Airspeed FM-50 User manual

P a g e | 2
Airspeed FM-50 Owner’s Manual, Ver 1.4
IMPORTANT SAFETY INFORMATION –READ FIRST
The lightning flash with arrowhead symbol within an equilateral triangle is intended to alert the user to the presence of
uninsulated “dangerous voltage” within the product’s enclosure that may be of sufficient magnitude to constitute a risk of
electric shock to persons.
The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operating
and maintenance (servicing) instructions in the literature accompanying the product.
1) Read these instructions in their entirety.
2) Keep these instructions on hand for future reference.
3) Heed all warnings, follow all instructions.
4) DO NOT use this apparatus near water.
5) Cleaning of the product should only be with a dry cloth.
6) DO NOT block any ventilation openings. Install in accordance with the manufacturer’s instructions.
7) DO NOT install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that
produce heat.
8) DO NOT defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades with one
wider than the other. A grounding type plug has two blades and a third grounding prong. The wide blade or the third
prong are provided for your safety. If the provided plug does not fit into your outlet, consult an electrician for replacement
of the obsolete outlet.
9) DO NOT use an extension cord attached to the power cord.
10) Protect the power cord from being walked on or pinched
particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.
11) Only use attachments/accessories specified by the manufacturer.
12) DO NOT move amplifier head and cabinet together, in order to avoid injury and/or damage from the risk of a tip-over.
13) Unplug this apparatus during lightning storms or when unused for long periods of time.
14) Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way,
such as when the power-supply cord or plug is damaged, when liquid has been spilled, when objects have fallen into the
apparatus, when the apparatus has been exposed to rain or moisture, when the apparatus does not operate normally, or
when either the amplifier head or cabinet has been dropped.
15) To completely disconnect this apparatus from the AC mains, disconnect the power supply cord plug from the AC receptacle.
16) The mains plug of the power supply cord shall remain readily operable.
17) WARNING –To reduce the risk of fire or electric shock, do not expose this apparatus to rain or moisture.
18) Do not expose this equipment to dripping or splashing and ensure that no objects filled with liquids, such as vases, are
placed on the equipment.
19) Maintain at least six (6) inches (or 15.25 cm) of unobstructed air space behind the unit to allow for proper ventilation and
cooling of the unit.

P a g e | 3
Airspeed FM-50 Owner’s Manual, Ver 1.4
20) CAUTION –For rack-mounted power amplifiers, keep all wiring and materials away from the sides of the unit and allow the
unit to cool down for two (2) full minutes before pulling it from a rack enclosure.
21) Amplifiers and loudspeaker systems, and ear/headphones (if equipped) are capable of producing very high sound
pressure levels which may cause temporary or permanent hearing damage. Use care when setting and adjusting volume
levels during use.
22) FCC COMPLIANCE NOTICE: This equipment has been tested and
found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC rules. These limits are designed to
provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and
can radiate radio frequency energy, and if not used in accordance with the instructions, may cause harmful interference to
radio communications. There is no guarantee that interference will not occur in a particular installation. If this equipment
does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and
on, the user is encouraged to try to correct the interference by one or more of the following measures: reorient or relocate
the receiving antenna, increase the separation between the equipment and receiver, and/or connect the equipment into an
outlet on a circuit different from that of the receiver. Consult the dealer or an experienced radio/TV technician if further help
is needed with interference.
IMPORTANT: AIRSPEED AMPS will not be responsible for unauthorized equipment modifications that could violate FCC rules,
and/or void product safety certifications.
23) WARNING –To maintain product safety, products with internal or external (battery pack) batteries:
-The product and/or batteries should never be exposed to excessive heat, such as that when exposed to sunshine, fire, a
heating system, or the like;
-there may be a danger of explosion if the batteries are incorrectly connected and/or replaced; they should be replaced
only with the same or equivalent type batteries specified in the instructions or on the product.
24) CAUTION –Unplug unit and allow it to cool before touching/ replacing vacuum tubes.
25) WARNING –Provide an earthing connection before the mains plug is connected to the mains. When disconnecting the
earthing connection, be sure to disconnect after pulling out the mains plug from the mains.
26) Apparatus with CLASS I construction (grounded type with a three-prong plug) must be connected to a MAINS socket outlet
with a protective earthing connection.

