View Full Version : Yamaha NS-1000M A Fresh Start
A Fresh Start.
I just can't get away from the fact that I like so much about the NS-1000m.
The re-cap I completed, using more neutral capacitors helped the overall presentation, but I decided to make another attempt at sorting out my minor dislikes.
Over the years I have found more 2-way systems that I feel happy with than 3-way. I often find a resonant distortion exists around the crossover point on a 3-way, at the hand over between woofer/midrange. This can add a nasty edge to male vocals and fingers on strings etc.
While taking some measurements of capacitors, to satisfy my curiosity regarding Equivalent Series Resistance (ESR) values, a possible cause of this distortion came to mind.
The following ESR values were measured using Dayton Audios Test System (DATS).
http://www.jkwynn.co.uk/Project_Images/Yam/yam_38.JPG
I took these ESR measurements from capacitors of 30uF. This is in the 20 to 30uF bracket, not uncommon for the series cap in a low order filter, used for the midrange High Pass on a 3-Way. This is usually the biggest value on the crossover that is in the signal path.
The first thing I noticed, was contrary to what I have been reading on the forums, there is not a massive difference between the capacitor types. The Alcap Lytic, Mundorf Low Loss (LL) Lytic and Ansar Supersound PP caps all have remarkably similar ESR curves with only small differences. The second and most noticeable thing, was that the ESR values rise substantially below 500Hz. This is the area where the woofer/midrange crossover area lies on a 3-Way speaker, a 2-Way would cross at say 2kHz where the ESR levels are much lower. It might be a coincidence, but I wondered if this could in some way be linked to the resonance that hampers my listening experience on the NS-1000m and previously on the Celestion 66 Monitors.
I decided to take some measurements of lower value caps.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_38A.JPG
The 4uF Alcap Lytic and Sonicap PP capacitor, also show similar ESR curves, with the Lytic having only slightly higher values, 21.3ohm against 19.7ohm at 2kHz for instance. It would seem though, that the smaller the cap value, the higher its ESR. I measured a 0.2uF and it had a massive ESR, over 1kohm at 200Hz and going off the scale at lower frequencies.
To try and rule any of this out, in terms of having a detrimental effect on the sound, I decided to run an experiment, using a passive crossover that doesn't use a cap, running into a large ESR value, in the midrange signal path. I would create a line level active filter operating at 500Hz for the woofer/midrange handover and use the stock passive elements for just the mid/tweeter handover at 6kHz, where ESR values are much lower.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_38B.JPG
I had a spare pair of 3-Way active crossover boards from KMTech, I modified them to work as a 2-Way, crossing at 500Hz. Basic polyester caps, but good enough for a quick look-see. I borrowed the discrete op amps from another board.
This diagram shows how it would be set up as a system.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_38C.JPG
I cobbled together a set up, as per the diagram, by disconnecting a leg on the unused components in the stock passive crossover and using the modified active filter, just to see if there was any millage in the idea.
It works, and very well, with a much smoother hand over at woofer/midrange, without any noticeable resonance. My reasoning may have nothing to do with it, who knows, but the positive results from this little experiment, can't be denied. I bet your thinking, why not go fully active? The synergy between mid/tweeter in passive form is extremely good and it is not likely to be bettered by going active. Basically, if it ain't broke, don't fix it! The obvious reason though, is that this set up uses only four channels of amplification, instead of the six needed to go fully active. This arrangement has the signature sound from the midrange/tweeter that the passive filter delivers, with the benefits of a cleaner hand over at woofer/midrange and a separate Amp to drive the woofers, which has its own advantages.
While I had this lash up hooked up, I decided to put another issue to bed, digital or analogue active?
The Analogue filter above uses a LR 24dB/Octave slope at 500Hz. I set up a similar filter on my Hypex DLCP (DSP) and did a shoot out between them and the stock passive. My conclusions? The passive has the ability to get to the heart of the music and to express the finer detail in a natural way. Its down side is the edgy resonance around 400Hz on voices like Gregory Porters. The Semi-Digital Active set up is by far the smoothest, with very clean sounding crossover points, but somehow it doesn't involve me like the passive and feels less interesting to listen to. The Semi-Analogue Active is almost as clean as the Digital, but it grabs my attention and draws me in like the passive.
So Analogue Semi-Active it will be, this arrangement also works extremely well with my Turntable, where the digital filters do not.
