Two-Rock Two-Rock Jet User manual

OWNERS MANUAL

Dear Customer,
Thank you for your purchase of a amplifier from Premier Builders
Guild.
As a discerning guitarist, you know the road to great tone begins with
great components.
Our Classic Design, carefully selected parts and hand-built approach
combine to make an extremely versatile instrument.
Please take the time to read this manual. We hope it will answer any
questions that you may have.
We extend a warm welcome to you as a member of a select group of
musicians who have chosen a amplifier.
Important Safety Instructions
1. Read these instructions
2. Keep these instructions
3. Heed all warnings
4. Follow all instructions
5. Do not use this apparatus near water
6. Clean only with dry cloth
7. Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions
8. Do not install near any heat sources such as radiators, heat registers, plugs, and the point
where they exit from the apparatus
9. Protect the power cord from being walked on or pinched particularly at plugs and the point
where they exit from the apparatus
10. Only use attachments/accessories specified by the manufacturer
11. Unplug this apparatus during lightning storms or when unused for long periods of time
12. Refer all servicing to qualified service personnel. Servicing is required when the apparatus has
been damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled
or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture,
does not operate normally, or has been dropped
13. CAUTION: To disconnect the unit completely from the MAINS, unplug the unit. Turning the power
switch off does not disconnect the unit completely from the MAINS.

Front Panel Functions
1. Input Jack- High impedance input to the amplifier. Plug in your instrument here.
2. Push/Pull Treble Control- Adjusts the high frequency response. In the full counter-clockwise
position, high frequencies are bypassed to ground. In the full clockwise position, high frequencies
are allowed to pass to the next gain stage. When the knob is in the “out” position, the high
frequency response is boosted. This is most effective when the input gain is set at 12 o’clock or
lower. The effect is less dramatic as the input gain control is adjusted past the 12 o’clock position.
3. Middle Control- Adjusts the mid-range response. In the full counter-clockwise position, the
tone will be somewhat “scooped” of mid-range response, emphasizing the highs and lows. In the
full clockwise position, mid-range frequencies are allowed to pass to the next gain stage.
4. Bass Control- Adjusts the bass response. In the full counter-clockwise position, low
frequencies are cut. In addition, the response of the treble and mid-range controls is greatly
reduced. In the full clockwise position, low frequencies are allowed to pass to the next gain stage.
5. Input Gain- Adjusts the overall gain of the amplifier. Start with this control in the 12 o’clock
position. Keep in mind that the amount of gain set here determines the signal level feeding the
lead channel. Low gain settings of this control will require higher lead gain settings for the same
amount of overdrive.
6. Master Volume- Adjusts the output level of the clean and lead channels.
7. Lead Gain- Adjusts the input level (gain) of the lead channel.
8. Lead master- Adjusts the output level of the lead channel.
9. Reverb- Mixes the dry signal with a high quality spring-type reverberation effect. This effect is
defeated with the control in the full counter-clockwise position.
10. Stand-by Switch- Should be in the “down” or “stand-by” position when you apply power to the
unit. After a few seconds, place the switch in the “up” position to use the amplifier. You may leave
the unit “powered up” and place this switch in the “stand-by” position to mute the output.
11. Indicator Lamp- This lamp will illuminate when the power switch is in the “up” position,
indicating the unit is receiving A/C power.

Rear Panel Functions
1. A/C Input -Connects the amplifier to A/C power via the power cord supplied. Unless
otherwise specified, your amplifier is designed to operate on 120 volts A/C, 60 cycles.
2. Fuse- 3 AG Type, 250 Volt, SLO-BLO
3. Power Switch- Turns power on.
4. Speaker Output Jacks- There are 2 speaker output jacks. Nominal impedance is 4-8 ohms.
NEVER OPERATE YOUR AMPLIFIER WITHOUT A PROPER SPEAKER LOAD CONNECTED.
Be sure to match the impedance of your cabinet with the impedance (output) of the amplifier.
5. Effects Send- Use this jack to send the amplifiers signal to outboard effects.
6. Effects Return- Use this jack to connect the output of your effects to the amplifier.
7. Footswitch Jack- The footswitch connects here. The clean/lead and tone bypass functions
can only be activated via the footswitch.
NOTE: All switches are ON in the “up” position
Fuse Chart
All Fuses are 3AG Type 250 Volt, SLO-BLO
Export 100 Volt/Domestic Export 220, 230, 240 Fuses:
2A- Jet and Jet Signature 1A- Jet and Jet Signature
FOOT SWITCH

