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-Ton...-/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 . 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....