Next, which Woofer, the Yamaha or the Skanspeak.
I set the two woofers up, one on top of the other and just swapped leads at the amp between the two, the passive x-over for the Mid/Tweeter and the analogue active for the woofers and of course, as a Pre-Filter for the passive. There was very little difference between the woofers, the Skanspeak seems to integrate just as well as the Yamaha and gives some extra depth when called for. As I already have the Skanspeak woofers, I may as well use them. They really are cracking drivers, as this near field response I measured shows.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_38E.JPG
Skanspeak 30W/4558T00 Bass driver.
Remarkably flat, +/- 1dB from 32 to 500Hz with an f3 of 29Hz in its 55L sealed cabinet, even better than predicted. Larger power handling and a massive xmax put it in another league to the venerable Yamaha Woofer I measured below.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_38D.JPG
I'm doing lots of listening to both bass drivers before making my final choice.
If I do choose the Skanspeak drivers, rather than bodge the Yamaha cabinets, a new pair will be made. Meanwhile, I'll work on the crossovers, both passive and active. I'll use Rod Elliotts active board, its the same basic filter circuit as the KMTech I've been using, but it has both Left/Right on the one PCB. It also has provision for balanced inputs and uses single channel attenuators on each output, which allows both amplifier and Left/Right channel matching. Also the board has the facility for output buffers, so all bases covered on these PCB's. The associated passive crossover, will be much simpler than the stock item, just two caps and two coils on each, I may as well make provision for a resistor network to replace the level controls. Again, I don't want to bodge the original boards, so a new x-over using good quality parts is in order.
I've summarized my findings and the work carried out, it actually took a couple of weeks to modify, try out and reach these conclusions.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_39.JPG
I selected Jantzen Superior Z-Caps, as they are supposed to be (like the basic Mundorf Mcap MKP I tried) very neutral, but also superb at handling high frequencies. As only the Tweeter cap is in the signal path I think it's a sensible choice.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_39A.JPG
This is my layout.
As previously stated, its the stock Yamaha circuit and values, as used for the Mid/Tweeter crossover at 6kHz.
By using the line-level Active Pre-Filter, I've taken the big bank of (21uF) caps out of the signal path of the midrange driver.
The board is point to point and uses a star ground, decent caps and air core coils. I've taken the longer wire runs under and over on the board to stop them flapping about, sticking them down with hot melt or using cable ties doesn't look very tidy. I've used spade terminals for the input/output connections, once the development is completed, the final build will have the wires soldered at these connections.
I need to order the parts and build these crossovers as a first step.
Audio Al
24-01-2018, 17:12
WOW , you are clever doing things like this :)
Respect ;)
Bksabath
24-01-2018, 18:23
What software are you using I see DATS ...
Can U please post same more details about it ?
Interesting stuff. Have to say I could not hear the midrange issue that you describe when listening to your modded Ditton 66 but then you hear a lot more listening over time and in your own listening room. I think I am also leaning towards the idea that passive crossovers, or at least fully passive, are the biggest bottleneck and the biggest cause of sound quality issues.
I’m afraid I don’t see the logic in having two crossovers in series with the mid and tweeter.
I think slight lower mid congestion can be cured by using a steeper crossover from the bass driver (3rd rather than 2nd order).
What software are you using I see DATS ...
Can U please post same more details about it ?
Just search on YouTube I think there are demos of DATS, I got mine from Parts Express from across the Pond, there is info on their site too.
I also have REW and a built in measuring facility within the Hypex HFD (Hypex Filter Designer) software, that came with their DLCP (DSP) unit.
Oh, and the demo version of ARTA.
I’m afraid I don’t see the logic in having two crossovers in series with the mid and tweeter.
I think slight lower mid congestion can be cured by using a steeper crossover from the bass driver (3rd rather than 2nd order).
The mid already has two crossovers in series on the passive as it is a band pass, I have simply replaced the passive High pass element with a line level one.
I take your point about doubling up on the tweeter, but in my opinion, it's still sounds better than the 30ohms or more ESR that the 21uF series caps add to the midrange at the cross over region.
I used my DSP and tried 2nd to 6th Order Butterworth/LR at frequencies from 300 to 600Hz and also different (unequal) slopes for the mid and woofer and what measured and sounded best (to me) was the 24dB/Octave LR at 500Hz which I am now using. This was best with both the Yamaha and the Scanspeak woofers in place, its the midrange driver that runs out of steam at the bottom end, if your not careful you end up with a valley in the response at the crossover region.
