VAD | DAC-10 DSD | User manual | VAD DAC-10 DSD User manual

VAD DAC-10 DSD User manual
Valve Audio Devices
DAC-10 / DAC-10 DSD Digital to Analogue Converter
User Manual
Version 2.1
The Valve Audio Devices DAC-10 / DAC-10 DSD valve DAC is an exquisitely engineered, handbuilt, point-to-point wired unit employing specifically selected components.
It is designed for the audio purist and refined over countless hours to produce exceptional high
definition sound with unparalleled musicality.
Every component is selected with sound quality as the highest priority and its specially
designed dual mono valve analogue stage, ultra-short “signal path” and advanced dual mono
digital to analogue conversion stage provides the optimum environment for digital audio
playback from a variety of signal sources.
When matched with similarly high quality components, the DAC-10 / DAC-10 DSD achieves a
standard of micro-dynamics, resolution and speed to satisfy the most discerning of audiophiles.
Closing the gap to the original sound and delivering unparalleled musicality, with all of the
original nuances, has now become closer than ever.
The DAC-10 / DAC-10 DSD stands comparison with the world’s finest reference DACs –
regardless of price - and comes with a 7-year Manufacturer Warranty. It has been designed and
built with reliability in mind and will last a lifetime with appropriate care.
Data Formats
The DAC-10 / DAC-10 DSD is capable of automatic recognition of sampling rates from 32 to
192kHz and bit rates of 16-24bit from SPDIF/AES3 digital audio compatible sources through:
USB Audio 2.0 input dedicated for PCM audio files up to 32 bit/192kHz
USB Audio 2.0 input dedicated for DSD64 datastream (DAC-10 DSD only).
In the DAC-10 DSD, the second USB input replaces the AES/EBU SPDIF input of the DAC-10.
Technical information
DSD64 playback (DAC-10 DSD):
In our dedicated DSD (Direct Stream Digital) module, the USB interfaced DSD Left and Right
channel bitstream data is passed through 1bit driver gates and applied to a high precision,
double differential FIR (Finite Impulse Response) filter and then a passive analogue filter. This
removes any DSD noise shaping high frequency carrier present in the signal and pink noise
above 30kHz. Retrieved pure audio is then amplified by vacuum tube triodes. Use of this
technique provides the purest possible representation of the DSD stream as music.
Our DSD playback module is free of digital processing and completely separate from the PCM
SPDIF playback:
SPDIF bi-phase signal is interfaced to a high frequency, high input impedance triode valve
configured in balanced digital mode and precisely matched to our selected SPDIF receiver in
balanced digital mode. This method gives the benefit of the DAC-10 / DAC-10 DSD being highly
immune to the sometimes-poor electrical signal quality from SPDIF transports and/or digital
coax interconnects, which can influence the sound.
A better transport will improve the overall sound. However, the DAC-10 / DAC-10 DSD will
sound exceptionally superior with even the most basic SPDIF signal sources and digital
PCM USB Audio playback:
High-end asynchronous USB audio is I2S interfaced to the PCM decoding stage with two mono
converters (L&R). The stage is free of any post filtering and coupled I/V to two mono vacuum
tube triode analogue output stages.
Power supply:
Power supplies are independent for digital and analogue and Left and Right channels. All
power supplies are inductor (choke) loaded, series resistor-less and bespoke designed.
Vacuum tube analogue output stage:
The DAC-10 / DAC-10 DSD vacuum tube triode analogue output stage is point to point
engineered to operate as:
1. PCM stage differential audio signal coupling (transformer-less).
2. DSD stage audio signal coupling.
3. Gain regulation - part of this function implemented in DC mode.
4. Signal dependent variable tube biasing.
5. Voltage amplification.
6. SE and balanced out signal stage.
The whole tube circuit is operating in pure Class A.
The unique VAD casing is designed as a monocoque structure with the fulfilled aim for
extremely high mechanical rigidity, EMI and RFI screening and vibration damping.
It is polymer coated and additionally polyurethane `silenced`.
The only structural parts fitted with screws are the aluminium top cover and valve cover.
Electrically the casing is directly fully grounded via the safety earth pin in fused IEC socket.
Direct grounding provides the highest electrical safety and also means that the EMI/RFI screen
really is a `screen`, not just a piece of metal in the way of interferences.
