Another Request for Information/Knowledge


What are some possible reasons for distortion in both channels following a cartridge swap? I used a basic pvc protractor and positioned the cartridge correctly at both null points and I set tracking force and anti-skate at the recommended settings for the cartridge. The cartridge is a rebuilt Yamaha MC-3 with a boron cantilever and a fresh re-tip both done by Namika in Japan. The arm is the stock dual tube arm on my Yamaha PF-800 turntable.

I am getting distortion from both channels that is most audible during soft passages.


I wasn’t sure how to use the protractor to account for overhang. As luck would have it, the original overhang gauge that came with the table is the one accessory missing from the box.  Could this account for the distortion?


I’ve learned a lot about vinyl playback over the past couple of months by reading through many discussions posted here but I may be in over my head with my first cartridge swap lol. Thanks again to all who who have helped me along the way.

128x128dmac67
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!


Which V T F gauge are you using. IME, some are pretty far off, like the Shure for instance.
Mine is low end. I think I remember paying only $39 for it. It’s made by Riverstone Audio.
I just saw its still sold on Amazon and its only $27.50 delivered.

I also just went to the official US Mint site. A US dime’s official weight is stated at 2.68 grams. Mine measured a nearly new dime to weigh 2.7 grams so, in that case, its fairly accurate.  
I will definitely recheck the clips.  I had one not attached properly and had to reattach after I first aligned the cartridge.  I think I got that one on securely and I did a visual inspection of the other three.  
I’m working from home so maybe I’ll start the whole process of installing the cartridge again tomorrow.  In the worst case, I’ll at least get some additional practice for the future.
This is your turntable
Buy yourself a Hi-Fi Test LP, there is a nice protractor inside. 
The record will help you to adjust and test your cartridge. 

  What are some possible reasons for distortion in both channels following a cartridge swap?

Do you have another cartridge to test ? If you have distortion with another cartridge then it's not a cartridge problem. 

the VTF is a range, not fixed amount. 

Make sure your stylus is clean, use brush to clean it first, then clean your record too. 

Since your cartridge has been re-tipped maybe it was a bad job ? 
The original cantilever on MC3 is aluminum. 



 0.12g above the original spec does not sound bad. I would appreciate a recommended tracking force from the retipper. I got a JICO SAS for my Shure V15 Type III and they recommend 1.25g (vs. original spec of between 0.75 and 1.25g). 
The original Yamaha MC3 vtf range is 1.2g ±0.2g , but since your sample recantilevered/retipped it can be different.

+0,20
or
-0,20

it’s normal for any cartridge, when it’s NEW you have to use maximum (not minimum) tracking force during burn-in period.

You need hi-fi news test lp to check suspension condition and to set up anti-skating.

When you said "retip done by Namika in Japan" i think you mean Namiki cantilever/stylus, this is manufacturer, not retipper.

Namiki website: 

https://www.ad-na.com/en/product/jewel/product/cantilever.html


Thanks to everyone who has taken the time to help.  Its greatly appreciated.  Once again, I’ve learned a lot of great information from each and every reply.
Chakster hit it on the head. Increase the VTF until the distortion goes away. You do not want that stylus rattling around in the groove as that will damage your records. If it is a linear contact stylus it will safely operate at higher VTF. I have seen elliptical styli do OK between 1.5 and 2 gr. Set your anti skate by putting your stylus down in the run out area between the groove. It should drift ever so slowly towards the spindle before the next groove catches it. Even better is the Hi Fi News Test Record. IMHO a must for every vinyl junkie. 

The first thing I would check is to see how the stylus looks under a microscope. I have a hand-held device I've used for this since the 1970s. Cartridges can make a lot of distortion if the stylus isn't right!

The other problem I've seen is the magnet structure can shift if the cartridge is dropped or the like.