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HDW microphones....whatever happned to....?

Discussion in 'Microphones' started by JoeH, Sep 27, 2013.

  1. JoeH

    JoeH Well-Known Member

    Just a shot in the dark here; mostly for fun I picked up a really cheap/inexpensive mic - an HDW203 - from Craigslist. It was a tiny brand that doesn't seem to exist anymore: HDW microphones, (Chinese imports) run by a guy named Hans Washburn. (Might even be an alias?) Any, I actually got this faux u-47 for a movie prop, but it actually works, has a nice case, power supply, remote pattern controller, and decent shock mount. The only thing I found on the web is a dusty old link (from 2008) here: (dead Link Removed) I tried emailing him at the address on this website, but it bounced back as no longer working. I'm really just looking for schematics; I'm attempting a few mods on it just to have some fun, learn about the tube circuitry inside, (swapping out the 12Ax7 for a 12AY7, and adding an upgraded RK-12 capsule from MicrophoneParts.com.) I see they (HDW) sold some stereo ribbon mics and some generic small/pencil style condenser mics...but nothing since 2008. Anyone have any experience with these?
     
  2. pan60

    pan60 Active Member

    Just looks like any of a number of rebadged import mics to me.
     
  3. JoeH

    JoeH Well-Known Member

    Yes, you're right, it certainly is. No question about that; but I haven't found anything that's similar to it from the other knock-off companies that I could copy or get a schematic. It's a little unique in that it's a dual-capsule, tube-driven circuit with rolloff switches and a 10db pad switch, along with a remote pattern selector box. (Not bad at all for what it originally sold for; around $250. The power supply, basket, case & cables are worth at least that much, let alone the capsule, circuitry, transformer, etc.) They say it's patterned after the u-47 and 251 type mic, but with their own circuitry, of course. I'm looking to contact the guy and see if by any chance he's got a schematic for it, as I'd like to do some mods to the circuit. And yes, since it's probably fairly common among importers/copiers, I'm hoping to find a similar mic/circuit from a similar importer.
     
  4. rmburrow

    rmburrow Active Member

    JoeH: The tube change to a 12AY7/6072 will cut the mic output a little but the 12AY7 may be quieter than a 12AX7/7025. Can you tell if both halves of the tube are being used (connections to all pins on the socket)? Pins 4 and 4 are heater, pin 9 is a heater center tap. If pins 4 and 5 are connected and pin 9 is not used, the heater voltage supplied is 12 volts (most likely dc). If pin 9 is connected, the heater voltage may be 6 volts (probably dc) OR there may be biasing to float the heater voltage above ground (to avoid exceeding heater to cathode voltage in some circuits).

    I believe pins 1 and 6 are plates, 2 and 7 are grids, and 3 and 8 are cathodes for the 12AU7/12AX7/12AT7/12AY7 family.

    It would be interesting to take one of these "inexpensive" mics, remove the cheap preamp, and build in a high performance preamp using a 12AY7/6072, EF86, 7586, EF14, 5703, D3A, 6EJ7, 5879, or some other suitable tube and mating output transformer. Supposedly, mod kits are available on line for those who don't want to build their own...

    Supposedly, a recording of the Wanamaker organ made in 1964 at Philadelphia's Wanamaker store (now Macy's) was made using a number of Neumann mics into a board using 5879 tubes in the preamp. The old Gates boards used in radio stations at that time had either 5879 or EF86 tubes in the preamps....

    It may not be a bad idea to use this U47 copy on drum overheads...rather see a copy get beat up by accident rather than a real U47....
     

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