the home of the turntable

What is the needle sizes for transcription disks?

the thin end of the wedge

What is the needle sizes for transcription disks?

Postby scrapjack+ » 17 Dec 2017 20:36

I recently saw a 12" 78 RPM vinyl transcription disk from WW2, and was wondering if that would use a standard 78 RPM needle? I read another site stating 2.3mm and 2.0mm "often" yield better results with transcriptions, I assume they are referring to the 78RPM transcriptions. I've read that the 33RPM 16" transcription disks had wide groove and later micro groove variants. I thought I read their micro groove was somewhat thinner then standard.

What diameter needles would be ideal to play these 3 types of records?
Hooked on phonics, Monophonic, Stereophonic, Quadraphonic, Vitaphonic, Douphonic, Orthophonic, Spectraphonic, Kneuphonic.
scrapjack+
member
member
 
Posts: 78
Joined: 28 Jul 2017 04:32

United States of America

Re: What is the needle sizes for transcription disks?

Postby Coffee Phil » 18 Dec 2017 06:23

Hi Scrapjack+,

Good to see another fast spinner here.

While I have a fair number of 78s I do not as yet have any transcription discs. I do believe that most transcription discs are 16" diameter or more. I do believe that early transcription discs are close to standard groove (2.5 to 3mil) regardless of if they are 78 or 33 1/3 RPM. I'm guessing that after the mid forties they would be close to micro groove. I think micro groove would be rare for shellac records. Vinyl 78s can be standard groove or micro groove. I actually have some 78 vinyl records which were "audiophile" records which are 1 mil microgroove. The Label of some is actually "Audiophile". They do sound remarkably good. This is an example: [img]19265[/img]

I tried to search for a list of styli for various vintages of transcription discs but didn't find much. I did find that some are made of acetate which requires different care than vinyl or shellac. I found this: https://en.wikipedia.org/wiki/Electrical_transcription
There isn't much on stylis size but I'm sure the info is out there.

I believe there are calibrated microscope devices to measure groove size for choosing styli. I haven't yet got one, but I'd like to have one.

Phil



scrapjack+ wrote:I recently saw a 12" 78 RPM vinyl transcription disk from WW2, and was wondering if that would use a standard 78 RPM needle? I read another site stating 2.3mm and 2.0mm "often" yield better results with transcriptions, I assume they are referring to the 78RPM transcriptions. I've read that the 33RPM 16" transcription disks had wide groove and later micro groove variants. I thought I read their micro groove was somewhat thinner then standard.

What diameter needles would be ideal to play these 3 types of records?
Coffee Phil
long player
long player
 
Posts: 4731
Images: 330
Joined: 20 Sep 2008 08:22
Location: California

United States of America

Re: What is the needle sizes for transcription disks?

Postby KentT » 18 Dec 2017 15:09

Broadcast transcriptions usually are best with 2.5 or 2.7 mil styli. Unless stated that a 1 mil stylus is recommended. 3 mil for worn transcriptions sometimes will get you a better playback.
KentT
long player
long player
 
Posts: 3544
Joined: 13 Mar 2008 20:44
Location: Athens, TN

Re: What is the needle sizes for transcription disks?

Postby denvertrakker » 18 Dec 2017 16:36

From my experience, many transcription disks, even though 33-1/3RPM, state on the label "Use standard needle".

Cheers,
Larry B.
denvertrakker
member
member
 
Posts: 138
Joined: 23 Nov 2004 21:25
Location: Colorado, USA

United States of America

Return to Cartridges and Preamps