BBC Turntable - possible to use at home ?

[PaulM]

From the SOS thread and on here, it looks like the OP has given up on the Technics?
I was looking forward to hearing how things progressed!

Enthusiasm to power my twin unit has somewhat evaporated :-(

Best regards,

Paul M

[Radio Wrangler]

Originally Posted by PaulM

Enthusiasm to power my twin unit has somewhat evaporated :-(

My apologies if I contributed to that. But do you intend to operate as a museum of BBC historical artefacts? If you do, you need to keep it intact.

If you don't, then you do have two very fine turntable units and the Technics SP10 are supposed to last very well. Hopefully you didn't pay as much as a pair of Garrard 301s go for in the audiophile world. It might be worth making a plinth to take one turntable and a less compromised arm and cartridge the only loss would be suitability for fast starts and back-cueing.

I bought an ex-BBC Revox B261 tuner. There were added connections for remote control, outputs, a different mains connector and the cabinet's plastic side cheeks were missing. Out came the added remote control wiring and the output connectors got tidied up, the sidecheeks were a problem, so I routed out a pair from solid oak. It is a VERY good tuner, but one from civvy street would have been less work It had run long how hours and dozens of small electrolytic capacitors had been baked to high ESR. Broadcast equipment is optimised for different purposes than domestic equipment.

David

[Ted Kendall]

Originally Posted by Radio Wrangler

Hopefully you didn't pay as much as a pair of Garrard 301s go for in the audiophile world.

Current form seems to be that a decent SP10 changes hands for a third to a half of the price commanded by a 301/401. Go figure...

[PaulM]

Hello David,

No, we're not a 'BBC museum' - the BBC has no monopoly on broadcasting

The plan is a bricks and mortar museum of broadcasting and we've been building this up for decades - our website describes what we do across the whole spectrum but largely centred on TV studio and OB equipment.

The twin unit was a donation to 'the cause' so it cost diddly squat, but that's by the by.

Also from the same source was a TD7 (pic attached) - a rather older 'version'!

This is not about domestic use, it's about long-term preservation long after we're gone - that's the goal along with keeping the kit operational for training and demonstrating to encourage the 'next generation'.

Best regards,

Paul Marshall
Chairman
Broadcast Engineering Conservation Group (BECG)
www.becg.tv

[Radio Wrangler]

Yep, you definitely want to keep yours intact and original. Glad to hear you didn't get taken to the cleaners for it. Are those Rabco arms, Paul?

I agree with Ted about the relative pricing of SP10s. If the OP wants to use one, should he get one domestically, then a plain (non-broadcast) SP10 might be a better bargain.

David

[derekheeps]

Rabco arms ?

I noticed tangential pickups in at least one other photo on this thread ; it strikes me as odd that broadcasters would use them due to their complexity , compared to conventional pivoted arms , given that the theoretical improvement in inter channel phase relationships ( and which some such as Russ Andrews would take issue ) is largely negligible in broadcasting .

They also can have advantages in lower mass ( particularly the B&O one ) but this is more applicable to delicate high compliance cartridges rarely used in broadcasting .

Curious .

[PaulM]

I never had any intention of breaking it up, just curiosity to see how much the BBC had managed to modify it - their work is not always good . . . in fact, sometimes it's shockingly bad!

As for Rabco arms on the TD/7, I don't know, it's not one of my specialisms. I suspect not.
There's a lot of information here: http://www.orbem.co.uk/grams/grams_1.htm

The TD/7 is another item that's never been tried or restored - just put away until one day (hopefully) we can exhibit it properly along with all the other hundreds of tons of kit . . .
It takes a lot of money and it's not an easy proposition.

Best regards,

Paul M
BECG
www.becg.tv

[Ted Kendall]

Originally Posted by derekheeps

Rabco arms ?

No.

The BBC parallel track arm was established long before Rabco were thought of. It was designed when nearly all programme recording was on disc, with a graduated scale to enable precise location of a particular turn (roughly corresponding to a single word at 78rpm), which is a pre-requisite for swift and accurate dub-editing. This was usually done by a play-lift-locate-drop sequence on the playing deck whilst recording the output on a second disc. Once found on rehearsal, the in and out points would be marked with a chinagraph stripe on the disc. For edits of a turn or two, there was a "nudge" or offset control. Sounds a bit barbarous, but skilled operators could trim individual words on transmission if the need arose, as noted by Pawley. The EMI No.12 pickups used were pretty tough - they had to be.

