Texas Tone 12 User manual

Blumentritt Amplification Texas Tone 12 Owner's Manual Rev 3 1
Texas Tone 12 Owner’s Manual
Congratulations!
You are now the proud owner of the Texas Tone 12 Guitar Amplifier. This amp packs dynamic vintage
tube sound into a compact cabinet –giving you an amp that’s small and easy to operate and produces
those sweet tube amp sounds and authentic tube tremolo!
Like all Blumentritt Amplification products, your Texas Tone 12™amplifier is designed by musicians and
built using the finest components available. Extensive testing confirms that this amplifier is the absolute
best it can be. In order to get the most out of your new amplifier, we strongly urge you to read the
information contained in this manual before you begin playing.
And thank you for choosing Texas Tone™!

Blumentritt Amplification Texas Tone 12 Owner's Manual Rev 3 2
READ, FOLLOW, HEED, AND KEEP ALL INSTRUCTIONS AND WARNINGS.
CAUTION: RISK OF ELECTRIC SHOCK, DO NOT OPEN
WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS APPARATUS TO RAIN OR
MOISTURE. TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE REAR COVER. NO USER-SERVICEABLE
PARTS INSIDE.
•WARNING: THIS AMPLIFIER PRODUCES HIGH DC VOLTAGE (300+ VDC). DO NOT REMOVE THE REAR
PANEL OR OPERATE WITH THE REAR PANEL REMOVED. SERVICE TO BE PERFORMED BY QUALIFED
PERSONNEL ONLY.
•DO NOT OPERATE NEAR ANY HEAT SOURCE AND DO NOT BLOCK ANY VENTILATION OPENINGS ON THIS
AMPLIFIER. FOR PROPER OPERATION, THIS UNIT REQUIRES 3” (75mm) OF WELL VENTILATED SPACE
AROUND HEATSINKS AND OTHER AIR FLOW PROVISIONS IN THE CABINET.
•DO NOT USE THIS AMPLIFIER NEAR SPLASHING, FALLING, SPRAYING, OR STANDING LIQUIDS.
•CLEAN ONLY WITH LINT-FREE DAMP CLOTH AND DO NOT USE CLEANING AGENTS.
•ONLY CONNECT POWER CORD TO A POLARIZED, SAFETY GROUNDED OUTLET WIRED TO CURRENT
ELECTRICAL CODES AND COMPATIBLE WITH VOLTAGE, POWER, AND FREQUENCY REQUIREMENTS STATED
ON THE REAR PANEL OF THE AMPLIFIER.
•PROTECT THE POWER CORD FROM DAMAGE DUE TO BEING WALKED ON, PINCHED, OR STRAINED.
•UNPLUG THE AMPLIFIER DURING LIGHTNING STORMS OR WHEN UNUSED FOR LONG PERIODS OF TIME.
•ONLY USE ATTACHMENTS, ACCESSORIES, STANDS, OR BRACKETS SPECIFIED BY THE MANUFACTURER FOR
SAFE OPERATION AND TO AVOID INJURY.
•WARNING: TO REDUCE THE RISK OF ELECTRIC SHOCK OR FIRE, DO NOT EXPOSE THIS UNIT TO RAIN OR
MOISTURE.
•SERVICE MUST BE PERFORMED BY QUALIFIED PERSONNEL.
•OUR AMPLIFIERS ARE CAPABLE OF PRODUCING HIGH SOUND PRESSURE LEVELS. CONTINUED EXPOSURE
TO HIGH SOUND PRESSURE LEVELS CAN CAUSE PERMANENT HEARING IMPAIRMENT OR LOSS. USER
CAUTION IS ADVISED AND EAR PROTECTION IS RECOMMENDED IF UNIT IS OPERATED AT HIGH VOLUME.
•WARNING: THIS UNIT REQUIRES A SAFETY GROUNDED 120VAC 60Hz OUTLET WIRED TO CURRENT
ELECTRIC CODES. THE OUTLET MUST REMAIN ACCESSIBLE.
Contents
Congratulations! ...........................................................................................................................................1
READ, FOLLOW, HEED, AND KEEP ALL INSTRUCTIONS AND WARNINGS......................................................2
The Texas Tone 12™......................................................................................................................................3
The Front Panel:............................................................................................................................................4
The Rear Panel:.............................................................................................................................................5
Important Information about Guitar Amp Vacuum Tubes (Valves): ............................................................6
Tube Types and Usage: .............................................................................................................................6
Tubes: Why (And When) To Replace Them: .............................................................................................6
Driver and Tremolo:..............................................................................................................................7
Survival Tips for Tube Amplifiers: .............................................................................................................7

