AT440MLB and VM540ML Right Channel Crackle / Increased Surface Noise

Hey all,

I have a peculiar issue with my AT440MLB and VM540ML cartridges and I'm looking for some advice as I'm totally out of ideas myself. My deck is a Rega Planar 3 (2016).

On about 10% of records I have noticed a crackle in the right channel, and generally increased surface noise specifically in the right channel on a further 10-20%. If I return an affected record for a replacement, normally the replacement will also have the same issue. The crackle usually occurs on and off throughout the affected side. I have taken one of the affected records to my local dealer, played it on their LP12 + Shibata system and there was no crackle/surface noise at all.

I have carefully tried the following to resolve this problem, but have had no luck in reducing the crackle/surface noise:

• Adjusted VTA of the tonearm (+2mm, +4mm using Rega spacers)
• Adjusted azimuth (in both directions, +/- 0.5mm, using paper or small plastic washers to shim the cartridge)
• Adjusted tracking force (min and max recommended values)
• Adjusted antiskate (between 0 and the VTF value, checked with a test record)
• Modified cartridge alignment using both Stevenson and Baerwald alignment protractors
• Checked turntable is level with a spirit meter
• Cleaning the stylus with brush, solution and magic eraser
• Cleaning the records using Record Doctor V and Knosti + l'Art du Son
• Replacing the AT440MLB stylus with a new AT440MLB > issue sounded exactly the same
• Replacing the AT440MLB with a new VM540ML > this actually made the right channel crackle and surface noice noticably worse

I had originally assumed this was some kind of common pressing flaw revealed by the AT440MLB microline stylus, but what is odd is that the crackle is always a similar sound and always in the right channel. I do not believe it's a defect with my AT440MLB as also have a spare AT440 stylus and VM540MLB which both produce the same issue with the same records.

Most of my collection sounds great, but it is worrying me that a significant minority of records have this crackling / surface noise in the same channel. Anyone have any ideas as what may be the issue, or a similar experience?

 

I had the same issue with a 440mlb. No amount of adjustment would resolve the issue. I ended up returning it and getting another which did not have the issue. Very strange that your 540 and other 440 are showing the same issue. What else is in the signal chain?

 

My phono stage is a Muffsy PP-3 (I've also tried my amp's inbuilt phono stage), my amp is a Rotel RA-04 and my speakers are Orphidian Minimos. I borrowed a Rega Brio amp from my local dealer and the issue was still there with that. It's also there with headphones. So I think I've ruled out an issue elsewhere in the signal chain.

Looking at the stylus of my VM540ML through a loupe, to me it looks like the diamond is not positioned straight down but at an angle (click for a bigger image):



As an experiment, I have tried shimming the VM540ML to correct the angle I'm perceiving on the stylus. With an extreme amount of shimming (approx 1.5mm on the left hand side), the crackling did reduce noticeably, but it was still there and I'm certainly not happy to leave my set up with this much of a shim.

 

If you've got a cart where the stylus is not set right on the cantilever and that bothers you, I'd return it for another one.

Is this one of the Regas that has automatic/non-adjustable anti-skate?

 

I am just surprised that this could have happened with 3 similar cartridges in a row (each purchased a year apart from different places), so I am not sure if the angle I have noticed on the stylus is the root cause. I can't return this VM540 as it was already a replacement for one of the AT440MLBs with the same issue and unfortunately the warranty is no longer valid.

The anti-skate is adjustable, adjusting it makes no difference to the crackling, but I know it is working because if it is set too high the tonearm does creep outwards when the lifter is raised.

 

@djhurley92, I've had 4 or 5 440 styli on my main cart (and old Signet) and have never encountered this problem. Sounds like you have bad luck. If the mounting of the diamond on the cantilever is off, that could cause problems. I don't know if there is something else going on with your turntable that is also making the issue worse. If you want to get technical, you could get a test record and then adjust azimuth and alignment according to that. If the diamond is way off, it might be more difficult to do that.

 

In that photo, the diamond looks slightly off to the left in the cantilever. Could be the lighting, but I have a pretty good eye for these things.

 

No issues with either AT440MLa's or b's on my system. However I will say that they are poor matches for a Rega.

I would actually say to be fair that Rega's are a poor match, not the other way around. As delivered out of the box they are poor to adjust in the VTA department.

I had a Rega RP3 and it hated the AT440Mla cart, it produced a hum from it. I had an RP6 before swapping it out to the RP3, and the RP6's hum was even louder. (No its not my kit, the dealers setup also revealed it). The RP6's problem was heightened by the box with the speed control on it. The RP3's hum was due to no grounding wire OR the power supply voltage, which I read somewhere was totally unnecessary spec for what it needed to do.

Once I had the RP3 fitted with the AT440ML cart, the problems didn't stop there. I also needed the spacer kit to get the VTA right. With that fitted, another problem occurred, the lid wouldn't shut because the counterweight was hitting the top of it. So I had to shell out another £80+ to get a smaller counterweight from my dealer.

