LR Baggs iBeam Onboard User Manual

L.R. BAGGS PICKUPS

iBEAM ONBOARD

INSTALLATION MANUAL & USER'S GUIDE

483 N. FRONTAGE RD.

NIPOMO, CA 93444

WWW.LRBAGGS.COM

TABLE OF CONTENTS

1. Package contents

2. Overview & cautions

3. Removal of previous system (retrofit only)

4. New installation woodworking

4.1. Routing the preamp hole

4.2. Drilling the strapjack hole

5. Strapjack installation

6. iBeam installation: pin bridge guitars

6.1. General positioning guidelines

6.2. Pin bridge installation

7. iBeam installation: non-pin bridge guitars

7.1. General positioning guidelines

7.2. Non-pin bridge installation

8. iBeam installation: classical guitars 

8.1. General positioning guidelines

8.2. Classical installation

9. Alternative placements

10. Preamp installation

11. User's Guide

11.1. Controls

11.2. Preamp gain trim

11.3. Phase

11.4. Feedback

12. Specifications

1 . P A C K A G E C O N T E N T S

iBeam:
one (1) iBeam b ridg e plate trans ducer
two (2) a dhes ive strips
one (1) iBeam q uick mount fixture kit (included in s teel string syste m on ly), inclu ding :
one (1) fixt ure instruction sheet
two (2) threaded posts
two (2) standoffs
two (2) .312" nuts
one (1) fixt ure board
two (2) small adhesive dots

Onboard Preamp:
one (1) onboa rd preamp
six (6) ½" bl ack installation scre ws
six (6) fiber washers
one (1) flexi bl e black preamp beze l
two (2) s elf- stick wire plat forms
one (1) pre am p routing templat e
one (1) .090" x . 048" pickup replace me nt shim
one (1) .120" x . 048" pickup replace me nt shim
one (1) strap ja ck harness

2 . O V E R V I E W & C A U T I O N S

The iBe am Onboard is a direct dro p- in retrofit s ystem for the larg er “ Brand X” onbo ar d pickup syst em that is of ten factor y-installed on Ma rtin,
Tayl or and many other popular guitars. Ne w (non-r et rofit) i nstallations can b e made simply by routing the appropriately -sized h ol e in the guitar ’s
side to accommodate the preamp an d onboard controls. This syst em includes the iBeam bridge pla te transd ucer and an onboard prea mp with
volume, EQ, phase inver sion and notch fi lter controls .

We reco mm end that this s ys tem be installed by a professiona l dealer/install er.
We do not pr ovide insta llati on adv ice or s up por t for h ome or h ob byist
in sta lla tio ns. In sta lle rs: ple ase read th e i nst ruc tio ns car efu lly befo re
proc eedin g. We wil l n ot be re spons ible fo r any damag e to the guit ar or
personal injur y resu lting from i nstallation, imprope r instal lation, use o r misu se
of the prod uct.

Before beginni ng, be sure that the screw holes in the iBeam pr ea mp bezel
(m ou nting f lange ) li ne up wit h the “Brand X ” p re amp scr ew holes on t he
guitar.

There are two versions of th is system (steel string and classical), each with its
own pickup insta ll at io n pr oced ure. Before beginning, co nf irm that the re i s
enough room between the bracing to install the pickup. The steel string i Be am
fits x-braced g ui tars with at least 3 inches of flat ope n sp ace directly under the
saddle (see fig ure 1). The classi cal i Be am fits most Torres-fan-br aced guitars
with a t least 3 inches o f clean, flat area b et ween the two braces on e ither side
of the ce nter brace un der the bridge (see figure 2) .

The preamp w ill only fit in guitars with a clearance of at least 2 7/16” be tween
the top and back braces, at the point where the pre am p chass is hangs inside
the instrum ent.

Agai n, ver if y tha t these r equ ire ments a re me t befor e mak ing any
alterat ions to the guita r.

If the space is too sm all to accommodat e t he iBea m, do not cut the iBeam
to fit a tigh ter space. Th is will ruin the pick up a nd void the war ranty.

fig. 1

fig. 2

The ste el a nd nylon string pre amps are voiced for their respective pic ku ps, an d
each will only work in the type of g uitar for which it is intended. The mounting
fixture included in the steel string s ystem will wo rk wi th pin bridge guitar s
only. I f you have a non-pin bridge stee l string guitar, see the non-pin bridge inst allation section (section 7).