Used components:
During long R&D process, all components were selected for the overall sound benefit of
the whole design without compromises.
The separate components count of the DAC-10 DSD is 600 and include: selected paper in oil
and silver mica capacitors, 0.1% tolerance foil resistors, selection of Sanyo OsCon and other
polymer caps, Rubycon ZLJ, ZLH, ZL, Panasonics FC, FM, FR, carbon resistors and metal
resistors, silver wire and tinned copper wire, fast RF relays and old fashion solder tags, chosen
top quality linear voltage regulators, Schottky rectifiers, FR diodes and valve rectifiers,
inductors, ceramic valve bases, newest digital IC`s and NOS (New Old Stock) valves, nonmagnetic screws, copper rails, Teflon, silicone, selection of C0G,NPO,X7R,MKP,MKS capacitors
and other parts including many VAD secrets. All components are new and current production
(apart from NOS vacuum tubes), sourced mostly from UK suppliers.
All designed and chosen by us for you to enjoy the music
Technical info
Before Switching ON
Safety and other information
Warranty Information
Warranty registration form
In the flight case you will find the following:
1 x VAD DAC-10 / DAC-10 DSD valve DAC
1 x RF remote control
1 x Power cord
1 x Hex key (for removing the valve cover)
User manual
Remove all contents. Keep the flight case in case of need to ship the DAC-10 / DAC-10 DSD.
Place the DAC on a sturdy surface (e.g. hi-fi rack or isolation platform) and plug in the power.
VAD DAC-10 inputs:
VAD DAC-10 DSD inputs
Digital inputs
DAC-10 digital audio connectivity:
AES/EBU balanced digital audio input
BNC SPDIF digital audio input
COAXIAL SPDIF digital audio input
TOSlink optical SPDIF digital audio input
USB 2.0 audio PCM input (up to 24bit/192kHz)
DAC-10 DSD digital audio connectivity:
BNC SPDIF digital audio input
COAXIAL SPDIF digital audio input
TOSlink optical SPDIF digital audio input
USB 2.0 audio PCM input (up to 24bit/192kHz)
USB 2.0 audio DSD input for DSD64 stream
AES/EBU: Use a screened, twisted pair cable from the digital output of your CD transport or CD
player to the AES/EBU digital input of the DAC-10 (AES/EBU socket is a receptacle type)
Coaxial: Use a RCA plug terminated, coaxial interconnect of your choice for the COAXIAL digital
input. The cable for the COAXIAL input should be no longer than 1.5m (5 feet) for the best
USB: Use USB 2.0 cable fitted with USB type B plug terminated for the DAC side. For best
results use a good quality USB 2.0 cable without any sleeve inductors.
NB - DAC-10 USB interfaces are powered from our on-board, purpose designed, extremely low
noise linear power supply (not from your USB socket – which is used for data transfer only).
TOSlink: Use preferably multi-strand glass fibre type optical audio cable.
NB - 24bit/192kHz sample rate playback through TOSlink cannot be guaranteed.
BNC: Use same type of preferred coaxial cable as used for the RCA Coaxial input, terminated
with the BNC plug.
Audio outputs:
Balanced: Use screened, twisted pair cables fitted with 3pin XLR plugs (receptacle type plug for
the DAC-10 / DAC-10 DSD end).
When using the balanced connection, pin 1 is “ground”, pin 2 is “hot” and pin 3 “cold”. Make
sure this complies with your other audio equipment and consult with your dealer for any
necessary modifications.
RCA: analogue interconnects for single ended outputs.
RCA cables should ideally be no longer than 1.5m / 5 feet between the audio outputs of the
DAC-10 / DAC-10 DSD and the line level input of your preamplifier or integrated amplifier.
NB - We advise that balanced and unbalanced audio outputs are not being connected/used
simultaneously (possibility of ground loop on some systems).
Input selector switches
The VAD DAC-10 / DAC-10 DSD has two, three position toggle switches (1, 2) on the back panel:
Switch 1 (SW1) will let you choose between the AES/COAX, BNC and Toslink inputs.
Switch 2 (SW2) will let you to exclude the SPDIF and choose the USB Audio options.
In the `middle` position of SW2, SPDIF sources are connected (further selectable via SW1)
In the `down` position of SW2, the SPDIF inputs are OFF and the internal I2S interface
asynchronous USB Audio input is connected for PCM music file sources (example: wav. flac.