P a g e | 4
Airspeed FM-50 Owner’s Manual, Ver 1.4
OPERATING YOUR FM-50 AMPLIFIER
1. The Front Panel
Section 1
This is the standard ¼” input jack. Use a standard guitar cable to connect your guitar to the amp.
Section 2
This section is where you will find the CLEAN channel controls.
VOL –Use this control to raise or lower the volume level of the channel.
GAIN –Use this control to raise the gain on the CLEAN channel. For a “clean” tone, set the gain control below the midpoint (for
clarity, the “12:00”position, in reference to a clock). If you are seeking more of an overdriven tone, set the gain control further to
the right of the midpoint (that is, after “12:00”).
REVERB –The reverb control allows you to increase the “echo”, or reverb, by turning it clockwise as indicated by the graphic.
TREBLE, MID & BASS –Use these controls to shape your sound. Start by setting the controls at the midpoint for all three
controls, and then experiment with making minor adjustments to each control, progressively, until the preferred sound is
achieved.
Section 3
CLEAN/CRUNCH Toggle Switch –This switch allows you to choose which channel is active on the amplifier. In order to use the
included footswitch to change channels, set the toggle switch to the CRUNCH position.
Section 4
This section is where you will find the CRUNCH channel controls.
VOL –Use this control to raise or lower the volume level of the channel.
GAIN –Use this control to raise the gain on the CRUNCH channel. For a “clean” tone, set the gain control below the 12:00
(midpoint) position. If you want more of an overdriven tone, set the gain control after the 12:00 position.
BOOST –This control allows you to set the level of boost (when the boost channel is activated by the footswitch) and is based
on the CRUNCH gain control setting.

P a g e | 5
Airspeed FM-50 Owner’s Manual, Ver 1.4
The BOOST stage gain is set to roll off some of the low end and low mid tone while adding a slight bit of punch, which may feel
like compression. We feel this will yield the best gain tone (which would typically be used for soloing).
At very low settings (the knob turned to the “9:00” position or lower), the BOOST will actually cut the underlying tone. Further
clockwise after the 9:00 position, the GAIN stage will be additive to the underlying gain of the CRUNCH channel.
REVERB –The reverb control allows you to increase the “echo”, or reverb, by turning it clockwise as indicated by the graphic.
TREBLE, MID & BASS –Use these controls to shape your sound. Start by setting the controls at the midpoint for all three
controls, and then experiment with making minor adjustments to each control, progressively, until the preferred sound is
achieved.
Section 5
This section is where you will find the controls for the DELAY and TREMOLO effects.
Delay Effect
VOL –Use this control to raise or lower the volume level of the DELAY effect.
TIME –Use this control to set the time between delays. Turning the control clockwise increases the DELAY time, while turning
the control counterclockwise decreases the delay time.
REPEAT –Use this control to set the number of repeats the DELAY effect produces. Turning the control clockwise increases the
number of repeats, while turning the control counterclockwise decreases the number of repeats heard in the DELAY effect.
Tremolo Effect
SPEED –Use this control to vary the speed of the tremolo effect. Turning the knob clockwise increases the speed, turning it
counterclockwise decreases the speed.
DEPTH –Use this control to set the depth of the tremolo effect. Turning the knob clockwise increases the depth, turning it
counterclockwise decreases the depth.
Section 6
This section is where you will find the controls for the MASTER volume controls and the STANDBY ("STBY”) switch.
MASTER 1 –Use this control to raise or lower the overall volume level of the amplifier.
MASTER 2 –Use this control to raise or lower the overall volume level of the amplifier when the footswitch for the MASTER 2
volume is pressed.
If you’ve never had an amplifier with two master volumes, think of them as follows. You have the opportunity to set two master
volume levels on the amplifier, and to switch between those levels simply by using the footswitch. For example, you might want
a boost tone that not only changes its tone via the boost gain control, but also has a louder volume as well. This is why we set
the last two switches on the footswitch closer together, allowing them to be enabled together at the same time.
STBY –Tube amps need to be warmed up when they're initially turned on. Putting the amp in standby (STBY) and then
switching the power switch 'On', allows the amp to be turned on but keeps full voltage from reaching the power tubes until
they've had sufficient time to warm up. This approach goes a long way towards protecting the power tubes and will
substantively prolong their useful life.
It is also recommended that your amplifier be turned off in the reverse order, setting standby switch to 'STBY’ and then turning
the power switch to 'Off'.