What I have written in this post is about a tenth of what I have actually tried, it would take too long to write up and be boring, so I just give the major events.
Interesting stuff. Have to say I could not hear the midrange issue that you describe when listening to your modded Ditton 66 but then you hear a lot more listening over time and in your own listening room. I think I am also leaning towards the idea that passive crossovers, or at least fully passive, are the biggest bottleneck and the biggest cause of sound quality issues.
I don't think your wrong Martin.
Trouble is the full DSP route, while having noticeably clean filters, just lacks something and I loose interest in whats playing. I have yet to hear one that does justice to vinyl. The ADC's they use just aren't good enough so digital sources always sound better than analogue. The Hypex DSP sounds slightly better than the miniDSP with an analogue source. But the analogue Active just sounds right, which is why I've partly strayed back to it, the digital is more of a development tool for me now.
Hi Ken. How easy is it to swap between the original speakers crossover and the modified version in order to hear the changes you are making?
Well, it's an interesting approach and not one I've seen done before. However, the whole signal is still going through the digital crossover. It may be passing on frequencies above a certain point but the signal is still being converted to digital and then back to analogue so it can pass through a further analogue filter. Are you sure you aren't in danger of reinventing the wheel as something that is very slightly oval?
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. :)
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. :D
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?
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.
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 :)
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.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_39B.JPG
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.
.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_40.JPG
This build is taking time, things keep getting in the way. :rolleyes:
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)
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.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_40A.JPG
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.......
Firebottle
21-03-2018, 16:35
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 :thumbsup:
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.
I purchased a case and got stuck in.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_40B.JPG
I've used a case from HiFi2000 in Italy.
I made holes for the connector sockets, then got a local engraver to do the lettering, some of which I then paint filled, to colour match the cable plugs I will be using. This makes it less confusing when plugging things in and I'm definitely in favour of that.
I'm ready to start populating the boards now.
I purchased a case and got stuck in.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_40B.JPG
I've used a case from HiFi2000 in Italy.
I made holes for the connector sockets, then got a local engraver to do the lettering, some of which I then paint filled, to colour match the cable plugs I will be using. This makes it less confusing when plugging things in and I'm definitely in favour of that.
I'm ready to start populating the boards now.
Very nice job Ken.:thumbsup:
Thanks James,
I'm taking my time with this build, especially the little details.
With the very encouraging results from the lash ups, this should be my end game speaker solution.
It's certainly better than anything I've owned previously and hasn't any of the traits that interfered with my listening before. ;)
Just a question of building everything, so finding the time/cash to do it.
It doesn't help that I just bought a new DAC half way through this build (NAD master Series M51).
I needed to improve this link in the chain to hear what the speakers can really do.
.
Most of the parts arrived, so I populated the main crossover board.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_41.JPG
One criticism I have of Rod Elliotts boards (Also KMTech for that matter) is he packs the components in tight.
This leaves little room to use more exotic parts, which are usually bigger.
Still, I persevered and used Polyprop output caps, instead of the Polyester listed on the BOM. I've omitted the output buffer stages and will be taking the filter outputs straight into balanced transmitter boards, this freed up sufficient space to keep the much larger output caps on board the PCB.
For the filter elements, I replaced the x20 Polyester crossover caps with 1% LCR Polystyrene caps and used x20 1% Takman metal film resistors. I cherry picked both of these from larger batches, to have less than 0.5% total spread in value.
I matched the resistors on the balanced inputs to be better than 0.1% to give good CMMR.
The main bypass caps on the power rails were basic electrolytics, these were replaced with Elna Cerafines.
The monolithic op-amp chips are replaced with discrete ones. The Sparkos Labs discrete device is in place as the input buffer and the Dip8 sockets for the others will allow some op-amp rolling.
I was going to use sockets for the input/output connections, but when I took one apart and saw how small the contact area was, I decided against it. The leads will now be soldered direct to the boards.
The trim pots on the HF outputs, will eventually be replaced with fixed value resistors, I may remove the Dip8 sockets and solder the x4 remaining discrete op-amps to the board while doing this. Until the fine tuning is done, I will leave these areas as adjustable.
Great quality and a great build; I feel confident you will love the results :).
Great quality and a great build; I feel confident you will love the results :).
Thanks, I'm really just pulling together all the bits that I'm listening to at the moment.