The pre amp requires a 9V battery, which is no t in cluded in this pack age.

There is a small slit under th e iB ea m cap about 1/2" from e ach end of the pickup. Do not pok e anything into t he slit.

The peel -and-stick adhes ive is the best way to adhe re the iBea m. It will hold the iBea m quite f irml y, yet it is p ossi ble to remove i t at a l ater time.
The use o f any adhesive ot her than the prov id ed self-stick pads is not recommended and will void the w ar ranty.

3 . R E M O V A L O F P R E V I O U S S Y S T E M (ret rofi t in stal lations only)

Remove the enti re p reamp, o ut pu t harness and pic ku p. Two precision mahogany woo d shims have bee n pr ovided to rep lace the installed
undersaddle p icku p. Choose the corre ct o ne to fit your sa ddle width, an d tr im to length. You will also nee d to remove the old strapjac k.

Most guit ar manufacturer s include cross-grain reinforce me nt panels on sol id wood guitars bene ath the preamp mou nting scr ew holes. If, upon
remov ing the old preamp from a solid wood guitar, you discover that th ere ar e no reinfor cement strips, we recomm end instal ling cro ss -g rain
reinfor cement shims un dern eath the screw ho les to preven t chipping the wo od o n the guitar body.

Once the previous system is removed, proc eed to the stra pjack installation in struct io ns in section 5.

4 . N E W I N S T A L L A T I O N W O O D W O R K I N G

4.1 Rout ing the Preamp Hole: T he pre am p will only fit i n guitars with a clea ra nce of at least 2 7/16” (61.9mm) between t he top and back b races,

at the poin t wh ere the pream p ch assis hangs inside th e in strument.

For solid wood guitars ( es pecially m ap le), we r ecommend g lu ing two 2.5” (63.5 mm ) x .5” ( 12.7 mm) plywood cross-grain reinfor cement p an els on
the inside of the guitar body where ea ch screw hole will be d ri lled. This prevent s th e wood from s plit ting during the drilling process.

If you are uncomfortable fre ehand-cutting this area using the encl osed paper template (as described belo w) , we recommend that you use the
paper tem plate to fashion a ha rd template o ut of masonite or P le xiglas or other sui tabl e material.

1. Choose a lo cation on the side of the instr um ent to mount the preamp. The fla ttest pos sible area jus t above the waist on the up pe r bou t and
below the sho ulder is recomm ende d. D ou bl e-check to make sur e th e preamp will cle ar a ll internal bra ce s and other obstacl es w hen installed.

2. Lay th e enclos ed paper template o n the chosen loca tion and secure i t with mask ing tape on all four e dg es. Wi th a shar p scribe put a dimple in
the center of each o f t he screw hole s and then drill out the holes usin g a #45 drill bit (.082”/2.08 mm). Cut out the area for the p reamp carefull y
and slowly using a rotary cutter with a sh ar p 1/8” cu ttin g bit. We recommend c utting just i ns id e the l in es for th e initial c ut and then cleaning u p
the edges wit h a file. Re move the te mp late and clean up any exce ss tape residue wit h a soft c loth and naphtha.

4.2 Drilling the strap jack hole: For proper installati on, this jack require s a
clean 1/2" hol e in the tail blo ck of the instrument. Start by pla ci ng a piece of
masking tape on the outside of the instrument ove r the drilli ng area (to avoid
chipping the fin ish), drill a small pilot ho le in the tail bl ock and then follow
with a step drill. Now proceed to th e strapja ck installa ti on as detailed in the
followi ng sec ti on.

5 . S T R A P J A C K I N S T A L L A T I O N

Remove the s trap ring, retaining nut and one washer f rom the e nd of t he jack.
Ther e sho uld s till be one star lock ing washer, on e flat wa sh er and a nut
remaining on the ja ck. Bring the jack do wn through th e soundhole into the
body and in sert it into the pre-drilled hole in the tail block. Using the int er nal
nut (be sure to include the flat and star washe r), s et the proper depth t hat will
allow the entir e sm al ler threaded section to protrud e fr om t he i nstrument (see
figure 3). Wit h the jack in place, lay the remaining washers over the threads
and at ta ch the ex tern al retaining nu t until it’s tight. Fin is h by at ta ching the
strap ring ( it should cove r the retain ing nut and washer) s o as not to cra ck the
finish of the ins trument by as serting to o much pressure.

