Azimuth&Bias on HIFI test record

Colitas, The HFN bias test tone varies from inaudible (good) to a steady "buzz" (needs adjustment) to a rough or warbly buzz (dangerously near mistracking). Unfortunately, bias force increases as the arm tracks across the record. So there's no "perfect" antibias setting, just a good compromise. As a rule, the anti-bias scales on Rega arms are off. Most people set it somewhat lower than their measured VTF.

Is there an azimuth adjustment on an RB300? I didn't know that. On my system switching to mono reduces the signal to a whisper, but not total silence.

Great post Lugnut. Agree about bias tracks on the HFN record. Why are they all near the inside? Tracks 1 & 2 are pretty useless anyway, they should have included just tracks 3 & 4 and duplicated them near the outer edge.

I've never looked to see if different antibias settings cause a visible change in cantilever angle. Might depend on the compliance of the cartridge. I suspect low compliance carts could be significantly mis-biased without displaying much visible deflection of the cantilever. You'd only know by stylus and/or groove wear.

Maybe Twl will straighten us out.

An old fashioned way to check azimuth is to scratch or use a marker to draw a line perpendicular to the bottom of a small pocket mirror. Then, IF your platter is level, slide the mirror up near the cartridge and view from the back side. If the cartridge has a perpendicular side edge it should line up with (be equidistant to) the scribed line. If the cartridge isn’t “square” it’s up to the eyeball for a manual setting, though even some of those have a vertical line on the front of the cartridge body. For anti-skate, I go with my ears, but Lugnut is correct that the only perfectly “accurate” way is to use a ‘scope. Oh, and I have seen it set using a ‘scope and having it subsequently fail the HiFi test record gauntlet!

Doug, did you mean azimuth test and not bias test with respect to the HiFi record when you say "Colitas, The HFN bias test tone varies from inaudible (good) to a steady "buzz" (needs adjustment) to a rough or warbly buzz (dangerously near mistracking)."?

My understanding is that there should ideally be no tone using a mono signal when doing the azimuth test. For the bias test, there should be a rock-steady tone and any "buzzing" indicates improper bias. If it is supposed to be silent, I can't get any of my cartridges past the first bias track! Ha!

Maybe we are mixing terms here. I just wouldn't want anyone that is using the test record for the first time to be confused.

Doug,

Thanks for the compliment as I was a little nervous about writing. So many people here know much more about these types of subjects and it's a little intimidating.

I'm sure about the canitlever statements I made. While I don't have a clue as to the construction inside a cartridge it must have a suspension of sorts which is, by its nature, very sensitive and prone to damage. If one has too much anti-skate the stylus will still want to track the groove as the tonearm tries to keep it from doing so. The result would be a cantilever that is more or less permanently tweaked to the side.

I actually saw this when an acquaintence asked me to look at his table. I had brought my blank record and after seeing the stylus pushed way to the side tried the blank. It confirmed my suspicion. We left everything as it was except for the anti-skate which we adjusted, played a few junk records while we watched tv and lo and behold it was more centered in the cartridge body. The next time I went over it was back where it belonged. Damage? I don't think it helped the mechanics of the cartridge to be mistreated in that way but it sounded fine. I suspect his records took a hit though. This kind of stuff is what makes buying used vinyl so "iffy".

Anyone reading this that takes issue with what I've said please be kind to me. These are honest observations and I still don't know if my rationale is right on. Enlighten me if you know the truth.

I don't use a test record. All my records are "test records". I just play them. I adjust everything by ear.

No azimuth adjustment on a Rega arm, except via shims. The above info on checking azimuth seems right to me.

On a mid to high compliance cartridge, if the bias is terribly off, it is easy to see by looking at the cantilever from the front. If it is angled off the center by the record during play, it is way off. With these more flexible cartridges, you can check for a basic center by looking at it, and then fine tune by ear. With low compliance cartridges, it is a little tougher because it won't be easily seen by looking.

Thanks Tom. Lugnut and I are both right? Must be a good day! BTW, what would we hear with a non-optimal anti-bias setting? Channel/image imbalance? Harsh HF's in one channel?

David,
I was talking about the bias tracks but certainly didn't state it clearly, thanks. It's just like you said. Hey, wanna swap one of those bum cartridges? I've got an ADC XLM that should track at .75g on an Illustrious. Deal?

I didn't bother with the HFN record after my last cartridge realignment. I'm either getting lazy or pretending I can hear like Twl!