Cartridge set up tip

[AJSki2fly]

So today I was fitting a new arm wand, this was due to a minor issue when changing headshells with mine and is being replaced under warranty by Pro-Ject.

I decided to take as much time as it took to set it up spot on as I wanted to be sure it was all fine. So having fitted the arm I set to checking the VTA and Azimuth with the tool I use, a BUM gauge, basically a Perspex block with lines on it that you can visually align the headshell/cartridge with, see https://www.ebay.co.uk/itm/Hi-Fi-Tonearm-VTA-Cartridge-Azimuth-Alignment-Ruler-Headshell-Alignment-Block-/113453007211. So this usually works fine with most cartridges the have a flat front but with my Goldring 2500 it is curve and being able to establish if the top of the cartridge is dead level to the record is very tricky due to parallax effect.

I then thought I know I will put on my HiFi test record and the track for test Azimuth listening test, instantly I could hear that the right channel was louder than the left. So this meant that the azimuth was not correct, in other words stylus not perfectly vertical.

So how to check accurately, then I thought I know I have a dB meter app on my iPhone, so I played the 300hz track again and measured each channel with the phone 1 foot from each. The right was measuring 91dB and the left 86dB, 5dB difference :eek:. So with the arm on its rest I placed a small bubble level on top of the head shell and loosened the grub screw and adjust accordingly, until the bubble was dead centre with the needle at record height, held on the arm cue. I played the test track again and this time right was 90dB and left was 88dB, so still not quite there. So another little tweak and this time I had 89dB left and right, so spot on. I rechecked the bubble level and it was just slightly off centre.

So why is the spirit bubble slightly off, the answer is likely to be that the head shell which is polished aluminium on the top is not perfectly level in relation to the base, not discernible by eye but shows up with a spirit level. I rechecked now with the BUM gauge and by very carefully getting my head and eyes lined up to the front of the cartridge I can no see that the underside of the head shell is exactly inline with a line on the gauge.

So what has all this faffing around done sonically, well I can say that the soundstage just seems more expansive, detail and separation is more precise, it just sounds great!

So it is well worth ensuring your Azimuth is spot on it can IMO make a big different. Oh and don't forget VTA, sounding too bassy and the arms down at the rear, too bright and even sibilance on vocals and it up at the rear, with some cartridges it only takes a small change for VTA to make a difference.

I hope some of you find this useful in the future.

[chris@panteg]

Easy to see why many can't be bothered with vinyl, but it's worth it isn't it.

Can't do anything about azimuth with my SME V, it should be spot on anyway but yeah I persevere with vta until I get it right.

[AJSki2fly]

Easy to see why many can't be bothered with vinyl, but it's worth it isn't it.

Can't do anything about azimuth with my SME V, it should be spot on anyway but yeah I persevere with vta until I get it right.

Yes Chris, I agree it is worth taking time and getting it right. I used to have an SME IV with removable head shell. I found with that I had to make slight azimuth adjustments for cartridges. I do wonder if sometimes the stylus is not exactly at 90 degree to the top of the cartridge base, so adjustment is necessary to get it spot on.

[Ali Tait]

Perhaps more likely the diamond is not exactly vertical in the cantilever.

[AJSki2fly]

Perhaps more likely the diamond is not exactly vertical in the cantilever.

Yes Don that’s what I meant in my last sentence.

[karma67]

these little gauges are fine for getting it in the ball park but you are relying on the stylus tip being 100% true to the cantilever and that's true to the cartridge body which in turn has to be true to the headshell,thats all a big ask imo,i do own one but quickly realised that you cant beat a good loupe for actually seeing the stylus tip in the record groove for setting azimuth,the very last knock in's are done buy my good old ears.

[high.spirits]

Good tip, thanks. I will give mine a test.

[WullieD20]

these little gauges are fine for getting it in the ball park but you are relying on the stylus tip being 100% true to the cantilever and that's true to the cartridge body which in turn has to be true to the headshell,thats all a big ask imo,i do own one but quickly realised that you cant beat a good loupe for actually seeing the stylus tip in the record groove for setting azimuth,the very last knock in's are done buy my good old ears.

