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I've been a keyboard player
since I was 15 and my first exposure to live rock music was when
a band composed of former high school alumni came to perform
in our auditorium. They opened with Footstompin' Music by Grand
Funk followed by Sweet Lorraine by Uriah Heep. I was taken with
the sound of the organ and those cabinets with the "spinning
things" from which that killer sound was emanating - a love
affair with what I came to know as a Leslie began. After playing
for a couple of years, with "passable" homebuilt rotor
cabinets, I decided to build something along the lines of a 145.
I was able to purchase parts through a repair shop on Detroit's
east side for what were pennies on today's dollars.. I was even
able to purchase a Leslie amp chassis from Bob Seger's keyboard
player (back in '75) for about 20 bucks. I lugged that thing
around to gigs for about 5 years before selling it for a scant
$350 - basically what I put into it. I bought the first simulator
- the Multivox Little David and it worked ok, but once you've
had the real thing, any simulator pales in comparison.
I took a 15 year hiatus from
playing as my kids were growing up and having gotten back into
playing recently picked up some decent digital keyboards and
am amazed at what you can get for so little. The organ emulations
are as B3 as you can get without the bulk, but they need a Leslie
to really bring out their true colors. Having seen mixed reviews
on the most popular simulators (which are in fact quite pricey),
I stumbled across Steve's site which was an inspiration that
I could again build my Leslie and coupled with the availability
of secondhand parts on eBay all things became possible.
After losing quite a few auctions
for Leslie components on eBay in the last seconds of auctions
for weeks, I stumbled on a guy selling a 147 that was coming
off of auction with no bids (I had previously won an auction
from him for a lower rotor with hardware and had called to provide
payment information). I casually asked him if he frequently dealt
in used Leslie components and he informed me of the 147 that
he was to part-out if he had no bidders. I ended up getting the
horn rotor and hardware, the motors, crossover, belts and belt
tensioner for just a little over $400. I found a 12" JBL
MI Series woofer also on eBay for about $20.
Steve invited me to document
my construction project here as it is a "built-from-scratch"
project and shows what is possible if you want to build your
own from the ground up. |
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About Drivers and Crossovers |
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Since
I had built a Leslie as a teenager with limited resources I learned
a few things. My Leslie built in 1975 used a high wattage EV
1823M midrange driver. It had high power handling capability
but didn't "sound like" a Leslie driver. Additionally
I was using rotating horns that did not have the deflectors in
place thinking that my Leslie would be "louder" without
them. Recent research on the Web revealed that such a configuration
has the acoustic result of the apparent position of the driver
diaphram moving from the bell of the horn down the throat inversely
with frequency. The resulting sound is more amplitude modulated
than amplitude and frequency modulated as the horn rotates.
Advice: keep the deflectors! Having built a Leslie both ways
I can tell you from firsthand experience that the deflectors
do not mute the sound at all and the resultant acoustic
characteristics with the deflectors are more desirable
than without (which is why they were included in the original
patent). To complicate things I also didn't have access to a
real Leslie crossover network so I drove full range into the
woofer and used a simple non-polarized capacitor to limit low
frequencies to the horn. My speakers were 8 ohm instead of 16
and so I was probably pulling a little more out of the Leslie
chassis back then than the stock 40 watts which was designed
for a 16 ohm load.
Today, with a professional
background in electrical engineering some 28 years later, I realize
the error of my teenage inexperience and know that a good part
of the Leslie sound fingerprint is what happens at the crossover
frequency and the physical and tonal characteristics of the driver
itself before firing into the rotating horn and lower baffle.
The original Jensen V21 driver had a phenolic resin dome which
results in a limited frequency response due to stiffness and
damping characteristics of the phenolic. My 1823M was a titanium
driver and while titanium results in a stiffer, lower mass dome,
it does so at the expense of being "shrieky". The 1823M
is a screamer but it doesn't come close to the original sound.
