Owner’s Manual
E
1
FOREWORD
n the popular domain of “Classic Rock” Brian May needs no introduction. Thanks
to his expansive body of work with Queen, he is quite literally a global institution.
In addition to being one of the genre’s finest songwriters and arrangers, fans and
I
critics alike consider him to be one of rock’s most distinctive and tasteful guitarists.
And, just like his unique playing style, Brian’s instantly recognisable guitar tone is
highly revered, fortifying his status as a living legend.
As you know, throughout his lengthy and highly successful career Brian has always
been associated with Vox amps and his celebrated wall of nine AC30 combos is a
“Brian May trademark” that is instantly recognized in all four corners of the globe. As
soon as said “wall” is spotted on a stage, the audience immediately knows who is
going to be plugging into it!
What isn’t as well known is the source of many of Brian’s most celebrated recorded
tones. Believe it or not, many of them have been made using a tiny, homemade
combo that was built for him by Queen’s bassist, John Deacon, back in the early
‘70s. Because of its maker’s name, this unique and wonderful sounding little device
was christened the “Deacy” amp and, as just stated, its unique voice can be heard
on some of Brian’s and Queen’s most famous recordings, including “The Fairy
Feller’s Master-stroke” & “Bijou”, to name but two.
By working extremely closely with Brian, we are proud to offer you this exciting
new product — the Brian May Special...
1
Brian’s Introduction for Vox Brian May Special!
© Richard Gray
For years I have been wondering what on Earth I would do if the Leg-
endary Deacy Amp one day stopped working! And so often I have been
asked where such an amp could be bought, to produce sounds as far
apart in time as “The Fairy Feller’s Masterstroke” from “Queen 2,” and
“Bijou” from the “Innuendo” album.
Well..... It’s here!! At last I am secure in the knowledge that Steve
Grindrod &Vox now know how to provide me—and you—with an
infinite supply of sounds that could NEVER be squeezed out of an Amp
Simulator!!!
THIS WILL DO IT FOR YOU!!!
Or my name’s not .....BM!
Plug right in and Enjoy!
Cheers!
Brian May
Dec 2002, London, England.
2
DETAILS: History, Use and Design Philosophy.
s stated in the FOREWORD, the original Deacy amp was made by Queen’s
bass player, John Deacon, sometime in 1970/1971, whilst he & Brian were
A
studying at University. The compact combo he built boasts no controls
what-so-ever and, according to legend, was put together from parts the bassist
managed to salvage from a rubbish skip (a large garbage container)! The amplifier
circuit-board* John used consisted of a simple, solid-state design that dates back to
a Mullard circuit that was published when tran-
sistors first became popular and was almost
definitely “rescued” from what was once a car
radio.The resourceful Mr.Deacon mounted this
amp board into a compact, 1960’s “bookshelf”
HiFi speaker cabinet and used it to drive the
small woofer and tweeter combination the cabi-
net contained.When connected to a 9Volt bat-
tery the Deacy produced a massive 0.45Watts
© Richard Gray
of power...RMS of course!
*NOTE: for more technical details regarding the original Deacy please refer to the “Tech-
nical Talk” section at the end of this manual.
The two friends quickly discovered that when the Deacy was coupled with Brian’s
homemade Treble Booster pedal (which actually accentuates the upper-mid frequen-
cies to be exact), and his world-famous, homemade “Red Special” guitar, the result-
ing tone was both extremely pleasing and unique. As a result of the great sound it
produced this 100% homemade set-up was used to record a large amount of Brian’s
lead and guitar orchestration work on Queen’s vast catalogue of hit albums and
singles.
Obviously the original Deacy is a very unique and, due to its age, irreplaceable
amplifier. Not surprisingly, Brian treats it with due reverence, as it is part-and-parcel
of his signature sound. Unfortunately, the electrical components it employs are long
gone from production, as is the speaker system it uses and, for that matter, the
batteries it requires are not readily available! Also, the original is extremely limited
because it has no controls and is also never used purely by itself — Brian always
uses it in conjunction with his homemade Treble Booster.
Because of all these truths, after consulting with Mr. May, it was decided that the
Brian May Special should be a variation of the original Deacy “system” (the Deacy
amp plus his homemade Treble Booster) that, in addition to emulating its unique
sound, offers a number of features and controls that the original doesn’t have. Brian
was also very keen for the resulting product to be as affordable as it is practical, so
that its sound could be brought to as wide an audience as possible. Hence the format
of the VOX Brian May Special recording amp you’re now the proud owner of...