Now procee d t o t he ap propriate iBeam installatio n ins truc ti on s ( pi n b ri dg e,
non-pin bridge or c lassical) in the fo llowing sections.

6.iBEAM INSTALLATION: PIN BRIDGE
GUITARS

6.1 Ge neral po siti onin g guidel ines : The iBeam is a highl y sens itive pi ck up;

th er ef or e, pl ac ement and t he uni que cha ra cteri st ics of the instru me nt are
critical fac tors in producing the o ut st an di ng results of which the i Be am i s
capable. A few millimeters in any direction can h ave pro found effec ts on the
quality of the sound. In short, b ecau se each guitar is dif ferent, we can tell you
approxi mately where the pic kup sho uld be placed, but we can not provide an
exact specificati on.

fig. 3

smaller threaded section protrudes

tail block

The iBeam is designed to atta ch to the bridge plate, di rect ly under the saddle
line a nd gen erally parallel t o the sadd le, with the attach ed peel-and -s tick
adhesive. Good res ults shou ld be consiste ntly had by attaching the pi ck up as
sh ow n i n f igure 4. However, becaus e e ve ry guita r i s u nique, y ou may be
rewarde d by searching fo r the optimum locat ion.

The optimum location wil l deliver a sou nd tha t is focused a nd tig ht, wit h
proper string balan ce an d good presence. It wi ll ca pture enough of the string
resonance to be art icul ate, bu t will be mel lowed by a fu ll and str ong b ody
re so nance . Ul timat ely, it w ill accur at ely ca pture the d is tinct ton e of th e
instrument. An unsatisfactory loca ti on will often be characterized by a woofy
or nasal to ne, po or s tr in g balance and a h igh sensitivity to fe ed ba ck.

In ge ne ral, placin g the iBeam di re ctl y u nd er the sadd le wi ll provi de the
greates t sense of immediacy, impact, sna p and “string” sound. Offsetting the
pickup either toward the so und h ol e o r toward the br idge pi ns in the area
sh ow n in figu re 5 will incre ase the a mo unt of “body ” in the so und and
generally hav e a more mellow and homogeneous sound wit h less midrange.
We have o ft en achieve d our very be st res ul ts by placing the pickup as close to
the string ball-ends as is pra ct ical and offse tt ing it about 1 to 2 mm toward
the treble side of the saddle . An al ternative location that has of te n wor ke d wel l, provided the x-braces are wide enough, is to offset the pick up
towar d the front edge of t he bridge plate.

Do not tes t the pickup pl acement without fi rm ly sec urin g the adhesive . With ou t co mple tely sec ur ing th e pickup, the sou nd tes t will produce
unreliabl e results.

6.2 Pin bri dge inst allation (initial plac ement):

1. A ssemble the mountin g fi xt ure.

2. R emove the str ings f rom the pin holes .

3. Reach inside t he hole and feel around und er the bridge t o be sure the bridg e plate is free f rom debr is and obstructions. If you ar e unsu re, stick
a mirror in side to inspect this area .

4. Place the sta tionar y rod of the mo unting fixture in the high-E bridge pi n
hole and adjust the m ovable ro d la terally in the slot until it drops into the low­E bridge pin hol e as shown in figure 6. Tighten the nut to secure the movable
rod.

5. Place the adhesive dots on the fixt ure over the sadd le, one on eac h sid e of
the big slot.

Remove the adhesive bac ki ng from the dots and po si tion the iBeam over the
fixture in the desired locati on. Stick the iBeam to the adhesive d ots o n t he
fixture as show n in figure 7.

6. Remove th e fix tu re an d i Beam to ge th er fr om th e bridge a nd re move the
adhesive ba ck ing from the bottom s urface of the iB eam.

7. Inser t the fix ture holding the iBeam i nto the gu itar. Find th e high - an d low-E
string bridge pin hol es with the rods on t he fix ture.

8. Ins ert the rods into thes e hole s an d th en e levate the fixture stra ight u p until
the rods just poke o ut of the holes about 1 /2". Gras p one o f the rods f rom the
outside of the g uitar an d hold i t. Do n ot pul l up yet. Wh ile hold in g the one rod
let go of t he fixture in si de of t he guitar and gra b the o ther rod on the ou tside
of the guitar.

