Broadcast turntables?

[BillWojo]

- It must be able to locate the starting point manually and, once required, be up to speed almost instantly, much less than 1/2 second. This is usually achieved by a dual platter: the lower platter is in constant rotation, while the upper platter is separated fom the lower platter via a velvet (usually) layer which transmits the rotation to the upper platter with a calibrated torque. After cueing the record, the lower platter starts spinning while the upper platter is held by a mechanical brake shoe on its side. To start playing, the brake is released and the upper platter speeds to normal speed almost instantly. Same thing for stopping, you just press the brake shoe and the upper platter stops.

2 piece platter is very rare and I'm not aware of any popular broadcast TT that use that. On my Russco Studio Pro idler drive the engineer would back cue the platter to the starting point, engage the idler and than could start the motor from his console. The platter comes up to speed in well less that a quarter of a revolution. 3 out of 4 of the Russco TT that I've had used a solid state relay to turn on the motor, control wires were still hanging off the relay where they had been cut.

Also,for broadcast it is almost compulsory to have a built-in preamplifier with balanced line level outputs, since radio mixing desks - at least the serious ones - don't have phono preamplifiers and radio stations didn't care to bother with external preamplifiers - at least, not those that I've known.

I know the Russco TT were generally sold without a phono pre, that was built into the mixing board that the engineer used. Sounds like the stations in Europe did things very differently.

BillWojo

 

[W9TR]

Very thick and beefy idler

Nice Broadcast Electronics BE-12. A variant of the QRK broadcast tables I believe.

 

[vinyldavid]

I
Also, for broadcast it is almost compulsory to have a built-in preamplifier with balanced line level outputs, since radio mixing desks - at least the serious ones - don't have phono preamplifiers and radio stations didn't care to bother with external preamplifiers - at least, not those that I've known. Only small community radios had "improved" DJ turntables with an external preamplifier, for cost reasons. The built-in pres were not usually of very high quality, and were matched to cartridges that weren't always the best sonically either, as the most important point was to be able to cue, so spherical stylus only. For instance Radio France used Shure SC35's for stereo, and the Stanton 500 was very popular too.

Here in the US, most broadcast mixers only had line level inputs, maybe a couple mic pres. External phono preamplifiers from Stanton, RDL, Ramko, MicroTrak, ATI, Radio Systems and others were common amongst those that cared a little bit, the cheap charlie Shure and Realistic small box phono pres were common in budget installations.

Those who really cared about audio quality would use a HiFi preamplifier on each turntable. KSHE 95 used SAE MkXXX preamplifiers in their airpath until 1986.

In classical music, more refined turntables were occasionally used when the need for instantaneous cueing was not necessary and budgets were tight.

The Technics SP-10mk2, SP-15, and the hyper rare SP-10mk3 seem to be the absolute best of the broadcast TT breed, since I've had my hands on just about everything except an EMT and the Russco DD offering.

 

[W9TR]

A little off topic but most broadcast TT’s sold in the US had outboard phono stages. Here is an example I’m familiar with because I designed it.

 

[Caryw]

My friend that owns a group of stations was telling me about trying to sell or give away the Russco’s when they went to Technics . Since the didn’t have a plinth, no one wanted them so they sat in storage then went to the dump. Employees did take the Technics when they phased them out

 

[belyin]

2 piece platter is very rare and I'm not aware of any popular broadcast TT that use that. On my Russco Studio Pro idler drive the engineer would back cue the platter to the starting point, engage the idler and than could start the motor from his console. The platter comes up to speed in well less that a quarter of a revolution. 3 out of 4 of the Russco TT that I've had used a solid state relay to turn on the motor, control wires were still hanging off the relay where they had been cut.



I know the Russco TT were generally sold without a phono pre, that was built into the mixing board that the engineer used. Sounds like the stations in Europe did things very differently.