3
In a nutshell, the Brian May Special is a 10 Watt, 1 x 6.5" combo that sounds
identical to Brian’s homemade “Deacy System” (i.e. his Treble Booster/Deacy amp
combination) and also offers the following additional features that dramatically
enhance its flexibility:
ꢀ
ꢀ
Controls for Gain, Tone and Volume plus a High/Low Gain switch.
A Booster Output that allows you to use the Booster section of the
Deacy to drive another amp. This is a very useful facility as Brian uses
his homemade Treble Booster to overdrive the AC30s he uses live
and the Booster section of the Brian May Special sounds exactly the
same as Brian’s homemade device.
ꢀ
ꢀ
An Emulated Recording/Headphone jack.
An External Speaker jack.
IMPORTANT NOTE: In Brian May’s “Original Deacy System” both the Treble
Booster and the Deacy amp are powered by 9 Volt batteries. Because of this the
Brian May Special has two “battery simulation circuits” (one for the Booster sec-
tion, one for the amp section) that emulate the unique characteristics of batteries.
For more information on the combo’s features, read on....
4
GUIDED TOUR OF THE BRIAN MAY SPECIAL’S
TOP PANEL
As you’re about to discover, this unique combo is a truly versatile piece of gear that’s
ideal for practicing, recording, or hooking-up to your favorite amp for added gain and
sustain. We’re sure it will provide you with a plethora of great additional guitar tones
that feel as good as they sound. Let’s take a quick tour of the features and controls
that make your new Brian May Special as flexible as it is toneful...
The Top Panel
1
2
3
4
5
6
7
8
9
1. INPUT jack
This is where you plug your guitar into the Brian May Special. Please use a high
quality guitar cable.
2. GAIN control
This adjusts the gain of the Brian May Special’s Booster section and, in so
doing, affects the overall gain of the amplifier. Turning this control up (clockwise)
will produce rich, overdriven tones that range from mildly crunchy to maximum
saturation. Also, when this control is turned down to low settings, your sound will
clean up nicely. This control is also extremely effective when you are using the
BOOSTER OUTPUT (3) to drive the pre-amp of another amplifier.
3. BOOSTER OUTPUT jack
This output allows you to use the Brian May Special’s Booster section to drive the
pre-amp of another amplifier. Doing this will “push” the input of the amplifier you
connect it to into a smooth, overdriven sound and will add sustain and musical
harmonics. Remember, the BOOSTER section of the Brian May Special is an
exact emulation of the homemade Treble Booster pedal Brian uses to drive the
Normal channel of his AC30s whenever he is playing live or in the studio.
5
IMPORTANT NOTE 1: Using the BOOSTER OUTPUT disconnects the rest of the
Brian May Special. So, when you use your Brian May Special as a BOOSTER you
can’t use it as an amp as well.
IMPORTANT NOTE 2: When using the BOOSTER OUTPUT, the only two controls
that affect its output are the GAIN knob (2) and the GAIN switch (4). The TONE
control (5) and VOLUME control (6) have no affect on the BOOSTER OUTPUT
what-so-ever.
BRIAN MAY SETTING TIP #1: For the BOOSTER to sound exactly like Brian’s
homemade Treble Booster:
— the GAIN control (3) needs to be set on full “10”
&
— the GAIN switch (4) needs to be in the HIGH “pushed in” position.
4. GAIN switch
This push switch allows you to select between High and Low gain settings for the
“pre-amp” section (see Flow Chart on page 11). The HIGH setting (switch
“pushed in”) produces natural sounding, heavily overdriven sounds while the
LOW setting (switch “popped up”) gives a smoother, mellower overdrive that’s
ideally suited for more subtle, dynamic playing styles. Keep in mind that the effect
of this switch will vary depending on how you have the GAIN control (2) set. As
always, experimentation is the best way to achieve your desired sound.
5. TONE control
This control has been placed after the overdrive circuitry of the Brian May Spe-
cial and adjusts the overall tone of the amp. Turning it clockwise from “0” towards
“+” adds in high frequencies and gives you a brighter sound, while turning it
counter-clockwise from “0” to “-” adds in bass frequencies, resulting in a rounder,
warmer sound. Setting this control in the middle (0) renders it inactive. As with the
other controls, please experiment with this one to find the settings that best suit
your playing needs.
6. VOLUME control
This adjusts the overall volume of the combo.
BRIAN MAY SETTING TIP #2: For the Brian May Special to sound exactly like
Brian’s homemade Treble Booster/Deacy set-up, here are the settings:
—
—
—
—
GAIN control on full “10”
GAIN switch in the HIGH “pushed in” position
TONE control in the center “0”
VOLUME control at “ ”
6
7. RECORDING/HEADPHONE jack
This speaker-emulated jack enables you to connect directly to a mixing console
or portable recorder such as a Korg PXR4 or D1600. Additionally, you can hook-
up headphones to this jack for a great emulated sound. Turning the VOLUME
controls (6) to zero will facilitate “silent” practicing.
8. EXTENSION SPEAKER jack
This jack allows you to connect an external speaker cabinet for added tonal
possibilities. Be sure to use a speaker cable (unshielded) when doing this and
that you’re using a cabinet that has an impedance not less than 8 Ohms and a
Wattage rating of 10 Watts or more.
IMPORTANT NOTE: Connecting an extension speaker here mutes the internal
speaker.
For optimum performance we strongly recommend the following:
a) ONLY use an extension cabinet of 8 Ohms impedance or more with this
amplifier NOTE:– using speakers with impedances of less than 8 Ohms
can damage the amplifier!
b) DO NOT use a speaker cabinet with a Wattage rating that is less than 10
Watts. If you ignore this warning, you could end up blowing a speaker —
and that’s definitely not recommended!
c) ALWAYS use a high quality speaker cable (unshielded) to connect an
external cabinet — NEVER use a guitar (shielded) cable
d) You must turn off the power before you connect the cable. The amp may
be damaged if you connect or disconnect the cable while the power is on.
9. POWER switch
This is where you turn on the power. Please be sure that all connections are
made prior to turning this unit on.
VERY IMPORTANT NOTE: Always make sure you turn on the Brian May Special
before connecting the BOOSTER OUTPUT to another amplifier to avoid doing any
damage to the front end of the amp you are connecting to.
7
Brian May Special Specifications
• Dimensions (W x H x D): 13.3 x 11.8 x 6.9 (inches)/ 338 x 300 x 175 (mm)
• Weight: 12 lbs. / 5.6 kg
• Output Power: 10 Watts (RMS)
• Speaker: 1 x 6.5" custom-voiced, full-range speaker
• Inputs: Input jack
• Outputs: Booster Output, External Speaker, and Recording/Headphone Line
Out.
• Controls: Gain, Tone and Volume. Gain (High/Low) push switch, Power
switch (with LED)
*Specifications are subject to change without notice.
8
Technical Talk
1) The Original Deacy
As already mentioned in DETAILS at the beginning of this manual, the original
amplifier itself dates back to a Mullard circuit that was published when transistors
first became available as a consumer product, and was probably “rescued” from a
car radio, as it is built on a commercial printed circuit board. The amp features the
total amount of four germanium transistors
— two for the preamp and driver stage, and
two for the push-pull output stage. The cir-
cuit also has an inter-stage driver transformer
(between the driver transistor and the push-
pull pair) and also an output transformer from
the output stage into the speaker.
When connected to a 9 Volt lantern battery the
amp produces a massive 0.45 Watts output.
© Richard Gray
The amp circuit-board was mounted into a 1960’s contemporary bookshelf HiFi
speaker cabinet, of quite small proportions (England’s bookshelves were not very
big at the time!), and contains a small woofer loudspeaker and a cone tweeter
that is coupled through a capacitor. Due to the speaker technology of the time
(and having been played for many years by Brian) it has a relatively mellow sound
when compared to today’s hi-tech, hi-fidelity speaker systems. As it happens, said
mellowness is actually quite complementary when the original Deacy is used in
conjunction with Brian’s homemade guitar and Treble Booster.
Due to the very low input impedance (12kOhms) of the amp John Deacon sal-
vaged from a pile of rubbish (remember, in all probability it was originally de-
signed for use in a car radio), it is actually not very useable when a guitar is
plugged directly into it. This is because guitar pickups need to see a much higher
impedance in order to do their job properly. Hence the use of Brian’s homemade
Booster pedal was vitally important, not only in terms of tone but also in terms of
the overall compatibility of the signal path.
As also already stated, all the components used in the original Deacy, including
speakers and the batteries used, are no longer in production. It is also worth
reiterating two other facts:
i)
The original Deacy had no controls what-so-ever.
&
ii)
It was always used in conjunction with Brian’s homemade Treble
Booster — which, to be accurate, actually boosted the upper mid-range
frequencies.
9
2) The new Brian May Special
To recap on DETAILS, after many meetings with Brian it was decided that this
model would satisfy the following three criteria:
i)
It would sound and feel exactly like his homemade “Deacy system”
which comprises of his Treble Booster and the original Deacy amp
built by John Deacon.
ii)
&
It would also offer more power, features and tonal flexibility.
iii)
It would be as affordable as possible.