After putting up with the Rega's idiosyncrasies (White belt upgrade indeed!) for about a year I got fed up with it, and sold it for a 2nd hand Technics SL1200, and I have never been happier.

The Technics is unfussy, you can adjust EVERYTHING, it has speed control built in as standard, it has detachable head-shells for ease of changing and adjusting carts, you can alter the height for VTA easily, and you can read the numbers on the arm control properly for the weight and anti-skate (WTF is that thing on the Rega arm, totally daft).

tl;dr version is, after being an owner of both the Rega RP6 (for a week) and the RP3 (for a year+) I find them the most overrated TT's around. They are so fragile, fussy and strange that I don't know why they keep getting rave reviews. Get something else you can easily adjust, and then excellent carts such as the AT440ML series can be enjoyed in their full glory.

I think the Rega might be the issue here, not the cart (especially as you have tried more than one of them)

 

A major issue is usually caused by a major fault. By the info you've given, your stylus is mistracking badly, even if only audible on a few records, and intermittently. The tweaks you made are valid, such as tracking force, alignment, etc.. but all of these when only slightly off would not cause a major audible problem.

By the photo you posted, the azimuth is way off. This I believe is the cause of the problem. I would restrain from using the AT cartridge for now. Also, could you take a photo of your other styli as well? Although it seems unlikely, I wonder if these styli also are not set properly in their cantilevers? The lighting can cause distortion in the photo, but thinking the stylus is indeed "crooked".

 

@englishbob I'm sure it is a marketing strategy from Rega that their TTs only work easily with Rega carts I also have the spacers and tungsten counterweight! However except for the crackling and surface noise issues on some of my records, I am very happy with the sound I am getting so if I can find a way to resolve those I will be content.

@The FRiNgE are you suggesting the azimuth is off because the stylus is at an angle? Or are you judging the azimuth to be off for any other reason?

Copied from above: As an experiment, I have tried shimming the VM540ML to correct the angle I'm perceiving on the stylus. With an extreme amount of shimming (approx 1.5mm on the left hand side), the crackling did reduce noticeably, but it was still there and I'm certainly not happy to leave my set up with this much of a shim.

 

I wouldn't want to leave a cart on with that much shim either. I would simply get another cartridge. Sorry for your bad luck with this cartridge. I would talk to AT about doing a replacement even if at first glance it seems that you can't do that. That's a manufacturing defect to have the diamond off by that much.

 

Nice angle on the cartridge, haha! good thinking! But the problem with this, now the suspension is way out of alignment with the groove. There is also the misalignment of the "motor" or magnets and coils in relation to the groove. The azimuth is off because of the angle of the stylus, yes!!!

 

You will we displacing the motor system and get serious channel crosstalk issues if you shim the cartridge that much. If the stylus is at an angle, it needs to be replaced. Were all stylii bent when you bought them? If not, there something strange with the antiskate or arm bearing friction that turns the stylus around. If you look at the stylus during needle-drop, does the stylus bend in one or the other direction (left-right)?

 

Funny how the 1200MKII is never part of the equation in such threads!

 

That's because the 1200 MKII is faultless. The Rega was designed by the devil!

 

@djhurley92 what tool are you using to measure the tracking weight?

 

Yes indeed, I only played it with this shim for 5 seconds as an experiment to see if it reduced the crackling (which it did).

I have set antiskate to about 1.2 on the Rega arm in which position the stylus goes straight down. With less antiskate, it deflects to the left, with more antiskate, it deflects to the right. I've also checked it with a HiFi News Test LP and it passes the first 3 tracking bands, with even distortion in both channels on the 4th band.

 

I have an Ortofon balance scale and a digital scale, I'm using 1.4g for the AT400MLB and 2.0g for the VM540ML. Both scales agree, so the values should be correct.

 

So this means some quality issues with the stylus. I've seen quite some examples of this, the QC is not what it used to be.

 

Crackle.m4a

For anyone interested... here is probably the worst example of the crackling (recorded using my phone in front of the right speaker). Interestingly, I get absolutely no IGD or sibilance with this setup, the only issue is cracking and increased surface noise in the right channel on a minority of LPs.

 

I have have had numerous 440's and now I have a 540 never ever have I had a problem with them. Have you tried other cartridges apart from the AT's? Very strange this would be on all of them.

 

Right, well if the VTA all looks good to you, the only thing left to tweak is the anti-skate. Are they still using that weird pull/push thing with the notch in the middle?

 

Hey,

Check out post #17, I did tweak the anti skate already :/

I’ll write to AT and see what they say. Thanks all for the feedback this issue has been driving me a bit mad so good to get some other opinions.

 

Well, AT replaced my VM540ML stylus for me, now the issue is resolved!

The replacement stylus looks to be mounted MUCH straighter in the cantilever...

Great service from Audio Technica !!!

 

So, NOT the fault of the Rega after all then? I have a 1990s RP3 and an AT440mlb which performs faultlessly!