BillWojo

I think we can see that the European usage was very different from the U.S.A. norm from the differences in the turntables. The exemplar European tables were the EMT and their several imitators with their built in preamps and tonearms. Note how the BBC built their own self-contained units with the SP10 motor. The European stations were large, bureaucratic organizations with strict division between engineers who spun the records and the on-air announcers.

In the U.S.A., once the broadcast networks were largely broken up and stations filled their time with locally produced d.j. shows, d.j.'s were frequently their own engineers and as such were frequently distracted, multi-tasking, and wired so durability and simplicity were the order of the day. I'm not sure why preamps were after-market and not more integrated with the tables, but they were not part of the board—often mounted under the counters or in the cabinets near the tables.

My only experience is a college station on the late 70's with Russco idlers and contemporary community radio with SL-1200's, with no remote control in either environment.

 

[jlb2]

2 piece platter is very rare and I'm not aware of any popular broadcast TT that use that.

EMT, Schlumberger, Bourdereau, Belin, Mondial Electronique are the names that come to mind right now, I'm sure I'll remember others as soon as I type "Post reply". All those were in wide use, at least in Europe.

On my Russco Studio Pro idler drive the engineer would back cue the platter to the starting point, engage the idler and than could start the motor from his console. The platter comes up to speed in well less that a quarter of a revolution. 3 out of 4 of the Russco TT that I've had used a solid state relay to turn on the motor, control wires were still hanging off the relay where they had been cut

This is why I said "usually", each rule has its exceptions I admit I've never seen a Russco in operation, just one that seemed to have served for breeding spiders and was being used as a static prop in a TV show. Incidentally, that one did have a built-in preamplifier, although I cannot be sure it was added at the Russco factory. I remember seeing photos of Garrard 301's and 401's used at the BBC too, so they might be another exception, although I don't know whether or not they were used for live broadcasting.

Community radios, that didn't have the budget, did use DJ turntables without a second platter - SL1200 and the like - but these were never marketed as broadcast turntables and their start-up time was slowish, which required the (usually non-professional) engineers to develop a particular knack of cueing back a half turn, starting the platter a second in advance, and raising the level only after a second, while wishing that you hadn't missed the cue point. Sometimes it went well, sometimes not. I certainly don't miss that.

I know the Russco TT were generally sold without a phono pre, that was built into the mixing board that the engineer used. Sounds like the stations in Europe did things very differently.

Personally I've never seen a broadcast mixing desk with built-in phono inputs, but if you remember names I am genuinely willing to learn. External preamplifiers were commonplace in the community radios that used DJ turntables, though.

 

[stratokaster]

EMT, Schlumberger, Bourdereau, Belin, Mondial Electronique, Technics are the names that come to mind right now, I'm sure I'll remember others as soon as I type "Post reply".

Which Technics models had 2-piece platters? Definitely not the SP10 mk2.

 

[adnick]

I’ve built several “Broadcast” turntables, most were idlers, however Fairchild had a few belt drives that were also used in commercial endeavors, I’ve seen one 412 and a few 750s set up for DJ use.

The big idler’s are special and with modern materials/parts and a well designed plinth they can be made much quieter than the LP noise floor.

My Builds:
Rek O Kut (ROK) Rondine Deluxe B12H


ROK TR12 & TR43 Therese ar very special tables the TR12 is 33/78 and the TR
43 33/55

This one will get passed down to my Grandchildren View attachment 2635381



As @BillWojo mentioned the Russco Studio Pro, sometimes confused with the Cue Master, but the Pro is a much better machine 33/45, another machine I’m keeping.





And for good measure the Fairchild 412-1, my version. ;-) asynchronous motor and dual belt drive, motor to intermediate pulley then intermediate pulley to platter….another heirloom





View attachment 2635381

My understanding is that a few Thorens TD 124’s were also used in Broadcast



VR
Andy

 

[jlb2]

Which Technics models had 2-piece platters? Definitely not the SP10 mk2.

Yep, my mistake. I remembered it had a mechanical brake and my memory fooled me into thinking that then it must have a dual platter too, but you made me check the manual again. A pretty amazing design, able to start in 1/4s just by its torque. So the SP10 Mk2 & Mk3 is another exception. I corrected my post.

