Aclam Guitars Windmiller Operator's manual

www.aclamguitars.com
C/ Consell de Cent, 201 - local
08011 Barcelona. Spain
Llevinac S.L.
CIF: B64412406
Thank you for purchasing The Windmiller Preamp!
Push your amp to its raw power!
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www.aclamguitars.com
Available in other languages at:
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Overview
Features
Specs & material Included
Power Requirements
Operating Diagram
Controls
Where to put The Windmiller Preamp on the effects chain?
Eq setting suggestions
What impedance is and how it affects The Windmiller Preamp’s tone
Setting up on a pedalboard
Trouble Shooting
Security Instructions
Warranty Terms
Your own settings
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6
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9
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19
20
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26
Index

4
Here it is! The Windmiller Preamp: drive your amp even
further with Pete Townshend’s secret weapon!
It all started on a lazy Sunday, surng through YouTube
looking for some old footage of The Who, when we
stumbled on some clips of The Who playing at the
Marquee Club in 1967. Despite the raw energy of those
four young men, what really caught our attention was a
weird device with a ashing light sitting on top of Pete
Townshend’s Marshall amps.
After some research we found out that between ‘66
and ‘67, Pete Townshend had several Grampian 636
Spring Reverb units in his arsenal and he used them as a
saturation tool, cranking his Marshall amps to the limit to
get his groundbreaking tone.
As it is quoted on an interview in 1967:
“I use a Granpiene [sic] reverb unit for distortion; it gives a
kind of clear fuzz dirge. I like a slightly broken guitar sound.”
Even though it was intended as a studio reverb unit, Pete
used the built-in preamp of the 636 to fatten his tone and
boost the guitar signal, bypassing the reverb altogether.
Since Pete used it for a short period of time, it ended up
forgotten and only the erudite of The Who knew the story
of the 636.
With that amazing story on the table, it was clear it could
be something for Aclam’s team to work on! So, we were
really decided to create a pedal version of the 636 preamp
but we had a slight problem, we had never tried one. So,
in order to recreate it to the nest detail we began our
search for an original unit that we could reverse engineer.
After many months we managed to get our hands on
an original Grampian unit! It was in a great shape and
sounded amazing!
As soon as we strummed the rst chords with the original
636, we found the combination of Grampian, old Marshall
stack and single coils to be pure magic. It enhanced the
amp’s natural saturation with a fatter, sweeter tone. This
unique coloring comes out of its primitive technology and
Overview

5
because of the low input impedance of the 636. This is
also quite common on guitar effects of that era, like the
Fuzz Face®, Range Master and many other 60’s effect units.
However, we felt the vintage 636 was less impressive
when used with other types of amps and pickups, specially
humbuckers. Because of that, we challenged ourselves to
make this preamp sound beautiful no matter what amp or
pickup you use, managing to eventually tweak the circuit
to extend its frequency range and include eq controls
while retaining its unique tone. The treble response has
been rened by adding a Hi-Cut control which allows you
to add a sweet sparkle to muddy humbuckers or tame
brighter single coils, as well as a Lo-Cut knob to control
bass content better, so the player can decide the tightness
of the resultant tone.
Another thing we achieved was to rene its background
noise. The vintage Grampian has a remarkable hiss,
especially when the Aux Channel was used (Townshend’s
choice). Chapter two of the Windmiller designing process
was to eliminate that hiss whilst maintaining the character
and behavior of the original Grampian 636 preamp. After
experimenting with a great variety of components and
ne-tuning the circuit to make it as quiet as possible, we
nally succeeded!
And nally, in order to pay tribute to the last detail,
we’ve included the overload indicator lamp found on the
Grampian 636, which is sensitive to your playing and
responsive to your attack, and you may agree with us,
looks really cool!
The result is a versatile pedal that can be used as an
'always on' preamp with a beautiful color, a booster for
solo parts, or a tool to saturate and enhance the amp's
natural overdrive.

6
Features
FAITHFUL RECREATION OF OUR OWN GRAMPIAN
REVERBERATION UNIT TYPE 636 S/N: 1138
We’ve been lucky enough to nd an original unit from the
60’s in great shape, so we used it as a reference to make
the most accurate replica of its preamp thus far. We traced
the original circuit and made our own schematic to ensure
you cannot get closer to the real thing!
HEAVILY IMPROVED SIGNAL TO NOISE RATIO AND
INCREASED TREBLE RESPONSE:
As part of the circuit’s adaptation to a pedal unit, we have
put an extra effort to make The Windmiller Preamp as quiet
as possible, you almost can’t tell it’s on even at full gain! In
addition, we have made the circuit a bit brighter, so you have
a greater frequency spectrum on higher frequencies.
HI. CUT AND LO. CUT TONE SHAPING CONTROLS:
To make The Windmiller Preamp more versatile we have
included tone cut controls for high and low frequencies,
which are extremely useful when using on different amps
and guitars. Single coils, humbuckers, El84’s, 6l6’s…
It will match any rig!
PREAMP OR CLEAN BOOSTER? IT’S UP TO YOU!:
Due to its low input impedance The Windmiller Preamp
will react in different ways depending on the signal source
you connect it to. Plug it straight to your guitar before
any other device and you will be delighted by its unique
coloring. Put it after a buffer and you will get a super
transparent and linear booster with the addition of the Lo
Cut and Hi Cut controls!
OVERLOAD INDICATOR LAMP:
We couldn’t resist ourselves to put this cool feature of
the original Grampian 636 thus it will be very useful as a
signal monitor!
CIRCUIT TAILORED FOR BOTH BASS AND GUITAR
INSTRUMENTS:
Since the Grampian 636 was designed as a studio tool
you can use The Windmiller Preamp with any kind of
instrument. Guitar, bass, keys... you are the limit!

