ''what is the optimal B-60 adjustments and what

are the variables''? The variables are the record thickness, the

bodies and cantilevers (angle) dimensions and the length of

the trench in the inside , moving part, of the construction. The

 trench determine max up and down movement of the arm.

The ''initial conditions'' to be established are parallel position of

the arm with stylus in the grove by recommended VTF. Easy to

establish with those small ''levels'' put on the headshell. By

positioning the arm in the B-60 halfway in the trench one get

the optimal position for up and down adjustment. For ''on the fly

adjustment'' one need, in my opinion , to remove the sticky

silicon oil and substitute for grease. Much more smooth movement

of the arm. This means no force is needed to move the round

adjuster. In order to get repeatable   results one need to use

test records. I try to get at least 60 microns pure by each of

my MC carts. If possible that is. Anyway 50 microns as minimum.

For masochist who like to adjust those variables by hearing there

is sufficient ''up an down'' space for their trial.





lewm
13,101 posts
 
ct0517,  The change in VTF associated with the typical minute adjustments to VTA/SRA is not worth worrying about.  You can calculate it as a percentage change, if you know your geometry and vector algebra, but it will be tiny and not worth your concern, at least not to the degree that you appear to be concerned.  Do you change VTA (or SRA) with every LP?  I cannot be bothered. 

Anyway, changing VTA by using the B60 is no different, in terms of its affect on VTF, from changing VTA by any other method.  So, if you are one who changes VTA frequently, and if you perceive this to be a problem with respect to VTF, the B60 is neither here nor there, except that it is a very convenient way to change VTA, if you own an FR64 or 66 tonearm.  I happen to think there is a secondary benefit to the B60; it adds considerable mass to the base of the tonearm, which (I think) helps to soak up resonant energy and improves coupling to the turntable and bearing.
nandric's avatar
nandric OP
4,086 posts
 

Dear Lew, I don't agree with you assertion that B-60 will work

as any other VTA adjuster.  The reason is dynamic function

of the FR-64. This means that both dynamic function as well

VTF adjustment are function of the same spring. I am not

mechanical engineer but don't believe that this spring will

work different depending from the ''up'' or ''down'' position

of the arm in relation to the record surface.

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