Inter Connects - What I know and don't know

@atmasphere

Hi, I asked T+A about whether or not their DAC 200 is AES48 compliant and they responded:

"The AES48 standard was paid attention to when designing this DAC. There is a small difference, though: the connection between pin1 and enclosure is not direct but via a 100nF cap. This cap has no negative effect on EMI or shielding."

However, their specs state 2.5V SE and 5V Balanced i.e. the typical doubling of output for non compliant balanced output. ("High level (RCA) 0...2,5 Veff / 22 Ohms, balanced (XLR) 0...5,0 Veff / 22 Ohms")

What do you make of their statement? As per your post above it sounds like this DAC is NOT AES48 ...

@nquery My guess is that it isn't.

If you think about a simple audio transformer that has an input and output, and the output is connected to the XLR connection, that transformer only has a winding driving the output and so there are only 2 wires for each end of the winding. One of them is tied to pin 2 and the other to pin3. You can see that grounding pin 3 to pin 1 would not change the output level, and you can see that the output of pin 2 is produced with respect to its opposite, pin 3.

There is no connection to ground- its only used for shielding. So its perplexing to me how the output voltage would double if both pin 2 and pin 3 are used as opposed to the RCA connection. Clearly an output transformer isn't used (although a lot of solid state pro audio gear does use transformers).

So my surmise is that in order for the RCA connection to work, the XLR connection that corresponds to it (IOW, if both are the non-inverting outputs) will be the same as the RCA. A digital voltmeter will reveal what that is about- there will be zero Ohms between the signal pin of the RCA and pin 2 or pin 3 of the XLR...

@69zoso69 
Iconoclast Cables has white papers that describe how they designed their cables- gives one a basic background on audio cabling design and cost.  This is a good place to understand the complexities of audio cable design and why some are costly.

@69zoso69 - here’s what I have learned in the past 10 yars of collaborating with many DIYers around the globe...

Having spent many years investigating cables, I have had first hand experience of how different things can positively impact the sound we get to enjoy from our systems

I have has success implementing cables on mini-systems costing as little as $200, up to pretty good systems in excess of $70k - other members have much more expensive systems and have observed similar improvements also

Unfortunately the cable companies like to spin their jargon as to why their cables are the best.

But the answer is pretty simple - a good cable will use...

1. excellent quality wire - copper or silver
   • There are varying grades of copper in used, the best being UP-OCC copper
   • There are varying grades of silver used, with UP-OCC Silver currently being the best
   • What is the difference? - Conductivity
     • beryllium copper, teryllium copper, Bronze or Brass
       • are all copper alloys
       • their Conductivty is 70% or lower
     • Pure Anealed copper is rated at 100% and is the Benchmark for Conductivity
     • OFC copper is around 101%
     • UP-OCC copper is 102% -103%
     • Silver is 106%
     • UP-OCC silver is 107%
   • What is the benefit of using a high conductive metal ?
     • better details and improved clarity
     • better/faster dynamic performance
     • better/faster transient processing response
   • there are many combinations you can use to tailor the wire to your liking
     • e.g. Dulund wire with cotton insulation is preferred by many for the signal wires in interconnects and speaker cables for a more mellow sound
2. good quality insulation
   • lowers cable related noise issues - so it lowers the noise floor of a cable
   • The Dielectric Constant (Dk) The ratio of the permittivity of a cable
     • is the metric used to indicate the electrical activity of the insulation
     • As the signal changes polarity in an AC sifgnal it charges the insulation in one direction
     • and then recharges it in the opposite direction when the polarity changes
     • this flip-flopping injects noise into the metal wire
     • using insulations with a low Dk reduces the maount of noise generated and improves clarity, details and imaging
       • PVC has a Dk of 4 (ish)
       • Teflon is 2.2
       • Foamed Teflon is 1.45
       • Cotton or Silk is 1.3
       • Air is 1.1
       • Vacuum is 1.0
3. built using a good noise cancelling cable geometry
   • Cable Geometry is how the individual conductors are situated with respect to each other.
   • When you have two wires side be side in close proximity, as with many cables in use, you get distortions induced from one wire into the wire next to it
   • This is noise and impacts overall cable performance
   • "separating" the wires will be beneficial
   • Some examples of cable Geometry are
     • twisted pair (the most prone to noise depending on tightness of the twist)
     • braided (e.g. Kimber Kable products)
     • Helix Spiral designs (e.g. Anticables)
     • Ribbon designs - Like Nordost speaker cables
4. use great quality connectors
   • many connectors use brass or some copper alloy, but as identifed above, the low conductivity metals will impede cable performance
   • Also, in the case of interconnects and speaker cables, the mass of the connector also impedes signal trasmisson
     • well enginnered Low Mass, high conductivity connectors provide significantly better performance
   • For Power connectors, pure copper or silver plated copper provides better performance
   • the flatness of the pins (US and UK style connectors) will also help

As with everything in this hobby there are improvements that can be achieved with "refinements" to the above basic design points and those refinements will be reflected in the cost.

RE: the "Power supply" to the system

• most power supplies to the house are stable, but some people do experience noise related issues often from commercial builds that are close by,
  • This type of "noise" is generally tiny voltage variations on the AC signal
  • for this type of issue a good power conditoiner or power regenerator is often reqired
• Othrewise, if the power supply to your house is relatively clean then simply having a good power cable to each component will improve sound quality, Why?
  • this is how it was explained to me by a very knowledgeable person with a wealth of Electrical Engineering experience
    • At each connection point in the "power supply line" i.e. at each breaker, outlet and plug - the transfer of electrical energy is only depedant on the quality of that connction and the quality of any wire used to bridge from one connection point to the next
    • This is why a good power cable will provide improvements in performance
• A dedicated line from the breaker panel to your system provides noticeable benefits
• Quality outlets, like Hospital grade MRI outlets from companies like Pass and Seymour, will grip the plugs more tightly and provide better power transmission

RE: the power supliies inside components...

• Power amps tend to have very large transformers and banks of capacitors (i.e. compared to source components), which are designed to supply enough power, especially when large transient signals are encountered
  • But even the very best amps can also benefit from having a very good power cable
  • But for the best amps you will need an exceptionally good power cable in order to achieve any noticeable benefit
• Source components, especially in the more budget oriented designs, tend to have a less capable power supply, so having a good power cable will provide a more noticeable benefit.
• Wal-Wart power supplies are perhaps the worst - I avoid them or replace them

The cable companies I typically recommend include

• Audio Envy - Great bang for the buck
• Zavfino - a little more refined
• In-Akustik - exceptional perofrmance but a bit pricey
• Hijiri - one of the very best out there

There are a few others, but these provide good and noticeable Bang-for-$Buck

Audio Envy features great wire, insulation and connectors for a great price

Zavfino is a great place to start and their product line caters to many budgets and their products actually perform.

There are many opinions out there.

Some believe in the benefits of cables and other do not

So use the Audogon search feature to aquire knowledge from postings from other members pertaining to cables.

Apologies for the long post, but this subject gets complicaed very fast

Hope it helps - Steve

||$300 Brand X will produce more detail than say $60 Mogami Gold||

so blunt man... so blunt.