[net.audio] Discwasher Antistatic Mat

grw@inmet.UUCP (04/21/84)

#N:inmet:2600066:000:1466
inmet!grw    Apr 20 10:59:00 1984



	I recently bought a Discwasher antistatic turntable mat.  I have had
	a very large static buildup problem on my turntable and I thought the
	mat would help drain off some of the charge that builds up on the
	disc.  However, I have a few questions for net.audio readers.  Is the
	mat more effective when used alone or in conjunction with the rubber
	mat.  (I don't see how the mat can conduct charge away from the record
	if it isn't grounded somehow and the rubber mat would seem to be an
	insulator.)  Should I buy two mats to get the same (approx) height 
	above the platter as the mat provides (some relationship to the angle 
	of the stylus in the groove)?  

	I should mention that I have noticed a lessening of static discharge
	noise when playing records with the Discwasher mat resting on the
	metal platter.  I also noticed that when I remove records from the
	turntable they no longer crackle and hiss.  I also find that records
	which sit on the turntable for a while after being played accumulate
	less dust.  Is it likely then that I would realize any additional 
	benefit from using additional antistatic devices such as Zerostat?

	I think this is a general enough set of questions to warrant replies
	in the notesfile.  However if I receive replies I'll try to condense
	them and post them to the net.  Thanks in advance.


					   Gary Wasserman
					...harpo!inmet!grw
					...hplabs!sri-unix!cca!ima!inmet!grw
					...yale-comix!ima!inmet!grw

grw@inmet.UUCP (04/26/84)

#R:inmet:2600066:inmet:2600069:000:1616
inmet!grw    Apr 25 11:41:00 1984



	Well, as usual I received several informative responses to my
	inquiry.  The salient points re: Use of Discwasher Mat are:

    -	Use the mat with the original turntable mat because the rubber
	mat damps vibration thus reducing rumble and feedback.

    -	When used in conjunction with a rubber mat the Discwasher mat is
	grounded through the spindle (now why didn't I think of that?!).
	However the suggestion was made that the turntable should be 
	grounded to something other than the amp (assuming the amp is not
	grounded) such as an outlet box to really benefit from the mat.

    -	The vta is affected by use of the mat.  One response put the vta
	change in the order of 8 to 10 minutes (nothing to be concerned
	with) and another response sited the lack of industry compliance
	with a vta standard during cutting of the master (also nothing
	to worry about).

    -	One response indicated that the mat could be cut to support only
	the grooved region of the disk (allowing the lip and label area to
	protrude below the surface of the mat) and that slippage (presumably
	when the mat is used directly on the metal platter) can be reduced
	by gluing the mat to the platter.

	One last question.  Does use of the mat mean I *must* realign my
	cartridge?  I borrowed a Cartalign to do the alignment several months
	ago.  I'm not sure I see why use of the mat should require cartridge
	realignment (I plan to buy a Cartalign or similiar device to check
	alignment periodically anyway).


					-- Gary Wasserman
					...harpo!inmet!grw
					...hplabs!sri-unix!cca!ima!inmet!grw
					...yale-comix!ima!inmet!grw