 

[jlb2]

My understanding is that a few Thorens TD 124’s were also used in Broadcast

I've heard that too, but I've only found a single example, in an unusual station based on a ship (http://www.offshoreradiomuseum.co.uk/page335.html). Although it did have a dual platter, the TD124 only had a manual clutch and I have never seen or heard of a TD124 with a remote control, so using it for broadcast must have been quite awkward. Or maybe it was a specific version with a remote control, or one of those few exceptions that can start the platter in 1/4 second with just the starting torque of the motor? This has always intrigued me.

 

[adnick]

I've heard that too, but I've only found a single example, in an unusual station based on a ship (http://www.offshoreradiomuseum.co.uk/page335.html). Although it did have a dual platter, the TD124 only had a manual clutch and I have never seen or heard of a TD124 with a remote control, so using it for broadcast must have been quite awkward. Or maybe it was a specific version with a remote control, or one of those few exceptions that can start the platter in 1/4 second with just the starting torque of the motor? This has always intrigued me.

Well the TD124 clutch gives it near instant starts and a brake, however most of the broadcast tables I’ve dealt with didn’t have brakes, the brake, was the DJs hand or they had dual decks, a very common setup.

The ROK TR12/43 have 1/100th HP motors and the idlers are huge, over 3 inches across and about 2 inches high, the large portion is turned by the capstan and the smaller upper portion drives the platter. Custom Delrin idlers and a Delrin bushing at the bottom of the shaft well along with a constrained layered plinth gets rid of any extraneous noise.

 

[T68]

An EMT 927 is defenitely on my TT bucketlist.

 

[mr_petit]

I've heard that too, but I've only found a single example, in an unusual station based on a ship (http://www.offshoreradiomuseum.co.uk/page335.html).

Actually radio stations based on a ship was very common back in that era. These were radio pirates (so without a broadcast licence; commercial radio was illegal then), and operated from a ship just outside national waters.
The UK, Netherlands, Belgium, Denmark, Sweden all had their radio pirates (Belgium/Netherlands alone had about a dozen).

The Thorens TD124 was originally marketed as a trascription turntable and thus aimed at studio's/broadcasting and used as such.

 

[jlb2]

Actually radio stations based on a ship was very common back in that era. These were radio pirates (so without a broadcast licence; commercial radio was illegal then), and operated from a ship just outside national waters.
The UK, Netherlands, Belgium, Denmark, Sweden all had their radio pirates (Belgium/Netherlands alone had about a dozen).

I live in northern France where we were aware of their existence. They seemed pretty exotic here. BTW a dozen radios is a grand total covering the whole era, in fact they did not all exist at the same time, and some of them only lasted for a few months. The offshore radios wikipedia page is very interesting to read.

The Thorens TD124 was originally marketed as a trascription turntable and thus aimed at studio's/broadcasting and used as such.

But then does "transcription turntable" really mean "aimed at studios/broadcasting"? I very much doubt it, especially when the term was used by Thorens. For example my TD126Mk3 is a "semi-professional transcription turntable". Try to use it for broacasting and see what happens I have never found an official or generally accepted definition of a transcription turntable, except maybe that they were originally machines intended to play 16" radio transcription discs - see for instance https://www.vinylengine.com/turntable_forum/viewtopic.php?t=2635. It is my understanding that any turntable to which you could add a long tonearm could be called a transcription turntable, and some manufacturers did not hesitate to do it. Either that, or it is just a marketing term for "high end".

The fact that "transcription" is not the same as "broadcast" is exemplified by the fact that the TD125 was marketed as a "transcription" turntable, while EMT modified it extensively to make it a "broadcast" turntable, the 928. The TD125 is useless for broadcasting since it does not allow instant start. The TD124 can do it, but not in an easy way even by 1960 standards. It is usable in DJ-style studios, but probably not in mainstream radio studios.

