Aclam Guitars Dr.Robert Vox UL730 Operator's manual

USER MANUAL & SAFETY INSTRUCTIONS

Overview
Features
Specs & material Included
Powering Requirements
Operating Diagram
Controls
Advanced Internal Controls
Setting examples
Setting up on a pedalboard
Trouble Shooting
Security Instructions
Warranty Terms
4
6
7
8
10
11
16
18
22
25
26
27
Index
www.aclamguitars.com
C/ Consell de Cent, 201 - local
08011 Barcelona. Spain
Llevinac S.L.
CIF: B64412406
Thank you for purchasing the Dr. Robert!
The most accurate replica of the legendary Vox® UL730 amplier!

4 5
Disponible en otros idiomas en:
www.aclamguitars.com
Available in other languages at:
www.aclamguitars.com
The Vox®UL700 amp series were the secret weapon
used by The Beatles to achieve the unique guitar tone on
Revolver and part of Sgt. Peppers. They were also used by
The Rolling Stones and Jimmy Page of Led Zeppelin.
Introduced in 1966 these state-of-the-art guitar amps
mixed a solid-state preamp with a tube power amp section.
Tubes were standard at that time but had the
inconvenience of being voluminous and prone to fail,
plus they needed bigger transformers due to impedance
matching and power requirements. Transistors were the
solution as they were way smaller, reliable and took much
less energy to operate. So, in 1965, Vox engineer Dick
Denney decided to develop a hybrid amp with a solid-state
preamp and tube powered amp section.
Thanks to the relatively new transistor technology, lots of
features could be added.
Top of the line models included two channels with three
band eq each, distortion, tremolo and reverb.
Overview
There were many variants with different power ratings, but
the ones used by The Beatles were the UL730 (30w) and
UL7120 (120w).
Unfortunately, aside from The Beatles, those amps weren't
popularly used at the time and most of them ended being
returned to Vox for their disposal.
Only a small number of UL730 units survived (around
20/30 units as some renown Vox connoisseurs state),
attaining the title of being the most collectable Vox amps,
with prohibitively collector pricing.
Now they are the missing link between tube and solid-
state amps.
The Dr. Robert is based on the Normal channel of our
Vox®UL730 S/N: 3042. We traced the original tag board
circuits and measured each component’s value to make
the closest replica of the amp’s soul and character.
One of the keys of its tone is the “Mids” control which is
one of the most interesting mid-range eq ever found on
an amp. By turning it counterclockwise, a great amount
of mid-frequencies will be subtracted creating a scooped
sound. On the other hand, when it's turned clockwise it
will bring out all the mids and the signal will build up in
gain. By tailoring the “Mids” knob you can control both
midrange and saturation.
As the solid-state preamp of the UL730 doesn’t create
much distortion by itself we’ve coupled it with a custom
FET saturation engine to mimic the attributes of the tube
power amp section. Not happy with that, we’ve gone
even further creating the “Mach Schau!” section, which
adds saturation to your main sound and includes an
independent volume control to allow you to have both a
rhythmic and a solo tone.

