Edgaronline

I downloaded the book. Its a rather fast read, I'll post what I think...

Since you also asked general experiences on the effects of taking care of your mains supply, just last two weeks I did a complete overhaul of my mains cabling. For the last decade I used proper power cables and had a dedicated group for my audio in the fusebox. But the wiring from fusebox to audio was normal unscreend installation wire. I decided to change to double EMI/RFI screened power cable normally used for powering electromechanical drives in industrial environments. I also changed my outlets to copper types with proper screw-on connections in stead of the normal plug in types which have been the norm in Europe since the 70's. Since my power amps are located away from the rest of my system, I had to include a power distribution box, which, to maintain screening I wrapped in aluminium tape connected to ground. So no "audiograde" cable or outlets, just some common sense and careful maintaining of screening as I believe the wiring in domestic areas picks up a lot of noise. After connecting and measuring to make sure all connections are correct AND of proper quality it was time for a listen. Now, I have absolutely nothing to prove to anyone but myself when it comes to sound quality, and I have done plenty of experiments and cable designs that did not improve my sound, and in this case I anticipated no audible change whatsoever. I was wrong. First thought was that I broke my power amps, as normally I hear slight noise coming from my speakers when I listen really close without any music playing. Now: nothing. No hum. No soft hiss emitting from the tweeters, drop dead silent. Okay, music. Does my music sound better? No. But al other improvements people tend to report when they improve their audio systems apply. You know; higher resolution, dynamics, transparency and so on. Most noticeable is the increase in dynamics, which I think is the result of increased system S/N ratio. Next project: a filtered mains distribution box, also properly screened and with a choise of filtered, protected (so, protecting the rest of the system from noise coming from audio equipment) and unfiltered outlets, together with rhodium plated shuko's which are under way from Hong Kong, should nicely complete a so far succesful mains overhaul project. Edgar

I have not crunched the numbers but, it may even be that this thread has more Dutch contributors than Americans :-) I also think that the native language is not really an issue. Most non-native english writers here seem to be able to get a message in proper writing. Yet, the way of basic communication for some -typically for Dutch- is a kind of direct "in your face" "straight foreward" "tell it like it is style". I know since professionally I deal a lot with Chinese and I can tell you that some of the more sophisticated discussions here would be considered direct insults in the Chinese culture.. But ofcourse there is style and there is content. The content does not have to prevail over style. Meaning, if one is right or think he is, there is still room for carefull wording.

Roll The Bones... Yes even Rush I think. Waters was still with the rest during the original Wall tour. They broke up after the Final Cut, which made that album title very meaningful. As for the lyrics, in all honesty, I play in a band myself and I don't even know the lyrics of our own songs (but I do know the rythms). -edgar

I have been experimenting with cables for the last 16 years. Used Monster, MIT, van den Hul, Cat 5 and copper ribbon cables on the speakers. MIT, Transparent and my own designs as interlinks. Still experimenting with USB. I had various results including poor(er) sound when I had high hopes! Today I use my own designs because I managed to get better quality at far lower cost than brand name cables I used, for a big part by trial and error combined with EE theories. I really see no relation between the (cost)price of a cable and its audible merits. Tip: I really had the most positive results with cat5 cable as speaker cable. 3 lengths braided per side and you're done. This replaced my MITerminator II cables, and I am sure most computer heads have this lying around.. -edgar

I am currently directly comparing my DAC through asynchronous USB vs S/PDIF through a USB/Hiface connection. I find the audible differences very small, it seems that the USB connection shows little more details in the music. This may be because my DAC has a very nice USB implementation... Based on my experiences I think your plan may not bring you what you hope. -edgar

Pulse and In The Flesh... I went to the delicate sound of thunder tour when Floyd was without Waters I think back in '89... Later I went to Waters' In The Flesh tour and realized that Roger Waters without the rest of Floyd sounded more like Pink Floyd than the rest of Pink Floyd without Roger Waters. Similar effect when I witnessed The Wall Live last year. Spooky though that I shared that concert hall in Arnhem with Julf... Shame that Richard Wright died. For me he really designed the floyd sound in many ways. They all have some poor albums. Even Rush does... -edgar

I auditioned the Wadia two weeks ago when I was in San Fransisco. (they have low availability in Europe). A wonderfull unit with what I would call an impressive soundstage. I was not so impressed by the switching power supply. But overall, impressive performance (to the extent I was able to judge a DAC performance alone...) Finally I bought the NAD M51, because it has some practical advantages, and I like their DSP volume control as I will be replacing my preamp with the DAC. Also the M51 is reviewed to be detailled and neutral and I like that. -edgar

