Results 1 to 7 of 7

Thread: Chinese Tube Mic Repair

  1. #1
    benpasley is offline Registered User
    Join Date
    Dec 2007
    Posts
    5
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0

    Chinese Tube Mic Repair

    Sign in to disable this ad
    Need help! I have Chinese tube mic, about 4-5 years old, distributed by Cascade Microphones. It is the same or almost the same as the SE Electronics 5600 series from the same year with a big cylinder design, removable tube, 9-point selector switch for patterns on the supply...I believe Cascade simply rebranded the SE models.

    It went totally out a few months ago. Then it came back on and worked few weeks and then went out. No noise, microphonics, warnings at all. The tube does not glow (assume it would), power is coming down the cable (tested that), replacing the tube did not help. Don't have a tube tester. Anyone want to repair this thing?

    Ben Pasley

  2. #2
    chance is offline 1K Silver Member
    Join Date
    Jul 2000
    Location
    Ontario California
    Posts
    1,434
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    177028
    Have you tried checking voltage going to the Capsule? This would be part of the process of elimination. As you rotate the "polar select switch", the voltage will change. If you're getting voltage from the PSU to the mic, that MIGHT eliminate the PSU. Does the tube get warm?
    Chance Pataki
    The Musicians Workshop
    musicians.workshop@gte.net
    http://www.the-musicians-workshop.com

  3. #3
    benpasley is offline Registered User
    Join Date
    Dec 2007
    Posts
    5
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0

    it is on again

    thanks for the reply. this is so ridiculous. while i am checking the voltage change--which i do get on one lead while dialing through the patterns--the tube came on, glows, and i have signal. i have no idea. the figure 8 and cardioid patterns work fine, the omni mode still has obvious cancellation nodes, but hey, it is on. the electroharmonix tube in the gear is the original, i think, moving the tube around it seems to be well seated, and there is no significant noise. what is up?

    ben pasley

  4. #4
    chance is offline 1K Silver Member
    Join Date
    Jul 2000
    Location
    Ontario California
    Posts
    1,434
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    177028
    The tube only comes on while checking the voltage??
    Chance Pataki
    The Musicians Workshop
    musicians.workshop@gte.net
    http://www.the-musicians-workshop.com

  5. #5
    pylet2000 is offline Junior Member
    Join Date
    Nov 2007
    Posts
    55
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    39942
    This is just a stab, but it sounds like the heater supply to the tube is intermittant. I would investigate the cable for intermittant breaks, the solder joints on the tube socket, and possibly the internals to the power supply. Sounds like something is loose and when you bend the cable/socket/wires a certain way, they make contact and the thing starts mysteriously working again.

    Be careful when working on these, there are voltages that can kill you! Even with the device unpowered, there are capacitors in there that hold enough enegry to give a real bad day, and possibly your last day. If you're unsure of what's what inside of there, I'd be VERY cautious about poking around.

  6. #6
    Join Date
    Feb 2007
    Posts
    20
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    I used to repair radio and amplifier circuits, and one of the ways to cut costs is to use single-sided circuit boards. The result of this is: Through-hole components are not well-supported, and can crack their solder joints on the soldered side, creating intermittent connections.

    You may not even see them, but sometimes these cracks appear as circular rings in the solder around the component legs... especially on heavier or heating/cooling components.

    I found this photo online:
    http://www.rangerovers.net/repairdet...rackjoint1.jpg

    Anyway, if you remove power to the mic (obviously) and re-flow the solder joints on the components with some new solder & flux, you can solve the problem.

    - Rickshaw
    Complete DIY Ribbon Mic plans available from:
    www.RickshawRecords.com

  7. #7
    benpasley is offline Registered User
    Join Date
    Dec 2007
    Posts
    5
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0

    thanks folks

    i am going with the connection/solder theory for a bit. i was already headed toward a re-soldering campaign on the most obvious connections. i love this mic and i am glad to get some quality encouragements on a repair plan. i will give it a go. i consider this thread done...thanks!

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Mic / Pre via solid state n tube
    By P. Rene in forum Microphones
    Replies: 1
    Last Post: 05-15-2006, 23:33
  2. Help: Mic Decisions and My Trip to Guitar Center
    By JohnnyMan in forum Microphones
    Replies: 61
    Last Post: 04-16-2006, 21:38
  3. The Mic Test Thread!
    By Rhythmschism in forum Microphones
    Replies: 41
    Last Post: 04-30-2004, 11:23
  4. Replies: 40
    Last Post: 07-08-2001, 07:41

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
A3E sponsorship event box

Check out A3E in Boston!