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DIY Mic - where do I buy parts ?

Discussion in 'Microphones' started by pcrecord, May 20, 2016.

  1. pcrecord

    pcrecord Don't you want the best recording like I do ? Well-Known Member

    Hi gang,

    Some of you know I did try a kit of microphone-parts.com
    I ran to a few problem with the kit. It didn't work and after a great help doing a dozen test I ordered another circuit without the transformer.
    I build the new circuit and got the same results.. so I'm in need of another transformer.
    It's a small 6.5 : 1 output transformer.

    I found this one on eBay but they don't sell to Canadian...
    images?q=tbn:ANd9GcRNLrXS5BjLUw22uyx3cQyfbXlsHnHmH-CKYHjmknOLkBIAmLO94Q.jpg
     
  2. Sean G

    Sean G Well-Known Member

    Where is the item located @pcrecord ?

    Worst case scenario maybe someone else can pick it up for you and forward it on if you cannot source another from somewhere...

    PM me the link and I'll see if I can get it for you (y)
     
  3. Sean G

    Sean G Well-Known Member

  4. Boswell

    Boswell Moderator Distinguished Member

    Marco - I'm a bit confused about your reported experience with the microphone kit. When you said the first one did not work, in what way did it not work? Then the second circuit board behaved in an identical fashion, is that right? I'm guessing you moved the transformer from the first to the second board. Does that mean you suspect you have a faulty transformer, hence your need to get another one?

    Is the transformer in your photo and Sean linked to on Ebay the same as the one that Microphone Parts incorporate into their designs? M-P seem to emphasise the "custom wound" credentials of their part, so it would be surprising if it were available to anyone.
     
  5. pcrecord

    pcrecord Don't you want the best recording like I do ? Well-Known Member

    After a bit of research the transformer in the kit is a cinemag CM-2461
    The photo I put was the one from eBay as an exemple only.

    I did the build and it didn't work. All the test points ended with a 10th of the power it's suppose to read.
    Matt from microphone-parts was extreemely patient and we exchanged more than 20 emails trying to diagnose the behaviour.
    I end up ordering him another circuit but without the transformer.. We thought that I might have overheated a part and we couldn't pin point which.
    I did build the new circuit with the original transformer and got the same result.. So I now want to replace the transformer before I throw everything out of the window ;)

    Seriously, I may resorb to use the capsule alone in my Studio project mic if I can't get the kit working, but I want to give a it shot with a new transformer first.

    Any places where I can buy a cinemag from canada ?

    Thanks for the offer Sean, I'm just not sure if it would be an equivalent to the cinemag..
     
  6. pcrecord

    pcrecord Don't you want the best recording like I do ? Well-Known Member

    I just sent an email to Cinemag directly and ask where to buy.. I might have a better chance that way ;)
     
    kmetal likes this.
  7. kmetal

    kmetal Kyle P. Gushue Well-Known Member

    If there's anything I can do to help let me know. Your welcome to use my adress over here in US, for forwarding or watever, or I could forward it to you, whatever it is, I'd be happy to help.
     
  8. Sean G

    Sean G Well-Known Member

    No worries Marco, I was only going off the pic as when I put the details into google, that was one of first things that popped up.
     
  9. pcrecord

    pcrecord Don't you want the best recording like I do ? Well-Known Member

    You are very kind guys ! Thanks.
    Cinemag offered to deliver it to me.. (127USD + 25$freight)
    I'm checking if I can get a better price but it seems honest so far.
     
    kmetal likes this.
  10. kmetal

    kmetal Kyle P. Gushue Well-Known Member

    I'm obviously just getting into electronic componentry, but 125$ sounds in line with my limited experience. Brand name transformers are usually an extra 1-200$ whenever companies offer them as an option. I'm kinda excited to see how everything turns out Marco. You just might have a 'happy accident' on your hands.!!
     
    pcrecord likes this.
  11. pcrecord

    pcrecord Don't you want the best recording like I do ? Well-Known Member

    I'd be delighted if it turns out working fine after this last attempt.
    Thanks for your support !
     
    kmetal likes this.
  12. pcrecord

    pcrecord Don't you want the best recording like I do ? Well-Known Member

    Good news my friends ! The mic is working fine with a new transformer. Dawm if I knew it was it I would have save ordering a second circuit...
    But anyway, since I have an extra circuit, I ordered all the other parts to build their T12 kit. So, I'll get two mics with same electronics but different capsule (RK47 and RK12)
    Matt gave me a good rebate on the extra parts..