Blumentritt Amplification Texas Tone 12 Owner's Manual Rev 3 3
The Texas Tone 12™
The Texas Tone 12 captures the dynamic performance and tube bias tremolo of those famous vintage
amps of the 1950s, while adding some unique touches and modern safety and construction methods.
Vintage tube guitar amplifiers suffer from outdated electrical grounding methods. Texas Tone amps
feature modern grounding techniques, three-prong electrical plugs, and shielded inputs for safe, low-
noise operation. Many amps from the 1950s also have very little clean headroom. Through careful
tuning and listening to musicians, the Texas Tone 12 allows the guitarist to get that sweet and creamy
tube crunch without splitting your eardrums, and yet still have enough headroom to play those clean
fills.
The grid bias tremolo circuit is lush and harmonic, with that “hypnotic slam effect”, not harsh like some
optical cut-off type tremolo circuits, and can be switched on and off via the included foot switch. For
manual operation, the tremolo circuit is engaged when the foot switch is removed, controllable via the
Depth knob, which effectively shuts off the tremolo oscillator when turned down.
The Texas Tone 12 features deep bass response and shimmering highs without being muddy or icepick
harsh. Break-up is easily controlled via the guitarist's attack on the strings and judicious use of your
guitar's volume and tone controls. From clean to dirty, this amp allows you to remain in control of your
sound. Jazz, country, blues, or rock, you'll be surprised at the variety of tones you can achieve with this
amp.
Other features of Texas Tone™ tube guitar amplifiers:
•Extensive use of MIL-Spec resistors and wiring.
•High-temperature wiring, capacitors, tube sockets, circuit boards and other components.
•Tight-tolerance components.
•Hand wired, with careful attention to lead dress.
•Shielded input signal cables.
Specific Features of the Texas Tone 12:
•Rugged steel chassis.
•Grid bias tremolo –the old kind, deep and rich, and foot switchable.
•An “EQ” tone control that is more independent from the volume control than a typical vintage
tube guitar amplifier.
•Jensen 12” C12Q speaker –Well rounded, straightforward tone with tight lows, mid bite and
bright highs.
•High and low gain inputs.

Blumentritt Amplification Texas Tone 12 Owner's Manual Rev 3 4
The Front Panel:
1. INPUTS: Two inputs allow you the flexibility to use the high-gain or low-gain input, or to input two
guitars.
a. HIGH: This is the normal, high gain, high impedance (1MegΩ) input. Connect your guitar
here by means of a shielded signal cable.
b. LOW: The second input features a -6dB attenuation compared to Input 1. Use Input 2 as a
lower gain input for quieter performance, or when using very high-gain pickups to gain more
headroom before the onset of distortion. When both inputs are used at the same time,
they offer the same gain characteristics.
2. VOLUME: Use this control to adjust the input gain and overall volume level. With the control
towards the counter-clockwise position, the gain is low and very little distortion is produced. As
you rotate the control clockwise the gain increases, producing more overdrive distortion and a
higher output volume level.
3. EQ (Tone): The “EQ” Tone control on the Texas Tone 12 offers less interaction with the volume
control than a typical vintage amplifier tone control circuit. It’s subtle, and yet offers a wide range
of tone control. If you’re used to vintage-type tone control circuits that interact with the volume
control, you may be surprised and pleased that this tone control circuit doesn’t raise or lower the
volume as you rotate the tone control. As the control knob is rotated clockwise from “1”, more
treble frequencies are emphasized.
4. SPEED: The Speed control varies the frequency of the tremolo effect, from about 2 cycles per second
to about 7 cps as the knob is rotated towards fully clockwise.
5. DEPTH: The tremolo depth control allows the user to vary the strength of the tremolo effect, from
minimal/off when rotated counter-clockwise, to pronounced when rotated fully clockwise. The
tremolo effect may be preset, and turned off and on by the included footswitch.
6. Indicator lamp: The lamp will illuminate whenever the amplifier is plugged in to a 120V power
source and turned on.

