Another Request for Information/Knowledge

Now that I’ve learned to use the overhang portion of my basic protractor, I’ve been able to measure the overhang and it is randomly AT or very, very slightly off from the required 16mm distance. Now I am completely unable to account for the distortion. I am pretty certain the cartridge is aligned and set up properly.

Might it be a case that the needed tracking force is different since the cartridge was rebuilt with a boron cantilever as opposed to the original material? I lightened up the VTF and the distortion became more pronounced. I Increased the VTF beyond the original recommended setting and the distortion is no linger present.

I guess at this point, I just don’t want to damage any records or the cartridge by setting VTF too high. I Guess I will back off VTF incrementally until the distortion returns and then increase it in one hundreth increments until the distortion disappears again.

Does this seam like an unreasonable strategy to anyone? Thanks.

Dear @dmac67 : The kind of distortion you experienced and coming from both channels seems to support your own advise. It's a VTF trouble, just do it and don't worry because I think don't be any damage to your records.

You can email too to re-tipper asking about and wait what he think and his advise.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

Right. Its VTF. I was thinking that right away even before getting to the second post.

You don’t mention what VTF you are at. If you had to raise it a couple grams that’s a problem. If you’re talking tenth of a gram or so no worries.

The proper VTF your cartridge requires is due to a combination of factors. One of these is the resonance and compliance of the moving mass of the cartridge- the stylus, cantilever, suspension and generator.

We like to think of the stylus tracing the groove. It does, but only to an extent. The groove is violently banging it up and down left and right and a fair amount of the time its bouncing side to side as much sampling as tracing. So we need enough VTF to minimize this.

But up at the other end, the tiny little generator is moving in a tiny little magnetic field, and this is where the signal is actually being generated. This is why VTF is a range with both a high and a low. The goal is to have the generator centered in the field. Neither too high nor too low. (Neither too left nor too right either, this is the reason we have anti-skate.)

Its amazing what we can do when we understand exactly how this works. While reading your post I was thinking and had figured out exactly what was going on even before you got the second post out.

Somewhere in the rebuilding either the internal positioning alignment, or maybe the suspension compliance, was changed just enough so now at the recommended VTF your cartridge is just far enough outside the ideal generator alignment to distort. Its not as obvious at high levels because the generator is moving so much more its spending significant time in the generator sweet spot. At low levels though its hardly moving at all and spending all the time far enough outside that range you hear it as distortion.

Its the only thing that makes sense to me. Because usually the distortion would be mistracking at high levels. Not enough VTF, too much bouncing around at high levels. But you’re not hearing that. You’re hearing distortion only at low levels. So the most likely thing I can think of is generator misalignment.

Going out on a limb here. If Ledermann chimes in different my goose is cooked! But pretty sure I nailed it.

So now the question is, how much extra VTF? A tenth of a gram or so I would probably live with it. Much more than that I would be take it back do it right or send me a new one. Either way next time I would be thinking Soundsmith.

Original spec was to set VTF at 1.2g. The lightest setting at which I am getting no audible (to me) distortion is 1.32g on my digital vtf scale so, by my scale, I am .12g above recommended VTF.

On a side note, I’m trying to figure out the worst part of growing old...failing vision making it difficult to read the markings on a protractor or losing my freaking memory.  I have no idea where I put my scale down!