How do I use it?
Quite simple. You connect the digital output from the digital audio source of your choice, which for most people will be their existing CD player or CD transport, to one of the Purcell's digital inputs. You connect the output of the Purcell to the input of a high sample rate D/A converter. Use the Input button to select the input you wish to upsample and the Output button to set the output sample rate. The other settings can be taken care of in one quick and easy step by selecting the Factory option in the Function Menu. Once set, there is usually no need to adjust them again. If you want to experiment with different settings, this is very easy to do via the Function Menu.

What sort of D/A converter do I need?
You will need a D/A converter that can accept sample rates up to at least 96kS/s and input wordlengths of at least 20 bits and preferably 24 bits. The greatest improvement will be achieved using the dCS Elgar 24/192 - DSD D/A converter. The Elgar, because of its proprietary dCS Ring DAC technology, has the finest linearity of any consumer D/A converter currently available. It is also able to accept PCM sample rates up to 192kS/s and decode DSD, enabling the full potential of the Purcell to be realised. The world's second best audiophile D/A converter, the dCS Delius, will also give excellent results.

Much more than just a simple Upsampler
The advanced technology employed in the dCS Purcell makes it possible to give the user a very wide range of extra functions beyond that found in ordinary audiophile digital products. This gives great flexibility in how the unit may be set up and used in any particular system. A brief look at the main features will confirm this.

PCM to DSD Upsampling Option
The Purcell may be ordered with a PCM to DSD upsampling option, which allows all sample rates from 44.1kS/s to 192kS/s to be converted to a DSD data stream running at 2.822MS/s. Many people regard the CD to DSD conversion as superior to even the CD to 24/192 conversion. Typical comments are that it is even more musical and natural, with better low level resolution. As always we advise you to try this out for yourself, but we are confident that you will be impressed.

The DSD data is output from the Purcell to our Elgar Plus and Delius D/A converters via an IEEE1394 digital interface. This is the digital interface that Sony will use to transfer DSD data between its audiophile products and is the only digital interface permitted for DSD data transfer in the latest version of the SACD specifications. We use IEEE1394 on our dCS Verdi SACD/CD transport for DSD data transfer.

Earlier Purcells may have the DSD upsampling option retro-fitted. Subject to a maximum 5 year warranty, all units upgraded with the IEEE1394 interface will benefit from an extension of 3 years to the balance of their existing parts and labour warranty. A new 3 year parts and labour warranty will be given to out of warranty units. For more details please contact us at support@dcsltd.co.uk and give us the serial number of your unit and also let us know where you are located.

Downsampling Function
In addition to being able to convert the input sample rate to a higher value, the Purcell can also convert the input sample rate to a lower value. This is called downsampling. Three conversions are available:
• 96kS/s to 48kS/s
• 96kS/s to 44.1kS/s
• 48kS/s to 44.1kS/s

Possible uses include converting the data from a 24/96 DVD to 48kS/s or 44.1KS/s for recording onto a CD-R or MD for use in car or other portable disc players. Recordings should only be copied where permitted by the copyright holders and the applicable laws of the countries in which the copies are made and used.

4 different user selectable digital filters are provided for each conversion. These affect the frequency response in the ultra-sonic region - above 20kHz. The filters have progressively wider transition bandwidths (gentler cut-offs) and hence progressively better impulse responses. This leads to an improvement in stereo imaging at the expense of a slight increase in aliasing. To use the filter, you simply choose the one that you think sounds best with the music that you are playing.

Comprehensive Digital Input and Output Interfaces
The standard Purcell is equipped with three digital inputs and has the provision for a fourth optional input.
• RCA Coaxial
• BNC Coaxial
• AES/EBU
• ST Optical - Optional

This wide range of interfaces combined with the unit's ability to lock to any standard sample rate from 32kS/s to 96kS/s enables the Purcell to be used with almost any currently available, or foreseeable audiophile digital source. Each individual input can accept the sample rates 32, 44.1, 48, 88.2 and 96kS/s. You can therefore upsample CDs, DATs, Digital Radio and even 24/96 DVDs.

