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Thread: Yamaha NS-1000M A Fresh Start

  1. #31
    Join Date: Oct 2012

    Location: The Black Country

    Posts: 6,089
    I'm Alan.

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    That looks fantastic Ken, you're certainly putting the work in

  2. #32
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

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    Thanks Alan,
    I tend to work on the detailing, while waiting for parts, and it will be another 10 days before the final part for the x-over board arrives.
    I should then be able to power it up, but only using the single ended output.
    Still, a step at a time, the Balanced transmitter boards need another four discrete op-amps at £85 a go, which wasn't in my original budget.

  3. #33
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

    Default Cabinet Construction

    .


    This is the material I've been experimenting with for the cabinet.
    It's a 24mm thick sandwich of 12mm MDF and 12mm Birch Ply. It seems to work well, extremely rigid and inert.

    The ply will go on the inside and the easier to machine/finish MDF will go on the outside.
    I already made routing templates for mid and bass so I just need to make a template for the tweeter.

    I'm getting close to being able to start the cabinets now.

  4. #34
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

    Default Update

    .
    First time assembly into the case to test the x-over board, the PSU has already been extensively tested and while it runs quite cool, I still drilled some extra ventilation holes under it.



    The outputs are single ended at the moment and use long unshielded leads extending outside the case, to a temporary panel with RCA sockets mounted on it. These leads will be much shorter in the final build (approx 30mm), connecting the x-over to the two balanced transmitter boards. These balanced boards are fully populated except for the four dual channel discrete op-amps. These will be acquired when funds allow and then the single ended output can be dispensed with and the XLR output sockets installed.






    I've kept the two input leads separated and cable tied them to the side panel, as it's not a good idea to run signal cables close together in parallel, even when shielded. Other than the DC power distribution (terminal) block and IEC mains inlet, all wires are soldered to guarantee a good connection.

    Time to get some hours on the parts, from experience, the Sonicap output capacitors in particular, take a long time to run in, I reckon 150 hrs, though some say 200 hrs. There is a noticeable mains hum at the moment, I won't worry too much about that, as there are lots of unshielded leads flapping around and the balanced outputs have not yet been implemented, which I'm guessing will both have an effect on this.

    I've been running the unit for three hours so far, and it already sounds very good, a denser more textured sound than the previous lash up circuit that used basic parts.

  5. #35
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

    Default Update



    The final four discrete Op-Amps arrived from the states, these were soldered into the balanced transmitter output boards. That is the active crossover assembly completed and for the first time it has both balanced inputs and outputs. I'm waiting on some feet and an illuminated switch before completing the final build in the case, the Nord NC500 Power Amps should arrive around the same time.

  6. #36
    Join Date: Aug 2009

    Location: Staffordshire, England

    Posts: 37,779
    I'm Martin.

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    This has been a real slow burner of a build. Can't wait to see them all finished and running but I guess that is still a fair bit away?


    Love the way you did the trim on the bass driver to blend in. Always some serious attention to detail in your projects.
    Current Lash Up:

    TEAC VRDS 701T > Sony TAE1000ESD > Krell KSA50S > JM Labs Focal Electra 926.

  7. #37
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

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    Quote Originally Posted by Macca View Post
    This has been a real slow burner of a build. Can't wait to see them all finished and running but I guess that is still a fair bit away?


    Love the way you did the trim on the bass driver to blend in. Always some serious attention to detail in your projects.
    Thanks Martin, I'm just plugging away at it. The cost has been a major factor in slowing my progress, not made of money and there's a Grands worth of components gone into this build of the active cross over alone. I may run out of time this year, as I have to build the cabinets outside and its weather dependent. Couple of festivals coming up and I just got back from Le Mans, so the amount of available free time is also restrictive.

  8. #38
    Join Date: Aug 2009

    Location: Staffordshire, England

    Posts: 37,779
    I'm Martin.

    Default

    I didn't realise how top spec you were going but it makes sense. Do it once, do it right.
    Current Lash Up:

    TEAC VRDS 701T > Sony TAE1000ESD > Krell KSA50S > JM Labs Focal Electra 926.

  9. #39
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

    Default

    Quote Originally Posted by Macca View Post
    I didn't realise how top spec you were going but it makes sense. Do it once, do it right.
    My thoughts exactly, I know the circuit produces great results from earlier builds and I've tried different caps and discrete devices to find my voicing preference. I purchased batches of 1% caps and resistors and matched them even closer myself. The resistors on the balanced inputs/outputs I matched to 0.1% to give good CMMR. I recon this final build will be as good as the circuit is capable of. If I didn't go the whole way, there would always be that nagging "what if I'd done this/that" doubt at the back of my mind.

    Got an email this morning from the courier, the parts I need to finish the case and the pair of power amps the crossover will supply are being delivered tomorrow.

    Should be able to wind up the electrical side of the project fairly soon, the wood work/cosmetics for the cabinet will come next. Not going for the traditional black and silver of the NS1000m so some sort of wood veneer is likely.

  10. #40
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

    Default Update

    That's the final assembly of the Active Crossover completed.
    Hooked it up and the mains hum has now gone, it was probably a combination of not using a fully balanced set up as per AES48 guide lines, for shield/audio ground connections and also having a temporary single ended output that created a ground loop. Now the correct wiring scheme has been implemented the problem has vanished.



    I mentioned some time back that I had a kind of plan for the Amplification.
    The two Nord Dual Mono Amps pictured below are what I had in mind and the reason for my choice of case for the crossover now becomes obvious. I had always intended for the cases to match but lots of things had to fall into place for this to happen and luckily they did.



    The electronics for this project are now completed. There is still some wiggle room, I have attenuators in place to adjust the levels between drivers at the moment, these will eventually be replaced with resistor networks. The Nord Amps are Class D and use the Hypex NC500 modules, each of the channels has its own SMPS and amplifier board, so they are true Dual Mono. The Amps use Nords own Input buffer board in preference to the stock Hypex item. The Nord uses superior discrete regulators and op-amps, I went for the Sonic Imagery op-amp option. These amps produce 700w into the 4ohm Woofers and 400w into the 8ohm Mid/Twtr combination. This is more than I will ever need and more than the drivers can handle, the Pre Amp I have in mind has an adjustable and lockable maximum output Gain. This feature can be used to protect the speakers from being over driven.

    I have the amps and crossover running in at the moment, so no comment on sound quality just yet.
    Last edited by Qwin; 30-06-2018 at 11:01. Reason: spelling

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