The Jensen V21's if you can find them these days are rare, command
a high resale market price, and can only handle 40 watts. Since
I have a 12" JBL woofer with 150W RMS power handling capability,
I wanted a driver with similar frequency characteristics to the
V21 and a little more power handling capability as I was probably
going to power this Leslie with a solid state amplifier.
Since the frequency characteristics
of the driver are only part of the equation and the speakers
I had were 8 ohm instead of 16 ohm, the Leslie crossover I bought
with the rest of the parts was pretty much useless at this point.
Crossovers designed for 16 ohm speakers will NOT crossover
at the same frequency with 8 ohm speakers. Additionally, the
Leslie crossover is a second order crossover with a 12db per
octave slope at the crossover frequency for low-pass and high-pass
elements - far more sophisticated than my simple non-polarized
capacitor for the horn driver in my 1975 Leslie. In the picture
at left the top crossover is the "vintage" Leslie crossover
shipped in most stock Leslies at that time. The lower picture
is the Eminence crossover I used in my Leslie. Notice the lamps
at the top of the board. These lamps track the high-frequency
program material and as more current flows in this branch of
the speaker these increasingly dissipate more power in the form
of light and heat, effectively protecting the compression horn
driver at higher volumes by providing analog compression of the
high-frequency program material as the power increases. |
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Topic Index |
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Acquiring the Horn Driver,
Crossover and Driver Plate |
Since
I had already purchased a driver-adapter plate via eBay from
BBOrgan
designed to adapt the horn rotor's spindle plate to a thread-on
driver, I also needed a driver that used a standard 1-3/8"
thread for mounting. Coupled with the high-powered woofer a suitable
compression driver crossed over at 800 Hz should result in my
Leslie possessing a very similar frequency characteristic to
an original 145. Fortunately I found both driver and crossover
at PartsExpress.com.
The horn driver handles 50W RMS (100 W peak),
and uses a phenolic dome with a very similar response graph to
the original Jensen V21. The crossover is an Eminence Pro Sound second
order crossover with 12db/octave slope on the low pass and 18db/octave
slope on the high pass. It has dynamic protection against horn
driver burnout, high wattage capability and provides as good,
if not better performance at the original 800 Hz crossover frequency
than the original. When I found this crossover at 800 Hz which
seems like an odd frequency for anything but a Leslie I couldn't
pass it up. Parts Express has great prices if you haven't noticed
yet, and they ship promptly. All parts I ordered through them
arrived in a day or two. Note: if you click the link to Parts
Express for the crossover the photo shown is incorrect. See my
photo above for what this crossover actually looks like. |
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Topic Index |
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Building the Cabinet |
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At
this point in the project I had pretty much all major components
in transit and so I set to work to build a cabinet to put it
all into. I will preface this section by saying that this is
NOT a cheap undertaking, but it is cheaper than buying
a secondhand Leslie or a new one. If you are fortunate to find
one close to home you could probably arrange to pick it up, but
if you pay any kind of freight on a used one, you're probably
talking $200 to $400 plus the cost of the unit. I was trying
to contain costs and wanting this to look as good as it sounds
elected to use top-grade birch cabinet plywood. I wanted to keep
the exterior of the cabinet into 1 sheet of 3/4" ply as
much as possible and to accomplish that I elected to build this
to Leslie 145 dimensions but had to cut the width down by 2"
to do so. The only downside to this is that you will not be able
to mount a "standard" Leslie tube chassis in the lower
rotor compartment, but since I was planning to use a solid state
amp that wasn't an issue. As I found out, Leslie chassis' in
a secondhand market are nowhere near the 20 bucks I paid for
mine back in '75. Additionally I can't even tell you how many
"monobloc" tube amplifiers I lost in auctions in the
last few seconds because they are so highly desireable to own
by vintage audio collectors. We are talking in excess of $150-200
for 20-25 watts of tube power! I gave up on that and decided
on a solid state MOSFET power amp discussed in the amplifier
topic below.