The Purcell has four digital output interfaces making it easy to connect to almost any high quality D/A converter.
• RCA Coaxial
• BNC Coaxial
• AES/EBU x 2

Each individual output can operate at the sample rates 32, 44.1, 48, 88.2 and 96kS/s. In addition, the two AES/EBU outputs can be used in parallel in what is termed Dual AES mode and this configuration covers the sample rates 88.2, 96, 176.4 and 192kS/s.

Software and Hardware Upgradable - Don't Fear the Future
Because digital audio formats and interface standards are in a state of flux, it is essential that new digital equipment should be easy to upgrade. Upgrades should also be available at a reasonable cost. Whilst some upgrades may require hardware as well as software changes and so be more expensive, it is our policy to make upgrades as inexpensive as we possibly can.

All of the major digital processing and control functions in the Purcell are performed by programmable logic. These software controlled devices give us the option adding new features or functionality should the need arise in the future. New software can be loaded by simply playing an update CD into the Purcell from a standard CD transport, in exactly the same way as you would play a conventional CD. It is quick and easy.

If you already own a Purcell and would like to find out what your upgrade options are, please contact us at support@dcsltd.co.uk and give us the serial number of your unit, together with the version number of the software currently installed.

Many of the new functions we have added to our equipment over the years have been the result of users' suggestions. If you have an idea for an improvement, we'd like to hear from you.
Please email us at suggestions@dcsltd.co.uk.

Function Menu
To make the Purcell easy to use and to save cluttering up the front of the unit with unnecessary buttons, only the main controls are located on the front panel. The secondary controls and a large number of additional functions are accessed via what we refer to as the Function Menu. To adjust a secondary control, you simply open the Menu using the Function button, scroll along until the appropriate page is shown on the main display, select the required setting and then let the Menu automatically close. The use of the Function Menu makes it very inexpensive and easy to add additional features or functions to the Purcell by simply changing the unit's operating software. Some of the pages in the latest Purcell Function Menu include:

• Output wordlength selection
• Noise shaping selection
• Dither selection
• Output mode selection
• Interpolation filters selection
• Display mode selection
• Input signal wordlength display
• Factory settings memory
• Cloning Mode
• Display brightness level selection
• Self test
• Software issue number
• Channel check
• Phase check
• System burn-in signal

5 Output Wordlength Settings
To avoid what is called truncation distortion, it is very important that the output of the Purcell be set to the maximum wordlength acceptable by the D/A converter being used. The Purcell provides the options of 24, 22, 20, 18 and 16 bit outputs which makes this matching very simple and ensures a perfect match with your D/A converter.

3 User selectable noise shaping settings
If the digital source that you are using has a longer wordlength than can be accepted by your D/A converter, you cannot just chop off the unwanted bits, as this will result in truncation distortion. Instead, the truncation must be performed "gracefully". One of the techniques used to do this is called Noise Shaping. This moves noise energy from the middle of the audio band where the ear is most sensitive and places it at the upper end of the audio band, where the ear is least sensitive. The perceived effect is a lowering of the noise floor. The Purcell has 3 noise shapers, 1st, 3rd and 9th order. They have each been individually optimised for all of the sample rates from 32kS/s to 96kS/s. They use the same DSP code as the noise shapers in our dCS 972 Professional Sample Rate and Format Converter and there is a good chance that you already own CDs that were processed using these noise shapers. Noise shaping is not available for 176.4 and 192kS/s, as we expect any D/A converter capable of working at these rates to be able to accept a 24 bit input.

The noise shapers may be selected either manually or automatically. In the latter case, the Purcell will select the noise shaper most appropriate for the output wordlength that has been set.

For more information about noise shaping, please see page 33 and pages 37 to 40 of the Purcell user manual. This is available as a pdf document on the User Manuals page of this site.

3 User selectable dither settings
Another technique for removing truncation distortion is dithering. This involves the addition of a very small amount of a specific type of noise to the signal. This has the effect of de-correlating the noise from the signal and the result is a smooth noise floor. The Purcell l provides the options of the standard Triangular dither, as well as Top Hat and Noise Shaped Triangular dither.

For more information about dither, please see page 31 and pages 35 to 38 of the Purcell user manual. This is available as a pdf document on the User Manuals page of this site.

