[78-L] 1952 lacquer record question

[ron at fial.com.invalid]

 Since it was from the 1950s, it is most likely grove designed for a 1-mil stylus.  You are 
unlikely to see a 0.7-mil grove that early on a monaural lacquer.    Lacquer groves are not as 
deep, so a transcription or reference disk could easily use higher pitch (grooves closer 
together for longer play time).

It sounds like an acetate (really lacquer) on aluminum disk.   If from 1952, maybe cut on a 
Presto 8N disk (year 1950) engraver or similar (look up Presto 8N ) .  Those cut at either 
33-1/3 or 78 RPM by changing lead screws on the carriage.   The lacquer disks were made 
on several substrate materials including glass, aluminum, hard cardboard etc.  Presto make 
many models of professional record lathes from the 1930s on -- like the interesting Presto 
75A.with rubber around the turntable edge and a metal edge-drive wheel.

Search for the 1950 Presto 8N on google for lots of pictures, history, for-sale links.    Presto 
made many models of cutters, and there is a used market.  There are also conversion kits for 
50 Hz and for 45 RPM cutting.   Cutting your own records is a well established hobby -- check 
out lathetrolls.com

If you search for Presto cutter needles ( or Rek-o Kut, like Model V), you may find cutter 
listings stating the size of the grove cut.  Since these lacquers were often sent to DJs for 
preview before the main production-runs, it is likely int the 1950s that the  most standard 33 
rpm grove-size was used. 

Lacquers were cut shallow, The lacquer is not very thick, seems it is hard to get a very level 
surface with thick lacquer over the large area.  The shallow cut makes it harder to start the 
needle in the grove on playback.  If this is a valuable disk, use a microscope with reticle to 
measure the max groove width. You must have full side stylus-contact down in the groove.

I would start on the low side for grams on the stylus, depends on cartridge, you could first try 
how low in grams you can go with a 1-mil mono or if you can find one) a .7-mil microgroove 
78.   You might be able to check tracking on the run-out groove of the lacquer first.  A  33 
rpm spherical would be better because lacquer is thin and on the soft side, elliptical has 
slightly more grove wear.  A new stylus would be best, unused it is more perfectly spherical.   
Use a low mass arm, rather than a heavy, weight-balanced arm because of shallow groves 
and higher lateral tonearm acceleration at 78 rpm.  And record the first-playing just in case 
the very old lacquer cracks or lets loose from the substrate.  Carefully adjust your anti-skate 
on a smooth disk at 78 rpm first before playing the lacquer.  Take your time lowering the 
needle very gently.   Lacquers were sent to DJs, so they would have been fairly though when 
new, but they dry out harder, so 60 years later not as good.  
 
It would be good to know how late lacquer recordings were made.  Anyone know what year?     
Sample lacquers were played for quick checks before record plating and pressing runs, so 
perhaps even today lacquers are being cut.  

Lacquer recording blank manufacturer Apollo Masters corp. in California had a big fire in 
2020 and closed, but their web site is still up, see: www.apollomasters.com/products.html#7s 
for starters and the home page also.  I believe a Japanese company still makes and markets 
lacquer masters.

Incidentally, lacquers are made with nitrocellulose plus a softening ingredient, usually castor 
oil.  The softener makes the material soft enough to cut well.   But it still gets too hard after 
about a year.   If you have an old blank and cut it, it will be very noisy.   But blanks are sold in 
boxes of 20 minimum.   Selling you just one blank and protecting it for shipment is really too 
expensive. You will go through several just setting up a cutting lathe properly.  You may even 
find the cutter must be on a heavy wood or stone block if you have a wood floor, so you can 
move around nearby when cutting.   Yes, I lived in an old wood house.  You can make  you 
own recording blanks with aluminum disks and nitrocellulose --  use care, tho, you could blow 
up your house.

If you have ever burned an old 1940s photographic nicrocellulose (guncotton) negative, it 
half-burns and half explodes, very exciting.  Hmmm  brought up a lot of old memories  :)

Keep any cardboard or paper lacquer-disks away from sun and heat.

_ Regards,  Ron Fial
_______________________________________

On 25 Aug 2022 at 7:15, Malcolm wrote:

> 
> Hello to whoever is left on this list!
> I recently received a 1952 NBC Reference Recording #113 - a sound 
> effects record. It's called "Buzzing Sound" and penned in below that is 
> "Flying Saucers". It is a 78... BUT it looks to me as if it is meant to 
> be played with a LP stylus. The grooves per inch are high and the groove 
> itself is far thinner than that of a normal 78. Was this the case with 
> other NBC instantaneous discs from the time? - I want to avoid damaging 
> the recording by using a 2.7 mil 78 stylus if that is so. Thus my question.
> Aloha,
> Malcolm R
> _______________________________________________
> 78-L mailing list
> 78-L at klickitat.78online.com
> http://klickitat.78online.com/mailman/listinfo/78-l
>