AES/COAX SW1 switch position will automatically choose an active signal source between the
AES/EBU and COAXIAL inputs.
DAC-10 SW2 `up` position is inactive
DAC-10 DSD only
The AES/EBU SPDIF input is replaced by a USB DSD input.
In the `up` position of SW2, the PCM USB is OFF and the dedicated DSD USB interface is ON for
DSD64 playback (example: dsf. dff. iso.).
SW2 also activates a separate analogue `path` for DSD playback.
If you have both formats (PCM, DSD) of music files on your computer connect both USB inputs
to your computer using quality USB 2.0 cables.
To play DSD files:
switch the DAC-10 SW2 switch to DSD position `up`
choose the DoP bitstreaming output format in the options of your computer software
To play PCM music files:
stop the DSD playback
switch the DAC-10 SW2 switch to PCM position `down`
choose the PCM compatible output format in options of your computer software player.
Initial position of SW2 (`up` DSD, `middle` SPDIF, down `PCM`) is not important, your computer
will recognise only one USB input when you determine by SW2 which format you are going to
Please note: your software won’t play native DSD into the USB PCM input or PCM into USB
DSD input.
- If you listen to PCM only: there is no need to connect the second USB cable to DSD USB input
- If you listen to DSD only: there is no need to connect the second USB cable to PCM USB input.
- We recommend that the DAC gain control is turned down before selecting the DSD USB Audio
format - once the output of your software player is set to DSD, the gain can be increased as
DAC-10 / DAC-10 DSD USB Audio file formats:
PCM music files: Any music file type supported by your computer audio software on Windows
OS and Apple OS platforms - up to 32bit/192kHz
DSD music file types: Windows OS: DSF, DFF/DSDIFF (Developed and tested with JRiver MP18 DoP 1.0)
Apple OS: DSF, DSDIFF, SACD ISO images (Developed and tested with Audirvana Plus).
Before switching on
Front Panel
Switching on / off
Powering ON: “Flip” the mains power switch on the rear panel of the DAC-10 / DAC-10 DSD
followed by pushing the “Power” button on the front panel.
Powering OFF: Press the “Power” button on the front panel of the DAC-10 / DAC-10 DSD.
When in use at home, there is no need to switch OFF the main switch on the rear panel – use
the back panel switch to completely power off the unit when leaving the house for longer
Power ON the DAC-10 / DAC-10 DSD approx. 2 min. BEFORE switching ON your other audio
components such as amplifiers etc.
Make sure that the Volume control of your amplifier or pre-amplifier is close to minimum
position (volume turned down).
Switch your other audio components such as amplifiers OFF before turning OFF the DAC-10 /
Whilst the DAC-10 / DAC-10 DSD will sound superb from the moment it is switched on, due to
the nature of valves, it’s sound will improve even further as it warms up. After 20 minutes it
will be on song, after approximately 40 minutes it will reach its peak performance.
To maximise the life span of the valves, it is recommended to minimise the number of times
that the unit is switched on and off - e.g. where several listening session may be planned during
the course of the day, it is better to turn the unit on before the first session and only turn it off
at the end of the final session – rather than on and off at the end of each session. Ideally, the
DAC-10 / DAC-10 DSD would be kept switched on.
The DAC-10 / DAC-10 DSD has the power consumption of 58W during normal operation (with
signal connected).
Gain Control
The remote-controlled signal output level (Gain) control is located in the centre of the front
panel. It is designed to match the output level of the DAC-10 / DAC-10 DSD to a wide range of
preamplifiers and integrated amplifiers but can also facilitate direct connection to power
In most circumstances, when used with a preamplifier or integrated amplifier, the output level
of 2Vrms will be achieved at the 12 o’clock position and pro audio level of 4.2Vrms at 3 o’clock
The remote control unit for the DAC-10 /DAC-10 DSD controls the gain control via RF (Radio
Frequency) and allows up and down gain control from the listening position.
The Lock indicator will “light up” when the compatible digital signal is detected and the input of
the DAC is synchronised with a digital signal source.
The `Lock` indicator is only used for SPDIF input sources.
The DAC is now ready to operate.