P a g e | 6
Airspeed FM-50 Owner’s Manual, Ver 1.4
2. The Back Panel
Section 1
PWR/OFF –Tube amps like to be warmed up when they're initially turned on. Putting the amp in Standby (STBY) mode, and
then switching the power (PWR) switch to 'On', allows the amplifier to be turned on while restricting full voltage from reaching
the power tubes until they've had sufficient time to warm up, thus protecting them and prolonging their life.
It is also recommended that your amp be turned off in the reverse order, standby switch to STBY mode, before moving the
power switch to 'Off'.
Voltage Selector –Use this control to select the voltage for the country you are in. For example, in the USA, switch it to 115v. In
contrast, for most of Europe, it should be switched to 230v. If you are unsure of what voltage your country uses, it may be
helpful to consult the following web page: https://w.wiki/5yp9
Section 2
When switching from 115v to 230v or vice versa, the mains fuses must also be changed. These two fuses are located in a tray
below the AC mains IEC cable socket (the power cable input). You can remove it by prying it open with a small screwdriver or
hooked implement, after which the fuse tray can be removed. The fuses installed in your Airspeed FM-50 amplifier are correct
for the default setting (115v or 230v) as set when received from the factory. Replace the fuses as follows:
•When the switch is at 115v, use two (2) 4-amp fuses
•When the switch is at 230v, use two (2) 2-amp fuses
Section 3
Power Tube Fuses and Test Points –The test points allow you or a qualified service technician to insert standard DMM (digital
multimeter) probes into the amplifier in order to read DC voltage mV for tube biasing (see the Service section of this manual for
more detail).
Section 4
IMPEDANCE –Use this switch to select the impedance connected to the speaker output jacks. This setting should be matched
to the connected load. When using Airspeed Speaker cabinets, the impedance of each cabinet is printed on the rear jack plate.
If using multiple cabinets, they should each be the same impedance.

P a g e | 7
Airspeed FM-50 Owner’s Manual, Ver 1.4
SPEAKER OUTPUTS: CLEAN and CRUNCH –Use these outputs to connect an individual channel to a speaker cabinet. For
example, you may have two (2) Airspeed 2 x 12 cabinets with different speaker sets, or you may have the Airspeed 4 x 12
diagonally switching speaker cabinet.
SPEAKER OUTPUTS: Both Channels –These output jacks output both the clean and crunch channel, whichever is selected. For
example, if you have one (1) Airspeed 2 x 12 cabinet, you would connect the speaker cabinet using one speaker cable to one of
the parallel outputs (it doesn’t matter which one. There are two parallel outputs for convenience.
Section 5
FOOTSWITCH –Use this jack to connect your Airspeed 7-switch footswitch.
DELAY POSITION –This toggle switch allows you to choose whether you want the delay effect before the effects loop (pre) or
after the effects loop (post).
LOOP –This is the effects loop SEND and RETURN jacks. Use these jacks to connect outboard effects. By connecting your effects
through the SEND and RETURN jacks, you can turn them off via the Airspeed 7-switch footswitch.
3. The Airspeed 7-switch Footswitch
The Airspeed 7-switch footswitch and cable come included with the Airspeed FM-50 amplifier. Connect the cable to either side
of the footswitch, whichever is more convenient to your setup, and then connect the other end of the cable to the back of the
FM-50 amplifier. In order to enable footswitch control of your amp, switch the “Clean/Crunch”toggle switch on the front panel
of the FM-50 to CRUNCH.
As you switch the footswitch to select and turn on different amp features you will see both an LED light on the footswitch
corresponding to an LED light on the front (or back) panel indicating which feature has been selected or is “on”. If the LED is not
lit it indicates that the feature is off.
IMPORTANT NOTE: When the footswitch is NOT connected, you can still switch between channels with the front panel toggle
switch. However, the default setting for the amp is to activate the following features:
•Reverb for both clean and crunch channels
•Delay
•Tremolo
•The effects loop
•Boost gain
•master volume 2

