Phil Jones Bass SESSION 77 User manual

SESSION 77
OWNER’S MANUAL

Thank you for purchasing the PJB SESSION 77.
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 two super high-efficiency and proprietary 7-inch speakers were designed by Phil Jones to
get the most of the 100 watts class D amplifier. These 2 amazing woofers are complimented
by our high energy 3-inch high frequency transducer. We have used this speaker in thousands
of our PA speakers and they are proven to be extremely reliable. The response of this speaker
system is of the highest fidelity from 30Hz to 20KHz, which means it does not only sound
great with bass but also with many other instrument, making it a very versatile amplifier.
The SESSION 77 is a single channel bass amplifier with 100 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 Session 77 is our statement of a great sounding and most reliable amp at an
unbeatable price.
READ THIS FIRST
Before using the SESSION 77 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.
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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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SESSION 77
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PANEL OVERVIEW
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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.
4. INPUT LEVEL ADJUSTMENT
Different instruments and 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 the amp and the
instrument, giving you the full extent of the amplifier’s tone and power.

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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 pre amp 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 the
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
This is a stereo mini-jack input for audio source. This can also be connected to the
headphone out of a PJB BIG HEAD headphone amp, giving this amp a 2 channel
capability.
10. AUXILIARY INPUT LEVEL CONTROL
Adjusts the level of aux source.
11. PRE AMP 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.

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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 a long period of time.
14. POWER INDICATOR
NOTE: When power is on, the indicator will light up. If no signal comes in, standby
mode will activate after 30 minutes and the power indicator will turn off. When
signal comes in from INPUT or AUX socket, the amplifier will restart in about 2
seconds.
AC INPUT SOCKET
Will light up when you have power cable connected and amp switched on.
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 (STEREO PHONES)
We recommend the PJB H850 headphones as they were designed for bass and high
fidelity music reproduction. They are a perfect match to the SESSION 77:
We recommend a unit such as the Switchcraft 314 DI box:

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OPERATION & POSITIONING
TURN THE VOLUME DOWN or switch the Mute on the SESSION 77 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 SESSION 77
When transporting or storing the SESSION 77, it is recommended that you
always use the optional cover (not included). A dedicated cover can be
purchased separately.
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 SESSION 77 permanently connected to a power source.
SPECIFICATIONS
Amplifier
100 watt D class amplifier with digital switch mode power supply.
Frequency Response
30Hz -20KHz
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-1V
Low Input: 50mV-2.4V
Pre Amp Out: 1.2V
VENTED ENCLOSURE
2 x7 inch PJB Ferrite Speakers + 1 x PJB 3 inch Tweeter.
Crossover Frequency 4KHZ@ 6dB/Octave
Weight: 27.5lbs
Dimensions: 17inches wide x 11.5 inches high x 14.3inches deep.
Included Parts
6 ft AC Power Cord

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SERVICE/WARRANTY INFORMATION
The SESSION 77 carries a 2-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