Single and two wire output interfaces
To transfer data at 88.2 and 96kS/s most equipment uses a single wire digital interface. A second type of interface is currently in use called Dual AES. This uses two AES/EBU interfaces in parallel, one for each channel. This is the most common interface for professional digital equipment working at 88.2kS/s and 96kS/s and it is possible that some hi-fi equipment may also adopt it. The Purcell has ability to use both interfaces and this gives it a far greater degree of compatibility than products that can only use the single wire interface.

4 User Selectable Interpolation Filters - Tune Your Purcell
4 user selectable interpolation filters are available for the most commonly used conversion of 44.1kS/s to 96kS/s . These effect the frequency response in the ultra-sonic region - above 20kHz. The filters have progressively gentler roll-off characteristics and hence progressively better impulse responses. This leads to an improvement in stereo imaging at the expense of a slight increase in aliasing. All that is perceived timbrally with increasing levels of aliasing is a progressive increase in brightness in the sound.

3 User selectable display modes
The main display may be set to one of three different modes according to your own preference.
• Input sample rate
• Output sample rate
• Input and output sample rate

Input signal wordlength display
The Purcell constantly monitors the selected digital input and is able to display how many bits in the input signal are actually active. It is important to know this, as it determines whether you will need to set Noise Shaping and or Dither. It is also a useful little check to see whether a maker's specification and reality match up!

Factory settings memory
This allows all of the Purcell's main system settings to be set in one quick and easy step. This greatly simplifies the initial set-up of the unit and enables you to get on with the important business of enjoying music. If you ever become unsure of what your Purcell's settings are, this feature can be useful to restore the unit to a known set-up state.

Cloning Mode
When in Cloning Mode, the Purcell passes through the input data bit-for-bit with no changes. This allows HDCD coded data to pass through unchanged and be decoded by your DAC.

7 Display brightness settings
A 7 level brightness control allows the display brightness to be set to match the ambient light level in your listening room. For the purists, it is also possible to switch the display off completely.

Self test
Every time the Purcell is switched on, it automatically performs a rigorous self test on its digital processing system. It also constantly analyses the input signal and flags errors if they occur. This can be very useful in trouble shooting problems with digital sources. A display self test can also be initiated from the Function Menu.

Channel check
An easy to use channel identification routine enables you to quickly verify that you have the left and right channels in your system correctly connected. This outputs a synthesised 1kHz digital tone, first on the left channel and then on the right channel. At the same time the main display indicates which channel is being tested.

Phase check
A phase check routine allows you to quickly and easily check the phasing of your speakers. This outputs a pink noise signal that is first in phase on both channels and then inverts the phase on one channel. At the same time the main display shows whether the test signal is in phase, or out of phase.

System burn-in signal
A system burn-in signal enables you to use the Purcell to burn-in new items in your system. Having this function and the Channel and Phase check built into the Purcell means that you will no longer have to turn your listening room up-side-down looking for that elusive test CD.

Parameter memory
When the Purcell is switched off, all of the unit's settings such as the Output Sample Rate, Noise Shaping, Dither, Digital Filter, Display Mode, Display Brightness etc are saved in a non-volatile memory. These are restored when the unit is next switched on and this removes the need to reset all of the parameters each time the unit is used.

Infra Red Remote Support
Units with version 1.2 software or later may be controlled via the New Universal Remote Control that is now being shipped with the dCS Elgar and dCS Delius D/A converters and dCS Verdi SACD/CD Transport.

1 Year guarantee
The Purcell, like all dCS audiophile products, is guaranteed for 1 year from the date of purchase if the unit is purchased from an authorised dCS dealer. The guarantee is transferable to subsequent owners. Purcell owners who register their purchase with dCS will be notified when upgrades become available.

Want More Information?
More detailed information on dCS Purcell may be obtained directly from dCS at info@dcsltd.co.uk . Alternatively have a look at the dCS Purcell User Manual. This is available as a PDF document and will leave you in no doubt that the dCS Purcell is much more than just an upsampler.

And Finally....
You've read the sales pitch. Now go down to your nearest dCS dealer and hear the reality. Don't forget to take some of your favourite CDs and DVDs with you. Remember...

You haven't really heard your music until it's been upsampled by dCS
or
It don't mean a thing unless it's a dCS upsampled thing