[derekheeps]

Interesting , I also seem to recall something very similar from Dynavector back in the day , although so called parallel trackers were something of a fad in the 1970s .

[Ted Kendall]

The Dynavector (DV 505?) was a pivoted job, but ridiculously complicated. There was a huge arm with a bearing allowing lateral movement only, and near to its end was a short arm, carrying the headshell, with a bearing allowing vertical motion only.
The rationale for this, apart from some sort of "mine's bigger than yours" argument, was that it was desirable for the cartridge to be carried by a system with much greater effective mass in the lateral direction than the vertical. Evidently they hadn't thought of swingers, and neither dd they care about warp wow, given the length of the headshell arm and the placing of its pivot far above the record surface. A folly, in short.

The best of the bunch as far as parallel trackers go were the B&O, which only worked with SP15 series cartridges, and the Revox, which anaged to get nearly everything right, or right enough. I've been using one for 78 transcription (suitably modified) for a long time.

[derekheeps]

I'm pretty sure there was a parallel tracker too , although I remember the one you talk about . The parallel tracker was designed primarily for use with their moving coil cartridges ( marketed here as Ultimo - including a high output one which worked into a normal moving magnet input ) .

I sold a few B&O ( Beogram 4000,8000 ? can't remember ) which were very nice , and remember the rev one which was demonstrated playing upside down and at all sorts of strange angles ( the tracking force must have been applied by springs or some such ) .

I had a brief dalliance with unipivot arms after first buying a used Transcriptor Hydraulic Reference with the so called fluid arm ( which was prone to leaking everywhere and being a pig to set up ) , played with the malware Formula 4 and the Hadcock GH422 - one of them used four dashpots filled with mercury for the lead out - such a bad idea . Then I saw the light and bought an SME Series III , Now I have a Rega RB700 on my Gyrodec , which is a nice arm and a nice turntable .

[Ted Kendall]

The mercury contact jobbie was the Keith Monks MB9A, although this was originally marketed by Audio and Design. God knows what they were smoking when they thought that one up.

I dallied with a Hadcock for a while - it worked but was far too finicky. Still using an SME iii - one of the very few arms which can allow an ADC 26 (compliance around 50 cu) to work properly.

[Radio Wrangler]

Originally Posted by derekheeps

I sold a few B&O ( Beogram 4000,8000 ? can't remember ) which were very nice

Hmmm, Hifi Corner, early '70s, 4000? If so, one of them is sitting here.

Are we about to have one of those 'small world' moments?

David

[Simondm]

So I pootled over here from the Lenco Heaven forum, as the OP seems to have continued his discussion here rather than there.

I write as an ex-BBC Bristol Audio supervisor (decades ago!), although I was primarily an operator, NOT a service engineer. I have a feeling Ted K. and I may have mutual friends (Chris Y. for example?). If I'm right you'll know who I mean...

I used these units a great deal operationally - we had them in several studios - and their close but simpler cousin, the RP 2/9 (twin deck version).

I also used the unit Ted refers to, and if it's the unit I suspect he means, it is NOT related to the RP 2/10 much at all, with the exception of having an SP10 Mk2 fitted. I'll come back to this unit later, as I own one of them too (never have too many turntables?).

"Over there" I posted a bit of info about specific questions regarding the RP2/10 (of which I own a late one, in near pristine condition). I won't re-post all that but a few points, on which I'm happy to be proven wrong:

1. it's a seriously good turntable.

2. It's seriously complex and arcane if you don't have documentation. For example there is no audio passing through the front panel, but it's got an early form of 'digital' control.

3. The design was in daily use in BBC TV and radio studios all over the place, with the possible exception of local radio stations (because they were the price of a small car). It's modular, and the configuration for each setting could be quite different. To be honest, almost all the ones I have seen have been as the pics above, complete with remote functions and RSAs (BBC-speak for tone controls). But there are some weird options, such as a mixer board to gang three units together (for TV studio and probably dubbing theatre use) - never seen one but it existed on paper at least.

