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EMI 806 mic amps (REDD style)

Discussion in 'Electronic Repair Modifications DIY' started by synthpunk, Jul 29, 2003.

  1. synthpunk

    synthpunk Guest

    a friend of mine brought me in a couple of these funky 60's ex abbey road pre's today for restoration- theyre a bit similar to the redd47 line amp in construction, but the circuit looks different- ill be tracing out the schems for them over the next coupla weeks, will post them when done.... they look well cool- little magic eye level meters, in a red cartridge, same size as the V-series.... one ef86 and an ecf80....

    of course, if anyone knows anything about em or has any docs, please share...

    rich
     
  2. Hi,
    Is it RS.806? I do know that the REDD.47 was also named the RS.812 (I think that's the right #) but I've never heard of an 806.
    Before Abbey Road installed the REDD.51 console, with its REDD.47 amps, I believe there was an attempt to make amplifiers that fit in place of the V72S' in the REDD.37 desks. Maybe that's what you have? It's interesting stuff. Can you post a picture of them?
     
  3. Learner

    Learner Guest

    Yea, please do! thumbup.gif
     
  4. Hi
    Some time ago I had 14 of these amps eminating from an EMI desk we retrieved from Gateway Studios London,back in the mid 80's
    The desk had 14 chanels each one with an 806 and a passive HI LO equiliser(very nice soft eq).The desk had been modified with solid state summing amps etc.The faders were dual chanel contant impedance type made by Elcom.These are works of art those guys new how to use a hot stick !
    I sold most of the amps and eq's about a year ago to various people in the London area.
    I was not over impressed by their performance but they had nice I/O trafos.I had a circuit diagram that I may be able to find.It is pointless contacting Hayes they have never heard of them !
    IMHO the best thing about the 806 is that it's bloody rare!
    I have some pics of most of the equipment together with a BTR2a (stereo) and a BTR4.if your interested.
     
  5. Shalimar

    Shalimar Guest

    Sounds funky, synthpunk! I'd luv to see pics of those and the gear you mentioned Andy..

    Beam it to of at shalimar dot dk

    Btw, any of you folks know anything 'bout BBC trannies? They got a bunch at Canford..
     
  6. Morpheous

    Morpheous Guest

    I have one of those BBC trannies. Canford are selling them for £40 a go. But I got mine from a surplus supplier for £6.5!!! And they've got more if anyone wants one.
     
  7. Shalimar

    Shalimar Guest

    Aha! I'll just go look in my Canford catalogue ('nother case of a useless website!), but I seem to remember them being rather odd looking with odd ratios etc. Perfect!

    What model# have you got? And where do I buy them?
     
  8. thermionic

    thermionic Guest

    A respected designer I know has a stash of the round black BBC trafos and rates them highly. He recently re-designed a linking adaptor for a vari-mu comp for me and used St Ives instead of the BBCs 'cos he said they were too good!

    Hey Morpheous, where are you getting them from?
    £6.50 ? Very nice!
     
  9. Mark Burnley

    Mark Burnley Guest

    This may be the place....

    (In a voice of mystery...)

    ;)

    BTW, I got a Canford "Summer Sale" brocure today. In the "Bargains" section, it cryptically mentions an AKG 12-pin female (?) connector, list price £70ish, "sale price" is £3

    Could be useful to someone :eek:

    ...I've seen those BBC trannies in Canford. I think I'll e-mail their Tech Support for further details.

    Mark

    --------------------------
    "Oscillators don't, amplifiers do....."
    Anon.
     
  10. Shalimar

    Shalimar Guest

    Didn't someone here just ask for that very connector recently?

    Special Agent Burnley, report back to HQ!

    We _need_ BBC trannies..
     
  11. Morpheous

    Morpheous Guest

    Here you are

    http://www.distel.co.uk/asps/viewimage.asp?ID=33001PM32&AP=10.87&CY=USD&ER=0.6209

    The model number is LL76/MSC I think. This one is listed in the canford catalogue for around £40.
     
  12. thermionic

    thermionic Guest

    Cheers Morpheous, I'm on the case!

    beerchug.gif
     
  13. axis.dk

    axis.dk Guest

    Hmmm,

    The LL/76MSC is listed 31.11 UK-pounds. Stock code 23-904 at canford uk.

    Kind regards

    Peter
     
  14. Tommytones

    Tommytones Guest

    I used LL88 ASC at the front of my SSL comp and they sound great. Very performant. The 76 is a little smaller in size but I would wager to be very similar in performance.
     
