Description
QEDs award winning Qunex P75 digital SPDIF cable to connect CD / digital player or streamer to DAC. Extremely rare 1.5m RCA to BNC as QED dont make this combination! I have fitted a new Sommer Cable of Germany Hicon BNC to a New Old Stock QED 75 Ohm cable. These BNC cables are designed for Audiophile use and cost me over £9 to buy from Germany, making this cable a bargain at under £30 delivered.Triple shielded and true 75 Ohm construction for reduced jitter.Burned in using the Tara Labs Cascade file for 48 hours producing a much smoother sound as a result.This sounds excellent with Chord, NAIM, Linn etc DACS with BNC as no adaptor is required which compromises performance by generating reflections and spurious signals causing jitter.Please see the excellent 100% feedback I have received for hundreds of QED digital and analogue cables.Length of cable – why 1.5m? SummaryThere are only two occasions in audio where a longer cable – or an optimum length cable is better than a short one. With Digital cables there is an optimum length of 1.5m or more. (The other occasion is for MM phono cartridges, which need a specific capacitance).The reason for this requires an explanation. Please refer to diagram in the photos. The signal travelling down a SPDIF (so called digital cable) is actually a square wave ANALOGUE voltage signal, however in reality this square does not have instantaneous changes - the squares are sloped and somewhat rounded off too as it takes some time to change state from 0 to 1 or 1 to 0. The accuracy of the pulses at the end of the cable determine how accurately the source can interpret the signal in value 1 or 0 and also timing which not so easy.The signal reflects back off the ends of the cable, the plugs and connected equipment (echoing back and forth) and produces ghost images of itself, which can fool the receiver into thinking that the “ghost” signals are the original signals. With short cables, under 1m, the ghost signals arrive close to the originals within the time frame of transition from 0 to 1 or 1 to 0, before the transition occurs. A 1m cable means the reflection arrives at about the same time as the transition is to be recorded. With longer cables the reflection arrives too late to influence the receiver (The transition has already been recorded). Longer cables also mean lower amplitude or signal reflection thus receiver can more easily determine between the correct signal and the spurious reflections. The bottom line as that a longer cable eliminates the false readings from the ghost images, and thus reduces timing errors, called jitter and thus sounds better.The optimum size has been determined by measurements and experimentation to be 1.5m or more. Detailed Technical Explanation for those with an enquiring mind.Why SPDIF cables should be at least 1.5m long. When the SPDIF signal is launched into the cable from the Transport, it is essentially a voltage square-wave, consisting of rising edges and falling edges. These edges are no more than transitions of voltage from about –250mV to +250mV, the rising edge transitioning from minus voltage to plus voltage and the falling edge transitioning from plus voltage to minus voltage. When an edge transitions, it can be described as having a rise-time or fall-time. This is the time it takes for the signal to transition from 10% to 90% of the entire voltage swing. (note that this DOES Not happen instantaneously) The rise-time is important because this is what causes reflections on the transmission-line. If the rise-time were very, very slow, say 50 nanoseconds, then there would be no reflections on the transmission-line unless it was extremely long. Alternately, if the rise-time were less than 1 nanosecond, reflections would occur at every boundary, such as the connection from the circuit board to the wires that go to the connector.Typical stock Transports have around 25 nanosecond rise-times. The primary concern for the manufacturer is to pass FCC regulations for emissions and electromagnetic interference, as well as making the interface reliable. When the regulatory testing is done, they attach very inexpensive, inferior cables and measure the emissions. To insure that the manufacturer passes these tests, they take a number of precautions. One is designing-in the slower than necessary 25 nanosecond rise-time. Another is the insertion of various filters in the Transport to eliminate high frequencies from the signal. As a result of these choices, there is a hazard created in using too short a digital cable.It is a result of the slow rise-time. When a transition is launched into the cable, it takes a period of time to propagate or transit to the other end. This propagation time is somewhat slower than the speed of light, usually around 2 nanoseconds per foot, but can be longer depending on the dielectrics used in the digital cable. When the transition reaches the end of the transmission line (in the DAC), a reflection can occur that propagates back to the driver in the Transport. Small reflections can occur in even well matched systems. When the reflection reaches the driver, it can again be reflected back towards the DAC. This ping-pong effect can sustain itself for several bounces depending on the losses in the cable. It is not unusual to see 3-5 of these reflections before they finally decay away, particularly when using the best digital cables, which are usually low-loss.So, how does this affect the jitter? When the first reflection comes back to the DAC, if the transition already in process at the receiver has not completed, the reflection voltage will superimpose itself on the transition voltage, causing the transition to shift in time. The DAC will sample the transition in this time-shifted state and there you have jitter. Let’s look at a numerical example:If the rise-time is 25 nanoseconds and the cable length is 3 feet, then the propagation time is about 6 nanoseconds. Once the transition has arrived at the receiver, the reflection propagates back to the driver (6 nanoseconds) and then the driver reflects this back to the receiver (6 nanoseconds) = 12 nanoseconds. So, as seen at the receiver, 12 nanoseconds after the 25 nanosecond transition started, we have a reflection superimposing on the transition. This is right about the time that the receiver will try to sample the transition, right around 0 volts DC. Not good. Now if the cable had been 1.5 meters, the reflection would have arrived 18 nanoseconds after the 25 nanosecond transition started at the receiver. This is much better because the receiver has likely already sampled the transition by this time.