I couldn't agree more.
I also have a couple of the tiny spirit levels mentioned earlier, but found them to be fairly inaccurate! If you rotate it to different positions on a level surface, the bubble adopts a different position each time, so not the best way to set azimuth!
Use a mirror, or a smooth record surface to determine azimuth from the reflection of the cartridge and the angle of the cantilever, then finish off with your "good old ears".

[Ali Tait]

A Fozgometer will do the job, at a price..

[Beobloke]

I've never tried a BUM gauge but I've heard the results are supposed to be sh*t....

[Scooby]

these little gauges are fine for getting it in the ball park but you are relying on the stylus tip being 100% true to the cantilever and that's true to the cartridge body which in turn has to be true to the headshell,thats all a big ask imo,i do own one but quickly realised that you cant beat a good loupe for actually seeing the stylus tip in the record groove for setting azimuth,the very last knock in's are done buy my good old ears.

Somehow I never thought of that but it makes great sense thanks.

[gwernaffield]

just used fozgometer , make sure it is calibrated first with the software off the site, to put a long story first , i had a benz micro given to me , it had a new ruby cantilever from sound smith fitted 7 years ago , the person who gave me it was never satisfied,
the cantilever seemed to be off center , using the fozgometer i found out the diamond was not central to the cantilever by 18 db to the right , channel , this is what has caused the cantileaver to pull to the right , on setting it up with the meter it is now
perfect with in .005db , according to the meter and sound is sharper and clear ,i was lucky to have a sme 309 that allowed me enough movement to adjust that out ,

[RobbieGong]

just used fozgometer , make sure it is calibrated first with the software off the site, to put a long story first , i had a benz micro given to me , it had a new ruby cantilever from sound smith fitted 7 years ago , the person who gave me it was never satisfied,
the cantilever seemed to be off center , using the fozgometer i found out the diamond was not central to the cantilever by 18 db to the right , channel , this is what has caused the cantileaver to pull to the right , on setting it up with the meter it is now
perfect with in .005db , according to the meter and sound is sharper and clear ,i was lucky to have a sme 309 that allowed me enough movement to adjust that out ,

Good on you Peter.

It's a right malarky this vinyl replay, hence some cant be asked with it and i can see why.

I'm a sucker for punishment so one of the number that wont ever be letting it go :mental: :)

[Pharos]

From Gordon;
"I also have a couple of the tiny spirit levels mentioned earlier, but found them to be fairly inaccurate! If you rotate it to different positions on a level surface, the bubble adopts a different position each time,"

If the surface is level, the bubble position should remain constant in the level regardless of its orientation, ie the same position in the level.

[Truckletheuncivil]

I suspect that alot of these tiny levels are poorly made and if the bottom surface is not parallel to the bubble it will move position when rotated

[WullieD20]

I suspect that a lot of these tiny levels are poorly made and if the bottom surface is not parallel to the bubble it will move position when rotated

Exactly my point. And the reason they cannot be relied upon for accurate headshell / cartridge alignment.

[legb4rsk]

My bubble level has helped me out many times.I removed it in the early 70's from a huge 80 column card punch that was used for commercial computers in the 60's.
Made from machined steel & glass and is extremely accurate.Like most things 'they don't make them like that anymore.' :(

[WullieD20]

My bubble level has helped me out many times.I removed it in the early 70's from a huge 80 column card punch that was used for commercial computers in the 60's.
Made from machined steel & glass and is extremely accurate.Like most things 'they don't make them like that anymore.' :(

:lol: Excellent..... So, not £1.59 worth then?? . . . (https://www.ebay.co.uk/itm/Tiny-Disc-Bubble-Spirit-Level-Round-Circle-Circular-Green-Tripod-t/283816099269?hash=item4214c1fdc5:m:mW0tqN0bOxS7ZAl DGLFygzA)

[Barry]

If you can, just borrow a double beam oscilloscope to measure and compare the output from each channel. Connect the two channels of the scope to the tape outputs of the pre-amp.

