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Hello all!

Could one use them outside of a studio? They seem to have useful features, such as the scratch noise filter, etc.
Are they good and how does one connect them up to the Rogers 5/8 etc.
How do they perform ?

Thank you

Alexander

Comments

paulears Thu, 11/19/2020 - 07:10

As in the other topic - a lovely piece of vintage gear from the 70s. From memory - the output is stereo 600 Ohm from the pre-amp, so equalisation is internal - so a normal line level input, although I think it's a +4dB level, so pretty hot. Lovely talking point too!

Feed with care into a spare line input!

vonrozen Thu, 11/19/2020 - 07:58

paulears, post: 466052, member: 47782 wrote: As in the other topic - a lovely piece of vintage gear from the 70s. From memory - the output is stereo 600 Ohm from the pre-amp, so equalisation is internal - so a normal line level input, although I think it's a +4dB level, so pretty hot. Lovely talking point too!

Feed with care into a spare line input!

Excuse me , Paul , as i am pretty much zero in audio electronics , could you explain what you mean by the above sentence ?
Thank you very much

FYI : I am using Rogers 5/8 from the BBC as my set up

Alexander (the audio simpleton)

paulears Thu, 11/19/2020 - 10:52

I'm confused Alexander? You have the rather nice BBC designed speakers, but presumably you are driving them from an amplifier of some kind? The usual turntables you could (and still can) buy have a very low level output from the pickup - it is also not remotely a flat response. The output from old fashioned records, and the pickups was very light on bass and very heavy on treble, so there was an equalisation curve agreed pretty much throughout the world - the RIAA curve. Too much bass on a vinyl recording can pop the stylus right out of the groove - so they deliberately recorded the bass very weakly in comparison to the HF - the preamp simply did the opposite curve - it boosted bass while tailing off the HF. Most hi-fi kit had this curve and the right gain built into the record deck switch position. The other inputs were 'line' level - sometimes described as the typical maximum voltage level .775V to give 0dB on a tape recorder meter. Professional equipment often used a different setting of nearly a Volt and a half. They also used three wire connections which had a totally separate ground - still found today int he common microphone connection system using XLR connectors. However, back then, 3 circuit jack plugs, looking like the current larger headphone types were common.

Your new record deck will connect to an amplifier without the EQ RIAA curve, because that's what that preamp section does for you. You plug that into an amp, and then the amp into the speakers. Interconnecting the +4dB pro level equipment to domestic amps can create distortion - after all they expect less than a Volt coming in on the loud bits. Some cannot handle the pro level standard. You do have the option on the BBC unit to reduce the output - so I'd guess matching will be fine. Your speakers should make the whole system quite nice to listen to, although remember the BBC designs were never very good with over-cooked bass - they were designed for a pretty neutral sound.

What kind of an amp do you have? If you want to be impressed by the turntable - put the stylus down, and hit the start button - it's impressive how fast it gets to 33 or 45! The motor unit is hefty!

vonrozen Thu, 11/19/2020 - 11:08

Thanks very much for the detailed and very, very helpful answer !

My BBC Rogers , the LS5/8, is a BBC-designed ones - two-way, active speaker originally powered by a modified Quad 405 amplifier which was known within the BBC as an AM8/16. The modifications entailed a transformer-balanced input with different input connectors (Postie jack and a male XLR3 in parallel) and a rotary sensitivity control, a different output connector (female XLR5), an XLR-LNE mains input connector, and the installation of a line-level active crossover board so that one channel powered the woofer, and the other the tweeter.

paulears Thu, 11/19/2020 - 12:24

Ah - then you should be fine, as it will cope with the output from the turntable preamp with no issues. The only thing you might need to pay attention to is the turntable it had very little isolation so the entire unit was designed to need serious mechanical 'sturdily' from whatever it sits on. Suspended floors or other non-rigid floor structures often got picked up. Sitting on concrete was fine. Most studios have nice sturdy sold floors so were fine. First floor converted offices were not so good!

paulears Thu, 11/19/2020 - 14:51

The current auction ended today but there were few real bargains, but that auction house are known for their good prices. The BBC kit was mainly older mechanical video. They moved all the newer stuff so tried very hard to get the older video machines and old cameras shifted. I think the audio equipment was probably the best to buy. The fact these were still in use says how good they are. Have fun with it.

paulears Thu, 11/19/2020 - 15:01

Gosh not seen one of those for a long time. If one ever comes up, I'll remember this topic.
The current auction that ended earlier today had a few interesting items but there were few real bargains, but that auction house are known for their good prices. The BBC kit was mainly older mechanical video. They moved all the newer stuff so tried very hard to get the older video machines and old cameras shifted. I think the audio equipment was probably the best to buy. The fact these were still in use says how good they are. Have fun with it.