The DAC-10 / DAC-10 DSD is equipped with an SPDIF `reset` switch (non-latching), located on
the back plate. Occasionally, the digital receiver may not lock onto the signal during the power
up cycle or hot swapping of digital input cables. Should this occur, simply single press and
release the `reset` switch. This will restart the receiver’s automatic ‘signal locking’ procedure.
The reset switch has no function for USB inputs.
Safety Information
Apart from the valves, which, by their very nature, are designed to run hot, the DAC-10 / DAC10 DSD is relatively cool running and operates well below the maximum allowed temperature
for consumer audio.
It should be positioned so as to allow free airflow around it and not placed on top of other
equipment – particularly Class A amplifiers, which run hot.
Possible vibrations should be minimised as far as possible. For example, the DAC-10 / DAC-10
DSD must not be placed on top of speakers. Ideally, the unit should be placed in line with (or
slightly behind) the plane of your speakers and additional benefits may be gained by placing it
on a good quality isolation platform.
Cleaning the unit.
Always disconnect the power cord from the mains socket when cleaning or performing other
Tube replacement.
The front pair of matched valves can be replaced with the same type allowing users to tune the
sound slightly. Please contact VAD or your dealer for advice on replacements. Valve codes
6SN7, 6N8S, 1578, ECC32, CV1988, 6SN7GT, 5692, CV181 or other direct equivalent to 6SN7 are
compatible. Please note: The protective cover will not fit over the taller CV181 valves.
Use of any other valve type will damage the circuit and invalidate the warranty. In case of
“valve rolling”, the use of octal valve socket savers is strongly advisable, as any damage to the
valve sockets caused by “valve rolling” is not covered by the warranty.
The matched pair of 6N6P should only be replaced with the same type or 6N30P.
The pair of CV574 rectifier valves can be replaced with the same type or 6C5S, EZ35 or 6X5GT
Only a VAD authorised service agent should replace the internal ECC84 HF valve.
Tube (valve) replacement
The DAC must be powered OFF by the mains switch on the back panel (mains IEC socket) and
then fully disconnected from the mains socket for a minimum of 10 minutes before
commencing any tube replacement.
(`bleeding` the circuit fully discharges power supplies within 2 minutes, but take care as the
valves may be still too hot to handle).
The unit is fitted with an Anti Surge 1A fuse, which is located in the IEC mains socket on the
back panel – this must be replaced only with the same amperage value! (a spare fuse is
provided in the fuse “drawer”). In case of subsequent fuse failure, the unit should to be sent to
an authorised VAD service agent for checking.
Earth connection
The unit must be earthed! This is provided by the safety earth contact in the IEC mains socket.
Make sure that the earth connection of your home mains electrical installation is in order.
Removing the protective Valve Cover.
The valve cover is secured to the top of the unit by way of 4 hex bolts being accessible through
slots in the valve cover. The cover may be removed in order to facilitate tube replacement by
using the supplied long hex key (2mm) tool to undo the bolts.
We do not recommend using DAC-10 / DAC-10 DSD without the protective cover – valves are
hot when operating.
DAC-10 / DAC-10 DSD valves operational `life span` information.
The DAC-10 / DAC-10 DSD has been designed to the highest parameters, with each component
rigorously tested. We have chosen to use NOS (New Old Stock) valves due to their audio
qualities and longevity. However, due to the nature of vacuum valves, we offer a 90 days from
purchase date warranty for the valves originally supplied for peace of mind.
`Burn-in` time.
Each DAC-10 / DAC-10 DSD is hand-built and then tested through for a minimum of 24 hours
`burn-in` test (all input sources, all output levels). This means that the DAC-10 / DAC-10 DSD
has a 24 hours burn-in period prior to delivery.
Once installed, we recommend a further 100 hours burn-in period for the DAC-10 / DAC-10
DSD to reach its full potential.