Use a test record with fixed tone tracks and adjust the azimuth so both channels have the same output voltage. This will also take into account any channel imbalance (difference in gain) between the two channels of the pre-amp/phonostage.

[gwernaffield]

i think the fozgometer is easy to use, just put the cable direct to the inputs, using the AP test lp did the trick for me, i find a oscilloscope a bit confusing , would not no where to start , with one , to be honest ,

[AlasdairB]

I have a Mayware unipivot arm, which is tricky to set with perfect azimuth. I found that a spirit level is a poor tool for the job: it is inaccurate, its weight upsets the arm alignment and errors in turntable and arm levelling can add to one another. However what matters is not whether the arm is level - it is whether it is parallel with the record surface and this can be checked accurately with an apparatus that is easy to make and costs nothing. Take a small piece of paper and fold it so that it will stand up on a record. Place the stylus close to the edge of a stationary record, stand the piece of paper alongside the headshell and mark a horizontal line on it level with the top of the headshell. Then stand the piece of paper near the far edge of the record and sight it again across the top of the headshell. Adjust the arm until they line up in both positions. If the top of the headshell aligns within 1mm of the line on the paper, you have aligned the azimuth of the arm parallel to the record to within a quarter of a degree, which is better than can be done with a spirit level and should be good enough for anyone. Simples!

[Old Grey Grump]

Re. using the little bubble levels, I found that the tiny ones are crap, but the small ones i.e. about 1cm in diameter, are fine and work well. And all I do is weigh mine (it's 1.4gms) and adjust the counterweight accordingly to ensure no undue downforce is being applied to the cantilever. Doing this at least gives you confidence that you are starting from a level position in terms of armtube (VTA and azimuth).

Next, re. using sound analysis, how do you know any observed channel imbalance isn't down to cartridge manufacture inaccuracy e.g. misaligned magnets, unequal/uneven coil windings (both of which are not that uncommon)?

In my experience you can only address azimuth with any confidence of accuracy via magnified head on visual observation on a mirrored surface (and don't forget to set A/S to 0!)

[karma67]

i agree, using an ociloscope will get you there but as you say you dont know if the sylus is aligned to the colis,i use the scope to get me in a very small ball park along with various loupes and finally my ears.

[Killie65]

For setting azimuth initially i sit my headshell flat on top of the azimuth block which sits on top of an old lp. Not as the maker intended but better than using the thin black lines. Then tighten the screw on the headshell just enouph to secure. Then return arm to cradle and tighten fully. Gives a good starting point. Audiomods have little cylinders which are very useful in different sizes which give a good starting point for azimuth & vta when the headshell sits flat on top of the cylinder. Choose one which matches manufacturer cartridge height when in play. I've used an Arche headshell, by far the best tool for dialing in a cartridge with micro adjustment of all parameters, bit of patience and you can't miss. For me it's good value to hear a top MC as it should sound. Must admit i've also bought/borrowed a fozgometer in the past using it once and returning for refund.
On VTA ; my advice is don't always assume you're hearing shrill highs because vta is too high as it more often than not is alignment that's out. I set azimuth close then vta to level then alignment has to be perfect before returning to perfect vta & azimuth. Also if vta is well off, assuming too much bass or too much treble is a result of too low or too high setting can baffle as i've heard too much bass when the arm is way too high and conversly too much treble when the pillar is way down.

For me, alignment is most critical, then azimuth, anti skate (on less than 2g trackers), tracking weight then vta, finally overhang which is over egged as even 1mm out doesn't make much difference. I've used my fr66s over a 5mm range and not heard a whole lot of difference.

It can be a maddening process, no exercise on The Cube tv programme comes close and at times i've sworn my next cartridge will be a spherical type stylus no matter how it sounds.
Or just go to a dealer but ask them how they fulfill the fitting as you might find your toolbox and skills are better than theirs.

Cheers,

William