Achromat turntable mat

henrylr · « **on:** 6 Aug 2023, 12:49 am »

I found posts about the Achromat mat and it got a lot of praise, and one post was very interesting. The poster said that since ads for the Achromat say their mat is so good because the material is very similar to vinyl LPs and it is stiff. He suggested trying an old LP as a mat and save $$$. Has anyone tried that?
Thanks

nlitworld · « **Reply #1 on:** 6 Aug 2023, 02:40 am »

I've heard of the old lp trick but never fully investigated it more than a quick spin. My turntable at the time was not adequate to hear any real change with that. When I bought my Schiit Sol a couple years back, I picked up the Achromat and never looked back. Great product to just set it and forget it, and a huge step up from cork or felt.

toocool4 · « **Reply #2 on:** 6 Aug 2023, 10:16 am »

I have not tried the old LP as matt, and I would not try it either. If you don’t have a good grip, the record will slip and the record you are playing will scratch.

I use the Achromat APM, which is Achromat and glass bonded together. Like nlitworld said I would not go back to any other matt.
Since using the Achromat APM, I get quieter background noise and many other benefits. One bonus benefit is, I no longer have static problems.

If you are going to go for the Achromat, make sure you can adjust your VTA on your tonearm. Achromat APM is 7mm thick.

https://thefunkfirm.co.uk/upgrades/apm-apm-black-wgokrt

henrylr · « **Reply #3 on:** 6 Aug 2023, 04:33 pm »

Has anyone tried a mat on a Dual 1249. I ask because the integral, molded rubber mat has three raised circular rings that the LP rests on, so a very high percentage of the LP surface area is not in contact with anything but air. It would seem the unsupported area could be prone to vibrate. Any thoughts on this will be appreciated.

Thanks

S Clark · « **Reply #4 on:** 6 Aug 2023, 06:05 pm »

Well, it couldn't hurt. But why put a hundred+ dollar mat on a low end table- and the Dual 1249 is a low end table that sells regularly from $100-175. $25 spent on PlastiClay damping the frame and plinth will likely yield better results.

My last word is to move on from it and put your money elsewhere.

henrylr · « **Reply #5 on:** 6 Aug 2023, 06:26 pm »

I was not going to buy the $100 mats. My max was going to be $25 or so.

henrylr · « **Reply #6 on:** 6 Aug 2023, 10:53 pm »

Now a question about VTA. Is VTA correct when, the cartridge is properly set up, including the proper tracking force, and the stylus is resting on the LP surface, the arm tube is parallel to the surface of the LP?

thanks

nlitworld · « **Reply #7 on:** 7 Aug 2023, 02:52 am »

Quote from: henrylr on 6 Aug 2023, 10:53 pm

Now a question about VTA. Is VTA correct when, the cartridge is properly set up, including the proper tracking force, and the stylus is resting on the LP surface, the arm tube is parallel to the surface of the LP?

thanks

Depending on the height of your cartridge and suggested SRA, the best answer is "Yes, Kinda, It Depends". First glance having tonearm parallel is a quick old-school trick but it's not exact. Look up some info on VTA/SRA and if you want to nitpick further get yourself an inexpensive usb microscope to double check. Especially dealing with some nicer cartridges, those stylus get way too tiny to stare at with the naked eye.

toocool4 · « **Reply #8 on:** 7 Aug 2023, 07:26 am »

Like nlitworld said, the parallel arm trick only works if the cartridge has been manufactured with correct SRA. Most are off, so doing a check when you setup is the only way to get it accurate.

If you have an acoustical systems arche headshell like you see on my turntable, you can do all that adjustment at the headshell so you don’t need to mess with the arm wand.

https://www.arche-headshell.de/accessoires/arch%C3%A9-5d-headshell/

Letitroll98 · « **Reply #9 on:** 7 Aug 2023, 09:32 am »

Quote from: henrylr on 6 Aug 2023, 04:33 pm

Has anyone tried a mat on a Dual 1249. I ask because the integral, molded rubber mat has three raised circular rings that the LP rests on, so a very high percentage of the LP surface area is not in contact with anything but air. It would seem the unsupported area could be prone to vibrate. Any thoughts on this will be appreciated.

Thanks

The entire idea of many aftermarket mats is to raise the lp off the mat by supporting it at a couple points. Check the Spot Mat or the Ring Mat for examples. I made several Spot Mats with cork as the base and a few of those stick on cork dots. They definitely sounded different than a stock rubber mat, if they sounded better is a matter of taste.

henrylr · « **Reply #10 on:** 7 Aug 2023, 03:28 pm »

I've searched the web trying to find out if the AT MV540ML VTA of 23deg is compensated to meet the 92deg SRA. Nothing found. Does anyone know if it is compensated? If so, with the tonearm perfectly horizontal, that would be a very good starting point.

thanks

henrylr · « **Reply #11 on:** 7 Aug 2023, 04:08 pm »

I finally found the answer here. SNR is correct when tonearm is parallel.
How Do I Install My VM Series Phono Cartridge? (audio-technica.com)

henrylr · « **Reply #12 on:** 8 Aug 2023, 02:52 am »

Before buying the AT VM540ML The height of the AT and my cart are within less than 0.01. I thought I would check if the tonearm, on my dual 1249, is parallel to the LP surface when the stylus is resting on an LP. The tonearm is angled down, and I had to put a .065 shim between the LP surface and the stylus to get it level. I was curious what the angle was, so I found the TT spec.s and the effective tonearm length was listed as 222mm. I did the trig and the tonearm angle without the shim was 0.426 deg.s. It seems that if I put a .065 shim between the top surface of the AT cart and the headshell mounting surface the AT VM540ML will be exactly at it's 23 deg.VAT. Or I could get a 1.5mm thick mat. Does that make sense.

nlitworld · « **Reply #13 on:** 8 Aug 2023, 01:54 pm »

Yep, that makes sense. I believe the Achromat are only a 3mm or 5mm option, so unless you can adjust the vta on your table, it may be out of the question. Even still, it's good to know you have that table correctly set up. That's a starting point a lot of people don't even get to.

henrylr · « **Reply #14 on:** 8 Aug 2023, 04:38 pm »

I'm looking to buy a tonearm cartridge alignment protractor and would like a recommendation for one that is considered the most accurate.

Thanks

S Clark · « **Reply #15 on:** 8 Aug 2023, 05:04 pm »

Contact member Wayner. He made one that is very easy, accurate, and cheap.... if he is still making them.

toocool4 · « **Reply #16 on:** 8 Aug 2023, 07:19 pm »

This is the one I use, Dr. Feickert alignment protractor.
To be honest you are better off borrowing one or get someone to setup your turntable for you, all the good alignment protractors will cost as much or more then your turntable is worth.

http://www.feickert.org/index.php?id=17&L=1

henrylr · « **Reply #17 on:** 8 Aug 2023, 08:04 pm »

That is very expensive. I bought a Dual 1249 protractor on ebay for $40 including shipping. The company is legendary audio in the Ukraine.

henrylr · « **Reply #18 on:** 8 Aug 2023, 08:08 pm »

I bought a Dual 1249 protractor on ebay for $40 including shipping. The company is legendary audio in the Ukraine.

Letitroll98 · « **Reply #19 on:** 9 Aug 2023, 09:49 am »

The Conrad Hoffman website has an arc protractor generator that's fabulous. It will make an arm specific 2 point alignment for any length of arm and any alignment theory including Stevenson, Baerwald, Loefgren, or any custom one you'd like to invent. All for free. After perfecting the printer settings on plain paper use heavy photo paper to make a permanent protractor dedicated to your arm.