Adjusting my cartridge

[keiron99]

I know this is basic. Apologies in advance.

I've recently bought a Jelco 750d tonearm and AT150MLX cartridge.

In the past, I have never worried too much about setup. Just got things sort of level and straight, set the manufacturer's recommended tracking force and off you go.

But I've tried to do it right this time.

First problem: I got a "mirrored" protractor but I simply cannot see a thing. The stylus is so thin, even with my most powerful reading glasses and magnifying glass, I haven't got the foggiest what's happening under the giant headshell which obscures my view of everything. So I have just set it up so that it looks about right.

Second, I've got a HiFi News test record. There are virtually no instructions with it in terms of what to do if your cartridge" fails" a test. Well, mine fails dismally on "Band 7, bias setting (anti skate) - 300hz tone, 14db". The sound is massively distorted from BOTH channels.

The only way I can rid it of the distortion is to set tracking force to 2 grams and setting the anti - skate to about 2.7.

This cannot be right can it? Most owners seem to have it at about 1.25g, 1.5g at most.

So do I have something else wrong? Should I move the cartridge back or forth in the headshell?

[struth]

I dont like these test records as i feel they give people dubious info. I would be inclinded to set it up at about 1.5 gm vtf and have a listen through a record and see what you hear. I believe it can go up to 1.75 gm but dynamics can be affected

[Stratmangler]

Don't worry about not tracking the torture tracks.
You shouldn't exceed the manufacturer's recommended down force with MM carts - the cart suspension is generally more compliant with MMs than is the norm with MCs.

The torture tracks are there for gauging the correct antiskate bias.

[keiron99]

Thanks.

So what I have done is put the tracking wight down to just over 1.7 (the max recommended).

It completely fails the final "torture test". But to get it to handle the 2 tests before the final one, I have to set the anti skate (same thing as bias?) to 2.5.

Is that right?

[Stratmangler]

What you need to do is adjust the antiskate to remove any audible distortion.
My antiskate dial is set between 2.5 and 3 .

[karma67]

dont worry about the last test as has already been said,if you get distortion on the other 2 then the idea is to have it balanced through both channels equally.
i gave up on my test record,its not the be all and end all,its far more important to have your cartridge aligned dead right,try the tracking weight in the middle of the recommended settings.
in regards to not seeing the stylus,try raising the turntable up on the kitchen worktop using 4 tins of baked beans or whatever i do mine like this in plenty of natural light.

[rdpx]

I simply cannot see a thing. The stylus is so thin, even with my most powerful reading glasses and magnifying glass, I haven't got the foggiest what's happening under the giant headshell which obscures my view of everything. So I have just set it up so that it looks about right.


I was considering the AT150 but I seem to remember that a few people mentioned it was quite nervous to being set up exactly. It sounds from what I lifted just above that you don't really know how close you have the needle set to where it should be... I would recommend you see if there are any AoS members near you with better eyesight who could drop round and help you get it set up properly. Failing that, find a dealer who you can throw £20 at to sort it for you.

There is little point worrying about VTF or BIAS if you haven't got the stylus in the right place to start off with.

Whatever you think about test records, your arm/cart set up should be breezing through most of them when set up properly.

R

[keiron99]

I'm still struggling with this cartridge. I know from research it's a bugger to set up properly.

And I know some say not to worry too much about test records, but I can't help it!

Again, forgive my ignorance - I know a little knowledge is a dangerous thing - but given that the problem seems to be through one channel, which can only be corrected by extreme settings on the anti-skate, could this be an "azimuth" issue? (I've just been doing some reading during lunch time...)

I'm aware that azimuth is an issue with the Jelco arm - the mounting collar is clearly a poor, wobbly design - hence the availability of after-market collars. I assume that the purpose of these aftermarket designs is to ensure the arm is accurately perpendicular to the turntable?

[struth]

Azimuth is of primary importance . wont sound right if its off.. Even the smallest of adjustment can make things sound very different. Worth getting level then minute adj if your not happy. Think Marco fnd this with his new one too. Even though the bubble was bang on a slight movement improved it dramatically. If the collar is poor then replacing it would be on my todo list

[Ammonite Audio]

I'm still struggling with this cartridge. I know from research it's a bugger to set up properly.

And I know some say not to worry too much about test records, but I can't help it!

Again, forgive my ignorance - I know a little knowledge is a dangerous thing - but given that the problem seems to be through one channel, which can only be corrected by extreme settings on the anti-skate, could this be an "azimuth" issue? (I've just been doing some reading during lunch time...)

I'm aware that azimuth is an issue with the Jelco arm - the mounting collar is clearly a poor, wobbly design - hence the availability of after-market collars. I assume that the purpose of these aftermarket designs is to ensure the arm is accurately perpendicular to the turntable?

Correct!

Getting the armtube and headshell level at all points across the record means that the arm's main pillar must be perpendicular to the platter's plane. You can achieve that with Jelco's original collar but you risk running out of swear words in the process. If you would like one of my improved collars, I have a couple which have been used at shows or for photography, available at a discount. Please PM me if you are interested.

As has been said earlier, the HFN test record is a poor guide to setting up a cartridge, since virtually no cartridge properly tracks those 'torture' tracks. The best way to start is to set the turntable level, using a bubble level on the platter (at various points), then ensure that the armboard is similarly level. If you're using one of my collars, it's then a simple matter of using a small headshell bubble level to adjust VTA and azimuth so everything is level when the stylus is on the record, at the correct tracking weight. This assumes that the cartridge is correctly aligned in the headshell - I use a Clearaudio Alignment jig which takes all the guesswork out, but you can use the printed card alignment disc that comes with the HFN test record, but make sure that the long arrow is pointing accurately at the centre of the Jelco's damping hole thingy above the bearing yoke.

Having set everything level, it's very likely that small adjustments of VTA and azimuth may be needed for optimum sound quality, but this can be done by ear. Indeed, it's better done by ear.

I hope that helps!

[keiron99]

Thanks Hugo, I will be in touch.

I hadn't thought of checking the level of the armboard. That's a good point. Suppose I'll have to get one of those diddy little bubble spirit levels for that. That said, if I find it's not level, what can I do? Put some spacers under it?

[walpurgis]

I'd certainly ignore the test records. Some cartridges will always fail the tests, despite sounding very good on 'normal' records.