Audio Signal Frequency Range:
5Hz - 20 kHz (PCM)
5Hz - 30 kHz (DSD)
Dynamic range:
Digital inputs:
1x AES/EBU (DAC-10 only)
1x RCA Coaxial
1x BNC
1x Toslink optical
1x asynchronous 32 bit/192kHz USB 2.0
PCM input
1x asynchronous USB 2.0 DSD input (DAC10 DSD only)
Output Signal Level (adjustable via gain control):
50mV to 4.4Vrms (approximate)
Analogue Outputs:
1x XLR (balanced) max. 4.5Vrms- adjustable
1 xSingle ended RCA outputs 50mV to
4.4Vrms – adjustable
Output impedance:
Total correlated jitter (SPDIF):
Digital input word widths supported
16-24bit (SPDIF)
16-24-32bit (USB PCM)
Digital input sampling frequencies supported:
All sample rates between and including
32kHz-192kHz (PCM)
USB Audio 2.0:(DAC-10 PCM):
16-32bit/up to 192 kHz PCM
(DAC-10 DSD): PCM, DSD64
Thermionic valves used:
2x 6SN7 dual triode (or equivalent)
2x 6N6P dual triode (or equivalent)
2x CV574 full wave rectifier (or equivalent)
1x ECC84 HF dual triode (or equivalent)
Power consumption:
AC mains operation voltage:
Factory set for 220-240V/50/60Hz
(100-120V/50/60Hz factory set version can be ordered at no additional cost)
Fuse type:
1A Anti Surge 20mm fuse
H 15cm x W 43.5cm x D 29cm
Net Weight (approximate):
Shipping weight (approximate)
Valve Audio Devices (VAD)
DAC-10 / DAC-10 DSD
Warranty Information
Valve Audio Devices Limited warrants this product to be free from defects in materials and
workmanship for a period of seven (7) years from the date of purchase (subject to the terms
set forth below). Valve Audio Devices will repair or replace (at VAD option) this product or any
defective parts in this product within the warranty period. Warranty periods may vary from
country to country. If in doubt, consult your dealer and ensure that you retain proof of
purchase. To obtain warranty service, please contact the VAD authorized dealer from which
you purchased this product. If your dealer is not equipped to perform the repair of your VAD
product, it may be returned by you or your dealer to Valve Audio Devices or an alternative
authorized VAD service agent. You will need to ship this product in either its original packaging
or packaging affording an equal degree of protection.
To qualify for the full seven year warranty, the customer must return the Warranty Registration
Form (included as the last page of this manual) to Valve Audio Devices Limited within 30 days
of purchase.
Proof of purchase in the form of a bill of sale or receipted invoice, which acts as evidence that
this product is within the warranty period, must be presented to obtain under-warranty
This Warranty is invalid if the factory-applied serial number and/or Warranty sticker has been
altered or removed from this product. This Warranty is invalid if the proof of purchase cannot
be presented. A returned product must be accompanied by a written description of the defect.
Any changes or modifications to the product (apart from replacing the tubes as directed in
the user manual) will invalidate the 7 year warranty
This Warranty does not cover cosmetic damage or damage due to acts of God, accident,
misuse, abuse, negligence, commercial use, or modification of, or to any part of, the product.
This Warranty does not cover damage due to improper operation, maintenance or installation,
or attempted repair by anyone other than Valve Audio Devices or a VAD dealer, or authorized
service agent, which is authorized to carry out Valve Audio Devices warranty work. Any
unauthorized repairs will void this Warranty. This Warranty does not cover products sold AS IS
Some Countries and US states do not allow the exclusion or limitation of incidental or
consequential damages or implied warranties so the above exclusions may not apply to you.
This Warranty gives you specific legal rights, and you may have other statutory rights, which
vary from state to state or country to country.
For any service, in or out of warranty, please contact your dealer.
Valve Audio Devices reserves the right to modify the design of any product without obligation
to purchasers of previously manufactured products and to change the prices or specifications
of any product without notice or obligation to any person.
DAC-10 /DAC-10 DSD is a UK Patent Office international registered design.
Valve Audio Devices Limited
17 Ashby Road
NN11 2JS
Company No. 08298028
Copyright Valve Audio Devices Limited 2013
Valve Audio Devices (VAD) Warranty Registration Form
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Last Name:
Full address (number and street):
Phone Number:
E-mail Address (receive up-to-date information on new products and promotions):
Date of Purchase (day/month/year):
Please indicate the serial number and warranty number of this product. (Found on the ID labels
attached to your product).
S/N No.
Warranty No.
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Please complete the form upon purchasing your product.
Detach and send it within 30days to:
Valve Audio Devices Limited,
17 Ashby Road, Welton, Daventry, Northamptonshire. NN11 2JS
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