They have some AKG 414 mics - the current price is more than a brand new one costs, and with the seller premium and VAT @20% the prices are going totally mad.

audiokid Thu, 11/19/2020 - 21:06

vonrozen, post: 466036, member: 49120 wrote: Hello all !

Could one use them outside of a studio ?

They seem to have useful features, such as the scratch noise filter, etc.

Are they good and how does one connect them up to the Rogers 5/8 etc.

How do they perform ?

Thank you

Alexander

Looks like you guys have a good conversation going (y) I just stumbled upon the thread and this is a first glimpse at this gem for me! Regardless of this being any use in our digital age, I'd love to have one to add as a collection piece. Pretty cool. From a sampling POV, I suppose it has a "sound" of its own. Or does it? Maybe the electronic crowd would find a use for sampling records. Thanks for sharing!

paulears Fri, 11/20/2020 - 01:02

It’s an interesting time in record history. BBC radio were using a mix of of American products and British products in the radio studios with slip mats. Usually green, for some reason in the studios I went to! This was how we did quick start, so you spun the turntable to find the track start, the rotated back exactly the amount to get to full speed. The American ones had a clutch that spun them fast. The British ones had heavier platters that needed the slip mats. Then suddenly Technics popped up with theirs which was amazing. The BBC at the time also had their linear tracking ones that still played in sound effects by dropping a needle into a groove on a 78! Actually quite neat with a numbered scale and a handle and little sort of viewfinder so you marked the record with a Chinagraph pen then on cue dropped the arm. Great stuff. The EMTs were popular, I understand in Europe, but we lagged behind, resistant to change. BBC radio one had the Russcos in numbers, then the sP10. Technics were a st4ange company, Panasonic did the cheaper and cheerful Hi-fi and Technics took the up market stuff. Their amazing reel to reel that looked out of this world. You were more likely to see Ferrograph in the studios. I started on the series 7, the previous models gone when I got there, but once Ferrograph died, Revox crept in with a few students in some departments, then of course the PR99, the version the BBC loved. You have to remember that discos had just arrived and the lower tier of record players used just two turntables in numbers. The Garrard SP25 mk III and the BSR MP60 being the two leaders here by miles! The SP25 was £27 in 1974, the Russco £127 and of course needed an arm too!

Attached files

vonrozen Fri, 11/20/2020 - 02:21

audiokid, post: 466076, member: 1 wrote: Looks like you guys have a good conversation going (y) I just stumbled upon the thread and this is a first glimpse at this gem for me! Regardless of this being any use in our digital age, I'd love to have one to add as a collection piece. Pretty cool. From a sampling POV, I suppose it has a "sound" of its own. Or does it? Maybe the electronic crowd would find a use for sampling records. Thanks for sharing!

Hello Chris ,

if you are very interested in the BBC turntable let me know ... I will figure out a way to make you the owner ;-)

paulears Fri, 12/18/2020 - 05:22

er, it doesn't connect to the speakers. It's a line level output as we spoke about above? It needs your amplifier to drive the speakers. The two cables to the left black and white, that go to A and B sockets are RCA phono, which are the same sockets fitted to most hifi amps that have a turntable input. The output from the multipins could be used to go to a line level input if you are careful with gain - the unit you have is 600Ohm output at +4dB - which is higher than some amps are comfy with.

The only snag are the BBC spec hypertac connectors - that were used for the umbilical wiring - they're really hard to find. The version you have is actually the TV one - which has the extra facilities the TV folk wanted.

paulears Fri, 12/18/2020 - 05:37

very left hand end sockets A and B which preamp do you have? The 405 is a power amp, isn't it?

