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What is an SDIF-2 interface?

SDIF is an older standard that is still popular in Japan. It transmits two serial data streams in unbalanced form over two coaxial cables terminated in BNC connectors. When used for PCM, each data stream contains up to 24-bit data for one channel, messages (to identify the data), status flags and synchronisation pulses (which can be used to extract the word clock). When used for DSD, the two cables carry DSD data only. The ‘Channel 1’ cable carries left channel data, the ‘Channel 2’ cable carries right-channel data. SDIF data streams are different to both AES3 and S/PDIF, they are not compatible. For reliable operation, the output stage impedance, the characteristic impedance of the cable and the load impedance at the receiver should all be 75 ohms. This interface is DC-coupled and carries a DC offset of typically +1.25V – it will not work if coupling capacitors or transformers are inserted in the cable. To avoid interference from other appliances, the screen wires must be securely connected to chassis at both ends. There are 3 common forms of SDIF: SDIF-2 PCM, SDIF-2 DSD and SDIF-3 which is for DSD only. These variations make it difficult to extract a word clock reliably, so it is common practice to use a third cable to carry word clock – dCS equipment requires this. A balanced version of SDIF is sometimes used in multi-channel systems, a multi-pin connector is used.

What are Toslink and ST interfaces?

S/PDIF data can be transmitted over fibre-optic cable using TOSLINK or ST-type optical transmitters and receivers. Optical interfaces have the advantage that they do not require any electrical connection, so they are useful for connecting to electrically noisy devices. A common problem is that optical receivers often use an automatic gain control amplifier (AGC), because the intensity of light reaching the receiver varies with the cable length, cable loss and other factors. AGC amplifiers are inherently jittery, so better performance is usually available from an electrical S/PDIF interface.

What is an SPDIF interface?

S/PDIF stands for Sony/Philips Digital InterFace, it is an industry-standard interface used for consumer equipment. It transmits a serial data stream (similar to AES3) in unbalanced form over a coaxial cable. The data stream contains a stereo pair of up to 24-bit data, messages (to identify the data), status flags and synchronisation pulses (used to extract the word clock). The data stream is similar to AES3, but the status flags are different and are not entirely compatible. For reliable operation, the output stage impedance, the characteristic impedance of the cable and the load impedance at the receiver should all be 75 ohms. To avoid interference from other appliances, the screen wire must be securely connected to chassis at both ends. The interface is commonly used at sample rates up to 192kS/s over short distances (less than 5 metres). The connector type can be RCA phono or BNC.

What is a Dual AES interface?

Dual AES is a digital audio interface invented by dCS in 1995 to allow high sample rate data to be split between two base-rate data streams for easy storage on the digital recorders of the time. For example, a stereo pair of 96kHz data could be split into two 48kHz streams and recorded as 4 tracks on a 48kS/s recorder. To replay, the 4 tracks are transmitted over two AES3 cables to the DAC, which reconstructs the original 96kS/s data. Dual AES was offered as an open standard and it was added to the AES3 specification. Almost 20 years later, we use Dual AES at sample rates as high as 384kS/s. Dual AES features lower jitter than Single AES or S/PDIF, so there is a sonic benefit. The raw data must be specially formatted as Dual AES pair at the transmitter and then decoded at the receiver. Two identical Single AES streams used together will be decoded by the DAC as a strange ‘phasey’ mono – this is not the same as Dual AES at twice the sample rate.

What is an AES3 (also called AES/EBU) interface?

AES3 is an industry-standard digital audio interface intended mainly for professional use. It transmits a serial data stream in balanced form over a screened twisted pair cable. The original idea came from a wish to re-use existing cabling in broadcast and recording studios, which typically contain miles of screened twisted pair cable already, used for balanced analogue signals. The data stream contains a stereo pair of up to 24-bit data, messages (to identify the data), status flags and synchronisation pulses (used to extract the word clock). For reliable operation, the output stage impedance, the characteristic impedance of the cable and the load impedance at the receiver should all be 110 ohms. To avoid interference from other appliances, the screen wire must be securely connected to chassis at both ends. The interface is commonly used at sample rates up to 192kS/s.

What are the final software issues for the Classic range?

Elgar Plus v4.31 (or v4.42), Delius v2.25 (or v2.30), Purcell v2.25 (or v2.30), Verdi v1.28 (or v1.30), Verdi La Scala v1.03 (or v1.10), Verdi Encore v1.10, P8i v1.10, Verona v1.21, 1394 Db:2.06. The issues in brackets are licensed versions which are equivalent to the previous issue and cannot be loaded by customers. Update discs for Classic products incur a service charge.

Is there any new software for my Classic stack to add the new DSD interfaces?

The original Classic stack software was “mature” in 2004, all 8 products were discontinued in 2007 so new software updates are possible.

Can I update my Classic stack to use single-wire 24/192 and DoP?

No. The digital interface circuitry used in the Classic products was originally designed in the late 1990’s. The devices used will operate at up to 96kS/s in single-wire mode, but will not work with higher PCM rates or DoP. The Classic DACs and Purcell Upsampler use Dual AES for PCM data rates over 96kS/s.