I cut the 5 sides of the cabinet
on a table saw and used Titebond wood glue, gluing blocks made
of 1x2 poplar ripped lengthwise in half, and drywall screws countersunk
into the blocks such that they only penetrated all but the last
ply. Since the cabinet would have to withstand high internal
sound pressures as well as support its own weight in transport
scenarios, every seam was blocked, glued and screwed and allowed
to set up overnight.
Next steps: cut the slots for
the upper and lower rotor compartments... |
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Topic Index |
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Slots for the Upper and Lower
Rotor Compartments |
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As
has been pointed out, Leslie had some pretty sophisticated tooling
to cut those "signature louvers" in their cabinets.
It seems like an awful lot of work was done to hide the secret
to the sound of the cabinet or to mellow it out, despite the
fact that most performing musicians turned their Leslies backwards,
removed the covers and exposed the rotor compartments to their
audiences. I toyed around with a number of ideas on paper to
come close to reproducing the louver effect and the most plausible
one would have involved me cutting louvers twice, once from the
inside of the cabinet at 2/3 depth and then on the outside at
the same depth, although offset from each other by nearly the
diameter of the router bit.
I ended up making a tradeoff
and used a jig very similar to Steve's to guide the router. I
created a single jig designed to cut both the long-side slots
and the short-side slots. Since this was a new cabinet with bare,
unfinished wood, my jig was designed to "bite" into
the edges of the cabinet with the points of drywall screws set
into the rails that engaged the cabinet edges. A half turn of
the screws was all that was needed to get the jig to lock in
place, and moving the jig to the next slot location was easily
accomplished. After the long-side slots were cut, that section
of the jig was sacrificed (cut off) to use the remaining part
of the jig to cut the two shorter sides. Once the slots were
cut, I remembered my '75 Leslie front-side bass-rotor-compartment
slots were a little too flexible for my comfort level, so in
this cabinet I added a stiffener inside the cabinet which
will be painted black on the exterior showing surfaces so the
lower slots appear to run the full width of the cabinet. There
are 20 slots total (including the split upper compartment) and
to do this right (without burning the toolbit or splintering
the expensive cabinet wood) each slot took at least 5 cuts before
plunging through. It was an all-day job! As you can see the cabinet
wood has gorgeous grain which was enhanced by staining and finishing. |

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Topic Index |
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Installing the Motors, Rotors
and Drivers |
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My
parts finally began arriving with the driver, adapter plate and
crossover first and then the whole lot of 147 parts next in three
shipments total. First order of business was to see just what
shape the two speed motor assemblies were in as they are the
most critical parts of the system. The 147 this stuff came out
of was in pretty much mint condition. Belts were old but not
worn, horn rotor bearings were like the day they were installed,
horn was a little dusty but in otherwise mint condition and the
bass rotor was also in mint condition. The only thing that really
needed repair and adjustment were the O-rings which couple the
chorale motors to the tremolo motor shafts when running at slow
speed. These were a little worn but until I could get replacements
from Goff
Professional the motor assemblies could be adjusted. The
bass rotor I procured was for a 12" speaker, although the
diameter of most of these rotors must be the same because the
rotor is 16" dia. for both a 12" speaker and a 15"
speaker. Good thing I built my cabinet to the depth of a 145
- I needed that space to accommodate the rotor.
Since the rotor compartment
shelves didn't need to be finish-grade, I had a half sheet of
3/4-inch laminating-grade plywood to make these from sitting
in the garage waiting for a project. I set to work determining
component placement on each shelf starting with the upper rotor
compartment which was easiest. After assembling my driver, driver
plate and spindle plate and determing mounting hole location,
I trial fit the shelf with horn rotor and motor in place before
gluing it and screwing it down. The real test would be if I could
remove both the rotating horn AND motor from the cabinet for
servicing without removing the shelf. Providence was on my side
for this one as I was able to both remove and re-install the
upper rotor compartment components without removal of the shelf.