Edit

Just a thought - if you can do some soldering you can probably get an output from the monitor socket, or possibly one of the others with a little bodging that would go into the Quad happily, and use the controls on the console?

Boswell Fri, 12/18/2020 - 09:49

It looks to me as though the two phono (RCA) cables on the left may be the L+R pair that come directly from the pickup cartridge. If this is the case, you need to take them into a phono input on a hi-fi pre-amp that has the correct input impedance for a magnetic cartridge and has RIAA equalistion. They won't work if taken directly into a power amp.

There must be circuitry in this box that does the job of a phono cartridge pre-amp. However, finding whether and where the outputs arrive on that rear-panel and how to take them out could be a fun few hours work. As Paul said, it's basically an adjunct to a TV control room rather than from a radio studio.

paulears Fri, 12/18/2020 - 10:25

The controls on those units do gain and filtering - think scratched and worn records, and many were used to play in the BBC sound effects library. Some were fitted with sensors to provide a readout of where the arm was too. Most would have had Shure cartridges but you could adjust practice tidally everything in the pre-amp, including switching it to stereo if you really thought it necessary. The interface for remote starting was part of the system too - something the Technics turntable was excellent at - so the DJ style record start, but with half a dozen of these, each cued up to play a thunder clap or car crash effect, the sound supervisor could hit a button in a different room and the things would burst into life. The black and white RCA cables are directly fed from the pickup and could easily be diverted. It was a surprise to find he thought he could connect the speakers direct, that never occurred to me - but the BBC were always designing things for their own use, that got standardised at the various TV and radio centres. The multi-way connectors are a bit of a pain, and I've looked in my old stuff and don't have a schematic. It's a shame those big connectors don't seem to be available. My memory is that repairing them was a real bodge as you couldn't get the pins out, so you snipped off the cable, left a short bit protruding and then soldered to that with Hellerman Sleeves providing the insulation. I hated those with the little bottle of lubrication and the strange tool! Modern heat shrink is so much nicer!

paulears Sun, 12/20/2020 - 01:57

Much depends on how much you want to keep it authentic. I suspect I’d just pull it out and open it up. Tag onto the multi ways from inside and feed a new cable out to the quad. Just avoid the ac and dc and you’re done. I’d enjoy that part! I think we just got a big surprise when you mentioned speakers!

vonrozen Sun, 12/20/2020 - 02:31

paulears, post: 466331, member: 47782 wrote: The controls on those units do gain and filtering - think scratched and worn records, and many were used to play in the BBC sound effects library. Some were fitted with sensors to provide a readout of where the arm was too. Most would have had Shure cartridges but you could adjust practice tidally everything in the pre-amp, including switching it to stereo if you really thought it necessary. The interface for remote starting was part of the system too - something the Technics turntable was excellent at - so the DJ style record start, but with half a dozen of these, each cued up to play a thunder clap or car crash effect, the sound supervisor could hit a button in a different room and the things would burst into life. The black and white RCA cables are directly fed from the pickup and could easily be diverted. It was a surprise to find he thought he could connect the speakers direct, that never occurred to me - but the BBC were always designing things for their own use, that got standardised at the various TV and radio centres. The multi-way connectors are a bit of a pain, and I've looked in my old stuff and don't have a schematic. It's a shame those big connectors don't seem to be available. My memory is that repairing them was a real bodge as you couldn't get the pins out, so you snipped off the cable, left a short bit protruding and then soldered to that with Hellerman Sleeves providing the insulation. I hated those with the little bottle of lubrication and the strange tool! Modern heat shrink is so much nicer!

BOSWELL , DO YOU THINK THE FACT THAT 2 ELECTRONIC PANELS ARE MISSING IS A PROBLEM ?
PLEASE DO LET ME KNOW !

Attached files

Boswell Sun, 12/20/2020 - 03:18

vonrozen, post: 466354, member: 49120 wrote: Boswell , why do you say this ? The unit does have a preamp in build , so the sensible thing is to use what is inside. It is just a question of finding the right pins in the multi way connectors, this is the headache I guess !

