Achromat Interface

[ProfTournesol]

I saw this interesting thread on stereo.net

As a long time fan and user of the Funk Firm Achromat on both my decks I have been satisfied with its benefits over other mats/combinations.
Preferring its presentation to direct on my acrylic platter on my modded P2 and using it with an SRM Tech 2mm silicone mat as underlay on my SL-1200.
I always use either a Michell clamp or a Bruil pattern weight with this mat, both to increase drive/reduce possible slippage and to ensure best contact of the record with the mat to enhance its dissipation of the excess energies generated within the record by interaction with the stylus (which is what it is designed to do).
I recently came upon the idea of improving the bonding of the mat to the platter by interfacing the two with a thin layer of either silicon grease or petroleum jelly (recommended on another forum in connection with the SL-1200 in particular and relating to the now available specially recessed Achromat for the SL-1200).
Not having that mat, I decided nonetheless to try the technique on my acrylic platter.
I carefully applied a thin coating of vaseline to the bottom of the mat, spreading it as evenly as possible with an old credit card, then placed the mat on the platter (which I temporarily removed from the deck) and slowly rotated the mat on the platter applying pressure to spread the vaseline and remove air from the interface (akin to making a "rubbed joint" in cabinetmaking).
After cleaning the small amount of squeeze-out and replacing the platter/mat on the deck, I naturally played several records.
To me, the good effects of the Achromat seemed enhanced, not startlingly, but appreciably, with surface noise being less obtrusive and somewhat softened, soundstaging somewhat better and previously difficult to follow vocals, such as Rickie Lee Jones on the "Pirates" album, being more distinct. Instrumental timbre on the Sargent/LSO recording of Pictures at an Exhibition also seemed enhanced with individual instruments showing more of their particular character.
Seems worth a try to me if you have the mat and a suitable platter (those from whom I took the idea were using the mat direct onto the Technics metal platter).

I'm on holiday at the moment so I haven't been able to try it yet. Has anybody tried anything like this?

[rolleye]

silicone grease and petroleum jelly.....would these have any effect on the achromat itself? silicone tends to 'creep' and i'm not sure i'd like the mess it would make.......yuk, think i'll leave this one for others to try

[satanfriendly]

There was a thread on this matter in the turntable section a couple of months back.

Personally. Think I'll stay clear and enjoy things for what they are and less the potential mess.

[ProfTournesol]

maybe even just some hand cream would do it?

[thezenroom]

anything sticky is gona be sticky/messy but only to apply, in place it shouldn't seep. doesn't mean its a badda idea as it sounds. what you end up with is a damping layer (say 50 microns) working in a similar way to the sounddeadsteel isoplatmat (as well as a non-slip mat).

[bubba45]

I used a 2 micron layer of snake oil with my Achromat. Wow!!! Bejeezuz!!!
Did the trick amazingly. More detail, positioning and the soundstage was wider, deeper, taller and a slight shade of mauve, which was unexpected.
Bass resgister more fully formed and there was a deep, fruity but well defined mid range.
On my copy of Franks Wild Years I could tell the drummer had blonde roots and the drummer sported a tash.

Sometimes don't we just hear an improvement when we try something but in reality it isn't there?

A chap on another forum got an engineering firm to make up some arm collars for Jelco arms and a few of us bought them. They were made purely and simply to correct a minor fault of the 750D arm collar so it was easier to adjust VTA and get correct azimuth without having to fiddle with the headshell. They work a treat for this.
One of the guys who bought one swore blind it added focus, detail, balanced out the tonal range, expanded the soundtsage in all directions and even rounded off a slight harshness in the top end he hadn't noticed before. Piano notes were more accurate and he could hear the edge of cymbals like never before.
Even the guy selling ther arm collars told him (politley) he was talking bollox.

Is a 20 micron layer of vaseline really really gonna make that much difference underneath a reasonably stiff platter mat?

[ProfTournesol]

I've tried adding some Nivea hand cream between the Achromat and platter, it stops the mat slipping but no audible difference in sound to me. Maybe I need a more upmarket cream!

[bubba45]

Try Clarins...........

[ProfTournesol]

Try Clarins...........

maybe something expensive and French. If it is too good at removing wrinkles it might remove the grooves on the LP though:(

[deeslexia]

I have some old fashioned Cow Gum which is rubber based - I wonder ... ?

[Zebbo]

Is a 20 micron layer of vaseline really really gonna make that much difference underneath a reasonably stiff platter mat?[/quote]


Well, I can see some merit in the theory. If you think about having two rigid surfaces placed together it is almost impossible to get them to sit PERFECTLY snugly face to face. When you think about the minuscule movements the stylus is making in the groove, any amount of movement between mat and platter would be disastrous. My guess is that the Vaseline is not there to provide any sort of acoustic property of it's own but simply a way of creating a sort of "vacuum" to suck the mat to the platter which makes sense to me.

[thezenroom]

Is a 20 micron layer of vaseline really really gonna make that much difference underneath a reasonably stiff platter mat?

people who know about "constrained layer damping" say it does/will have a effect.