+ Reply to Thread
Page 2 of 7 FirstFirst 1234 ... LastLast
Results 11 to 20 of 64

Thread: Yamaha NS-1000M A Fresh Start

  1. #11
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

    Default

    Hi James
    It depends which bit of the process as to how quick.
    When I was exploring the many variations on slope and crossover point I used my DSP. I could just drag the crossover point or type in a new value from my laptop at my listening position. When I upload the new values to the DSP unit (while music is playing) there is a short break of 1 maybe 2 seconds while it takes effect, so it is fairly instant.

    When comparing bass drivers I have both types set up with the same type of cable running to the back of the power amp, which is out into the room, so as long as it takes to unplug one set of banana plugs and insert the next. I do this while music is playing, not the best thing to do, but it makes it quick.

    When comparing the all passive to the partly active/passive I had two set ups inside the Yamaha cabinet, the original passive crossover and a lash up similar to my proposed layout, using cheap caps and some old coils I wound down to the needed values and stuck them with hot melt to some 6mm MDF. I used my 3-way backplate with 3 sets of terminals (from my fully active experiments) and had the two options available by swapping banana plugs at the back of the speaker. This took a little longer, but again I did it hot, so not too long. The results were so obviously in favor of the semi-active I modified the original x-over strait away, so I could take advantage of the better parts used. Nothing that can't be easily reversed, just unsoldered one leg.

    All parts were well run in before comparison.

    I got the Celestion 66 as good as I could, but still wasn't happy.

    I can spot what I'm looking for pretty instantly, I've been trying to resolve this and find a set of speakers I feel comfortable with, for many years. I hear new gear at shows, that sounds terrible, its ok with instrumentals, which is what they tend to demo, but stick some well recorded vocals on and they are anything but natural or realistic with a horrible edge to the end of words, not sibilance, I can't stand that either, it's I suppose, the equivalent at the other end of the scale. I've heard very few multi way speakers that I could say were good enough and even fewer I could afford. I've heard quite a few two ways that bettered most of them and for a lot less money, the trade off being a lack of deep bass. Some speakers that don't exhibit these faults are just to soft and rounded off for my taste, many of the JBL models fall into this category, but many are happy with that sound.
    Maybe I'm just being over fussy.
    The distortion just gets in the way of my enjoyment, I know that someone sat in front of me wouldn't sound like that and I know there are speakers out there that can achieve it. So my quest continues.

  2. #12
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

    Default

    No, not quite my set up Mark, I used a purely digital crossover to establish slopes and best crossover frequency. Then built a fully analogue active filter that replicated this, using expensive but transparent discrete op-amps from SparkoS Labs and Burson Audio. So no ADC/DAC in the chain, other than my CD/DAC source plugged into my Pre Amp of course.

    I just can't get a DSP to work with my TT, probably because of the multi analogue/digital/analogue conversion elements you mention. This all analogue, partly active, partly passive approach, seems to give me what I am looking for, its early days, we will have to see, I hope so, I've been chasing my tail long enough with this.

  3. #13
    Join Date: Jan 2013

    Location: Birmingham

    Posts: 6,772
    I'm James.

    Default

    Although you can do work on the crossovers to change the top end characteristics it still comes down to the particular type of tweeters used and I would say the Yamahas are not the most subtle. I have always found soft done tweeters more natural especially when adding their contribution to vocals, hence the old BBC type speakers excelled in this area. I have heard some very good dynaudios with their own manufactured tweeters and they are in the same ball park. I have not thought JBLs to be particularly underachieving in this respect but midrange for vocals was a bit blahhh.

    I am sensitive to top end information and find many modern speakers unlistenable hence my use of older SP2s, the detail is all there but not in your face and certainly no sibilance. Maybe try some SP1s. Your endeavours with the yammys may never give you what you are looking for because of their inherent tweeters design?
    Main system : VPI Scout 1.1 / JMW 9T / 2M Black / Croft 25R+ / Croft 7 / Heco Celan GT 702

    Second System : Goldring Lenco GL75 / AT95EX / Pioneer SX590 / Spendor SP2

  4. #14
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

    Default

    Strangely enough, the Tweeters are not a problem, very clean, sweet and sibilance free.
    But you are right, the stock NS-1000M set up has that reputation, of forward top end needing careful amp matching.

    The active pre-filter I'm using can tailor what happens down stream with a bit of op-amp rolling. The combination I've installed seems to take the harshness out of the top end without loosing any of the famed clarity and imaging. I'm reasonably happy with that end, if I could get the lower mids as good, I'd be in clover.

  5. #15
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

    Default Update

    Not much I can do at the moment.

    I've made the passive Crossover boards, but the coils are being wound by Jantzen with a two to three week lead time.

    Also ordered the PSU and Active Crossover PCB's from ESP (Rod Elliott) with a two week postage time from Australia.

    Ho Hum

  6. #16
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

    Default Update

    The caps and coils arrived earlier than expected from www.hificollective.co.uk

    Jantzen Air Core Coils:

    These are very thick Copper to keep the dcr at the low level required. This was as close as I could match the values, another turn would have taken the values below what was required and a partial turn would have one or both the leads out of alignment with the holes in my boards.

    The pair of 0.47mH (0.45 required) were wound down to 0.4518 (dcr 0.124) and 0.4529 (dcr 0.122).

    The pair of 0.33mH (0.3 required) were wound down to 0.302 (dcr 0.0913) and 0.303 (dcr 0.0928).

    So inductance and dcr for the coils are now very close to ideal.