7
TRUE BYPASS RELAY SWITCHING:
We have incorporated a soft touch switch activated relay
switching system so, even in the quietest situation you
won’t bother the audience and band-members with click
or clack noises. And obviously like all our pedals it is true
bypass to ensure signal integrity.
SMART TRACK®FASTENING SYSTEM:
All our pedals use a custom enclosure designed to
perfectly match our Smart Track®pedalboards. Using
the side thumb screws you’ll be able to lock safely the
stompbox into one of our pedalboards.
It was also designed to t the other pedalboard options in
the market.

8
DECLARATION OF CONFORMITY:
This product complies with the requirements of
MADE IN SPAIN
MATERIAL INCLUDED
1 x The Windmiller Preamp pedal
1 x Anti-sliding rubber pad
1 x Velcro®pad
THE WINDMILLER PREAMP REF:
AP0030
DIMENSIONS:
13,6 x 8,7 x 5,5cm (5.4” x 3.4” x 2.2”) with knobs
WEIGHT:
450g. (0.99 lbs)
BYPASS:
Relay True Bypass
POWER REQUIREMENTS:
9V DC Center Negative 100mA minimum
CURRENT DRAW:
≈38mA
Specs &
Material included

9
Power requirements
POWER SUPPLY
This unit must be powered with a 9VDC negative tip power
supply with the standard Boss type 2.1mm connector.
Current supply should be a minimum of 100 mA just to
leave a safety margin for the DC adapter.
Make sure you use a good quality power supply and avoid
using generic SMPS type adapters which can induce high
pitched noise to the audio.
CAUTION:
Please note this pedal MUST not be powered with
any voltage above 9VDC. It already has an internal DC/DC
converter to make it work to the adequate tension for it to
work properly and with its max dynamic range. Powering it
up with a 12V or 18V power supply will damage its circuit
and immediately void the warranty.

10
Operating Diagram
GUITAR AMP INPUT
OUTPUT INPUT

11
Controls
INPUT JACK POWER JACK OUTPUT JACK
1 2 3
1 32

12
5
6
BYPASS SWITCH: Engages the unit allowing the
signal to ow through The Windmiller Preamp circuit.
It also lights up the LED above it.
GAIN: This control lets you set the amount of
signal boost of the instrument you plug into it. At
counterclockwise position will increase around 3dB’s
(depending on the settings of the Lo. Cut and Hi. Cut
knobs) compared to the bypassed signal. As you start
to turn the Gain up, it’ll build up more volume just like
a regular preamp or booster. Please bear in mind this
is a “clean” preamp meaning it doesn’t add saturation
per se (a little bit of asymmetrical clipping with the
Gain fully clockwise though) but will clip any following
device after it like an overdrive pedal or the amp.
OVERLOAD LIGHT: We felt we needed to pay tribute
to the vintage Grampian 636 by including the Overload
indicator light! In this pedal version it only serves as a
“signal in” indicator, although the higher the gain and
the harder you play, the brighter it will glow as it reacts
with the signal dynamics.
LO.CUT: When using The Windmiller Preamp a la
Townshend style (to saturate your amp) you may
nd the resultant overdrive is a bit fuzzy. This is not
necessarily a bad thing, but we have found useful to
include this Lo. Cut control to reduce bass content
and make mid frequencies pop out a bit more. When
it is fully counterclockwise it will reproduce the entire
bass frequency spectrum (like the vintage Grampian
636) and as you start turning it clockwise, low
frequencies will drop. This control is meant to be a
ne tune, so it doesn’t have a drastic effect like many
eq’s found on other pedals or amps.
HI.CUT: The vintage 636 tone is perfect for single
coils because it tames its high end and makes it
sound slightly round and mellow, just the perfect
amount. But on the other side, we found that
humbuckers were a bit unhappy with that. For this
reason, we made The Windmiller Preamp brighter
than the 636 and included this Hi. Cut control so it
is more versatile with any kind of guitar and pickup.
Fully counterclockwise is the brightest position, ideal
47
8

13
for darker pickups and as you move the knob it will remove highs until the fully clockwise position where it is enough to
tame the brightest pickup.
4
5 6 7 8

14
Where to put The Windmiller
Preamp on the effects chain?
Due to its low input impedance, the location of The
Windmiller Preamp on the effects chain is crucial to get
the desired functionality.
We will not extend ourselves on technical stuff (see page
19 to read a more in depth explanation of what impedance
is and how affects The Windmiller Preamp’s tone) though
it’s important for you to know how it will behave depending
on the position on your pedalboard.
To keep things simple, we will say The Windmiller Preamp
will add color to the tone when it's able to “see” the high
impedance signal coming from the guitar or bass pickups.
On the other hand, when a low impedance signal source
is plugged, like the one that comes out after a buffer,
engaged effect pedal or active pickups, will make The
Windmiller Preamp behave in a more transparent and
linear fashion. Almost no coloring besides the eq controls.
Having this in mind here’s some practical examples that
will help you out to nd the best setup for your beloved
The Windmiller Preamp.