4. It is hard to extract just the SP 10 to use as a domestic turntable, for a number of good reasons - this version was a 'special' for the BBC (look at the data plate on the back of the SP 10 itself). There are obvious mods, such as the missing S/S and speed-change buttons, and less obvious stuff, such as a different power supply, differences in the strobe feed, and so on.

5. Because it is so modular, it is relatively easy to get a useful output from it. There is a spare Edac / Varelco connector on the back of the electronics tray, and it's easy to get a suitable output to that, and thence to your external kit. Similarly, you can access the very comprehensive start/stop logic (out on the same Edac). mine has a long umbilical, terminating in a connector box to the PC or a recorder (bal or unbal), with a remote start switch and 'primed' LED. It isn't a remote stop - the logic allows for this setup - so you can't accidentally stop the turntable once you have started a transfer - you have to go back to the machine itself to do that.

6. As far as I know, pretty much all of it was designed _and_ built_ in house by BBC Equipment Dept, apart from the turntable itself, obviously. It is ludicrously over-engineered, and was the last "gram desk" the BBC made - after that it bought EMT/Thorens, with the 940 and 950 series being common.

Which brings me to Ted K's unit, which I think has this configuration:

• SP10 MK2 (NOT BBC version), 0-80 RPM varispeed and muting circuit; Technics "small" PSU external to the wooden case; NO remote start (apart from the Bristol mod below, and the 3.5mm socket to plug-in the commercial SP10 remote, hidden inside the unit)
• Mechanically modified Quad 33 (for the preamp);
• BBC line send (buffer) amp cards and line receive (for incoming circuits);
• Rotary fader and headphone amp & sockets
• SME Series 2 9" arm (but still an SC35C at 5g!)
• Mahogany veneer plywood box with lift-off perspex squarish lid and a square-steel-tube black trolley (some had a shelf behind like the older Phillips tape machines used to)

These were an oddity and this is my (reasonably informed) speculation as to how they came about:

E.D.'s RP2/10 was launched in 1978-9, and was lovely but stupidly expensive to make. It was realised in the early 1980s that there was a demand for a much lower cost unit, for non-critical applications, such as transfers and dubbing-theatres (and I think quite a few went to local radio too). These were made in a hurry, using off-the-shelf components as much as possible, but are probably actually sonically better than the RP2/10s because of the SME arms.

I know they were the standard units in Film Department (Ealing) dubbing theatres, in Lime Grove and Ealing (can't remember about TC), when I worked there in '85. IIRC, the 'Starship' in LG had four or five of them for the assistant, in a semicircle.

In 1984 or 5 Film Dubbing in Bristol, was extensively refurbished, giving us three units in the theatre proper, and two more in our transfer suite. All of them unofficially got SME dashpots and an extra (properly debounced!) stop-start button next to the fader that could be thumb operated when you were too busy to use both hands on a single turntable. Personally I hated the SP10's big button as it wasn't properly debounced and discs would just twitch sometimes*, and our maintenance team hated getting called out to them - so we collaborated in a mod that I think got passed to London. My unit is one of the Bristol "originals" although I came by it off eBay decades later!

These later, slightly more compact units were _not_ BBC coded equipment, so I have been unable to find out any more about them. If you want something for domestic use, they are by far the better bet, as they have a relatively unmolested SP10 / 2, a nice SME arm, and a 1/2" thick aluminium mounting plate cut out for said arm. Trouble is they lose their parts too easily, which is why I"m still rebuilding mine...

Hope that helps a bit.

S.

*this must be one reason why the RP2/9 and RP2/10 have BBC stop-start buttons (the other reason is to keep the operational controls/indicators in the same places as older generations of grams. There was a mod for our dubbing units, but it didn't solve the problem, whereas the extra button we had fitted did!

[Ted Kendall]

Which bits are you still missing? I've got a partially denuded carcass somewhere. I agree the only common factor between this version and the 2/9 is the use of an SP10, and it's far nicer for non-broadcast use. Most local stations I saw at the time had desk-mounted SP10s and the RP2/9 arm - I think the turntables were standard, with the remote jack connected to the fader backstop on the LR MK iii RAF blue desks.