Thank you for the photos, especially the Radio London one. So that's how they used non-broadcast turntables there, the engineer started the platter with one hand while operating the faders with the other hand. A pretty crude and error-prone way of doing things. Even in the community radios here, they usually added a fader start to their DJ turntables - admittedly, it was a different era.

 

[Westy56]

Nice Broadcast Electronics BE-12. A variant of the QRK broadcast tables I believe.

I just went back to check the original post.

Someone just gave me a Broadcaster Electronic 12C turntable with a ROK Micropoise arm.
I've read that ROK licensed the TT to BE under the BE name.

Wow, I got this for free.....

 

[mr_petit]

I live in northern France where we were aware of their existence. They seemed pretty exotic here. BTW a dozen radios is a grand total covering the whole era, in fact they did not all exist at the same time, and some of them only lasted for a few months. The offshore radios wikipedia page is very interesting to read.

Yes not all at the same time and quite a few didn't last very long; but they made the news when they were caught, or when their ship sank or whatever, so the general public knew of that. However there were also some very popular ones that did stay longer in the air. So not a very 'unusual' situation imho.
Most people that lived around the north sea and were alive back then know of the history. I think veronica was on air for 15 years or so. Where I live no one doesn't know where they come from, and they spawned a generation of famous radio hosts that later had careers on TV and national radio.

But then does "transcription turntable" really mean "aimed at studios/broadcasting"? .....

Yes, the semantics of a word can result in an endless discussion.
However it was used in studio's, as shown in some pictures. Maybe not as popular as the Garrard 401 (I assume used in the same way as the 124's; lots of foto's of radio veronica using those on their ship ) or EMT's, but still used nonetheless. Regardless what transcription means.
I'm sure there are more pictures around when searching long enough.
Some of the pictures show a felt slipmat and the radio dj holding the record to start instead of holding the platter to start. I guess the slipmat was already from a time before house DJ's .

 

[Taketheflame]

As for durability, I would buy a broadcast turntable only after carefully assessing its condition, as many were beaten to death and then left for dead in a basement. Such is the life of pro equipment.

So is buying a typical non-rebuilt example of a broadcast deck (over a gently used TOTL or close consumer deck) akin to buying a decommissioned cop car instead of a gently used garage queen? What is there to look for besides the obvious like unusual noises or bearing play?

And other new questions...

1. Any distinctive advantage or sonic character that a rebuilt and modded idler deck offers over DD?

2. If Technics SP-10/15/25 are the gold standard of DD, how do some of the early Sony units (PS-2251, TTS-4000) compare? I've read that Sony DD decks are underrated/a good value compared to more popular TT brands.

 

[mr_petit]

2. If Technics SP-10/15/25 are the gold standard of DD,

That is very debatable. The SP-10/15/25 use a cored DD, whereas most hifi tables use coreless DD's.
Recently technics also switched to coreless (although they also made coreless DD's in the 80's, but the classic sl-1200 and such are cored).

The advantage of cored DD is that they start and stop really fast. The motor is much more powerful.
Downside is that the core is iron, so as the platter rotates, it is also attracted to other cores as it spins. This phenomenon is called cogging.
The first coreless DD (I think) was the dual 701. Totally not suitable in a studio enviroment, but as hifi drive arguably better. In the early 70's dual catalogs the phenomenon of cogging was already explained, so it was already known back then.
Cogging is not measurable in wow, and very difficult measurable in flutter, as the speedvariations are so short.
If this is a sonic issue of importance, everyone for themselves has to make that out.

I have no idea how an sp-10 compares to a TTS-4000 or PS-2251. (I think both these have a cored motor too)
Sony also made the incredible PS-X9 and denon made the DP-100 but these are way more expensive than a SP-10 and way more rare.

 

[Taketheflame]

That is very debatable. The SP-10/15/25 use a cored DD, whereas most hifi tables use coreless DD's.

I should have been more specific, as I meant gold standard in the context of DD broadcast decks, not necessarily hi-fi decks.