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Linn Selekt DSM Streamer, Pre-amplifier, Katalyst DAC mint from Krescendo HiFi Click images to enlarge Description Here for sale is a stunning Linn Selekt DSM digital music streamer with the Katalyst DAC line out module This advert represents a considerable saving on the £6860 list price. The Selekt DSM still has the remainder of the Linn Factory warranty in Europe - approximately two years. The Linn Selekt DSM is a stunning musical source that transforms your digital music into an amazing event. The Selekt DSM allows you to stream most forms of Digital Music including Apple AAC and ALAC as well as FLAC and WAV. It will also connect to the internet and stream digital radio, TIDAL, Spotify and Qobuz. The Selekt DSM can be controlled using the Linn app on both Apple and Android tablets and phones. This is a free download and we highly recommend this solution. The Selekt DSM also includes a built-in preamplifier with both digital and analogue external inputs for connection to your choice of power amplifier. It also includes a moving magnet and moving coil phono stage for a record player. The Linn Selekt DSM has already been updated to the very latest Linn Davaar software. The Selekt DSM has a factory fitted Dynamik power supply and Katalyst DAC. The Selekt DSM is in mint condition Included in the box are the original Linn remote and power lead. Please ‘click’ on the pictures to see much larger views of the condition for yourself and the serial number. We will ship very carefully in the original Linn box. It will be fully insured anyway. Please check shipping costs in GREEN at the end of this advert. We will ship WORLDWIDE. NOTE that this item is advertised on a ‘Buy it Now’ basis and NOT an ‘Auction’. If you have any questions please do not hesitate to ask - we keep all questions confidential so dont feel embarrassed! A very reasonable price considering how great it sounds. Krescendo HiFi is a specialist in Linn and Naim HiFi. We aim to provide the best Linn and Naim products backed up by excellent customer service and always with a 14 day no quibble return option. We are always interested in buying quality used Linn and Naim equipment. Feedback We are very proud of our feedback so please do check it – comments include: ‘I cant rate this seller high enough. First class and brilliant to deal with.’ ‘Supreme eBayer. Met in person and this guy cares. Buy with confidence. AAA+++’ ‘Wow! The best seller ive met on Ebay:perfect in every way!!!!Thanks a lot!’ ‘Excellente produit ,rapidité et conformité !!merci encore !!’ ‘Beautiful sounding CD player. Carefully boxed. Exceptional customer service.’ ‘Best E bay transaction ever!!! The fastest service and communication++++++++++++’ Wow! Best seller Ive had in over 10 years on eBay. Perfect - buy again gladly! Excellent comunication. Never been that satisfied ‘Wonderful to deal with and extremely helpful. Amazing after sales service!!’ recommend to all,you can trust him. Ultra fast delivery, friendly and trustly, thanks a lot !!! ‘alles perfekt’ ‘Very nice people as it should be thank you’ ‘oggetto come da descrizione-comunicaz eccezionale- gran cura in imballo e spediz’ ‘todo perfecto gracias’ ‘Excellent transaction not dealt with anyone as efficient to date credit to ebay’ Shipping We do not charge for packing and if when it comes to ship the price has dropped we will charge you the lower price. Shipping costs including FULL insurance are: UK - £10 EU - £19 Rest of the World - £89 Pictures sell! Auctiva offers Free Image Hosting and Editing.300+ Listing Templates! Auctiva gets you noticed! The complete eBay Selling Solution. Track Page Views WithAuctivas Counter
Zum Verkauf steht ein gebrauchter Linn Majik DSM Vollverstärker/Streamer. Das Gerät wurde 2013 neu für 3212 Euro gekauft. Der Majik ist optisch in sehr gutem Zustand (siehe Fotos) und technisch voll funktionsfähig. Lieferumfang: Majik DSM, Fernbedienung (mit Gebrauchsspuren), Netzkabel, Quickstart-Anleitung. Die Originalverpackung ist leider nicht mehr vorhanden.
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