[Simondm]

Thanks for the thought Ted.

Originally mine was missing the Technics PSU and the arm, but I was given an old PSU to refurbish, and bought a nicely refurbished SME S2 to replace the broken one that was seriously bent (I could salvage the dashpot though )

So now I have all I need, except time to finish the refurb and the perspex lid, which I shall have to make. I bought an original Quad 33 volume knob to use instead of the BBC modded one (the BBC knob is actually a cover--I assume yours is the same--with a hole drilled through the centre so you can insert a screwdriver to set the output level. It mattered in a broadcast environment, but not domestically!

I've removed the Hypertac socket, and put in a new plate with XLRs, and at time of writing I'm not sure if I shall use a domestic amp or the Quads in the LS 3/7 system that's also waiting to be finished. If domestic I may take the output straight from the 33, if not the XLRs - although thinking on that, a single 5-pin or a 20-way EDAC would've been neater - may change that!

By the way, do wee possibly have friends in common or is it my somewhat suggestible imagination?

S.

PS: thinking of crafting hinges and a stay for the lid (I don't like the lift-off idea), and possibly some sort of lamp for it (Ikea hack). The only annoying thing is that the PSU will still have to be external. I tried all sorts of mucking about to find a home for it inside the woodwork, but it's impossible, because of the space the Quad 33 takes up.

[Ted Kendall]

Originally Posted by Simondm

By the way, do wee possibly have friends in common or is it my somewhat suggestible imagination?

I was attached to Bristol in 1981 for a few months on the SCPD training tour, before I got out and went to Transcription Service. I remember meeting Peter Copeland without realising who he was - I'd have bored him rigid about the Goon Show if I had! - and watching Brian Fickling carding out on a Quadruplex machine, but not much else.

Originally Posted by Simondm

The only annoying thing is that the PSU will still have to be external. I tried all sorts of mucking about to find a home for it inside the woodwork, but it's impossible, because of the space the Quad 33 takes up.

Given the external hum field of that PSU, a bit of distance from the pickup is no bad thing...

[derekheeps]

Originally Posted by Ted Kendall

The mercury contact jobbie was the Keith Monks MB9A, although this was originally marketed by Audio and Design. God knows what they were smoking when they thought that one up.

I dallied with a Hadcock for a while - it worked but was far too finicky. Still using an SME iii - one of the very few arms which can allow an ADC 26 (compliance around 50 cu) to work properly.

Thanks , hard to recollect from the mists of time , but so it was ; think we only got one in . Perhaps they were inhaling the mercury vapours ?

ADC 26 . I remember it well , fine cartridge ; my Hydraulic Ref came with a 10E MkIV when I got it . Sold a couple of 26s but never owned one .

The SME was great for high compliance cartridges and I ran an AKG P8ES in mine for a few years , before getting into moving coils , eventually swapping it for a Rega RB700 .

[derekheeps]

Originally Posted by Radio Wrangler

Hmmm, Hifi Corner, early '70s, 4000? If so, one of them is sitting here.

Are we about to have one of those 'small world' moments?

David

Hi David , no I never worked in Hi-Fi corner , though I knew the place well , both from the days when Russ Andrews ran Haddington Place and the Colin McKenzie era ( I also knew Colin as a young salesman in Elena Mae in Princes St ) . I worked in what became Hi-Fi Corner’s Falkirk branch , both as Talisman Hi-Fi then Russell Hi-Fi , up to George’s untimely death around 1977/8 . While there I latterly worked with Terry Richardson ( ex Audio Aids, and also knew Edie before she worked for HFC ) . During my time there Ewen Patrick started as my Saturday boy ( as I had done so many years earlier , and he went on to run a shop in Edinburgh, the name of which escapes me ) ; I also knew Michael Dyce who started Music Mill after visiting my house with some mutual pals and catching the hifi bug . Also knew Nigel Kinniburgh while he worked in Rose St branch , and before he left to open In Hi-Fi, along with Joe Fernand ( bought my Gyrodec from Nigel there ) , I know they still run an AV company down Musselburgh way as I work on and off with Joe’s brother Jerry , who is an AMX/Crestron programmer.

It is indeed a small world .

[paulsherwin]

Let's try to keep on topic please.