10
Brian May Special Signal Path Flowchart
HEADPHONE
T
9V BATTERY SIMULATOR
9V BATTERY SIMULATOR
AND
R
RECORDING
OUTPUT
S
OUTPUT
TRANSFORMER
SIMULATION
SPEAKER SYSTEM
EMULATION
TONE
BOOSTER ONLY
OUTPUT JACK
GAIN
TREBLE
T
S
T
R
S
VOLUME
BOOSTER
T
S
PREAMP
& DRIVER STAGE
PUSH-PULL OUTPUT STAGE
10 Watt
POWER AMP
EXTERNAL
LOUDSPEAKER
OUTPUT
GAIN SWITCH
With reference to the above flowchart:
i)
The TREBLE BOOSTER stage is a direct copy of Brian’s homemade Treble
Booster pedal. The only things different are:
a)
Our circuit is connected to the gain switching circuit to reduce the
pedal booster gain in the LOW Gain switch position. This is required
to clean up the operation of the pedal circuit
b)
The output is fed through the GAIN control. The original pedal does
not have this. With the GAIN control turned up full (i.e. on “10”) and
the GAIN switch on HIGH, this is equivalent to the original pedal. The
GAIN control allows for different sounds to be produced.
ii)
The BOOSTER OUTPUT jack allows the Booster to be fed into another
amp (AC30 Normal channel for instance) for Brian’s on-stage sound. Use of
this jack makes the rest of the Brian May Special inoperative. This has
been done for the reason that, due to circuit constraints, the output from the
booster pedal section is different depending on whether or not it is plugged
into the “Deacy” circuit, or into another amp that has a much higher input
impedance.
iii)
PREAMP & DRIVER STAGE.
This follows the original as much as possible, but:
a)
Silicon PNP transistors are used in place of the original obsolete
Germanium types, but they have been chosen for similar operation,
and also have extra circuitry to help them “believe” they are Germa-
nium.
b)
c)
The inter-stage driver transformer has been replaced by an electronic
transformer simulation. This was required to try and emulate the
performance of the original obsolete transformer.
The addition of the gain switching circuit.
11
iv)
PUSH-PULL OUTPUT STAGE. Again the original format was studied and
for the reasons outlined above has been changed to accommodate avail-
able technology:
a)
b)
Germanium PNP changed to Silicon PNP.
The output transformer has been changed to an electronic simulation.
v)
The TONE circuit was not on the original Deacy amp. This has been added
to give more flexibility to the amp. It is placed after the distortion developing
original circuitry, and can be used to colour the sound from mellow “-” to
quite aggressive “+.” Its effect is inactive in the central, “off” position “0.”
vi)
SPEAKER SYSTEM EMULATION. This circuit emulates the “miced” tonal
response of the original speaker system. The output of this is sent to both
the RECORDING/HEADPHONE OUTPUT jack, for direct connection into a
recording or PA system, and into the onboard 10-Watt POWER AMP sys-
tem.
vii) VOLUME controls the output volume of the POWER AMP.
viii) 10 WATT POWER AMP. This is a flat response amplifier and speaker sys-
tem, recreating the same signal that is sent to the recording/PA system.
ix)
EXTERNAL LOUDSPEAKER JACK. This allows the monitor amp output to
be sent to an external speaker system (NOTE: using this mutes the internal
speaker). This can either be a full range monitor system or, if desired, a
guitar type cabinet. Both will work and give great results, but obviously their
inherent tonality will be somewhat different.
x)
While the original Treble Booster and Deacy amp are both battery powered,
the VOX version is fitted with a mains power supply for practical reasons
(NOTE: the batteries do not last long!). This necessitated the design of the
“9 VOLT BATTERY SIMULATION” circuitry to mimic the unique characteris-
tics that are present in batteries.
xi)
It should be noted that the signal circuitry uses a “phantom” ground; there-
fore ground loop problems when the amp is connected to other external
equipment should be non-existent.
12
IMPORTANT NOTICE TO CONSUMERS
This product has been manufactured according to strict specifications and voltage
requirements that are applicable in the country in which it is intended that this
product should be used. If you have purchased this product via the internet, through
mail order, and/or via a telephone sale, you must verify that this product is intended
to be used in the country in which you reside.
WARNING: Use of this product in any country other than that for which it is intended
could be dangerous and could invalidate the manufacturer's or distributor's warranty.
Please also retain your receipt as proof of purchase otherwise your product may be
disqualified from the manufacturer's or distributor's warranty.
2003 VOX AMPLIFICATION LTD.
Printed in Korea
|