But doing it neatly in a presentable fashion, rather than the snake pit of cobbled together bits, with jumper leads, patched/repaired boards etc.
I'm using better quality parts, that are closely matched, but I'm not expecting that to make a big difference, it's basically the right set up for what I've been trying to achieve.
It wont be to everyone's taste, it still has a bit of the monitor accuracy over musicality, but I'm loving it.
By the time its finished, this version of the active crossover will have cost more than I paid for the NS1000m's in the first place.
I wouldn't be spending that amount on them unless I already new, from the prototype lash up, that the results would justify it, this is my end game.
When I finally get them finished, posh new cabinets to make yet, I will do some bake offs and maybe the WAM show at Harrogate and people can make up their own minds. The folks that have heard my latest lash up have been impressed, time to give it all a new set of clothes ;)
Looking forward to hearing these at some point, Ken.
Macca - Still a lot of work to do, but getting there slowly.
By the time they are ready I'm hoping to have 4 channels of class D to power them, 700w for each bass driver and 400w for each mid/twt pair. I wont be using anywhere near that, but it will be on tap.
I have a kind of long term plan that includes the power amplification set up, if it all comes together, some of my current choices will make sense. :)
.
Wires
I have been using Klotz MC5000 for my balanced interconnects for some time and I have no issue with the sound quality.
There are however a few drawbacks to using it.
1. The jacket is one of the largest and too big for the stock Nuetrik XLR plugs, without a slight mod to the chuck that clamps it.
2. The primary insulation on the conductors, shrinks back far too easily when you solder the wires.
3. The conductors (0.5mm sq) are too thick to go through the holes in most of the PCB's I've come across.
4. It's chunky jacket is quite flexible but still not the easiest to manage for short internal wiring runs.
I made a decision early on, to use the same type of wire along the whole of the line-level signal path, this ruled out the Klotz.
Instead I turned to the Van-damme cable range, their Microphone cable for balanced Interconnects, Pro-Patch for internal balanced runs and I will strip the conductors out of the Pro-Patch for any hook up or very short internal connections.
The Classic XKE Microphone and Classic XKE Pro-Patch use exactly the same conductors, the only difference in their make up being the type of Copper shielding and jacket thickness. The 28 strands of conductor are 75% OFC and 25% Silver Plated OFC. The idea being this blend gives you the warmth and richness of copper for mids and a strong bass, with the detailed high frequency that Silver brings. I don't know how much of that is just marketing Hype, but the VD cables have a loyal professional following, so I'm guessing they must be pretty neutral. On the occasions where I've heard VD cable used as Interconnects, it didn't draw attention and just got on with the job, which is what I want. At less than £2/m this is about as exotic as I will be getting. The more experimenting I did on this project, the simpler my taste in cables became and the money saved has been used to better effect elsewhere.
http://www.jkwynn.co.uk/Project_Images/Yam/Yam_41A.JPG
The Mic cable is a perfect fit for the Nuetrik XLR's, the conductors fit through the PCB holes and the insulation doesn't shrink back, unless you are really heavy handed with the soldering Iron. The Pro-Patch version is thin and flexible, ideal for inside an enclosure, so my choices are made and from a purely practical point of view, will be easier to work with than the Klotz.
Some time ago, I made the choice of using the Scanspeak bass driver, due to its superior performance.
However it doesn't sit well with the Yamaha mid or tweeter styling, so I needed to try and address this.
http://www.jkwynn.co.uk/Project_Images/Yam/Yam_41B.JPG
As the before and after pictures show, the bass now looks as though it was meant to be mated with the other drivers. But this was not easy to achieve.
I used paint stripper and carefully removed the paint from the driver frame, not the whole frame, just the top flange. But this revealed a textured finish to the alloy, almost like a fine sand casting. The frame is a high pressure die casting, in effect an injection molding. So the texture is most likely on the mold tool or bead blasting of the post molded part, to help with paint adhesion. Either way I needed the texture removing, so a bit of elbow grease with a sanding block and various grades of abrasive paper did the job. I normally would give a part like this a simulated brushed finish using wire wool, but you don't want that stuff anywhere near a magnet, so I resorted to using a plastic abrasive. I stripped the green plastic scourer off the back of a washing up sponge and that worked a treat.
The Black screws were replaced with flange head stainless fasteners, I think the end result actually looks better than the featureless all Black original.