Is it possible to change the voltage of my dCS equipment?

Yes, all dCS units can be set for 100V, 115/120V, 220V or 230/240V operation. Please contact your dealer or distributor to arrange this, there may be a small charge for this service.  Please do not try to change the setting yourself, as this frequently causes hardware damage.

If I am upgrading from Scarlatti to Vivaldi which unit should I upgrade first?

The Vivaldi DACwill bring the most significant performance improvement so always start with the DAC.ace that first.The next upgrade will depend on whether you are a disc spinner or moving into computer audio as both the Vivaldi Transport and Vivaldi Upsampler will improve your system by some way. Finally, the Vivaldi Clock will outperform the Scarlatti Clock so we advise you to find a local dealer and listen for yourself.

Is Vivaldi compatible with Scarlatti and Paganini?

Vivaldi uses Dual AES to transmit DSD data between units instead of 1394. We released a set of software updates for the Scarlatti and Paganini ranges in 2013 to add the same Dual AES DSD interface. This allows Scarlatti and Paganini owners to upgrade only part of their system to Vivaldi and get most of the benefits of the new technology. As an added bonus, the Dual AES DSD interface sounds better than the 1394 interface. Please press the Menu button three times to check the Control software issue and then compare with software history to see if your system is loaded with compatible software.

What do I do if dCS has no distribution in my home country?

Please contact us directly. We will do our best to help, we aim to respond within one working day.

How do I update my dCS DAC to play DSD over PCM (DoP) files?

A software update is all that is needed to add DoP capability to our current range of DACs. The earliest software versions that support DoP are Scarlatti DAC v1.30, Paganini DAC v1.30, Debussy DAC v2.10, Puccini Player v1.41 and all Vivaldi DAC versions. Please check the current Control software version loaded in your DAC as described in the manual. If your unit is loaded with older software, please request an update disc with instructions from your dCS dealer or distributor. If you do not have local support, contact us.

Sorry, we cannot add DoP capability to the Elgar / Elgar Plus DAC, Delius DAC, Purcell or P8i Player.

Do I need a USB driver for my dCS products to use with a PC?

If the product is set to USB Class 1 (96kS/s maximum), no special driver is required. If the product is set to USB Class 2 (192kS/s maximum), no driver is needed for use with Mac OSX 10.6.3 or later, load the Windows driver supplied with the product if you are using a Windows PC. Click here to download the driver.

How do I arrange to have my dCS product serviced?

Please contact your dealer or distributor for help. State the model, serial number, software issue(s), describe how the unit is used, describe the symptoms in detail and give them your contact details. With your co-operation, they will try to solve the problem. If this is not successful, they will arrange to service the unit, either locally or in the UK. For used units imported from a different country, please contact us.

My PC with USB 3.0 interfaces does not see the dCS USB Class 1 device reliably.

This is a known bug in some versions of the USB 3.0 chip set in your PC or sound card. Sorry, we do not have a solution for this, as our USB Class 1 interface uses the generic USB driver built into Windows and OSX.

My PC does not see the dCS USB device.

Make sure the PC’s operating system version is compatible with the USB interface. If you are using the USB interface in Class 2 mode with a Windows PC, you must load the dCS USB Class 2 driver first. USB Class 2 with a Mac requires OSX 10.6.3 or later. Try connecting to a different USB port on the PC or resetting the USB port. USB Class 1 mode should work with almost any PC with USB 2.0 interfaces so try switching the dCS device between Class 1 and 2 mode.

Can I update my dCS units via USB from a PC?

For DACs Upsamplers or Clocks – yes, provided the system is set up correctly. The update will not run unless the dCS software is received completely unchanged. For bit-perfect playback, the streaming program must be set to disable the following features: volume adjustment, fade in/out, re-sampling to 24 bits and sample rate conversion. If the unit being updated displays 24/44.1 for example, the data has been re-sampled and the update will fail. If appropriate, set the unit to Audio sync and disconnect any clock cables. Play a few seconds of the disc or file so that the PC outputs a 44.1 stream. Follow the instructions supplied with the disc or file. It is possible to update from iTunes but difficult – the file has be imported into the iTunes library (where it will be given a spurious identification!) and then played bit-perfect. Transports and Players must be updated from a disc.

I am having difficulty using my NAS drive with the Vivaldi Upsampler.

The Upsampler and App are UPnP compatible. Please make sure the Upsampler software, network firmware and dCS  Vivaldi Controller App are up to date, make sure the system is connected correctly. The NAS drive must be loaded with UPnP server software as well as music and set up correctly with UPnP Discovery Mode turned on in both the NAS and router. If the problem persists, please ask your dealer for advice. For help resolving network problems, please consult an I.T. professional.

Which DAC output is better – balanced or unbalanced?

The balanced output uses complex class-A stages, they give noticeably better sound quality than the much simpler unbalanced output stages. The balanced outputs behave like coupling transformers so they can drive an unbalanced input provided that XLR connector pin 3 is connected to pin 1 at the end of the cable farthest from the DAC. Used like this, you may find that muting clicks are more noticeable. We recommend using the unbalanced outputs to drive an unbalanced input.

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