P a g e | 8
Airspeed FM-50 Owner’s Manual, Ver 1.4
We have configured the amp this way to prevent the amp being limited in use if, for example, you’ve forgotten your footswitch
and you still need to use the amp. Note that if you want to use a crunch sound instead of “boosting the crunch”signal as would
normally be the case, simply set the Boost Gain control at 12:00 and then vary the crunch tone by the crunch control. Even
though the boost channel will still change the tone of the crunch setting as described previously above, you will be able to get a
very close approximation of the crunch channel tone when boost is not enabled. If you don’t want to hear a certain effect for
example, you would just turn all the control knobs for that effect or setting fully counter-clockwise, essentially turning the
feature off.
You will also notice that you cannot utilize tow master volumes. In this case, master volume is lit and you would only have use of
one master volume control until you re-connect the footswitch.
4. Connecting your Amplifier and Speaker Cabinet(s)
In order to achieve the truest possible tones, each channel needs its own set of speakers, i.e., a speaker matched for that
particular tone. As is commonly known among guitar amp experts, different speakers are required in order to optimize for
different tones. Why do you think those vintage Marshall® and Fender® amps have different speakers? Speakers are the most
important component in defining your tone!
Airspeed’s patent-pending Circuit-to-Speaker® technology allows you to get the truest tone possible. The Airspeed FM-50
provides completely independent CRUNCH channel and CLEAN channel outputs on the head unit. That means that you can
connect two or more 2 x 12 Airspeed cabinets, each with its own set of speakers, that you can alternate between, so that when
you switch channels, you switch speaker sets/cabinets. You're playing the right speakers for the right tone. No other amp
company in the world gives you the ability to do this. It’s one of the key features that differentiates Airspeed’s amps among the
most discerning guitar professionals worldwide.
Your Airspeed FM-50 amp has four (4) speaker outputs on the rear backplate panel. The two “Switched Channels” outputs, as
described above, allow you to connect one Airspeed cabinet (with one set of speakers) to each of the different channels, clean
and crunch, which automatically output each of those signals to different cabinets when you switch channels (either by the
front panel toggle switch or the footswitch).
The other two outputs, “BOTH CHANNELS/ Parallel Outs”, are two distinct outputs, each allowing both channel’s signals, clean
and crunch, to output from each output jack (the signal that is output is determined by whether you have your amp set to CLEAN or
CRUNCH). Use one of these outputs (either one is okay, they are both outputting the same signal) if you’re using one (1) Airspeed
2 x 12 cabinet. In another example of a scenario, you could connect multiple cabinets to these outputs for more overall speaker
volume (the amp would be pushing more signal into more speakers).
The following examples of configurations are not the only ones possible. You can use your creativity to essentially “daisy chain”
multiple speaker cabinets in any number of ways, given the fact that there are parallel outputs on the amp and on the Airspeed
2 x 12 speaker cabinets.