    Jantzen Superior Z-Caps:

    The 2.7uF pair measured 2.699 and 2.702

    The 3.5uF value is not available so this pair were made up of 1+1+1.5 These groups, when measured were 3.5001 and 3.5065.

    I must admit, I'm impressed with the accuracy of the values of these Jantzen caps, they are rated at 2% but all measured well within this band. All but one being better than 1%, the odd one out was just over 1% outside the stated value.





    I've built the passive crossovers on 4mm Paxolin Board.

    Left out the attenuating resistors for the Mids and Tweeters for now and just used wire links in their locations. I will voice everything in the final cabinets before measuring the level pots and buying resistors to replace them.

    The Active crossover is up next, still waiting on the boards.

  7. #17
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

    Default Update

    .


    This build is taking time, things keep getting in the way.
    I built the Power Supply for the active crossover on the p05 rev-D board from ESP (Elliott Sound Products).

    For others building this supply/crossover, I configured the board as +/- 12 Vdc output and used 3R9 resistors at R1 and R2 locations, which gives an output capability of 250mA. Rod supplies all the other information required to build the PSU when you purchase the PCB.

    The active crossover board, fully loaded with discrete op-amps, will draw just under 200mA (monolithic chip op-amps will draw a lot less) so the selected 250mA leaves a bit of headroom for even the worst case. The PSU therefore requires just under 5VA, I am running it off a 12-0-12Vac Talema 15VA encapsulated Toroidal Transformer (from RS) again this allows decent head room. You can see the Tranny at top left on the picture above.

    I used Panasonic FC caps (from RS) and Takman 1% metal film resistors (from HFC).
    The PSU is pictured running my old crossover, which draws 100mA and the heat sinks run at 35 deg C when supplying this, all be it, out in the open and not in a case.

    Next up is the crossover itself. (ESP p09 rev-C)

  8. #18
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

    Default Update

    The whole of this crossover and output boards require less than 5VA. The original transformer I used was a 12-0-12 15VA (More than enough) but after playing around with various transformers, I found a beefier 12-0-12 30VA seemed to sound better, so it's the one I will be using moving forward.

    I've made a slight change to my plans, so I need to order some additional boards from ESP.

    My audio system is fully balanced and while the p09 crossover can be built to accept balanced inputs, it's a single ended circuit with single ended outputs. Rod Elliott also produces boards for a dual balanced transmitter project, which has two single ended inputs and a pair of balanced outputs (ESP p87B). My plan now, is to use a couple of these boards after the crossover, to give me the 4 balanced outputs needed. These will connect to a pair of Hypex class D stereo amps, which Hypex recommends should be fed a balanced signal. I could use Phono to XLR converter leads, as the distance involved is short, but if a jobs worth doing........... It's a bit over the top and maybe a bit of a cheat using these ESP balanced output boards, but not as OTT or extravagant as it first appears. The crossover has a buffered output stage on each channel, these items can be left off and the signal from the filters fed straight into the balanced transmitter boards, which act as a unity gain buffer anyway. This also clears up some board space for the Polyprop output coupling caps I want to use. The Hypex based Power Amps are DC coupled, these coupling caps will help prevent any stray DC finding its way to the speakers.

    It's going to take up a bit more space, having to accommodate the additional pair of PCB's, but there's plenty of room, now that I've made the decision to put the crossover in its own case, with it's own power supply. Space was tight when trying to fit it into one of the amplifier cases, by making the crossover external it means there are no longer any modifications required to the Amps, should I ever want to sell them on. They can also now be used for general duty and put into other systems, as the outputs won't be filtered and dedicated to this active set up, so it will be much more flexible.

    The pair of balanced transmitter boards arrived, so I need to finalize the layout ready for fitting it all into a case.



    This layout seems to work, with good separation of Signal/AC/DC cables.
    The DC supply cables and signal input/output cables at the rear are on different "Z" planes so not as close as you might think, based on the diagram.

    Now, to find a suitable case.......

  9. #19
    Join Date: Oct 2012

    Location: The Black Country

    Posts: 6,089
    I'm Alan.

    Default

    Quote Originally Posted by Qwin View Post
    The following ESR values ........
    Just a little point Ken the graphs you have shown are showing the capacitor impedance, not the ESR.
    The ESR is the residual resistive element of the capacitor, made up mainly from the lead and foil resistance.

    Excellent project

  10. #20
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

    Default

    Yes, you are right chaps, tripping up over the technical terminology and also not reading whats in front of me.
    The ESR values can be recorded with DATS v2, but only for three fixed frequencies and displayed as part of a table, with other info, so no full sweep graph of the ESR.

    I've been using the power supply I just built, with a crude version of the intended active crossover, with Polyester caps and no name metal film resistors fitted.
    In conjunction with the passive crossover element I built, the results are very impressive.
    Can't wait to complete the build proper, with 1% Polystyrene caps and Takman 1% metal film resistors.
    The proper build will also have balanced input and output, instead of the single ended on the current version.
    I know from previous experiments (now on v5 build), that when hooked up to my fully balanced Pre amp, on a purely subjective level, the sound quality does seem to benefit from using the balanced input option.

    Lots of stages to go through yet.
    I just ordered the Polyprop crossover output caps from the States, a trade off of size v quality very much governing my choice. I went for Sonicap Gen 1, which I have used a lot in the past. Compact, very transparent and a crisp, clean top end. I'm using highly transparent discrete op-amps, so I don't want to downgrade things by having a muddy or grainy cap at the end of the chain. I tried some Sonicaps I had (close-ish to the right value) on the current set up and they work very well in that location.
    Last edited by Qwin; 21-03-2018 at 19:33.

+ Reply to Thread
Page 2 of 7 FirstFirst 1234 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •