Phil Jones Bass MICRO 7 User manual

MICRO 7
OWNER’S MANUAL

Thank you for purchasing the PJB MICRO 7.
Phil Jones Bass has been building bass amplifiers for the most demanding bassists. Phil
thought it was about time that a bass amp delivers the true tone of a bass instrument, and
yet still be affordable. We looked into the most efficient way we could to build an amp
without sacrificing the most important aspect: TONE!
The one super high-efficiency and proprietary 7-inch speaker was designed by Phil Jones to
get the most of the 50 watts class D amplifier. This amazing woofer is complimented by our
high energy 3-inch high frequency transducer. We have used this speaker in thousands of our
PA speakers and it is proven to be extremely reliable. The response of this speaker system is
of the highest fidelity from 36Hz to 22KHz, which means it does not only sound great with
bass but also with many other instrument, making it a very versatile amplifier.
The Micro 7 is a single channel bass amplifier with 50 watts output. By using all digital
circuitry, the amp works on AC voltage from 100 to 260 Volts without the need of a selector.
Digital circuits are far more efficient than their old analog counterparts with the benefit of
less wasted power as heat, thus giving the amp a greater longevity. (Heat is an amplifier's
worst enemy since it slowly kills electronic components.)
We have not skimped on quality of parts. We designed around the basic needs of most bass
players. To ensure longevity we equipped this amp with a solid kick proof, acoustically
transparent curved steel grill. This amp uses the same level of quality parts found on all PJB
amps. The Micro 7 is our statement of a great sounding and most reliable amp at an
unbeatable price.
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READ THIS FIRST
 Before using the MICRO 7 please read ALL the instructions.
 On receipt of product, check for any signs of physical damage arising from shipping. If any
damage is visible, contact your retailer.
 Do not install this equipment in a confined or building-in space such as a bookcase or
similar unit. The amp should remain in well ventilation conditions at an open site. The
ventilation should not be impeded by covering the ventilation openings with items such as
newspaper, table-cloths, curtains, etc.
 WARNING: Only use attachments/accessories specified or provided by the manufacturer.
 WARNING: To reduce the risk of fire or electric shock, do not expose the amp to rain or
moisture. The amp shall not be exposed to dripping or splashing. Objects filled with liquids
such as a coffee cup shall not be placed on top of the amp.
 When not in use and during movement, please take care of the power cord, e.g. tie up the
power cord with cable tie. It shall be free from sharp edges which can cause abrasion of
the power cord. When put into use again, please make sure the power cord being not
damaged. If any damages found, please replace it with one specified by the manufacturer
or with the same specifications as the original one.
 Correct Disposal of this product. This marking indicates that this product should not be
disposed with other household wastes throughout the EU. To prevent possible harm to the
environment or human health from uncontrolled waste disposal, recycle it responsibly to
promote the sustainable reuse of material resources. To return your used device, please
use the return and collection systems or contact the retailer where the product was
purchased. They can take this product for environmental safe recycling.

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1. BASS INSTRUMENT INPUT JACK
This is a standard ¼ inch mono jack socket.
For the best possible sound we recommend you use the PJB BI-12 instrument
cable as it has very low self-capacitance and absolute shielding resulting in
greater transparency of sound and less noise.
2. LED CLIP/MUTE INDICATOR
When the amplifier output is clipping, the LED will light up in red. When the
amplifier is muted, the LED will light up in green
3. INPUT /MUTE SWITCH
Top Position: Mute On
Middle Position: Low sensitivity for mainly active basses.
Bottom position: High sensitivity for passive basses.
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PANEL OVERVIEW

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4. INPUT LEVEL ADJUSTMENT
Different instruments and also different playing styles or even players will
affect the signal level. Adjust this control so that the signal overload Clip light
does not light up. This optimizes the signal to noise ratio between amp and
instrument, giving you the full extent of the amplifier’s tone and power.
5. BASS CONTROL
This is centered on the fundamental frequencies of 4 and 5 string basses.
Boosting or cutting this will have significant effect on the weight of the tone.
6. MID RANGE CONTROL
This gives the “voice” of your instrument. Generally, you will find that cutting
this control instead of boosting it will give a “truer” bass sound. Boosting may
be useful for soloing or special effects.
7. TREBLE CONTROL
This gives the instrument the definition to the sound. Boosting it for ”slap”
bass or cutting back for ”Reggae” bass sound.
If you boost excessively you may get noise as hiss and that could be due to the
noise coming from the preamp in your bass, or a poorly shielded instrument
cable. PJB has a dedicated bass instrument cable (Model BI-12) that is totally
noise free and actually will improve the tone of your instrument.
8. MASTER VOLUME CONTROL
This is the master volume control. It controls how much power you send to
your speakers as well as the line out socket on the back of the amp. When
setting up your tone or plugging in your instrument, you should keep this
control at a low level. Instruments are all different when it comes to how
much output is from the pickups. It is likewise for players depending on how
hard or soft you play. Note this control is a true “Audio Taper” control so that
the level position may be set higher compared to amps that use a “Linear
Taper” control. An “Audio Taper “ control has far more precision in controlling
your output and uses the full rotation to control the level. A Linear control on
the other hand uses the first few degrees of turn to give the impression that
the amplifier has more volume than what it actually does.
9. AUXILIARY INPUT LEVEL CONTROL
Adjusts the level of aux source.
10. AUXILIARY INPUT
This is a stereo mini-jack input for audio source. This can also be connected to
the headphone out of a PJB BIGHEAD headphone amp, giving this amp a 2
channel capability.

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11. PREAMP LINE OUT
This output can be used to drive a powered cabinet.
This can also be connected to a passive DI box for connecting to a PA or
recording console.
We recommend a unit such as the Switchcraft 314 DI box:
When a headphone is connected to the jack, the speaker output will be
disconnected and the speakers will be muted.
13. POWER SWITCH
This switches off the amplifier from the DC supply but AC signal will still be in
the internal supply. We advise that you disconnect the power supply from AC
source if you do not intend to use the unit for long periods of time.
14. POWER INDICATOR
Will light up when you have connected and amp switched on.
AC INPUT SOCKET
supplied cable
15.
Connect to your power source. Make sure the specified voltage is correct for your
country, Connect to a grounded outlet in accordance with the input power voltage
and frequency specified just below the power inlet.
12. HEADPHONE SOCKET (STEREOPHONES)
We recommend the PJB H850 headphones as they were designed for bass and
high fidelity music reproduction. They are a perfect match to the MICRO 7:

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OPERATION & POSITIONING
TURN THE VOLUME DOWN or switch the Mute on the MICRO 7 before
plugging in your instrument.
ALWAYS USE A HIGH QUALITY GROUNDED AC POWER CABLE. NEVER USE
THIS AMPLIFIER WITH THE GROUND CONNECTION REMOVED. We
recommend you use PJB cables for speaker connections as they have virtually
no loss so there is maximum transfer of power from amplifier to speaker.
Loudspeakers also vary in efficiency with frequency. Most loudspeakers are
louder in the mid range than in the bass or extreme high frequencies: which is
one reason we need EQ in am amplifier. An EQ control is just a frequency
selective volume control: It boosts or cuts level at a specific frequency.
Excessive boosting of frequencies, especially on bass frequencies where
nearly 90% of the amplifier power is used can rob a bass system of its
headroom.
Amp positioning and EQ
Nearly all bass speakers are Omni-directional at all the fundamental bass
tones from about 200Hz
(the fundamental of a G string on 12th Fret) down to the lowest frequency a
speaker can reproduce. The open E is 41.2Hz and open B string is 31Hz.
Mid range and high frequencies tend to be directional. This is why many
players angle their cabinets to ear level so they can hear the definition better.
Because bass frequencies radiate all around the cabinet, the bass will sound
weaker when the cabinet is placed on a large stage with no boundaries. By
placing the speakers close to a wall or even to a corner, the bass frequencies
will appear to be much stronger and it may not need to have much boost on
EQ to allow the amp to have more headroom.
By careful positioning of your bass speakers, you may be able to get a fuller
low frequency without the use of boosting too much EQ. This will give not
only give your amp more headroom, but also put less stress on your speakers.
Keeping the cabinet on the floor will give deeper bass than if it is placed on a
stand or chair, as the floor reinforces the low frequencies.

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TRANSPORTING AND STORING THE MICRO 7
When Storing:
Keep in a dry location preferably at room temperature.
Do not store in temperatures below -20 Degrees C or above 40 Degrees C.
Do not allow it to get wet. If this occurs, never turn it on in this condition.
Do not leave the MICRO 7 permanently connected to a power source.
SPECIFICATIONS
Amplifier
50 watt D class amplifier with digital switch mode power supply.
Frequency Response
36Hz -22KHz
Signal to Noise Ratio
≥82dB(A) (EQ center, Volume on Full.)
Impedance
High Input: >500KΩ/22pF
Low Input: >30KΩ/22pF
Pre Amp Line Out: < 2KΩ
Levels
High Input: 30mV-0.5V
Low Input: 50mV-1V
Pre Amp Out: 1.2V
VENTED ENCLOSURE
1 x7 inch PJB Ferrite Speaker + 1 x PJB 3-inch Tweeter.
Crossover Frequency 4KHZ@ 6dB/Octave
Dimensions: 11.2 inches wide x 9.7inches deep x9.8 inches high.
Weight: 15.5 pounds
Included Parts
6 ft AC Power Cord.

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SERVICE/WARRANTY INFORMATION
The Micro 7 carries a 1-year limited warranty on parts and labor.
Products must be purchased from an authorized PJB dealer.
Buyer must complete and return the enclosed warranty card within 15 days of
purchase, or register online by www.pjbworld.com
This warranty covers defect in materials or workmanship that occurs in normal
use. Within warranty period PJB or its local distributor will repair or replace the
defect unit free of labor and parts charge. It is the buyer’s responsibility to use
the unit strictly according to instructions written in the owner ’s manual.
This warranty is not transferable; it is provided to original owner only.
Damage/defects caused by the following conditions are not covered by this
warranty:
Improper handling, neglect or failure to operate the unit in compliance with
the instructions given in user manual;
Connection or operation in any way that does not comply with the technical or
safely regulations applicable in the country where the product is used;
Repairs or modifications by anyone other than authorized PJB service agent;
Damages/defects caused by force majeure or any other condition that is
beyond the control of PJB.
IMPORTANT:
In all warranty issues your first line of communication should be to the retailer
you purchased from, even if you have purchased product from an online
source.
When a local distributor is available, customer who prefers to purchase across
country online maybe required to pay shipping charges to retailer in order to
obtain service.
Warranty policies differ in countries outside of USA. Please check with local
distributors for warranty information in your region. Register first with your local
distributor if available will give you better and quicker service when needed.
Further questions, please contact your local distributors, or PJB by email
[e-mail].
PHIL JONES BASS
American Acoustic Development LLC
8509 Mid County Industrial Dr St Louis,
MO 63114 USA
Tel: [phone] (855-BASS-510)
www.pjbworld.com
[e-mail]
For servicing outside USA please contact our distributor in your country.
Information can be found on our website.

PHIL JONES BASS
American Acoustic Development LLC
8509 Mid County Industrial Dr, St Louis,
MO 63114 USA
WWW.PJBWORLD.COM
Printed in China