I glued and screwed this shelf, remounted the components and
proceeded to the lower shelf.
This one was a little more
involved as I had selected a location for and already installed
the bass rotor lower bearing. The location of components on this
shelf had to be centered around the placement of the speaker
and thus the upper bearing assembly, and it had to be perfectly
aligned both vertically and (the rotor) horizontally. Never more
than here was the adage "measure twice, cut once" so
true. Since the JBL woofer I bought was grilled and the grille
could not be removed, I needed some way to distance the grille
surface from the bearing hardware which normally protrudes into
the cone area of the speaker. The woofer platform in the picture
elevates the woofer by a little over two inches providing adequate
clearance.
Not shown in the picture is
the underside of this shelf. Between the hole cut for the speaker
and the hole cut for the motor pulley are two channels or "beltways"
cut to allow clearance for the belt to pass between the two pulleys
without rubbing on the cabinet shelf. I used the same jig to
cut slots for the cabinet to guide the router in cutting these
beltways. Belt tensioning was accomplished in the same manner
as the 145 with a semi circular slot to swing the motor around
a pivot and using the hardware that came with the lower motor
to tighten it down. I didn't want to push my luck, being two
for two in the alignment department, but I had to set power to
the motors and see those components spin. What a beautiful sight!
The central compartment cover was made of the same grade of plywood
as the cabinet exterior and ported like a 145 is ported with
an approximately 4" x 3" hole in the rear center cover.
Felt blanket placed on the glue blocks of this compartment insured
that I could install and remove the cover without any vibration
due to wood warping or misalignment when the lower tones on the
keyboard are played. |
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Topic Index |
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Installing the Crossover,
Power Amp and Power Supply |
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As
I had largely been unsuccessful in procuring a tube power amp
from eBay (and having learned that I had no room to mount it
in the lower compartment anyway) I had decided to go down the
road of looking for a solid state amp. I already have a Behringer
KX1200 4 channel keyboard amp which pushes 120WRMS into a 3 way
ported cabinet and as an interim solution decided to modify it
to include a switch and external speaker jack. The switch, I
decided would allow me to select the Behringer's internal speakers
or route the amp output to the Leslie. If anything it was more
for a convenient testing capability as I was already on the prowl
for a MOSFET amplifier that I could bolt into the cabinet. When
I put power amp to the speakers and plugged in the rotor motors
I could not believe my ears! This was a Leslie in every sense
of the word, albeit with modern components.
After some research, I learned
that even a low-end solid state home-audio amplifier couldn't
be had for small cash. However my son had been talking recently
of subwoofers for his car and I realized that through PartsExpress.com and Pyramid Car Audio, I could get a fairly
clean, high-power MOSFET power amplifer for a reasonable price...and
in a fairly small package. I decided on the Pyramid Super Blue PB444X with 2x60W RMS
bridgeable to 120W RMS Mono. All I needed was an external 12V
high current power supply. I had one of these laying around with
a total current limited power output of 14.4V (adjustable) up
to 7 amps (which means that I could realistically get 90-100
watts out of it before the power supply started current limiting).
I've heard 40-50 watts out of a Leslie and it's loud, even in
a medium sized venue. 100 watts would be more than enough!
In order to provide a good
solid mount for things mounted to the inside of the cabinet (such
as the amp, crossover and the speed switching module), I added
3/4-inch blocks glued in appropriate positions to which the components
were installed. This allowed for airflow around components like
the crossover and power amplifier as well as the power supply,
which as it turns out was mounted in the lower rotor compartment
where a Leslie chassis would typically be mounted. Since the
power supply is a linear supply and linear supplies are typically
inefficient and dissipate a fair amount of heat, putting the
power supply in the "fan-effect" of the lower rotor
aids in its cooling. MOSFET power amps on the other hand are
very efficient and based on how overpowered this amp is for how
I will be using it, I expect very little heat dissipation (after
all these are made to mount in the trunk of a car - a far less
pristine environment than the inside of my Leslie!). If I find
that the amplifier is shutting down due to thermal conditions,
the simple addition of a 12v computer fan blowing through the
heatsink should resolve any problem with thermal shutdown. The
heatsink is at the rear of the amp and is easily seein in the
catalog page link above. This heatsink is tubular and runs the
width of the power amplifier. The way the amplifier is mounted
this tubular orientation is vertical so that "chimney effect"
and normal convection will provide cooling. The crossover and
the power amp use neoprene washers or grommets to avoid any resonant
frequency vibration which may be encountered.