Firebottle
06-05-2018, 16:12
That looks fantastic Ken, you're certainly putting the work in :respect:
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. :(
.
http://www.jkwynn.co.uk/Project_Images/Yam/Yam_41C.JPG
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. :)
.
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.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_42.JPG
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.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_42A.JPG
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.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_42B.JPG
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.
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.
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. :)
I didn't realise how top spec you were going but it makes sense. Do it once, do it right.
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.
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.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_43.JPG
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.
http://www.jkwynn.co.uk/Project_Images/Yam/yam_43A.JPG
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.
Beautiful and professional-looking workmanship there! well done, :)
id have to agree,very tidy work,i wish i understood more about what you doing and how it affects the speakers for the better.
Beautiful and professional-looking workmanship there! well done, :)
Thanks Barry, its taken time to get here but worth the effort, even with 20hrs on the set up its sounding very good, not sure I believe in the 500 to 1000 hrs required to run in a class D I've seen quoted, I find that discrete op-amps take about 100hrs and no audible improvement from there, so I will give everything 100 hrs before reviewing the sound.
Jamie - It's basically an NS1000m on steroids.
I have the speakers bi-amplified, one stereo amp drives the two Woofers and one drives the Mid/Tweeters with the benefits that brings in control.
By using the active crossover I have removed the bank of 6 capacitors from the passive x-over, which were in series with the mid range driver, this improved the mid range detail and clarity.
The passive filter for the mid to twtr hand over has better quality components, which are closely matched, this and my discrete op-amp choice in the active filter, before the passive element, gives a much smoother less forward and less sibilant treble, which also has the benefit of making the speakers less Amp fussy. Replacing the Yamaha Woofer with the Scanspeak has taken the F3 from 52Hz to 29Hz, both measured in my room, which does give some bass lift. This extra depth is very noticeable on tracks that go there and there is no loss of quality, I would go as far as to say the quality in the upper bass has improved. The response of the Scanspeak is much flatter.
It is just all round better in every way you could wish for and somewhat more musical.
I always liked the basic sound of the Yammies, the forward treble and lack of deep bass niggled me. It has taken 3 years, but I've finally managed to eradicate the things I wasn't content with and without loosing the character that drew me to them in the first place. All this is just hot air without other opinions though, people will have to judge for themselves, if and when they get to hear them. I can't see me ever changing from this set up, it gives me what I want, but may not suite everyone. :)
Like I said earlier, the mains hum has been eliminated.
Now that has gone I can hear a much lower level hiss, minor, only audible a couple of meters from the drivers between tracks, but I was expecting a VERY quite background.
I did some box swapping and eliminated the new class D amps, also my active crossover.
The only common factor left was my Pre Amp.
I bi-passed this with my NAD Master series DAC, which can also acts as a digital Pre Amp, that's the culprit, quite as the grave through the NAD.
My Project RS Pre Amp has a valve output stage, maybe some slight valve rush present?
Whatever the cause, I have eliminated it, I can hardly tell the system is switched on now, even with my ear up to the drivers at Idle, or when playing with the volume down. :)
Edit: It's funny, but with the new, for the first time fully balanced set up, my fridge starting and stopping no longer makes clicks and pops through the speakers.
Really lovely Ken. Good to hear you rid yourself of hum and your fridge is no longer intrusive.
Your thread is very educational and has given me some thoughts on my project (still vaporware :)) for which thanks for your help.
It will be fascinating to see/read about your cabinet build when you get to it.
I see you get various stuff from ESP. You probably have now got everything you need but in case not my daughters are flying back from Oz in August. So if you want more stuff from ESP drop me a PM.
Thanks Edward, and thanks for the offer, all the serious electrical is done though. I used ESP power supply board, crossover board and a pair of balanced transmitter boards. Rod also gave me good advice. He knows what he is talking about, his site is a wealth of information and tempting projects.
FrostEOne
01-07-2018, 10:52
Here's some capacitor comparisons I came across. http://www.humblehomemadehifi.com/Cap.html
You've inspired me to recap my oldest set of NS1000M serial 15,xxx as they no longer have the sound of my slightly newer set Serial 33,xxx
I've decided to use all Mundorf:
4 - 47uF 70VDC 50VAC Mundorf E-Cap Plain
2 - 2.7uf 600v Mundorf MCap Supreme Capacitor
2- 1.5uF 600V Mundorf MCap Supreme Capacitor & 4 - 1uF 600V Mundorf MCap Supreme Capacitor to replace 3.5uf
8 - 3.3uF 600V Mundorf MCap Supreme Capacitor & 4 - 3.9uF 600V Mundorf MCap Supreme Capacitor to replace the 6 - 3.5uf
Keeps all values correct, haven't decided whether to use any bypass caps or not, will experiment there.