6 7
THE MOST ACCURATE REPLICA OF THE ORIGINAL
UL730 PREAMP:
Sometimes you can’t trust the internet or an old schematic!
We’ve found major discrepancies between the published
schematic and the real thing, such as component types
and values, so we can assure this is the closest you can
get to the rarest Vox amp!
Following the preamp there’s a custom FET based circuit
emulating the saturation produced by the UL730 EL84’s
tube power amp section.
Additionally, the circuit works with the same voltages
found on the original amp thanks to a charge pump circuit
which takes the 9VDC from the battery or DC plug and
converts it to 18VDC.
MACH SCHAU! FUNCTION:
Extra saturation function via a footswitch with an
independent volume control. Hit it when the venue’s
manager wants you to play harder!
CIRCUIT TAILORED FOR BOTH GUITAR AND
BASS INSTRUMENTS:
Although based on the UL730 preamp, the UL400 series
(designed for bass) shared almost the same circuitry.
When doing tests using different instruments and amps
By tuning the FET circuit a bit, we managed to make the
Dr. Robert suitable for both guitar and bass. No low-end
drops resulting in a prefect preamp and distortion tool to
plug directly to the desk or into an amp.
CUSTOM GRAPHICS BY REVOLVER’S COVER ARTIST,
KLAUS VOORMANN:
We’re so honored to have Mr. Klaus Voormann, designer
of The Beatle’s Revolver album cover, sign the artwork for
the Dr. Robert!
HIGH END COMPONENTS AND TRUE BYPASS
SWITCHING:
components to the original amp on the Dr. Robert.
Features
Carbon comp resistors, Nichicon Fine Gold and Wima
caps, Alpha pots and switches makes the Dr. Robert a
reliable pedal with a superb tone.
SMART TRACK®FASTENING SYSTEM:
All our pedals use a custom enclosure designed to match
perfectly our Smart Track®pedalboards. Using the side
thumb screws, you’ll be able to lock safely the stompbox
into one of our pedalboards. It also was designed with the
other pedalboard options in the market in mind.
(see page 22)
DECLARATION OF CONFORMITY:
This product complies with the requirements of
MADE IN SPAIN
MATERIAL INCLUDED
1 x Dr. Robert pedal
1 x Anti-sliding rubber pad
1 x Velcro
®
pad
DIMENSIONS: 13,6 x 8,7 x 5,5cm (5.4” x 3.4” x 2.2”)
with knobs
POWER REQUIREMENTS: 9V DC Center Negative 100mA
minimum or a 9V battery
WEIGHT: 410g. (0.90 lbs)
BYPASS: True Bypass
Specs & Material included

8 9
Loosen the side thumb screws and disassemble the
Smart Track®system of both sides of the pedal.
Unscrew the four bolts of the baseplate using a
pozidriv screwdriver to access the inside of the pedal.
Power requeriments
9V BATTERY
To operate the Dr. Robert with a 9V battery you’ll have to
follow the next steps:
1
2
POWER SUPPLY
This unit can be powered with a 9VDC negative tip power
supply with the standard Boss type 2.1mm connector.
Current supply should be a minimum of 100 mA just to
leave a safety margin for the DC adapter.
Make sure you use a good quality power supply and avoid
using generic SMPS type adapter which can induce high
pitched noise to the audio.
CAUTION:
If used improperly, batteries may explode or leak
and cause damage or injury.
- The use of an incorrect type of battery can void the
safeguard mechanisms of the device (for example, in the
case of some lithium battery types)
- Batteries must never be recharged, heated, taken apart,
- Do not expose the unit to extremely high temperatures,
direct sunlight or other devices that radiate heat, as it may
Put the 9V battery in the position showed in the
diagram. Make sure to use a good quality alkaline
battery to ensure the longest time of operation.
Tight back the lid with the 4 screws and reassembly
the Smart Track®system.
3
4

10 11
Operating Diagram
GUITAR AMP INPUT OUTPUT INPUT
Controls
INPUT JACK POWER JACK OUTPUT JACK
1 2 3
1 32

12 13
5
6
BYPASS SWITCH: Engages the unit allowing the
lights up the LED above it.
VOL: Controls the overall volume of the Dr. Robert
when you’re not using the Mach Schau! section.
GAIN: This control is placed in the same position of
the circuit as the original UL730’s volume control.
Since none of the Vox®UL series had a master volume
control the user had to turn it all the way up to bring
the amp into saturation, and believe us, this thing is
loud. To solve that we put the Vol control at the end
of the FET section so now, the volume control on the
original amp turns into a gain knob on the Dr. Robert.
At lower settings the Gain knob will produce a clean
tone, but as you approach the 12’o-clock mark the FET
section will start entering the saturation region.
Have in mind that due to Dr. Robert’s great dynamics,
different types of guitars and pickups will affect the
clean range of the Gain knob.
MIDS: This is the most critical knob to tailor your
sound. Unlike most equalizer circuits (which get placed
after or before the volume control) Vox®separated
the mids control from the rest of the tone stack in the
followed by the Mids control before the volume pot.
After this, Vox®placed a special gain stage coupled
with the Bass and Treble controls. Thus, you can
control the midrange without interacting with the rest
of the eq, as traditional tone stacks do.
By turning it counterclockwise, it will subtract a great
amount of mid-range, creating a really interesting
scooped sound.
Turning it clockwise will bring mid frequencies and the
overall gain builds up hitting harder the EL84 tubes,
creating saturation.
4
7
Just like the real amp does, Dr. Robert’s “Mids” control has the same behavior thanks to the FET section specially tuned
to mimic the power amp saturation on the UL730.
So, keep in mind, the “Mids” knob will have a great effect on the overall saturation of the unit.
4
567
MS VOL MIDS

14 15
THE MACH SCHAU! SECTION
The Mach Schau! section was conceived during the design
process of the Dr. Robert to make it more versatile in live
scenarios. Every now and then, you need an extra push
in terms of gain, to play solo parts or for songs you want
people to shake their waist at.
Taking The Beatles “She Said She Said” cut for example,
there’s a lead part, clearly saturated and the main rhythmic
arpeggio in a cleaner tone. With the Dr. Robert you could
play both tones using the Mach Schau! section for the
lead parts.
The Mach Schau! extra saturation will always be
determined by the Gain and Mids knob settings, meaning
that the heavier your main setting is, the grittier this
section will build up from. Paired with the extra gain circuit
there’s an independent volume control labelled “MS VOL”
to allow you a better control of this section.
Easy and simple :)
MACH SCHAU! SWITCH: Activates the Mach Schau!
Section. It also lights up the LED above it.
(Note that the Mach Schau! function works only
when the Dr. Robert’s bypass switch is activated.
This function is not an independent overdrive but an
extra tone of Dr. Robert’s main circuit)
MS VOL: Independent volume control for the
Mach Schau! section.
8
9
8
9
MS VOL MIDS

16 17
Advanced Internal
Controls
The original UL730 had a 3 band eq, but since the Middle
control is the one that helps to tailor the tone better we
decided to put the Bass and Treble controls inside the
pedal. Just to make the user interface cleaner and easier
to operate.
HOW TO ACCESS THE INTERNAL CONTROLS:
Just follow the same steps described on the 9V battery
replacement instructions. To adjust the internal controls,
TREBLE:
Controls the amount of high frequency content of the
signal before reaching the FET section. Setting this
knob will have an effect over the overall gain.
SIDE TRIM POTS:
These trim pots are for calibration of the FET stage
during the manufacturing process.
They are not intended to be set by the user so
PLEASE DON’T MESS WITH THEM or
the warranty will be void!
BASS:
Sets the amount of low frequency content reaching
the FET section. The Treble and Bass controls work
together in a tone-stacked manner, so they are a bit
interactive.
Both controls are factory set at 12 o ‘clock.
2
3
1
BASS
1TREBLE SIDE TRIM POTS
23
3
2
1
3

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Setting
Examples
To show you the immense potential of the Dr. Robert, we recommend you trying the following setting examples.
Bear in mind the Vox®UL730 is a British amp so we noticed a certain preference of the Dr. Robert to amps powered with
EL84 and EL34 tubes.
ON
OFF
ON
OFF
PAPERBACK WRITER (LEAD GUITAR) SHE SAID SHE SAID RAIN DR. ROBERT
Epiphone Casino & Gretsch 7120 Epiphone Casino & Gibson SG (with Maestro Vibrola) Epiphone Casino Epiphone Casino
MIDS MIDSMS VOL MS VOL MS VOL MS VOLMIDS MIDS

20 21
TAXMAN TAXMAN (SOLO) SGT. PEPPER'S (RHYTHM) SGT. PEPPER'S (LEAD GUITAR)
ON
OFF
ON
OFF
Fender Stratocaster Fender Stratocaster Epiphone Casino Epiphone Casino & Fender Stratocaster
MIDS MIDSMS VOL MS VOL MS VOL MS VOLMIDS MIDS

22 23
Setting up on
a pedalboard
All our effect pedals use a custom light aluminum
®
pedalboards. We incorporated a proprietary locking
system which allows the user to fasten the pedal without
the need of using the typical hook and loop method.
This custom fastening system follows the same
philosophy behind the Smart Track®fasteners but
integrated in the enclosure reducing the space occupied
by each pedal.
That translates into more pedal density for the same
space, and who doesn’t want that?
We strongly recommend you to take a look at our line of
pedalboards, which are the best complement to our pedals!
Add the anti-sliding rubber pad at the bottom of your
pedal, specially shaped for this unit.
Surface must be clean and dry before applying
adhesive pad.
1
HOW TO MOUNT IT ON A SMART TRACK®PEDALBOARD:
!
Loosen the 2 thumb screws to unlock the bottom
pieces out of the pedal.
Place the pedal, inserting the bottom pieces inside
the grooves.
2
3
4

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Tighten the two thumb screws with your hands or
with a screwdriver.
5
Hook and Loop: Take the included super strong Velcro®
pad and stick it on the base plate.
Again, make sure the base is clean of dirt and dust.
Pre-drilled pedalboard: Fix it with a bolt and a nut you
zip tie over the pedal you can take advantage of the Smart
Track®enclosure and put the zip ties over the holes.
DIY woodboard: You can screw the pedal directly with
wood bolts through the enclosure side holes.
No board: If you use the pedals standalone make sure
you place the included anti-sliding rubber pad on the
baseplate.
USING OTHER PEDALBOARDS:
Trouble
Shooting
SIGNAL PASSES THROUGH IN BYPASS BUT NOT
WHEN ENGAGED:
Make sure you´ve connected the input and output jacks
correctly.
PEDAL DOES NOT WORK WITH THE POWER SUPPLY:
Take a look at your power supply output voltage and
polarity. Make sure it’s 9V DC negative tip with a minimum
output of 100 mA.
PEDAL WON’T ENGAGE WITH BOTH THE POWER
SUPPLY AND BATTERY:
Check there’s a plug inserted into the Input Jack.
PEDAL SOUNDS DISTORTED AT REALLY LOW
SETTINGS:
- If you’re running on batteries replace it with a new one or
check the voltage with a multimeter.
- The Dr. Robert is a really dynamic pedal the same way the
original amp is. Different types of guitars and pickups will
make it saturate in different regions of the knobs. That is a
totally correct response from the unit.
- Make sure there’s not any pedal before the Dr. Robert
increasing too much the guitar’s signal output, like
boosters, preamps compressors and other overdrive
pedals.

26 27
Security
Instructions
- Read these instructions carefully.
- Keep them for future reference.
- Heed all warnings.
- Aclam Guitars shall not be held liable for any damage
to persons or property caused by incorrect operation or
installation.
- Use the product in accordance with the assembly
instructions. Do not modify or operate the product
incorrectly.
- Incorrect installation could result in serious damage to
persons and property.
- Open the package and check that the assembly
instructions and all the parts of the product are there.
Check that none of the parts are defective.
- Keep out of reach of children. This product contains
small parts that represent a choking hazard if swallowed.
- If you do not understand these safety instructions,
or if you have any queries regarding the safety of the
installation, please contact Aclam Guitars:
- If you wish to contact Customer Services at Aclam
· Unsuitable use
· Incorrect storage
· Explosions or burns caused by incorrect power supplies.
· Other causes not attributable to the manufacturer.
To make a claim, the purchaser must return the product to
the store where it was purchased within one month from
discovering the fault, and report the nature of the problem,
the time and the circumstances under which it occurred.
If the product was purchased through our website, the
purchaser must refer to www.aclamguitars.com and
complete a RMA (Return to Manufacturer Authorization)
form before returning the unit.
We strongly recommend looking at the “Troubleshooting”
section of the manual before panicking!!
This product is covered by a two-year warranty from
the purchase date, under the conditions and supporting
evidence regulated by current Spanish Legislation.
The product warranty will only be applicable by presenting
the proof of purchase (which is the invoice or the receipt)
and serial number.
A product is covered under warranty if it presents lack of
product characteristics, is defective which prevents its
normal use according to its purpose, or does not function
as described. The purchaser has the right to have the
article repaired or replaced (either the product or the faulty
component, at the discretion of the manufacturer.)
The warranty is not transferable and won’t cover the
following issues:
service center.
Warranty
Terms

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