Upon testing with fairly high
volume levels in the mid to upper registers I actually got the
protection lamps on the crossover to light up the interior of
the cabinet quite brightly, confirming that my compression driver
is getting the protection it needs. Interestingly enough this
has a sort of "automatic L-pad" effect by keeping the
sound pressure levels of the woofer and horn in balance throughout
the dynamic range of the speaker. |
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Topic Index |
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The Speed Switching Circuit |
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Lacking
a Leslie amplifier chassis which has the speed switching relays
and filtered outlets, I had to come up with an alternative approach.
In addition it appears that many of the simulators out there
have both slow/fast controls AND a brake control to stop
the "rotors" completely. This is something the Leslie
chassis' never had the capability to do. Earlier (non "100
series") Leslies had stop and tremolo speeds with the "100
series" units having chorale and tremolo but no ability
to stop the rotors. Since this was a scratch built Leslie I pretty
much had carte-blanche to build my speed controller to my own
specifications.
This involved using 3 duplex
electrical outlets mounted in a 3-gang plastic electrical box
designed for mounting behind drywall. In addition I used "button-head"
hook and loop fasteners to mount two relays, one each for the
speed and brake controls inside the box. I used AC-powered relays
due to availability. Filter capacitors were mounted on both the
motor sockets, and the relay coils themselves to suppress inductive-kick
transients which occur at motor turnoff and de-energization of
the relay coils.
As I have planned to control
this leslie from a footswitch in the form factor of the "Combo
Preamp", the relays, in addition to powering the motors
also had to switch an indicator lamp back on the footswitch so
double-pole-double-throw relays were incorporated (see schematic).
The brake control relay is normally de-energized and supplies
power in this state to the motor-common contact of the speed
control relay. This supplies power to whichever motor pair is
selected by the speed control relay, and the second pair of contacts
supplies power to the "Rotor Power" lamp on the footswitch.
The brake control switch is momentary and will apply the brake
when pressed and release the brake when released restoring the
motors to whatever speed the speed control relay has selected.
The speed control relay is normally de-energized supplying power
to the chorale motors in this state and to the tremolo motors
when energized. The second pair of contacts on the speed control
relay supplies power to a "Fast" lamp on the footswitch.
The speed control switch is a push-on/push-off type and when
alternately pressed and released will switch between chorale
and tremolo and vice versa. Note: in the "Audio" schematic
below, the input to the crossover is wired to the left speaker
"+" and the right speaker "-" terminals.
This causes the amp to detect the load and operate in bridged
mono mode automatically and produce twice the wattage to the
speaker network (120W RMS vs. 60W RMS to each stereo channel).
This can be a LOUD Leslie!
A complete set of schematics
(sans the control cable) are in the following links:
This module is mounted on the
inside of the center compartment in a manner similar to the power
amp and crossover. Two wires go in with 18 gauge wire carrying
the power to the motors and the control circuits. The control
interface is a 5 wire interface carrying: AC-control-common,
brake-control switch, speed-control switch, rotor-power lamp,
fast-speed lamp. The wiring is routed through the shelf and to
the power-distribution panel mounted in the lower rotor compartment
in front of the 12V power supply. |
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Topic Index |
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Power Distribution |
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Since
I was not carrying power from the foot controller (see below)
to the Leslie I had to get the mains power into the cabinet directly.