    BTW the mic sound very good, I'll do some tests and share the results very soon ;)
     
    dvdhawk and kmetal like this.
  13. DonnyThompson

    DonnyThompson Distinguished Member

    So it was a faulty transformer then?

    Cinemag is far from rare in the XFO world; and their various models are very common in mics, pre's and other hardware processors; but, I suspect that like any company, occasionaly a lemon or two can slip past QC from time to time.

    I'm glad you got it resolved Marco, and looking forward to your thoughts on the new mic you've built - and - wink wink - it would be cool to eventually hear some samples of the mic in action. ;) ;)
     
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  14. kmetal

    kmetal Kyle P. Gushue Well-Known Member

    Man that's great to hear Marco!!! Now you can try both, and your only one capsule away from a pair. Between the focusrite and cinemag stories, you've had some strange situations with otherwise reputatable companies, albeit the interface not necessarily the mantufactuers fault. The upside, is you probably know way more about mic design from all your troubleshooting, than you would if the thing just worked right away. I'm happy you finally got it going man, without having to use the "mic meets wall" effect.
     
    pcrecord likes this.
  15. DonnyThompson

    DonnyThompson Distinguished Member

    :mad:

    :LOL::LOL::LOL:
     
    kmetal likes this.
  16. pcrecord

    pcrecord Don't you want the best recording like I do ? Well-Known Member

    Actually the transformer I got from microphone-parts.com didn't have any branding. Matt assured me it was more effective than the cinemag in his circuit. That's why I bought a second one from him and discovered the first one was defective.
    I can't hold it against Matt because the transformer was reading the right resistance on the tester. I guess it was a magnetic or induction problem.. (really not an expert)

    Thanks for the moral support guys !! :)
     
    kmetal likes this.
  17. kmetal

    kmetal Kyle P. Gushue Well-Known Member

    I'm curious about the magnetic induction, and how it effects or defects operation. Just for my knowledge. Maybe boz will chime in.
     
  18. Boswell

    Boswell Moderator Distinguished Member

    Yes, interesting, Marco. I've de-gaussed microphone transformers from both pre-amps and large-format studio mixers that have managed to get themselves magnetised through faults in that channel's phantom-power circuit.

    It's a matter of setting up a saturating level of sinewave current through the transformer primary which you then reduce smoothly and linearly to near-zero level over a timescale of a few seconds. Depending on the design of transformer, you may be able to use line-level drive or you may need a power amp for this job. I usually load the secondary with 600 Ohm and view the output on a scope to check for a suitable level of saturation. The sinewave frequency is not important; 50Hz is fine.

    I remember going into one studio and seeing strips of bright red sticky tape over many channels of their 32-channel desk. "We don't use those channels" I was told. I managed to get out of them that they had had some problem cables between the control room and one of the live rooms, and that's probably what had caused the troubles. I persuaded them to let me take one of the channel strips away with me. I brought it back a few days later with the transformer de-gaussed. I couldn't test the strip while I had it, but they plugged it back into the desk and it worked fine, so I got to work on the others in turn. It turned out I was a bit lucky with that first one, since only two of the other faulty channels had the same problem. However, it meant it was easy to get them three more working channels without their spending large amounts of money on significant repairs to the desk or losing much studio time.
     
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  19. kmetal

    kmetal Kyle P. Gushue Well-Known Member

    Boz if you ever write a book I would like an autographed copy. I'll frame it, and use another copy for reference. :)
     
  20. pcrecord

    pcrecord Don't you want the best recording like I do ? Well-Known Member

    I must admit you lost me there Boswell, I never De-gaussed a transformer.. ;)
    It's amazing to see how many electronics circuits are in our lives and most of us have no idea how they work.. You are Lucky to know that much Bos.
    Imagine how much time it would take to start everything from scratch... How many years would it take to produce a computer CPU again ?
     
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