  15. synthpunk

    synthpunk Guest

    right... my internet access is buggering up (again!), so i might not be about much over the next week, but ill borrow a camera and post some piccies of the two amps when i can.... theyre pretty hammered, but i reckon theyre saveable... any schematics would be a real plus, otherwise ill draw a new one as i go....

    rich
     
  16. rafafredd

    rafafredd Member

    HI.

    Very interested on this schematic. If you can draw it, it will be really nice!
     
  17. Russell

    Russell Active Member

    I helped with the design of these mic preamps the 806 and the line amp 805, also its powersupply system and Studio feedback amps. I amade up all of the protype metalwork and electronis for them in 1958 and 1959 at EMI of Hayes in the Studio Sound section with P. D. R. Marks who had come from Marconi to work in the EMI STUDIO SOUND of Research Engineering and Development at Hayes. I still have two sets undrilled prototype cabinets for them that I made up in the laboritory, as the workshop said that the front panel and chassis with the runners was impossible to make, Marks asked me if I would attemt to make up one, so I set to and made ten of them!
     
  18. BrianK

    BrianK Member

    Although most people assume an EMI name means Abbey Road - that was just one of dozens of EMI studios around the world; Abbey Road became the most famous. EMI built a lot of stuff that went to these studios. In some cases (like the BTR2 tape machine) they sold things to the BBC and other parties.

    These were designed NOT for EMI studios but as "for sale" to outside studios. From what we can tell, these "maroon" 806 modules are the ones from Joe Meek's former Lansdowne Studios in London, circa middle 1960s. At the time, they said Joe had ordered a "purple" desk, but if you see the modules, they're really more reddish/maroon. Many people have these now. The EMI "BRED" desk was used at Lansdowne until about 1970.

    Don't confuse these with REDD designs (which are much sturdier and generally higher quality). REDD and RS items were built for EMI's own studios and these were from a division called BRED that was make products to be sold to outside firms. Much of this detail is in the Recording the Beatles book, although the Joe Meek info is not, there is a book on his life and gear, too. It's not very detailed, but it's all we have for now.
     
  19. Brian_G

    Brian_G Active Member

    I don't know where your information came from but it's wrong, the REDD47 was never named an RS812.
    RS numbers finished at RS175.
    There was a proposed design for solid state amplifiers for the REDD 51 but they never happened.
    There are also solid state versions of the V72 but they were not used by EMI.

    These 806 amplifiers do not come from either REDD or Abbey Road, they were manufactured by the Broadcast Equipment division of EMI (BRED), which was a separate department. Although the mechanical construction is very similar to the REDD47 they are different in their power requirements. The REDD47 needs 6.3V heater supply and 380 volts smoothed DC, the 806's take 325v AC and rectify and smooth it inside the unit. They are not interchangeable with the REDD47, nor were they intended to replace them.
    Interestingly, Joe Meek had an EMI desk which used these 806 amps. This was a custom order and has sometimes been described as painted purple. In reality the colour was a sort of dark maroon and some of the amps from it are still around.
    Here is one.

    EMI806maroon1.jpg

    This is the type of console they were originally used in.


    BRED Valve.jpg

    Regards,
    Brian.
     
  20. Brian_G

    Brian_G Active Member

    Very interesting.
    In the course of my research I have always been confused by the number of different departments at EMI that were building mixing desks and recording equipment. Your post makes things even more confusing, since I had never heard of a "Studio Sound" department as a separate division, despite the fact that the 806 amplifiers are marked "EMI Studio Sound".
    I've also never come across a "Research Engineering and Development" department.
    REDD was Record Engineering Development Department and EMI Research Laboratories was a separate department who worked in various areas, not just recording equipment. REDD was closed in about 1964/65 and EMI Research took over further mixer development, resulting in the TG12345 in 1967, although there are some TG numbered circuits in the REDD51, which were modifications to the original design.
    Neither REDD nor EMI Research manufactured equipment for sale outside of EMI, it was all for the company's own studios.
    BRED (Broadcast Equipment Division) was a commercial department, who manufactured equipment for sale to people like the BBC and IBA.

    I find it very strange that "the workshop said that the front panel and chassis with the runners was impossible to make" since the mechanical construction of these is virtually identical to that of a REDD47, which were produced in quite large numbers.
    I had often wondered, because of the mechanical similarities, if there was an exchange of information between REDD and BRED.
    I wonder if you know which came first, the 806 or the REDD47?
    I have always presumed that the REDD47 was designed by Len Page of REDD. As far as I know, the first REDD47 were produced in 1958.
    Are you saying that P.D.R. Marks designed the metalwork for the 806, or did the design come from elsewhere?
    How does this fit with the dates you have for the 806 production and do you have any idea how many were produced?

    Regards,
    Brian.
     

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