Normally a commercially available Leslie accomplishes this either
from the organ console or the Combo Preamp. I decided to create
a "power distribution" panel which would not only hide
the 12VDC power supply in the cabinet but also allow me to get
power directly to the cabinet, provide an on/off switch and fuse
the cabinet power without having to directly carry a high-current
AC voltage in the foot controller and interface cable.
The same ABS plastic panel
(see below) material was used to create this panel to which was
mounted a circular "twist-lock" power connector, SPST
power switch and fuse holder as well as the 9 pin interface connector
which interfaces the footswitch with the functions of the cabinet
it controls. Picture is shown with lower-rotor-compartment rear
cover in place.
For further details on power
distribution see the Foot Controller
topic below. |
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Topic Index |
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Building the Foot Controller |
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Knowing
that I wanted to build my foot controller similar in function
to the "Combo Preamp", and also realizing that I didn't
need an actual preamp due to my amplifier accepting a line-level
signal directly the purpose of my foot controller is simply to
control the Leslie some distance from the actual cabinet, and
to get the organ's signal into the Leslie without stringing a
whole bunch of extra wires between the location of the organ
and the Leslie. Leslie accomplished this with the 6-, 9-, or
11-pin interface cable, but upon investigating that approach
for this project I decided that it was not appropriate, especially
since mine was built from scratch.
I ended up building a 20 foot
long remote control cable using 8-channel snake cable from Parts Express
and wiring it to some Tyco/AMP CPC connectors from Allied Electronics. I will caution here though
that while the connectors and strain reliefs are relatively cheap
($2-3 each), they do not come with either pins or sockets and
you can only buy them in bags of 100, and you would do well to
also get a pin-extraction tool if you make a mistake or need
to repair a pin or socket or both for any reason (about $90 dollars
for a package each of pins and sockets and the extraction tool
plus shipping). I elected to use these connectors because I have
a background with them designing industrial electronic equipment
and they are for the most part bombproof and reliable. My interface
was a 9 pin interface (5 wires for motor control and indication,
2 wires for audio signal, and 2 wires to carry +12VDC and ground
to the footswitch in case I want to add an overdrive circuit
later on).
The basic form of the pedal
was made of some leftover cabinet plywood (I had plenty by this
point in the project!) and some 1/8" textured ABS plastic sheet panels
on which to mount the components (also from Parts Express). Speed
and brake control switches were mounted on the slope front, indicators
on top, and the interface connector and 1/4" phone jack
were mounted on the front. Additionally I used a switching phone
jack so that when no instrument was plugged in the audio input
was grounded to avoid extraneous noise.
The control cable was assembled
from the snake cable described above. This cable is normally
used for building microphone snakes between a stage and remotely
operated board and due to the fact that each of the 8 channels
has its own shield the cable actually has 8 twisted pairs each
of which is shielded. I doubled up the control wires for the
relays and indicators so that each pair was effectively one wire,
albeit a heavier gauge than the individual wires. Each of the
shields for these were tied to 12V ground so that any noise they
might generate when open or energized was shielded from the audio
input. The 12VDC and ground wires were shielded through the cable
as was the audio input whose shield was tied to its own signal
ground. Shielding is a tricky undertaking to avoid ground loops
which could contribute to overall noise if not done correctly.
I leveraged my electronic design experience and what I learned
still holds true. Once the cabinet was powered up and the foot
controller connected the audio was as clean as it was when the
keyboard was locally connected to the amplifier through a path
that was 20 feet shorter.