I joined to learn and teach. Others know more than I do, and I have experiences others don't have. I am sure there are lots of helpful people here, but I am affraid they get burried in the continues objectivist vs subjectivist discussions which seem to dominate. Coupled with an unhealthy "fear" of anyone who is earning some money with audio products, I find it hard to get some actual valuable information. I lurk around because the platform is great and I sincerely hope that self-regulation will kick in at some point and we can have some discussions aimed at learning in stead of disqualifying each other. Today, I build a low capacitance double screened pure silver USB cable and I test it by listening... I would love to share my thoughts and experiences here, we all can predict the type of thread that will turn into. -edgar

Yes, it's an interactive thing between amp and speaker. I ma not saying it is of no importance, I am just saying that damping factor is no input parameter for a loudspeaker designer. It may be a restrictive parameter. If you want to design a loudspeaker to work with a tube power amp, you set different priorities than with a high current solid state amp. As you say, its how the amp handles things... So its an amp design parameter. -Edgar

For me, what I look for in my sound system is: Am I able to experience what the artist was trying to accomplish. This may sound trivial but leads to the difference between hearing a violin, or hearing someone playing a violin with dynamics, movement, power, and all. This all breaks down to more technical things like resolution, impulse behavior, phase, time alignment, lobing, baffle step, high frequency edge diffraction, and your choice of capacitors. In many cases, the difference between hearing a song or experiencing a song is the relative position of the tweeter, thus phase alignment. This can be modeled very well, but in my higher end speaker designs I included a tweeter that could be positioned back and forth to empirically find the best phase position. The audible difference were not in sound quality as such, but for sure in involvement. I also tap my feet in the car listening to 128 kbs MP3's with too much bass and no imaging at all... -Edgar

The NAD M51 is definitely on my wishlist to audition. I have read very good reviews and it has a couple of features I really like. On power, as most people in audio know, Watts really mean nothing. You can have high watt rated amps not being able to properly controll the bass on ported speakers. It's -indeed- all about current and being able to deliver this current fast, which tells about damping factor. or, in the case of the amps i use is nicely described here "In my view, an important amplifier design goal should be minimal load interaction. And that can only be achieved through a high damping factor, implying a low source impedance. The AW180 sports a source impedance of 0.008 Ohm! That translates to a damping factor of 1,000 relative to an 8-Ohm load and guarantees good behavior even when driving difficult loads. The MartinLogan Summit X is a case in point. The impedance of its stat panel is capacitive in nature and decreases with increasing frequency, reaching a minimum of 0.8 Ohm at 20 kHz. That makes the Summit a prime candidate for amplifier-speaker interaction, especially when you consider that the average tube amp exhibits a source impedance of around 1 Ohm. Several tube amps rolled off the Summit's highs dramatically. One amp in particular managed a whopping -10dB at 20 kHz. The AW180, on the other hand, was unperturbed by such a load." -Edgar

I have been designing loudspeaker for over a decade, and while -indeed- the DC resistance (Rdc) of components is part of the design, damping factor of the amp is not. Usually the Rdc of the coils are way higher than any cable used and thus the biggest impact on the design. One tries to keep the coil Rdc below 0.15 ohms. A speaker designer tries to keep the speakers' impedance (normally measured at 1 kHz) at a nominal value (usually 8 ohms) but it can fluctuate highly over the frequency range. That is where the amps damping factor comes into play telling us something on how well the amp is able to cope with fluctuations in speaker impedance. For speaker cables, in my experience, Inductance is the deciding factor, not resistance. When designing speakers for use with tube amps, this becomes more important, since you want high sensitivity, thus low losses in both the filter and the drivers themselves, and you want a ruler flat impedance curve, which limits your ability to play around with filters. Alternatively, you mostly need heavy amps to drive monitors, due to the low sensitivity (~87dB/W/M) and the fact that bass ports are present in the 60-70 Hz range causing a big impedance peak... -Edgar

nice... so far so good.

Then I see a big artic 8L fan... That would surely take some of the musical joy away... Anyway, in my project, I powered the motherboard with the switching PSU it was supplied with, used a separate lineair PSU for the DAC (basically the MF VPSU). The next step I am thinking is to supply the USB/SPDIF converter with power which is not coming from the motherboard, so, a separate 5V DC supply which I want to take from the lineair 12V supply I already have... Nothing for sale here.. don't want to upset Chris his sponsors... projects...projects....