Blumentritt Amplification Texas Tone 12 Owner's Manual Rev 3 5
The Rear Panel:
1. Fuse: In the event that the fuse blows or the amplifier will not power on, consult a qualified tube
amp technician. Use only a Slow Blow 120V 1 Amp rated fuse.
2. POWER switch: To turn on the amplifier, make sure that the RUN standby switch is off, and then
turn on the power switch. After sufficient time for the tubes to warm up, about 15 seconds, turn on
the Standby switch. To turn off the amplifier, place this switch in the off position
3. AC Line Cord: The grounded power cord should only be plugged into a grounded power outlet that
meets all applicable electrical codes and is compatible with 120 Volts AC, 60 Hz power. Do not
attempt to defeat the safety ground connection.
4. RUN (Standby) switch: The RUN switch controls the high voltage to the tubes of the Texas Tone 12.
This switch may also be used to quiet the amplifier for short periods of time.
5. Speaker connector: The Texas Tone 12 is shipped with a 1/4” cable connected from the chassis to
the internal Jensen 12” C12Q 8Ω speaker.
•To connect the amplifier to an external speaker cabinet, ensure that the amplifier is
powered off, disconnect the 1/4” plug from the amplifier, and use the jack to connect the
external cabinet to the amplifier by means of a heavy duty speaker cable terminated with
1/4” plugs. The minimum impedance for the external speaker is 8 ohms.
•NOTE: Do not power on or operate the amplifier without a speaker plugged in!
6. Footswitch connector: The Texas Tone 12 is shipped with a 1/4” cable connected from the chassis to
the tremolo footswitch. This switch allows the guitarist the set the tremolo speed and depth as
desired, and then turn the tremolo effect on and off by means of a footswitch. With the footswitch
disconnected, the tremolo may by temporarily disabled by turning the Depth control fully counter-
clockwise.
7. Tube sockets (from right to left):
•V1: Use only a high quality 12AX7/ECC83/7025 type vacuum tube.
•V2: Use only a high quality 12DW7/ECC832/7247 type tube. Use of a low-quality tube in
the V2 socket will result in a loss of tremolo effect functionality. The Texas Tone 12 is
equipped with a GE 7247 for maximum tremolo performance.
•V3 & V4: Use a matched pair of high quality 6V6GT tubes. The power tubes are self-biased,
so no bias adjustment in necessary when changing tubes.
•V5: Use only a high quality 5U4GB type rectifier tube. A 5Y3GT may be used, which results
in a colder bias. You may or may not like the results. A 5AR4/GZ34 or Solid State
replacemen is not recommended, as the 6V6 power tubes wll be over-biased (100 + %)

Blumentritt Amplification Texas Tone 12 Owner's Manual Rev 3 6
Important Information about Guitar Amp Vacuum Tubes (Valves):
The sound produced by a tube powered amplifier is significantly different from that produced by a solid
state amplifier with identical design specifications. When pushed past their limits, solid state devices
tend to go immediately into distortion.
Tubes, on the other hand, are non-linear devices that transition more smoothly into distortion, and
produce a more musical set of harmonics, the intensity of which can be controlled by the player. This
characteristic adds warmth and definition to the sound which has become the hallmark of tube
amplifiers. When tubes are driven into clipping, the harmonic overtones can be both sweet and
pleasing or intense and penetrating, depending on the musician’s musical taste and playing technique.
Modern application engineers have designed a number of outstanding solid-state amplifiers that sound
quite good. Some use modeling circuitry which enables them to simulate the distortion characteristics
of a tube amplifier. Since the response of tubes is both dynamic and non-linear, the true range of
characteristics of tube amplifiers can only be approximated. Modern tube amplifiers such as Texas
Tone™ amps, offer that classic, dynamic vintage sound in today’s contemporary market.
Tube Types and Usage:
Preamp tube circuits amplify the signal from your instrument and shape the sound, and they can often
be microphonic (mechanically pick up and transmit external noises). Since these tubes are used in the
critical first stages of a tube amplifier's circuitry, it is very important to use high-quality, low noise/low
microphonic tubes for this application. Although tubes of this quality may typically cost more than
standard tubes, the improvement in performance is worth the investment, and in some cases, critical.
Preamplifier tubes are also used to drive the power tubes. The power tubes convert the low-level,
conditioned signal from the preamplifier into a level that is sufficient to drive the speakers. There are
several types of power tubes available, each of which offers a different performance/sound
characteristic. The 6V6 tubes used in the Texas Tone 12 produce a creamy sound with nice distortion.
Some tubes are available in matched sets. These tubes have been extensively tested for optimum
performance and longevity. Matched sets of power tubes are highly recommended.
Tubes: Why (And When) To Replace Them:
Tubes are made up of a number of fragile mechanical components that are vacuum-sealed in a glass
envelope. A tube's longevity is based on a number of factors, including how hard and often the
amplifier is played, vibration from the speakers, road travel, repeated set up and tear down, etc. Any
time you notice a change in your amplifier's performance, check the tubes first.
If it's been a while since the tubes were replaced and the sound from your amplifier lacks punch, fades
in and out, loses highs or lows or produces unusual sounds, the power tubes may need to be replaced.
If your amplifier squeals, makes noise, loses gain, starts to hum, lacks dynamic sensitivity, or feels as if it
is working against you, the preamplifier tubes may need to be replaced.