P a g e | 9
Airspeed FM-50 Owner’s Manual, Ver 1.4
Sample Configuration #1
Your system comprises the Airspeed FM-50 Amplifier head and two (2) Airspeed 2 x 12 cabinets. This is the quintessential
Airspeed setup using different speakers for different channels. IMPORTANT: Please check to make sure you have the correct
impedance selected on the Airspeed amplifier head for the cabinets you are using.

P a g e | 10
Airspeed FM-50 Owner’s Manual, Ver 1.4
Sample Configuration #2
Your system comprises the Airspeed FM-50 Amplifier head and one (1) Airspeed 2 x 12 cabinet. IMPORTANT: Please check to
make sure you have the correct impedance selected on the Airspeed amplifier head for the cabinet you are using.

P a g e | 11
Airspeed FM-50 Owner’s Manual, Ver 1.4
Sample Configuration #3
Your system comprises the Airspeed FM-50 Amplifier head and one (1) Airspeed 4 x 12 cabinet. IMPORTANT: Please check to
make sure you have the correct impedance selected on the Airspeed amplifier head for the cabinet you are using.

P a g e | 12
Airspeed FM-50 Owner’s Manual, Ver 1.4
Configuration #4
Your system comprises the Airspeed FM-50 Amplifier head, two (2) Airspeed 2 x 12 cabinets, and one other generic speaker
cabinet (not manufactured by Airspeed). IMPORTANT: Please check to make sure you have the correct impedance selected on the
Airspeed amplifier head for the combination of speaker cabinets that you are using.
In this configuration, the generic speaker cabinet is always active, but the Airspeed 2 x 12 cabinets will switch when you switch
between clean and crunch.

P a g e | 13
Airspeed FM-50 Owner’s Manual, Ver 1.4
5. A Few Tips for Getting the Most Out of your FM-50
•Tone controls –when you receive your amplifier, the tone controls for both channels should be set to the midpoint
(“12:00”) position. We designed this amp so that with the controls at that position, both the clean and crunch tones
should sound awesome at any volume level.
The midpoint (“12:00”) position is always a good starting point if you are not yet getting the tone you desire. We
recommend adjusting one tone control at a time, while listening to the effect each adjustment has on your sound.
Small changes can make a big difference, so take your time as you gradually adjust each of the control knobs.
•MASTER volume –MASTER volumes 1 and 2 are completely independent of each other. That means that these
controls, combined with the channel volume controls, give you an infinite number of settings through which to achieve
the results you desire. Many players will set MASTER volume 2 a little louder than MASTER volume 1, so that when they
are seeking just a bit more volume to spotlight what they’re playing (e.g., a solo), they simply step on the MASTER
volume 2 footswitch, without having to subject their tone to another gain stage, or some other boost stage, as would
be required on other amps. This is a key differentiator that makes the Airspeed system an essential tool for
professionals.
Setting these controls at the same position will yield no difference in volume when switching between MASTER volume
1 and MASTER volume 2. Remember, that MASTER volume 2 is only accessible through the footswitch.
•CLEAN Gain –Think of the CLEAN gain control as being just like the sole volume control on an older Fender® twin
reverb amp, for those of you familiar with it. As you increase the gain, you’ll start to hear some natural breakup of the
tone. This breakup is unique to the channel and entirely independent of the clean volume control (as well the two
master volume controls). Set the gain to get the breakup/tone you want, then set the volume to get the room loudness
you want.
If you want to achieve a very clean tone, any setting less than about the ”10:00” position will work well. Then use the
CLEAN channel volume to increase the volume. You’ll also notice that increasing the MASTER volume leaves the quality
of the tone intact and just increases the overall volume.
•Effects –The effects on the FM-50 are not designed to replace pedals that are distinctly made for specific effects,
whatever they may be. The whole idea behind having DELAY and TREMOLO incorporated into your FM-50 amp is more
for convenience: it’s sometimes nice to just put a little delay or tremolo on your tone when you’re “roughing out”
creations and experimenting to get a sense of what’s possible.
If you want a super-long delay effect, then we recommend using a dedicated delay pedal and running it through the
effects SEND and RETURN channels. The delay in particular has a nice analog feel about it, and it starts to change after
several repeats –so it’s not the typical digital “sterile” delay effect you might encounter elsewhere. We designed the
delay on the FM-50 to have a more musical and usable sound, while still giving you enough range in the setting options
to achieve many different delay effects.
•Delay (Pre- and Post- options) –Speaking of delay, you’ll notice a switch on the back with two positions, marked PRE
and POST. This allows you to put the onboard FM-50 delay either before the effects loop (pre) or after the effects loop
(post).
•Boost gain stage –The boost gain stage control allows you to take your tone to another level. The FM-50 Boost Gain
Stage is based on the initial crunch channel and its gain control. This boost adds (or subtracts) from the crunch gain.