My usual way of starting this type of investigation is to begin at the beginning. If you unplug the pickup outputs from the internal electronics and plug them into the phono inputs of an external hi-fi pre-amp, you can check that you get output from the pickup. The next stage would be to inject inputs from a generator or an audio source into the phono inputs of the deck amplifiers instead of relying on playing a disc in order the chase the signal through the internal electronics. You can't position the unit on its side or upside down to chase the signal and play an LP at the same time.

vonrozen, post: 466356, member: 49120 wrote: BOSWELL , DO YOU THINK THE FACT THAT 2 ELECTRONIC PANELS ARE MISSING IS A PROBLEM ? PLEASE DO LET ME KNOW !

Where are these panels missing from? What I see is a pair of multiway cable connectors that connect to the unwieldy cabling looms that are an inevitable part of a video control room.

paulears Sun, 12/20/2020 - 05:10

I don’t remember if the ones I used had a full rack of cards. Sometimes the cards had big transformers which meant an empty card slot. The good thing is that you have all the options. At worst it’s just a turntable and arm so it can easily go into any amp with RIAA equalisation. Or, if the electronics function, use them via line outs. For what it is worth, the preamp is designed to reduce record issues so scratches and tonal loss from low recording levels are what it does. In most cases, for hi-fi reproduction, you'll want all the potential modifications turned off!

paulears Mon, 12/21/2020 - 03:15

Well, You've spent an awful lot of money on a very good turntable but you have electronics built in the 70s from 60s designs, primarily made to solve TV and radio issues when the broadcast chain topped out at maybe 15KHz for radio and often lower than that for broadcast TV. Hi-Fi folk take extreme care of their vinyl and keep it in pristine condition. In TV and radio, putting them things back in the sleeve is optional and when we had record libraries, quality was very variable. As a result surface noise crept up, so being able to slice the top off works great for radio. You'd hate it I guess - Maybe a 9K limit, or even lower for really worn records. Old 70s LPs might be recorded very hot, so you could turn down the output. For TV, playing sound effects would often have for the grams operator notes to turn down for cue 123, but boost for 124 to give the person balancing better fader control. The concept of normalising we take for granted didn't exist in the 70s so often engineers would mark the sleeves with helpful level info.

My experience of the Hi-Fi people is that they are not remotely like recording people - they want purity, they want absolute maximum everything, so the controls on your turntable reduce levels and drop cutoff frequencies. I suspect you won't want that. There's little point buying wonderful record playing equipment if you have rubbish records to play on them. Typically we'd also play with much greater stylus downforce. It wasn't unknown for troublesome records to have a penny placed on the headshell to stop it bouncing out of a groove!

rossbin Wed, 05/25/2022 - 07:44

 Hi, i just subscribe to this forum as i discovered now that i own this BBC machine... i purchased it a year ago with another one same model from a guy in Holland... i know it is exactly the same machine as the barcode sticked in the front panel as the same number of mine... so, i'm restoring it and in fact the MA4/12 board is missing, and as far as i have understood this is the board that allowed the tone control of the front panel to work, and is probably a preamplifier board... i suspect this machine was missing this board from the beginning as maybe used in a television studio... if you have more info's about this machine could you let me know? where did you get it? did you ever use it? do you have any manuals or information about it? why did you sell it?

thank you in advance, all the best

alex

paulears Mon, 05/30/2022 - 12:51

As a renovation job, I can see the satisfaction in having the machine restored to it's BBC spec. The thing that makes me wonder is that the BBC modified commercial kit to do specific jobs, and often that was not a quality process but a reliability, simplicity, reliability, connectivity reason. A record deck that could cope with playing worn records, and filters that could slice out annoying clicks that could be very unhealthy to the transmitter chain. It wasn't unknown for the engineers to place a penny on the pickup arm to make a temperamental record play!

I've not seen any of these for a while now, so finding replacement boards will be difficult I am afraid. If you want to use it, I'd be tempted to to just take the cartridge output to a decent hifi amp. Making the unit function will be a hard slog.

 

Don't forget that for some odd reason, these workhorse turntables command ridiculous prices - there is one currently on ebay - just the turntable in a box at over eleven THOUSAND pounds. https://www.ebay.co…

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