Blumentritt Amplification Texas Tone 12 Owner's Manual Rev 3 7
The power tubes are subjected to considerably more stress than the preamplifier tubes. Consequently,
they almost always fail/degrade first. If deteriorating power tubes aren't replaced they will ultimately
fail. Depending on the failure mode, they may even cause severe damage to the audio output
transformer and/or other components in the amplifier. Replacing the tubes before they fail completely
has the potential to save you time, money and unwanted trouble. Since power tubes work together in
an amplifier, it is crucial that they be replaced by a matched set. If you're on the road a lot, we
recommend that you carry a spare matched set of replacement power tubes and their associated driver
tubes.
After turning off the power and disconnecting the amplifier from the power source, carefully check the
tubes (in bright light) for cracks or white spots inside the glass or any other apparent damage. Then,
with the power on, view the tubes in a dark room. Look for preamplifier tubes that do not glow at all or
power tubes that glow excessively red.
Driver and Tremolo:
The driver tube determines the shape and amplitude of the signal applied to the power tubes and has to
work almost as hard as the power tubes. NOTE: The driver tube in the Texas Tone 12™ is a special
design GE 7247 (12DW7/ECC832) type, and also controls the tremolo circuit. Replacing this tube with a
12AT7 or 12AU7 type tube will result in a loss of tremolo effect. A 12AX7 type will change the tone and
output characteristics. Use a 12AX7 type at your own risk.
You can check your preamplifier tubes for microphonics by turning the amplifier on, turning up the gain
and tapping lightly on each tube with a chop stick, or other light wooden dowel. You will be able to
hear the tapping through your speakers, which is normal. It is not normal for a tube to ring like a bell
after it’s tapped. If it does ring then it’s microphonic and should be replaced. Remember to use only
high quality, low microphonic tubes in the preamplifier section. Even though power tubes are rarely
microphonic, you should check them anyway. The power tubes can be checked for microphonics just
like pre-amp tubes.
Survival Tips for Tube Amplifiers:
To prolong tube life, observe these tips and recommendations:
•Make sure the speaker(s) are properly connected prior to turning on the amplifier.
•Allow the amplifier to warm up to room temperature before turning it on. The heat generated
by the tube elements can crack the cold glass housing.
•After playing the amplifier, allow sufficient time for it to properly cool down prior to moving it.
A properly cooled amplifier prolongs tube life due to the internal components being less
susceptible to the damage caused by vibration.
•Match the impedance of your speaker cabinet(s) to your amplifier. Improper impedance
matching will contribute to early tube degradation and may cause premature tube failure.
•Replace the output tube(s) before the performance degrades or the tubes fail completely.
Replace the tube(s) on a regular basis (at least once per year or as often as every 4 to 6 months
if you play long and hard every day).

Blumentritt Amplification Texas Tone 12 Owner's Manual Rev 3 8
•If the locating notch on the base of a power tube breaks off, replace the tube. This significantly
reduces the risk of damaging your amplifier by incorrectly inserting the tube.
•Protect the amplifier from dust and moisture. If liquid gets into the amplifier proper, or if the
amplifier is dropped or otherwise mechanically abused, have it checked out at an authorized
service center before using it.
•Proper maintenance and cleaning in combination with routine checkups by your authorized
service center will insure the best performance and longest life from your amplifier.
CAUTION: Tube replacement should be performed only by qualified service personnel who are familiar
with the dangers of hazardous voltages that are typically present in tube circuitry.
TEXAS TONE 12 TECHNICAL SPECIFICATIONS:
Output Power Rating
10W RMS, 8 Ohm load
Gain:
65Db Typical
“EQ” Tone Control
Wide-range High pass/Low pass
Speaker
12”, 35W Jensen C12Q, 8Ω, 1.25” copper
voice coil, 15oz ceramic magnet, 94.6 dB
sensitivity, 87.3 Hz resonant frequency.
Preamp Tubes
1 x ECC83S/12AX7, 1 x 7247/12DW7
Power Tubes
2 x 6V6S
Rectifier Tube
1 x 5U4GB
Power Requirements
120VAC, 60Hz
Size and Weight
17-1/8” H x 21” W x 9-1/2” D, 28 lbs.
The Texas Tone 12 is covered with a durable Tolex material: wipe it clean with a lint-free cloth.
Never spray cleaning agents onto the cabinet. Avoid abrasive cleansers which would damage the finish.
Specifications and information in this manual are subject to change without notice.