P a g e | 14
Airspeed FM-50 Owner’s Manual, Ver 1.4
You’ll notice a more compressed, tighter tone which has slightly less pronounced lows and mid tones. We designed this
as such on purpose based on input from professionals who would typically apply a boost setting when launching into a
guitar solo.
In such scenarios, the volume is usually louder, as is gain breakup. In the case of the Airspeed amp, by rolling off the
lows and mids, you avoid getting a tone that can wander and/or become too “loose” for the tone and music (a solo
typically) that you’re playing.
Remember that this gain stage boost can only be accessed through the footswitch. Also, remember that you can couple
the boost gain with a MASTER 2 volume setting increase to reach those searing solo tones.
Maintenance, Service and Adjustment
Tube Maintenance. Your new Airspeed amplifier comes equipped with the highest quality tubes available, designed and
tested for use in the demanding world of musical instrument amplification. IT HAS ALREADY BEEN BIASED AT THE FACTORY.
UNLESS YOU CHANGE TUBES, THERE’S NO NEED TO BIAS IT AGAIN.
Please make note of the rating information on the base of the power tubes. You may find this extremely useful if
purchasing a spare set of power tubes (for backups), or when replacing power tubes.
If you replace power tube sets with the same rating, no adjustment should be needed.
If you decide, however, to tweak the performance characteristics of your amplifier with a different power tube set, you
should have a qualified technician set the bias accordingly.
We highly recommend if you need service on your Airspeed amplifier that you take it to a qualified guitar amplifier service
repair technician. If you are a technician reading this manual, you’ll notice that on the back of the Airspeed FM-50 amp,
there are several adjustment points that you can use to “tune” the amplifier and bias the vacuum tubes.
Follow the steps below to bias your tubes:
1. Remove the back cover via the four (4) #2 Phillips screws in order to access the Bias control on the top-right side of the
chassis.
2. Set your DMM (digital multimeter) to DC mV, or simply DC V if it is an auto-ranging meter.
3. Plug the black DMM probe into the Black Bias Test Point. Plug the red DMM probe into the Left Pair –Red Bias Test
Point.

