Download 22 Watt Chassis (LW1322)

Little Walter Tube Amps
22 Watt Chassis (LW1322)
Specifications Manual
European Power 220 VAC/50 Cycle
Serial Number: LW1222-_____
Lacquered Tweed Combo
Celestion Creamback 65 Speaker
Custom Built for
New Customer,
Thank you for purchasing a Little
Walter musical instrument amplifier.
It is our intention
to create a valve (vacuum tube) amplification device using old school techniques and
the best possible components available while remaining true to the tone of the early
amplifiers that are sought after today by collectors and professional recording
musicians. This amplifier was built entirely by hand by Phil N. Bradbury and uses no
printed circuit boards or tag boards in order to give you a true Point-To-Point
constructed unit. This amplifier uses octal (8-pin) pre amp tubes as opposed to the
normal 9 pin pre amp tubes utilized in the bulk of amplifiers built today. Although the 8
pin 6SC7 pre amp tubes do not have quite the gain of the 9 pin tubes they exhibit
exceptional tone and interact with the musicians’ tactile feel and attack on the strings in
a much more sensitive manner. Preamp / Phase splitter tubes are 6SC7’s The Power
tubes are JJ -6V6 tubes. The rectifier tube is a 5Y3. This amplifier puts out 22 watts
through an 8 ohm load. We suggest you use JJ power tubes as they will handle high
levels of voltage and bias.
Specifications of the Little
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Walter 22 watt chassis:
Electrical requirements: 220 Volts AC (50 cycle)
Pre Amp Tube: 6SC7
Phase Inverter Tube (PI): 6SC7
Power Tubes: 6V6GT
Rectifier Tube:5Y3
Filter Capacitors: 1-30uf @ 450v, 2-20uf @ 450v
Input 1: Bright Input
Input 2: Normal Input
Controls: Volume for bright input, Volume for Normal Input / Tone for Both Inputs
Output: 22 watts @ 8 ohms
Direct Output Jack (Direct connect to Board or PA System) Must use w/Speaker
Cabinet: Lacquered Tweed Dove Tail Joined Combo cabinet
Speaker: 12” Celestion Cream Back 65 Speaker
This amp contains very high voltage and the chassis should not be opened or worked on by
an inexperienced person. Please use a professional electronics technician when working
inside this chassis.
Operation of this unit:
Power Up:
When you turn on the amp push the far right switch down to the ON position and wait
at least 1 minute before pushing down the next switch from STANDBY to ON. This will
allow the heaters in the tubes to warm up to operating temperature before the high
voltage is applied. This practice will increase the life of your tubes.
INPUT and VOLUME
This amp has a separate volume control for each input. The INPUT 1 (far left) is the
bright input. This will have a slightly brighter tone. The INPUT 1 VOLUME knob
controls the volume for the bright input. The INPUT 2 VOLUME controls INPUT 2. This
is the normal input and has a slightly less bright input. You should try both and see
which suits your pickups and playing method the best.
NOTE: You should set the volume at the highest level you will be playing. Now roll
your instrument volume back to achieve the level of clean you desire. Add overdrive by
rolling on more instrument volume. Also, this amp is biased on the high side to
achieve the desired tone. Your amp will be at or near saturation at the 3 o’clock level.
TONE
There is a single tone control that controls the tone for both inputs 1 and 2. This
passive tone control has a wide range. When the knob is turned all the way to the right
(clockwise) the amp is exhibiting its full range of tone. By turning the tone knob to the
left (counterclockwise) you are bleeding off high frequency to the chassis ground.
OUTPUT
This amp uses an 8 ohm output transformer. You should try to use an 8 ohm load
when using this amplifier. NOTE: This chassis is being used with a pair of 8 ohm
speakers to create a 4 ohm load in many cases very successfully.
DIRECT OUT JACK
Located to the right of your speaker jack is a direct out jack that can be connected to a
board of PA system. This will allow you to use your amp in larger venues. This output
should give you the same tone through your PA (you MUST always use a speaker
cabinet to maintain a proper load on your amp).
Builders Statement
I take great pride in the construction of each and every Little Walter tube amp. It was
hand built by myself with the best components available in North Carolina, USA. This
Combo amp was custom built for Ron Mehl of ProGuitar.
Suggestion for playing this amp for the first time:
I would plug into the bright input (input 1) set the volume at 9 o’clock (left volume
knob), tone at 2 o’clock, and then back your guitar volume down to about 6. This
should give you a really clean sweet tone. After you have experienced the clean feel
of the amp I would roll the volume up and experience the naturally overdriven tone.
Never subject the amp to overly damp, dusty, hot, or cold environments (to quote
Gerald Webber of Kendrick Amps “always store your amp in a place where you would
sleep). This amp should give you, your children, and your grandchildren many years of
trouble free operation. Again, I thank you for your purchase of this amp.
Phil N. Bradbury
littlewaltertubeamps.com
You should always have an extra complete set of tubes for any good tube amp when
playing. At the end of a tour put the new ones in and use the old ones for
spare/backup/emergency tubes. Here are some ideas on the tubes and where you
can find them.
Tubes and this amp:
When the signal enters the amp via your guitar cable the first stop is the 6SC7 preamp
tube. This tube is connected to the tone stack (Volume and Tone) this is where the
tone starts to be shaped. The 6SC7 tube is an octal (8 pin) tube that amplifies the
instrument signal and allows the player to use dynamics that are not possible with a 9
pin miniature tube. The next tube in the signal chain is another 6SC7 octal tube. This
tube splits the signal 180 degrees (this sends a signal to each power tube so that when
each tube is in saturation the other power tube is in cut off). Since this is a Class AB
amp the Power tubes can go to saturation and this is where you get that overdriven
tone. The next stop in the signal chain is the pair of 6V6 power tubes. These tubes
are the main amplification point in the amplifier. You may want to experiment with
different brands of 6V6 tubes. This amp comes with good quality J.J. 6V6 tubes (these
are our favorite 6V6 tubes at this). NOTE: All the vacuum tubes that you can buy today
are from Russia or China. I prefer Russian tubes due to the quality. You may want to
try other brands of tubes in your tone quest but I recommend JJ power tubes as they
handle extra high voltage and bias well. You may find certain tonal differences in the
tubes and may prefer one brand over another. The other tube in the amp is the 5Y3
rectifier tube. This tube converts the AC power from your wall outlet to useable DC
current for the grids on the preamp and power tubes. You should acquire a couple
extra 6SC7 tubes as they are not as easy to find as the 6V6 and 5Y3 tubes. You can
find these tubes as NOS/NIB U.S. tube online or in new, reissue form from
www.Partsexpress.com. The 6SC7 is a Sovtek brand tube and costs just under $18.
This is the tube chart for the chassis. Notice the keyway alignment for each tube. You
should always have a spare set of tubes on hand. NOTE: the 6SC7 tubes can be
acquired from www.partsexpress.com.