Thanks for enhancing my desire to recap!
Here's some capacitor comparisons I came across. http://www.humblehomemadehifi.com/Cap.html
You've inspired me to recap my oldest set of NS1000M serial 15,xxx as they no longer have the sound of my slightly newer set Serial 33,xxx
I've decided to use all Mundorf:
4 - 47uF 70VDC 50VAC Mundorf E-Cap Plain
2 - 2.7uf 600v Mundorf MCap Supreme Capacitor
2- 1.5uF 600V Mundorf MCap Supreme Capacitor & 4 - 1uF 600V Mundorf MCap Supreme Capacitor to replace 3.5uf
8 - 3.3uF 600V Mundorf MCap Supreme Capacitor & 4 - 3.9uF 600V Mundorf MCap Supreme Capacitor to replace the 6 - 3.5uf
Keeps all values correct, haven't decided whether to use any bypass caps or not, will experiment there.
Thanks for enhancing my desire to recap!
Your welcome :)
I've been using the humble cap comparison for several years and for the caps I have experience with, ClarityCap ESA, Ansar Supersound, Jantzen Superior Z, Mundorf Superior, Sonicap Gen1, to name a few, I find the description on the site to be very accurate as far as their use in crossovers goes. I personally have never had any luck with bypassing, whenever I have done it I ended up reversing it, as ultimately the sound was somehow not right. There was a difference in sound and some things improved, but at the expense of others, came to the conclusion each time, it sounded more natural without, YMMV.
I've found the Jantzen Superior Z to have a slightly cleaner top end to the Mundorf Superior, and the Mundorf to have slightly fuller bass, but not much in it, they are both good caps for crossovers. I used the Mundorfs myself in my NS1000M recap. For this final build using new boards and air cored coils, I used the Jantzen, as the passive crossover is only operating in the 6KHz region, so the top end properties were more important. The active crossover handles the 500Hz hand over.
Using one manufacturer can work, but I have mixed things up in the past. One cap that does not like being mixed with others is the Sonicap Gen1, if you ever use these, use them throughout.
FrostEOne
02-07-2018, 09:06
Ken,
I've read your NS1000M recap thread also.
I have the Ansar Supersound caps you used first and the Mundorf MCap MKP caps you used next.
Also 2 - Mundorf Supreme 22uf (within 5% of 21uf) and 2 - Sonicap Gen1 3.5uf (doesn't sound like I should use them with others)
I was told the Mundorf MKP in the midrange would be too bright/forward. Any thoughts would be appreciated.
Thanks in advance
Mark
Ken,
I've read your NS1000M recap thread also.
I have the Ansar Supersound caps you used first and the Mundorf MCap MKP caps you used next.
Also 2 - Mundorf Supreme 22uf (within 5% of 21uf) and 2 - Sonicap Gen1 3.5uf (doesn't sound like I should use them with others)
I was told the Mundorf MKP in the midrange would be too bright/forward. Any thoughts would be appreciated.
Thanks in advance
Mark
Hi Mark - There is not that much difference between the Ansar and Mundorf MKP, they are both mid price/performance PP caps.
I find the Ansar to have a slight focus on the top end the Mundorf a bit more balanced over the whole spectrum and maybe sounding a bit smoother at the top due to it not highlighting it as much. We are talking small differences.
To achieve much improvement, you would have to spend more on the mid range and the large value does not help in that regard. Mundorf Supreme or Jantzen Superior Z Cap etc and gains are subtle for the considerable outlay. My semi active set up does away with this 21uF bundle of caps for the 500hz high pass filter. This improves things a lot so it highlights the contribution these caps make to the overall sound.
You should match the caps as close as possible to the value required as it defines the crossover point, the bundle of Mundorf MKP I used were measured and matched to be within 0.1% of 21uf. Maybe overkill, but 1% would be good. I have found Jantzen Superior Z Caps to be very close to the stated value, they are rated +/- 2% but I measured 8 of these and the worst one was within 1% the rest were within 0.5%.
Remember your equipment is going to effect the overall results and only you can decide what type of sound you prefer anyway.
ClarityCap ESA have a warm mid range, but lack definition IMO, bit woolly. Humble cap tests say adding a percentage of Mundorf Supreme sorts this, maybe this is a way of keeping the cost down? I have not tried this, so can not comment, much of this is trial and error with no black or white solutions as equipment/taste is a variable.
I wouldn't get too hung up on capacitors, the circuit and drivers characteristics are what they are, different makes of cap will make small changes, cables could have as much impact. As long as you have caps within spec, either the Ansar or Mundorf, they will work well.
The NS1000M is all about the midrange driver, it is the dominating factor in the presentation, the tweeter contributes little and the woofers performance is average. With crossover points of 500Hz/6KHz it has a wide frequency band and is the main thing you hear, try disconnecting the drivers one at a time and you will see what I mean.
I have had to go to considerable lengths in cost and complication to change things by any significant amount, which should also be borne in mind.
FrostEOne
03-07-2018, 03:30
Ken, thanks for the info, agree the 22uf isn't close enough, that's why I went to 4 - 3.3uf and 2 - 3.9 uf to make the 21uf. I considered an active crossover before purchasing caps, I admire what your doing, a bit beyond my capacity though. -Mark
It's not as complicated as it looks Mark!
All the elements, PSU/crossover/balanced transmitters are individual projects on Rod Elliotts web site, I just put them together in one box and upgraded all the parts.
If using single ended (RCA) connections, the balanced transmitters are not needed and the fully documented instructions use ordinary chip op-amps for the build.
You can construct a complete 3 way crossover with attenuation on each channel from the instructions, many scenarios are covered.
I started with KMTech boards (ebay UK) which use a similar circuit, you can even buy these ready built and just specify your required crossover points. The down side is the ready made use Polyester caps and not the best op-amps. Its how I first got my feet wet on the subject.
FrostEOne
03-07-2018, 08:58
wow, Rod Elliotts web site is going to take some reading, thanks
which project are you using for guidelines?
here is what I was looking at a while back http://www.marchandelec.com/index.html
wow, Rod Elliotts web site is going to take some reading, thanks
which project are you using for guidelines?
here is what I was looking at a while back http://www.marchandelec.com/index.html
The PSU - Project 05 Pre Amp Power Supply. - I have this set for +/- 12vdc and is as quite as the grave powering the x-over/balanced transmitters.
The X-over - Project 09 24dB/Octave 2/3 way Xover. - I am using a 2way.
The Balanced Transmitter - Project 87 Balanced Line Drivers II.
When you buy the boards you get a password that allows you access to a secure part of the site, that gives all the component values and build tips. Rod uses the money from the PCB sales to fund the site and develop more projects. There is a x-over calculator on the open access part of the site that will give you the resistor and capacitor values required in project 09 for any x-over frequency required.
His guides and basic theory pages are a must read, well written and easy to follow tutorials, I learnt a lot from these. Five years ago I could hardly put a passive cross over together from instructions, I have worked on projects (his and others) of ever increasing complexity from there and improved my soldering skills etc along the way. It's a very rewarding pastime. :)
I had seen those ready made x-overs and some others using valves, all a bit expensive though.
I could have gone the whole way and had a completely active 3way crossover.
This would be more expensive, needing more channels of amplification, but I didn't think this was necessary anyway. The Passive element I used is the standard NS1000m circuit and is so simple/effective. The tweeter has one capacitor in series and a coil in parallel. The midrange (normally bandpass) only needs a 6kHz low pass filter, consisting of a coil in series and a cap in parallel as the passive crossover is only fed 500Hz + from the active crossover. You need a cap in series with the tweeter anyway to protect it. These second order filters are about as simple as you can get, so not expensive when using good quality parts, due to their low number and values. It seemed a perfectly logical solution for my needs. The midrange no longer has the big bank of (21uF) capacitors in series with it and opens up nicely.
FrostEOne
03-07-2018, 20:29
Ken, you have definitely stirred the pot here, I'm intrigued. Have a lot of reading to absorb now!
I'm just easing my way in, built Transcendent Sound's Son-of-Beast OTL and their Grounded Grid preamplifier so far, Yamaha crossovers will be 3rd project.
Take your time and read everything Rod has to say about active crossovers and the #09 project.
Are you single ended or balanced in the rest of your set up?
The 09 x-over board can be wired for either input method, it is however a single ended circuit, the input buffer op-amp is used to combine the two halves of a balanced input. You can add the balanced output transmitter boards, as I did, if you want to keep a balanced set up. These use a pair of op-amps which act as line drivers to send the signal over longer distances. The first op-amp is the non inverted signal and the second inverts this for the other half of the balanced output.
FrostEOne
04-07-2018, 19:26
Ken, single ended RCA here. Still reading, lot to absorb.
-Mark
Ken, single ended RCA here. Still reading, lot to absorb.
-Mark
Yes, he has built up quite a library of articles and a huge number of projects.
Check out things like his views on op-amp and power rail by-pass caps etc.
The 09 x-over boards, have all the options on a single board, so you would just wire and fit parts for the single ended input method.
You don't need the Balanced transmitter boards I used.
There is an output buffer option on each output channel, I spoke to Rod and he said it was debatable if this section was needed, if your power amps were close, say a meter or two, it was for longer distances to avoid HF loss. You could leave the buffers out and just use the multi turn pots (catered for on the PCB) to control the output to match your drivers/Amps sensitivity.
You will need two boards for a 3way set up.
If your not used to op-amp circuits, the schematic can look daunting, but its just the same basic circuit cascaded several times.
Having built quite a few variants of this type of circuit now, I can probably talk you through any areas your not sure about, so feel free to ask away. :)
Well I have 150 hrs on the Amps and Crossover and things have settled nicely.
The things which niggled me about the NS1000m, the forward and in my opinion somewhat sibilant treble has gone and the already punchy bass now has depth to match. The semi active x-over combination coupled with the Nord amps has power and control, they have a damping factor of something like 2000! Timber and detail, texture on strings etc has improved. Voices are virtually sibilance free, if there's any evident on a track its probably in the recording.
The background is totally silent, even when you go right up to the speakers, the Nord (Hypex) amps have this reputation, but the rest of your system has to be able to match this level of Blackness.
I have finally got to a place were I can listen to the music and forget about the gear, as it doesn't draw attention to itself. I'm sure this current set up is more musical than the stock NS1000M, it still has that monitor accuracy going on, but not quite as much in your face, just a little more subtle for home listening. I will have to try and do a direct comparison with the stock speakers at some point. I've been through some classic designs, Tannoy Cheviot, Celestion 66 Monitors and finally the modified Yamaha's. The more I hear this latest combination, the more convinced I am that these are my final Speakers.
The NAD master series DAC works great as a digital Pre Amp, but it has to go, as there is no way of accommodating my vinyl set up. So my next steps are to build the final cabinets for the speakers and arrange a demo of the PS Audio Stellar Dac/Pre, which has both digital and analogue inputs.
Got any links? It's a huge site to trawl through and I'd be quite interested to read his thoughts on op-amps and power rail bypass caps.
I haven't unfortunately, it influenced me when specifying caps, and gave some substance as to why Rod had specified what he had, I just can't remember where it is on the site, so would have to trawl through it myself.
I seem to remember I did a google search on the subject and Rods site came up as a hit, the link took you straight to the page, you might try that.
I suggest reading through what ESP Rod says about damping factor.
Is it this page?
http://sound.whsites.net/articles/coupling-caps.htm
He says bypass capacitors should go between the +ve and -ve supply rails, not from each rail to earth. This is correct, though often not applied.
A plus for Rod :)
Yes that's one of the references, I think there are other mentions and as part of other subjects as well.
I had seen it suggested in several places, including op-amp spec sheets, to put a cap from each power rail (+/-) to ground but Rod, as you point out, puts a single cap across the rails as do many others. I followed Rods build instructions to the letter and it works great.
Having changed my PC recently I have lost all my addresses, and don't even have the one to Rod's site.
He is rather opinionated and comes across as maybe arrogant, but I have experienced that in my career numerously with graduate engineers, there is a snobbishness by many because it is a hard discipline especially compared with liberal arts for eg.
He may well have validated much of his beliefs and statements by measurement, and my opinion is that he is a good engineer despite the above.
There are loads of articles on damping factors showing that the number is a complete artefact bearing little relation to the actual damping achieved. The number looks great when it is high, but the reality of an amplifier and speaker cct limits the reality of damping factor to far less.
My experimentation with the NS-1000M has concluded.
My final and best results were with a semi active set up, which can be seen here:
https://theartofsound.net/forum/showthread.php?66160-NS-1000M-Upgraded
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