Urei 610

Discussion in 'DIY Pro Audio Forum' started by ciminosound, Feb 10, 2003.

  1. ciminosound

    ciminosound Guest

    Anyone have any info or links to info on the old Urei tube gear? Like the mixer the new 610 pre is designed after.
  2. IJR

    IJR

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    Israel
    Hello!
    I am interested in this schematic too.
    Maybe some people have it? ;)
  3. Mark Burnley

    Mark Burnley Guest

    Kerrrrr-BUMP!

    ...did anyone ever find this schem?

    Just checking the 'ole archives before asking again!

    ;)

    Mark

    --------------------------
    "Oscillators don't, amplifiers do....."
    Anon.
  4. bauman

    bauman Guest

    yea, have no luck looking for this one too, anyone got it?
    [​IMG]
    Last edited by a moderator: Mar 31, 2014
  5. NewYorkDave

    NewYorkDave Guest

    I've got the schematics for a Universal Audio tube mic pre and the optional equalizer that goes with it. Without knowing the particulars of the output transformers (which have tertiary feedback windings) and the EQ inductors, you couldn't build an exact copy from the schematics. But you can take inspiration from the circuit topologies. There's too much copying going on around here anyway, in my opinion :D

    These schematics were included in an AES paper by Bill Putnam, Sr. that describes the UA recording console (complete with photos and block diagrams). Since they were published, I don't think the present UA company could invoke any kind of proprietary information offense if they were put on the web, but the AES might be pissed off because they get $5 each for copies of the paper.

    It IS a good read, though, and I thought it was worth the five bucks. I forget the exact title, but it contained the phrase "of advanced design" and the author's name is Milton T. Putnam. Check the AES website.
  6. The AES paper you are refering to does not have schematics and info on the 610 channel amplifier. I believe that particular paper talked about 108 amplifiers and 508 eqs but I don't have it on hand at the moment to check.
    I designed the current UA 2-610 which is quite similar to the original 610 and while I won't give away current UA proprietary information,
    I don't see any reason why I couldn't post a redrawn copy of the original circuit. My website is currently "under consruction" but maybe I'll pop a copy up there for a week or two so anyone interested can grab a copy : ) I'll be back in a day or so.
  7. Go to:
    www.johnhinsonaudio.com

    and scroll down to the link at the bottom of the page. Hope that helps.
  8. Shalimar

    Shalimar Guest

    Thank you very much!
  9. Mark Burnley

    Mark Burnley Guest

    Hollowstateman,

    Thank you very much for that!

    ...I'm more interested in equipment schematics for their learning potential than just making a clone. I like to see the topologies and signal flow. Some things you can't learn out of text books!

    [​IMG]

    Mark

    --------------------------
    "Oscillators don't, amplifiers do....."
    Anon.
    Last edited by a moderator: Mar 31, 2014
  10. gyraf

    gyraf Guest

    Thanks!

    This is very interesting reading!!

    Jakob E.
  11. Learner

    Learner Guest

    WhoOH! You are a CHAMPION!!!! :eek: [​IMG]

    RESPECT! RESPECT!!! [​IMG] [​IMG]

    Back to schematic digestion...... [​IMG]
    Last edited by a moderator: Mar 31, 2014
  12. NewYorkDave

    NewYorkDave Guest

    Yes, you're correct, it's not the same model. The mic preamp shown in my schematic has a cascode front end and is a very interesting circuit in its own right. The optional EQ is inserted in the feedback loop.

    The AES Journal Article, by the way, is called "Recording Studio and Control Room Facilities of Advance Design", Vol. 8, Number 2 pp. 111 (1960), Author: Milton T. Putnam, Abstract: "A decided departure from conventional control room design, involving new planning of layout for improved stereo monitoring, is described in detail. In addition, the control console mixing facilities incorporate many unique features..."

    The article includes a detailed block diagram of a console, schematics of a mic preamp, EQ and program amp (and possibly other schematics--I don't have my copy handy) and photos of the console. It's quite a good read.

    I'd be happy to post it somewhere, except I really don't want any legal trouble from the AES [​IMG]
    Last edited by a moderator: Mar 31, 2014
  13. adrianh

    adrianh

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    AES is very picky. I would not post it even Jensen
    cannot post their stuff. Jensen will send their's in the mail if you ask.

    But AES will send the Putnam article in the mail to you for a fair price of USD$5.
    I just ordered mine.

    Thanks for the tip!

    adrianh
  14. thermionic

    thermionic Guest

    This place rocks! Thank-you!

    [​IMG]
    Last edited by a moderator: Mar 31, 2014
  15. bauman

    bauman Guest

    WOW!
    THANKS!!!!!!
    [​IMG] [​IMG] [​IMG]
    Last edited by a moderator: Mar 31, 2014
  16. ciminosound

    ciminosound Guest

    Thanks! It will be interesting to compare with some other units from the same period.
  17. rascalseven

    rascalseven Guest

    Does anyone have information about the UTC transformers used in the 610? Model numbers are on the schematic, but do we know turns ratios?

    Any known suitable alternatives?

    Thanks!
  18. Steffen

    Steffen Guest

    the output trannie says impedance ratio 30kOhm:600ohm. if I my calculation is correct the turns ratio is 7:1 ( turns ratio=voltage ratio= sqrt(30000:600) )primariy inductance more than 55 H (with dc applied!!!!)

    the core must be able to take a little dc....

    btw: thanx for posting this schemo :)

    steff
  19. edanderson

    edanderson

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    the input utc O-1 is a small transformer with primary taps for 50, 250 and 600ohms and a single secondary 50k ohm winding. pretty common in broadcast gear. the O-2 is the same thing with a center tapped secondary.

    connecting to taps 3 and 4 on the O-1 would give you a 50ohm primary, and with the 50k secondary that's a 1:31 ratio. yikes.

    ed
  20. NewYorkDave

    NewYorkDave Guest

    I was surprised to see that UTC 0-1 "ouncer" on the input. I've got one or more of those floating around somewhere. Maybe I'll breadboard a 610 for fun...
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