(Tube Complement)
V1- 12AX7, Rhythm channel
V2- 12AX7, Lead Channel
V3- 5751/12AT7, Reverb Driver
V4- 12AX7, Reverb/effects
V5- 12AX7. Phase Inverter
V6, V7- 6V6GC/6L6GC, Output
Each fine production tube is tested and matched to our exacting specifications. External bias
adjustment and test points are located on the chassis near the output tube sockets. A digital
voltmeter and small screwdriver are required for bias adjustment.
BIAS ADJUSTMENTS:
Power up unit and connect proper speaker load.
Set master volumes and effects return controls to zero.
DO NOT apply any signal to the input during the biasing procedure!
Take unit off standby and allow a few seconds for the circuit to stabilize.
Set voltmeter to Millivolt scale (or lowest volt scale 60 millivolts=.060 volts.)
With meter grounded to chassis and + probe at test point, measure voltage.
A reading of 0.055 to 0.060 volts is normal for 50 Watt amplifiers with (2) 6L6’s. A reading of 0.115
to 0.120
volts is normal for 100 Watt amplifiers with (4) 6L6’s. If not in this range, adjust by turning bias
screw SLOWLY a small amount. Do not set above .070!
For other tube types (5881, 6550, EL34) check with the manufacturer or contact us for
recommendations.
Settings higher than .065 with 6L6 tubes may cause premature tube wear and possibly damage
the amplifier.
Keep in mind that tubes vary in quality, and some tubes can handle upwards of 40 ma each (a
reading at the test point of .080!) However, to be on the safe side, use the above as a guide.
NOTE: Some amps are equipped with 2 bias pots, one for low power, and the other for high
power. Adjust bias in both hi and low power settings!
NOTE: Some amps are Class A/AB. In LOW POWER MODE (CLASS A), you will not get a proper
reading- adjust bias in high power mode only.
WARNING! No user serviceable parts inside! Refer to qualified service person only.
LINE CORD- For your safety, connect to grounded A/C receptacle only.

amplifiers are brought to you by Premier Builders Guild.
We know your new amplifier will provide many hours of enjoyment and
inspiration in the years to come. This manual is a resource for some of your
questions. Please contact us with any other questions or comments that you may
have. We look forward to hearing from you!
PHONE: [phone]-TONE (8663) (M-F 9am-5pm PST)
FAX: [phone]
ADDRESS: Two-Rock
619 Martin Avenue, Suite 6
Rohnert Park, CA 94928
SERVICE: [e-mail]
WEB: www.two-rock.com
PRECAUTIONS:
DO NOT expose to rain or any other moisture.
DO NOT use cleaning solvents. Wipe exterior with a clean, dry
cloth only.
Refer servicing to a qualified service technician.

This is a product of
Premier Builders Guild
619 MARTIN AVENUE, SUITE 6
ROHNERT PARK, CA 94928
707-584-8663
www.two-rock.com
SERIAL NUMBER: _____________________________

Guitar Amplification
619 Martin Ave. Ste 6
Rohnert Park, CA 94928
[phone]
DECLARATION OF CONFORMITY
Report #R070212
We, Two-Rock Amplifiers, in coordination with CES Laboratories, declare, taking this declaration under our
total responsibility, that the below models are in conformity with the provisions of the following EC
Directive(s) when installed in accordance with the installation instructions contained in the product
documentation:
73/23/EEC Low Voltage Directive
89/336/EEC EMC Directive
And that the standards and/or technical specifications referenced below have been applied:
Applicable Standards:
EN55013
EN60065
Custom Reverb
Jet
Studio Pro
Sensor
Eric Gales
EXO-15
Classic Reverb
Bi-Onyx
TS-1
Classic Type Series
Gain Master
Matt Schofield
Signature:
January 1, 2013
Approved By:
Chandra Garudachar
President
CES LABORATORIES
Prepard By:
Jyotsna Bedi
23361 Cypress Pt
Mission Viejo, CA 92692