Results 1 to 9 of 9

Thread: DC protection with Crown amps?

  1. #1
    Senior Member Doc Mark's Avatar
    Join Date
    May 2008
    Location
    Southern, California, USA
    Posts
    1,371

    DC protection with Crown amps?

    Greetings, Friends,

    I have several Crown power amps, and have used them for years in PA applications. In all that time, I've never had a lick of trouble with them. However, I do know that once our band was using an old Crown DC300, with 802 Bose (PATOOIE!!) clones that our drummer cobbled up, and the amp passed DC to the speakers and fried the works!! We got the amp fixed, and used some other speakers whilst our little Bose copies had all their little speakers replaced.

    Now, since I'm going to be using Crown power as part of my "new" stereo system, I'm wondering if there is something I can do to protect my speakers, should any of those amps decide to pass DC along the line? Any thoughts, comments, or suggestions would be greatly appreciated. Thanks, very much, in advance! Take care, and God Bless!

    Every Good Wish,
    Doc
    The only thing that can never be taken away from you, is your honor. Cherish it, in yourself, and in others.

  2. #2
    Senior Member Fred Sanford's Avatar
    Join Date
    Jun 2005
    Location
    Shenandoah Valley
    Posts
    1,608
    I have a DC sensing relay card in a little project box for use with my DC300A. I'll find you the Parts Express part # for the kit, and maybe snap some pics. The idea is that when DC is sensed on the speaker line, a relay coil energizes and disconnects the amp from the speaker loads.

    je

  3. #3
    Senior Member Fred Sanford's Avatar
    Join Date
    Jun 2005
    Location
    Shenandoah Valley
    Posts
    1,608

  4. #4
    Senior Member Doc Mark's Avatar
    Join Date
    May 2008
    Location
    Southern, California, USA
    Posts
    1,371
    Morning, Fred,

    Outstanding info! Thanks, very much! I just told Sweet Bride about this idea, and she thinks it's a good one, too. When all is said and done, before I begin using this system too much, we'll avail ourselves of several of those little disconnects. I'll get some boxes for them, and call it good. I guess you just mount some input and output terminals on the sides of the box, eh? Sounds simple and quite easy, actually. Thanks, again! Great info, and much appreciated! Take care, and God Bless!

    Every Good Wish,
    Doc
    The only thing that can never be taken away from you, is your honor. Cherish it, in yourself, and in others.

  5. #5
    Senior Member Fred Sanford's Avatar
    Join Date
    Jun 2005
    Location
    Shenandoah Valley
    Posts
    1,608
    I didn't have a lot of time to type earlier, so here's the rest of my disclaimers: I use my Crown DC300A as a utility amp- sort of a loaner if any other amp in circulation goes out for repair. I can't say that I've done any critical listening with these boards in line, just tested them for function with meter and then with speaker load. Others here may have more to add, either good or bad. This project box was made with whatever was around at the time, in retrospect I'd have put binding posts as the speaker terminals in case of use in a PA situation.

    Pics as promised...

    je
    Attached Images Attached Images   

  6. #6
    Administrator Robh3606's Avatar
    Join Date
    Apr 2003
    Location
    Rocinante
    Posts
    8,170
    Are you going to be running any passive sections in the crossovers?? If you are any series capacitors will protect the driver behind it. So if you were biamping say a 4344 or 4333 as examples you would need it on the woofers and the 2122 only. The rest of the drivers all have a series cap in the crossovers. Always check the schematics to be sure.

    Rob

  7. #7
    Junior Member alotawatts's Avatar
    Join Date
    Jan 2007
    Location
    Seattle
    Posts
    15
    I was going to put mine inside each encloser but I like Fred's L&R project box better. Also like the fact that Fred's (older kits ?) have clear/see-through relay cases. They are opaque now with the kits.......

  8. #8
    Senior Member SMKSoundPro's Avatar
    Join Date
    Apr 2005
    Location
    Anchorage, Alaska
    Posts
    1,019
    WOW!

    GREAT IDEA!!!

    Thanks for the info!!!!!

    Scotty.
    One step above: "Two Tin Cans and a String!"
    Longtime Alaskan Low-Fi Guy - E=MC² ±3db

  9. #9
    jbl
    Guest
    Fred's relay board looks like it uses either the MY-2 or LY-2 type relay. Nice layout.
    Anyone know the relay contact rating of the PE board? You'll need at least a 5A rating.

    Ron

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. crown dc 300a power amps
    By gene in forum Professional Amps
    Replies: 33
    Last Post: 07-24-2009, 03:36 PM
  2. Replies: 7
    Last Post: 02-22-2007, 05:56 PM
  3. crown pro amps?
    By oldschool in forum Professional Amps
    Replies: 17
    Last Post: 03-18-2006, 12:02 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •