.....I ended up excluding 500Hz down and manually tweaking the lower frequencies manually to what suited me/the room at the time.
Over a wide range of music/genres/recordings you can progressively home in on what is 'right'.
In the photo you posted of your lounge room, it appeared that the back of the cabinets are facing into a hard surfaced hallway/void ?.
I have lived with a situation such as this, and my solution was to attach a heavy carpet to a timber frame and stand it up against the back side of the wall cutout.
This killed delays/reflections from the void/hallway, and markedly/nicely improved bass and mids and highs and imaging....etc etc, you get the picture.
I forget the company name, but I read a magazine article a while back where for studio mastering environment they advocated/insisted live zone/dead zone environment.
Dead (heavily damped) zone behind the speakers and along the walls up to where the speakers are, and live zone for the rest of the room with strategically mounted absorber panels on the side walls and ceiling.
Dan.
Over a wide range of music/genres/recordings you can progressively home in on what is 'right'.
In the photo you posted of your lounge room, it appeared that the back of the cabinets are facing into a hard surfaced hallway/void ?.
I have lived with a situation such as this, and my solution was to attach a heavy carpet to a timber frame and stand it up against the back side of the wall cutout.
This killed delays/reflections from the void/hallway, and markedly/nicely improved bass and mids and highs and imaging....etc etc, you get the picture.
I forget the company name, but I read a magazine article a while back where for studio mastering environment they advocated/insisted live zone/dead zone environment.
Dead (heavily damped) zone behind the speakers and along the walls up to where the speakers are, and live zone for the rest of the room with strategically mounted absorber panels on the side walls and ceiling.
Dan.
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Yes, it is sound coming from the ferrites. They are clamped pretty secure by the plastic clamp. I think the plastic is transmitting the vibration. There is a quiet buzz coming from them if I am right next to them in a quiet room, which doesn't change if I shift the wires or the clamps. Squeezing the ferrites together doesn't change the sound but touching certain parts of the plastic sometimes works.
Do you have a current clamp meter ?.
It sounds like you have high leakage current across the Dac power transformer, and consequently in the shields of the interconnect ?.
Measurements would be interesting.
Dan.
It sounds like you have high leakage current across the Dac power transformer, and consequently in the shields of the interconnect ?.
Measurements would be interesting.
Dan.
A significant amount of energy there. I would love to know the common-mode and differential mode currents
.
The exact setup is 3 of those clamps on a 3 turn coil of 12ga joining chassis from DAC to amp in another room. The interconnects have an isolator on them, so the wire bypasses it. If it doesn't make sense, it is because the system is in stages of development and troubleshooting.
I measured 5.4mA through the clamps with a Fluke 79 II DMM (which is not very useful since it has 11R resistance in the mA range and the 10A fuse is blown - so the real value is probably much higher). Voltage across the clamps was 43mV. Voltage between chassis with the wire disconnected was 640mVAC.
Based on the datasheet, the set of clamps has a total inductance of 172uH.
I measured 5.4mA through the clamps with a Fluke 79 II DMM (which is not very useful since it has 11R resistance in the mA range and the 10A fuse is blown - so the real value is probably much higher). Voltage across the clamps was 43mV. Voltage between chassis with the wire disconnected was 640mVAC.
Based on the datasheet, the set of clamps has a total inductance of 172uH.
Are you on the same AC phase for both systems ?.
What do you mean by 'The interconnects have an isolator on them' ?.
Dan.
What do you mean by 'The interconnects have an isolator on them' ?.
Dan.
The signal is isolated not unlike a Jensen trafo. Otherwise the interconnects would be shunting the ferrites.
With the wire passing through a 90mH CMC with both windings in series for a total of 98 turns, shunted by a 93 ohm resistor, I read 6.4mV on the meter. This means at least 210mA AC is flowing. But if the CMC were saturating I wouldn't know, and it has highpass point at 46Hz.
Assuming that's correct, 44mV/210mA=0.209 ohms impedance. The 12ga contribution would be really tiny.
172uH has 0.209 ohms at 193Hz. So a lot of the energy must be harmonics, to produce that much voltage with relatively low current through a 172uH inductance.
With the wire passing through a 90mH CMC with both windings in series for a total of 98 turns, shunted by a 93 ohm resistor, I read 6.4mV on the meter. This means at least 210mA AC is flowing. But if the CMC were saturating I wouldn't know, and it has highpass point at 46Hz.
Assuming that's correct, 44mV/210mA=0.209 ohms impedance. The 12ga contribution would be really tiny.
172uH has 0.209 ohms at 193Hz. So a lot of the energy must be harmonics, to produce that much voltage with relatively low current through a 172uH inductance.
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My experience with skin effect is high speed digital and mainly high power high voltage SMPS, where we quite often use transformers litzs wound or copper foil wound, stranded or solid copper are no different, in stranded it is a bit worse because the outer layer in misshapen due to the strands. I was reading a paper on this recently that detailed this, I cant remember whether it was put up on this thread or from my own collection. I will try an dig it out.
Edit.
Reading Jneutrons response it seems I am misinformed, though I believe the difference is small, I will double my efforts to find the paper now.
Edit Edit
I also don't get to play with super conductors. But I would be interested in how big a difference there is between stranded and solid and whether it is of concern to us mere non-superconducting mortals...😀
This has some nice pictures of proximity effect, in my case its usually traces on a PCB where the current density is greatest at the edge of the trace that faces the signal return path.
http://www.generalcable.co.nz/getat...d3/AC-Resistance,-Skin-Proximity-Effects.aspx
Edit Edit Edit
Bit of searching regarding stranded vs solid, my initial view was rather simplistic, but we don't often go to the lengths that JN does, but this link explains the difference... I am now curious how JN alters the interstrand conductivity, larger strands with more air gap?
https://www.st-andrews.ac.uk/~www_pa/Scots_Guide/audio/skineffect/page1.html
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For the ferrites to be physically vibrating there must be magnetizing current, which suggests they are saturating which means they may not be dropping as much voltage as a perfect inductor would. So maybe if they are buzzing it's time to reduce the turns?
I would have thought the HF would concentrate on the bottom edge next to the return...
My thought would be a series of signal and return plates so you have numerous thin signal paths interleaved with numerous return path plates. Or Two return plates top and bottom would give to edges of high current density rather than one.
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Sound of the Sequerra tuner was very good, appearance within the scope to, but it was the only one high-end tuner for 15'000.- Swiss Franks which had thermal drift , apx. 200 Khz within 2-3 hours, somehow he forgot to design a thermal stabilisation of the power supply. Same with the Day Sequerra version. But as far as i could see, the ps was made by someone else...
The MET7 speakers are 'kiddie' speakers like I previously said, BUT they sound better than one would think that they should for the price and size. Scott is right about this, but they are too forgiving to be reference speakers for electronics. I use the cheapest amp that I have ever designed for Parasound, the HCA1000 (stock) to drive them, and it does it well. However, I would not even use an A-25, a larger and more modern amp, to to drive the Wilson Sasha speakers. It is too hard a load, and has too much high frequency extension. This was also true when I used the Wilson WATT 1's for a number of years. In many ways I think that the WATT1's were closer to the MET7's in overall character, and I think this is because of simpler xovers and driver polarization, compared to the Sashas. The Sashas sometimes leave me with the feeling that there is something wrong with them and I think it is over-design of the xovers, as well as the tweeter (that has been replaced in the MK2 version). I suspect that the primary secret of the MET7's and probably the WATT1's is the time integrity of the step or pulse waveform.
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JN
I thought RNM was too clear about his current distribution question!
But that gets way off topic.
More interesting was his mention of critical distance. Not sure there would be a classically defined one in his listening space.
Keany, Fluke fuses are much cheaper from a Fluke repair source rather than a parts distributor. (You don't want to know how many I have gone through to learn that!)
A buzz is often the sign of saturation or loose bits. I would try loosing the ferrite plastic cover and super gluing the core halves or just using a rubber band to hold the bits tight and close.
I thought RNM was too clear about his current distribution question!
But that gets way off topic.
More interesting was his mention of critical distance. Not sure there would be a classically defined one in his listening space.
Keany, Fluke fuses are much cheaper from a Fluke repair source rather than a parts distributor. (You don't want to know how many I have gone through to learn that!)
A buzz is often the sign of saturation or loose bits. I would try loosing the ferrite plastic cover and super gluing the core halves or just using a rubber band to hold the bits tight and close.
Yes, I know not to get the fuse from Fluke, just haven't gotten to it yet.
The buzz is not from being loose, but saturation is a strong possibility. 200mA should not be passing through ground at all in any situation, so gluing the ferrites together would be rather missing the point. I will be fixing that, although in a way it was a useful test of my signal isolator.
The buzz is not from being loose, but saturation is a strong possibility. 200mA should not be passing through ground at all in any situation, so gluing the ferrites together would be rather missing the point. I will be fixing that, although in a way it was a useful test of my signal isolator.
Agreed, heavy cabinet, one tweeter series cap and suitable drivers can work quite well.....Bose made a fortune out of it.
Yeah, we have all heard complex crossover loudspeakers that sound 'loaded down' for want of another term....and funny little transient quirks that don't belong.
Agreed, and that's one area where my little Behringers excel......image height position and depth position stays nicely fixed wrt to frequency.
Dunlavy went to trouble to get the impulse response right with the Sovereigns, and the proof is in the listening....magical speakers.
Dan.
I used to just solder a strand of fine bare wire across the fuseholder....worked for me.
So where/why is such ground current coming from ? 😱 .
If you disconnect the long ground wire at the DAC, what voltage are you measuring between DAC and the ground wire ?.
So what is the signal isolator....line level transformers ?
Dan.
You are right - there's quite a lot of energy around if they are making a noise like that.
Probably a good idea to reduce the turns - but I think you will need to know the current draw. I would have surmised that the chirping and clicking would only take place at switch on and off but not during normal operation since the current draw on a DAC and pre should be pretty constant.
At least you know one thing: if it's chirping and clicking, you are dissipating electrical energy - lets hope its mostly noise - into mechanical energy and ultimately heat. Exactly what ferrites are supposed to do.
🙂
(A colleague of mine put a ferrite bead on the lead of an axial cap in an SMPSU output filter many years ago. The ferrite got so hot you could not touch it - great demonstration of the usefulness of ferrites IMV)
Many thanks for the detailed reply! I fully follow what you mean now... Settling time vs stereo placement isn't something I'd thought about so the next job will be to make some measurements on my system I think...
Interesting!
Also another reason to accelerate the bi-amped speakers project - tidier short load connections and digital input to speaker...
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