P a g e | 15
Airspeed FM-50 Owner’s Manual, Ver 1.4
4. Turn the amp’s global MASTER volume all the way down (off).
5. Ensure a proper load is connected to the Speaker Output and the impedance selector matches the load.
6. Turn on the amp via the Power On.
7. After a 60 second warm-up, flip the Standby (STBY) switch to ON.
8. Check the mV reading on the DMM.
9. For a 6L6GC loaded amp it should be between approximately 30 mAV, which is equivalent to 30 mA per tube. Amps
are setup at the factory at 30 mA per tube, however it is safe to run up to 40 mA per tube.
10. While watching the DMM, adjust the bias setting with the Bias control on the top right side of the chassis.
Counterclockwise rotation lowers the bias, whereas clockwise rotation increases it.
11. Take note of the Left Pair reading, then plug the red DMM probe into the Right Pair –Red Bias Test Point. Compare the
Right Pair reading with the Left Pair –they should be within ~5 mA of each other.
NOTE: If you see strange numbers, here are some possible reasons:
1. If one side reads 0 mA and the other looks good –then likely both tubes on one side are out.
2. If one side reads about half of the other side, then just one tube is out.
3. If the two readings are close, just not within ~5 mA, then the tubes are not properly matched and should be replaced.
One can also swap one tube from each side in order to try and balance the readings more.
FM-50 Specifications
The Airspeed FM-50 Amplifier (Head unit)
•50-Watt Class A/B Head
•Two (2) 6L6GC power tubes, seven (7) 12AX7 pre-amp tubes (one tube used for the tremolo effect), one (1) 12AT7 tube
for reverb, one (1) 5U3B rectifier tube
•MASTER volume 1 and MASTER volume 2 (MASTER volume 2 activation accessible through footswitch)
•The CRUNCH circuit and tone of a vintage Marshall® amp
•The CLEAN circuit and tone of a vintage Fender® Reverb amp
•Treble, bass and mid controls for each channel
•Tube reverb for luscious reverb tone faithful to Fender® Reverb amps. Tube reverb for the crunch side as well but
scaled back to recreate a typical late 90’s Marshall® head
•2 switched outputs (CLEAN and CRUNCH) and 2 non-switched, parallel outputs
•Non-switched output for using one 2 x 12 Airspeed speaker cabinet (or alternatively, can be used with one or more 4 x
12 Airspeed speaker cabinets that have all the same speakers).
•CLEAN output to an Airspeed 2 x 12 speaker cabinet or an Airspeed 4 x 12 switching cabinet.
•CRUNCH output to an Airspeed 2 x 12 speaker cabinet or an Airspeed 4 x 12 switching cabinet
•Effects loop SEND and RETURN
•DELAY and TREMOLO effects as part of the effects loop circuit (which does not alter the tone of the channel)
•PT2399 digital delay chip
•Standby switch on front, power switch on back
•Boost gain stage for CRUNCH channel (activation accessible through the footswitch)
•Exotic wood accent panel
•LED indicators to highlight activated features on both front panel and footswitch
•Baltic Birch wood construction
The Airspeed Speaker Cabinet
•Upward tilt of the speakers inside the cabinets (15 degrees for 2 x 12, 7.5 degrees for 4 x 12)
•Wood accent panel
•Caster quick-release plates pre-installed and caster wheels included
•Recessed handles
•Airspeed 4 x 12 speaker cabinet with Airspeed internal diagonal speaker switching capability
•Baltic Birch wood construction

P a g e | 16
Airspeed FM-50 Owner’s Manual, Ver 1.4
Other Features
•115/230 volt selector switch
•Included 7-switch footswitch: channel, delay on/off, tremolo on/off, reverb on/off, effects loop on/off, crunch channel
gain on/off, master volume 2 on/off
Dimensions and weights
•Airspeed FM-50 Amplifier (Head)
oDimensions: 11 5/8” x 29 3/8” x 11 1/8”
oWeight: 46 lbs.
•Airspeed 2 x 12 Speaker Cabinet
oDimensions: 22 3/8” x 29 3/8” x 14 1/8”
oWeight: 63 lbs.
•Airspeed 4 x 12 Speaker Cabinet
oDimensions: 31 7/8” x 29 3/8” x 14 1/8”
oWeight: 81 lbs.
NOTE: Weights may vary slightly depending upon the speakers installed.
6. Support
Airspeed Amps™and Circuit-to-Speaker™are trademarks of Airspeed Amps, Inc. Fender® is a registered trademark of Fender Musical Instruments Corporation. Marshall® is a
registered trademark of Marshall Amplification. All other trademarks owned by their respective companies.
©2023 Airspeed Amps, Inc. All Rights Reserved
Table of contents
Other Airspeed Musical Instrument Amplifier manuals