15
TOWNSHEND SETUP PREAMP WITH TONE COLORING
In this example The Windmiller Preamp receives the signal
directly from the guitar output jack, so the scenario is a
high impedance signal into a low input impedance circuit.
The result is the same as Townshend’s rig. Tone coloring
and as you turn the Gain knob up drives the amp’s preamp
to increase saturation.
When placed in a pedalboard, the location of The
Windmiller Preamp pedal within the effects chain is crucial
to get the desired functionality. In this case the guitar/pedal
interaction stays the same, the player gets the 636 tone
coloring but the signal boost can overload the following
pedals before the amp. This is really interesting for
overdrive pedals, in order to get new textures from them.
OD
pedal

16
PREAMP WITH NO COLORING TRANSPARENT AND LINEAR BOOST
When the The Windmiller Preamp pedal gets the signal
from a buffered pedal (like a Boss, Ibanez etc) it changes
its behavior, becoming a transparent preamp. You can use
it again to add gain to the following overdrive pedals but
bear in mind the tone will not be “colored” anymore but
just a louder version of the bypassed signal. Still, you can
use the eq controls to shape and ne tune your tone.
To use it like a regular booster (louder signal with the less tone
coloration possible) without overloading the following pedals,
you should put it at the end of the effects chain. By doing this
there are a lot of chances some buffer or effect circuit will be
placed before the Windmiller Preamp, isolating the pickups
and, at the end, converting the signal to low impedance. The
Windmiller Preamp will react as a transparent booster without
adding its color. We found this ideal for solo parts or to
recover some gain after all the effects chain.
one pedal shoud have a
buffer/buffered bypass
Buffer Buffer
OD
pedal
OD
pedal

17
EQ Setting
suggestions
VINTAGE GRAMPIAN TONE
There’s not a particular way to set the The Windmiller
Preamp’s controls to get a certain The Who’s song tone.
It depends on your amp, guitar and obviously your hands!
But since the The Windmiller Preamp has more features
than the vintage Grampian 636, we can suggest you some
basic settings to start from so you can ne tune them to
match your current setup.
The gain control is not represented because it will
depend on how you want to use The Windmiller Preamp,
either as preamp, or a booster to saturate your amp or
overdrive pedal.

18
SINGLE COILS HUMBUCKERS

19
What impedance is and how it affects
The Windmiller Preamp’s tone.
Impedance is a really complex concept that requires deep
electronics and math knowledge to fully understand, so
to stay simple we’ll say its resistance over frequency.
Resistance is the concept of electronic components
(usually resistors) force against a current ow, commonly
known as electricity, through it. In direct current (the one
that powers most effects pedals for example) this value
is linear as DC has no frequency, it’s a steady source of
voltage with no variations.
On the other hand, the guitar signal is swinging voltage,
more commonly known as alternating current and is a
combination of a lot of frequencies.
Because of how the pickups are made, most of them create
high impedance circuits and this means they have inherent
resistance to certain frequencies. Those frequencies will
have dicult times traveling through the guitar cable and
ultimately getting into the circuit of the effect pedal.
And here’s the second actor of this game! The input
impedance of the effect pedal.
When we talk about a high input impedance circuit we
mean it won’t suck (or load) the signal source of the device
connected to it. Its inherent resistance will help the guitar
signal stay strong and all the frequencies will make its way
to the circuit with no diculties.
On the other hand, when a circuit has a low input
impedance it will mean it will load the signal source trying
to suck more energy out of it and here’s when certain
frequencies will struggle.
So, this is the case of The Windmiller Preamp pedal!
Its low input impedance creates a unique interaction
with the instrument pickups circuit and shapes its
particular tone.
Otherwise when a low impedance signal gets into its input,
the coloring is far less noticeable since no frequency has
tough times traveling to The Windmiller Preamp input
circuit and there’s also much less loading.

20
Setting up on
a pedalboard
All our effect pedals use a custom light aluminum
enclosure specially designed to t our Smart Track®
pedalboards. We incorporated a proprietary locking
system which allows the user to fasten the pedal without
the need of using the typical hook and loop method.
This custom fastening system follows the same
philosophy behind the Smart Track®fasteners but
integrated in the enclosure reducing the space occupied
by each pedal.
That translates into more pedal density for the same
space, and who doesn’t want that?
We strongly recommend you to take a look at our line of
pedalboards, which are the best complement to our pedals!
Add the anti-sliding rubber pad at the bottom of your
pedal, specially shaped for this unit.
Surface must be clean and dry before applying
adhesive pad.
1
HOW TO MOUNT IT ON A SMART TRACK®PEDALBOARD:
!