How much interest is there for a Pre-Built Linkwitz Transform?

Discussion in 'Archived Threads 2001-2004' started by Anthony_Gomez, Aug 14, 2002.

  1. Recently I built myself a linkwitz transform system complete with powersupply and case. How much interest is there in me building a bunch of these? I would be looking at doing 10-20. (I'll try and get pictures of mine so you can see what they look like). I have mine in a PE #320-776 case with an external wall wort (power supply and LT boards in the case). Safer and "quieter" this way.
    Would people be interested in one so that all you had to do was plug it in? or in a semi kit form where you have everything without a case and you need to wire it up....or everything without a case and the holes that you stuff your custom values are empty. Building to custom responces gets tricky since I would have to by lots of extra parts since everyones board would be different. The power supplies would be the same though.
    Any thoughts?
    Oh, what price would you be willing to pay for these? I need to see if it is viable at the wanting price[​IMG]
     
  2. Jack Gilvey

    Jack Gilvey Producer

    Joined:
    Mar 13, 1999
    Messages:
    4,948
    Likes Received:
    0
    Trophy Points:
    0
  3. With the new uber 15 (Tumult 15....damn...will I ever learn [​IMG]), I could make a bunch of kits for the recommended 17" cube uber 15=)...if we can settle on a final electronic Fb and Qtc that would make it easy =)
    Jack, I figured' you would want 1 or 10 [​IMG]
    I will create a spread sheet now to see how much this would end up costing. I would probably have people pre-pay (atleast 1/2) since this would make a big temporary dent in the pocket book!
     
  4. Hank Frankenberg

    Hank Frankenberg Cinematographer

    Joined:
    Oct 13, 1998
    Messages:
    2,573
    Likes Received:
    0
    Trophy Points:
    0
    Anthony, I'm interested. A customizable one though, so I could plug in different resistor values. Also, what voltage are you looking for, +5V? Is that not available in the plate amp circuitry. If so, the L-R circuit shouldn't draw too much current. A professional circuit board is the trick. Look at this link for a recommendation from Jon for a low-cost circuit board source:
    http://www.htguide.com/CFBoards/inde...estTimeout=500
     
  5. I have a customizable one right now. I have some pins in the important sockets that allows me to remove and replace the caps and resistors.
    I believe the LT boards need +/- 12VDC (i think that is what mine measured). THe boards I would be using are indeed professional looking. They would be supplied (i spoke with him a while ago about possibly doing this) by Rod Elliot at www.sound.au.com THis will not be a bread board thing.
     
  6. Bill Fagal

    Bill Fagal Stunt Coordinator

    Joined:
    Jul 8, 2002
    Messages:
    166
    Likes Received:
    0
    Trophy Points:
    0
    I'm nobody's legal eagle, but I feel I should remind you guys that the Linkwitz transform concept is covered by a patent or two, IIRC. If that's true, then any commercialization of it needs to be agreed upon by Linkwitz hisself, and proper royalties figured into the selling price.

    That said, he seems to be a DIY-friendly kind of guy, so give him a call, Anthony.

    Shoot, if you work it out in a legal sort of way, I'd be interested in one.

    Bill
     
  7. Brian Bunge

    Brian Bunge Producer

    Joined:
    Sep 11, 2000
    Messages:
    3,716
    Likes Received:
    0
    Trophy Points:
    0
    Since Hank didn't let me be the first to ask: What do you think you'd want for such an animal?

    Brian
     
  8. Fred Seger

    Fred Seger Stunt Coordinator

    Joined:
    Aug 13, 2000
    Messages:
    136
    Likes Received:
    0
    Trophy Points:
    0
    sign me up
     
  9. Bill Fagal

    Bill Fagal Stunt Coordinator

    Joined:
    Jul 8, 2002
    Messages:
    166
    Likes Received:
    0
    Trophy Points:
    0
     
  10. Hank Frankenberg

    Hank Frankenberg Cinematographer

    Joined:
    Oct 13, 1998
    Messages:
    2,573
    Likes Received:
    0
    Trophy Points:
    0
    Anthony, I have a suggestion. If the voltages are not available from the plate amp circuitry, why not make the board a bit larger and put in optional circuitry to take a higher plate amp voltage and bring it down with a couple of voltage regulators and caps. Getting rid of a wall wart requirement would be good, since some folks might incorporate this into subs they'd sell to local real live customers who wouldn't care to plug a plate amp and a wall wort to power their sub (kinda DIY-looking, you know +[​IMG]
    The current draw is really small for the L-R circuit.
     
  11. Jack, I will see what I can do with those pins thing since I have to get certain PCB sockets and pull the pins out ([​IMG] takes a bit of time, but is worth it). Doing it this way would mean that the buyer would need to get his/her own custom cap/resistor values...then again, I might be able to accomidate that too=) You would just have to stuff them and would later be able to remove them by hand.
    Bill, already shot off an email to Siegfried and to Rod[​IMG]
    Brian I need to see how much it would cost for me to get everything first[​IMG] I built mine piece wise, so I am not sure what it ran in total. What do you think would be a good price on them? Any idea on a "construction fee" over the parts cost?
     
  12. Brian Bunge

    Brian Bunge Producer

    Joined:
    Sep 11, 2000
    Messages:
    3,716
    Likes Received:
    0
    Trophy Points:
    0
    Jack,

    Dan was supposed to be checking into how much difficulty would be involved incorporating an LT circuit board onto a Hypex amp but we've never heard back from him about it yet. I'd love to have his input.

    Brian
     
  13. Frank, I was trying to make this as easy as I could on myself since I am not making any real money on it. I don't want to have to try and customize each of the power supplies. If people really wanted to, they can remove the transformer in the wall wart, build a fancy case and create a new item for their "seperates" system. I may or may not do a case thing, so the DIY look may be up to the buyer.

    the wall wart is on my power strip with all sorts of other power cables. The LT and powersuply board fit in a box that is about 3x4x5...pretty small as a unit. If this is too much for the buyer, then they don't need to get it =)
    Some plate amps have spots where you can tap off +/-12Vs to supply to the boards, but that is not something I am going to tackle.

    Hope you understand
     
  14. If I knew how to do a variable LT like the Marchand Basis I would, but I have no idea how they do it=)...it might not even be an LT but a varient.
     
  15. Hank Frankenberg

    Hank Frankenberg Cinematographer

    Joined:
    Oct 13, 1998
    Messages:
    2,573
    Likes Received:
    0
    Trophy Points:
    0
    Jack, I'd like to be able to incorporate it in a plate amp with nothing external. If most plate amps have the voltage available, I'd just hook up to it and it's done. It doesn't matter what size amp; 90 watts to 350 watts - theyre all possible candidates for a little L-R depending on the subwoofer design goals.

    Anthony, that way, it could be used with any plate amp - the customizing part is really nothing. Like I said, if all plate amps have the voltage already, then the only customizing is changing the frequencies with different resistiors/caps like you're already planning for, and customizing among different plate amps would just be finding a spot to mount the board on.

    Speaking of legal, I just rememberd, since we deal with this at work. To sell mains-operated electrical device legally, you must have agency approval (UL in the U.S.). If you sell a modified plate amp to a customer with an extra power supply (wall wort), I'm sure you'd need to submit your plate amp or subwoofer with integral plate amp to UL for testing and approval since you modified the A/C- connected amp. My personal opinion and I'm not a lawyer either. DIY, you're okay, but if you want to sell amps/subs, it would be best to pursue Brian's idea and get the plate amp manufacturer to incorporate a L-R circuit into their amp so that it's agency approved as it comes in the box.
     

Share This Page