The pictures below show details
of the foot controller, interface cable and the connection of
the interface cable into the power distribution panel. Also shown
is a temporary setup in my studio before bottom molding was attached
to the cabinet and cabinet staining and finishing, to check the
Leslie as driven by the Behringer mixer on the upper left of
the keyboard stack. Incidentally, the keyboard stand is a custom
design I created by taking a base Ultimate Support A-Frame dual tier stand
and purchasing extra tubes, and hardware to create what you see
in the picture. The "music stand" is actually a nylon
plastic cutting board which has had a 2" strip removed with
a table saw and screwed to the back to implement something to
hold music, books, etc. This was mounted to Ultimate Support
hardware and is part of the stand. Additionally there are two
vertical tiers on either side of the upper keyboard. The left
tier holds the Behringer mixer and the right one holds an Alesis
MMT-8 Sequencer and a Yamaha QX-5 Sequencer. The Behringer mixer
is used to mix keyboards, a microphone (Hohner Blues Blaster)
I use for my harmonicas, and a future organ module. The Yamaha
keyboard on the lower tier is actually not supported by the Ultimate
Support stand at all but rather by an "X-Stand". This
allows me to take the Yamaha out along with my amps and mixer
should the need arise, without having to dismantle everything.
Not shown in the photo and at the diagonally opposite end of
the room is the Behringer KX-1200 keyboard amp. The Leslie is
driven off of the left channel of the stereo mixer with the "dry"
keyboard amp driven off of the right channel. Upon testing the
Leslie definitely had "the sound", including full spin
up from a braked condition as well as using the brake to achieve
intermediate speed changes between chorale and tremolo. Some
of the sound I was looking for was the deep FM/AM effect achieved
by Santana on "Jingo". For those who do not know, the
organ was played through a Leslie with the vibrato through stopped
rotors in the beginning of the song, and then, at an appropriate
moment the rotors were spun up into a full tremolo. The resulting
FM/AM at the moment the upper rotor was beginning to spin up
provided an effect that I've never heard in an "acoustic"
Leslie environment. After playing with a microphone position
on the upper rotor compartment which was sent to the "dry"
amplifier and performing this stopped-to-tremolo spin-up it became
readily apparent HOW it was accomplished - the microphone
is the key and puts a new spin on the sound (no pun intended).
It is a result of taking a 3 dimensional sound and squeezing
it down to 2 dimensions (due to the microphone's directionality)
- you lose something overall but gain in another area. |
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Topic Index |
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Finishing the Cabinet |
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As
I planned on this cabinet having the "furniture finish"
of the original 145 and the fact that I used top-grade birch
cabinet plywood this Leslie was stained with a "New England
Maple" finish, with the rotor compartments being stained
to tone them down a bit so they wouldn't contrast with the finished
exterior if it was played with the rotor-compartment covers off.
Rather than use a urethane based finish which would show scratches
and be time-consuming to touch up I elected to use a tung-oil
finish. I found a reference to another site which refinishes
Leslies for road use and they sandblast, stain and use tung-oil
to refinish specifically for this reason. The photo shows the
cabinet with the covers in place, which are also made from the
same plywood as the rest of the exterior, even though they were
"unfinished" in the original 145. Since the possibility
exists that this could be played in a "traditional"
position (reversed with the rotor-covers off) I wanted the cabinet
to be finished on all 4 sides. The rotor covers and the rear
center-compartment cover were finished with the same stain, and
tung-oil finish.
Incidentally the reason the
covers don't fit tightly to enclose the compartments is because
the surface area of the openings are chosen to match those of
the openings on each of the other three sides. The thought being
is that I did not want major sound-pressure-level differences
resulting in inconsistent "3D reflections" when the
rotors spin from the vented sides to the rear side with the covers
on. I believe that this was the original design intent with the
"commercial" Leslies as they were designed to be played
with the covers on. The picture below shows the rear covers in
place before finishing. Stainless steel screws and washers are
used to avoid corrosion.
And yes...even lacking the
"official" Leslie chassis this unit did not disappointment
me when I and my teenage son tried to pick it up! It reminded
me so many years ago of why I sold mine after gigging every weekend
with it for 5 years. I've resolved though that after all this
work - I'm keeping this one!
If you have any questions on
this project please feel free to e-mail me at obxwindsurf@yahoo.com |
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Topic Index |
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