9. Now pull strai ght up on the rods as shown in fi gure 8 to ele vate the iBeam
until it co ntac ts the bridge plate . Tug up on the ro ds to secure the pi ckup.

10. Pop the fix ture o ff the iBeam inside the gui tar and remov e the fixture.

fig. 6

fig. 7

11. Press up firmly along the top surface of the iB eam, especi ally on th e ends,
to secure it. It ’s usually a g ood i de a t o press down on the b ri dg e f rom t he
outside of the gu itar as you p ress up o n the iBeam fro m the i ns id e to equalize
pressure and avo id cracking the top. Wig gle the iBeam front to back a little as
you pre ss.

12. Plug in and test the pickup placem ent. If the sound i s satisfactor y (see 6.1:
general positio ning gui delines for a rough definitio n of thi s), proceed to the
preamp i nstallation inst ruct io ns (section 10) . If the sound is un satisfactory, we
encoura ge you to exp erim en t with alternativ e placements (s ee s ec ti on 9).

7 . i B E A M I N S T A L L A T I O N : N O N - P I N
B R I D G E G U I T A R S

7.1 Ge neral po siti onin g guidel ines : The iBeam is a highl y sens itive pi ck up;

th er ef or e, pl ac ement and t he uni que cha ra cteri st ics of the instru me nt are
critical fac tors in producing the o ut st an di ng results of which the i Be am i s
capable. A few millimeters in any direction can h ave pro found effec ts on the
quality of the sound. Because ever y guita r i s uni que, you may be rewarde d by
searching fo r the opti mum loc ation. In short, because each guitar is differen t,
we c an tell you approxi ma tely where the pickup sh ou ld be place d, but we ca n
no t pr ovide a n exa ct spec ifica ti on. W ith n on -pin br idge gu itars, i t is also
unlikely that the first selected spot will be ideal.

The optimum location wil l deliver a sou nd tha t is focused a nd tig ht, wit h
proper string balan ce an d good presence. It wi ll ca pture enough of the string
resonance to be art icul ate, bu t will be mel lowed by a fu ll and str ong b ody
re so nance . Ul timat ely, it w ill accur at ely ca pture the d is tinct ton e of th e
instrument. An unsatisfactory loca ti on will often be characterized by a woofy
or nasal to ne, po or s tr in g balance and a h igh sensitivity to fe ed ba ck.

fig. 8

In general, placing the iBeam dire ctly un de r the saddle will provi de th e greatest sens e of immediacy, impact, sn ap and “string” sound. Of fsetting
the pic ku p either toward or away from the so un d hole will incr ea se the am ount of “body ” in the sound and generally have a more mellow and
homogeneous s ound with less midran ge.

Do not tes t the pickup pl acement without fi rm ly sec urin g the adhesive . With ou t co mple tely sec ur ing th e pickup, the sou nd tes t will produce
unreliabl e results.

7.2 Non-pin bri dge inst allation (initial pla ceme nt):

Installatio n on non-pin bridge guita rs requires that you remove the saddle, drill a small hole in each end of the sadd le s lot, and ins er t gu id e pins

to act as a reference when locating
th e iBe am . T he ho le lo catio ns wi ll
correspon d to the smal l slots in the
bo tt om of each end of the iB eam
(see fi gure 9). A good star ting place
is to dri ll the ho les so tha t t he
iBeam wi ll be centered under the E

fig. 9

Th is t op-d own vie w de pic ts t he b rid ge w ith

th e sa ddle re moved . The se p in h ole loc atio ns

ap ply to a ll stee l an d n ylon str ing non -pin

br idge s.

saddle slot

drill pin hole here

iBeam

strings. You will need an inspection
li gh t, in spect ion mir ro r, d rill, 1/16 "
dr ill bi t, w ood en mat chs ti cks or
toothpick s, and a sho rt penci l.

1. Dr il l a 1/1 6" hole throug h the

bridge

tie block

bridge

br id ge at bo th ends of the saddle
slot. If the guitar alrea dy has a hole
in the sadd le sl ot for a pic kup, you
may be able to use this as one of the holes. The minimum distance b et ween the holes should allow t he n otches in each end of the iBeam 's b as e to
nest ov er the protruding matches or tooth pick s that you wi ll i nser t as a refere nce to place th e iB ea m.

2. Press the matchsticks or toothpick s into the hol es unt il they ju st protrude (1/16" to 1/8") into the guitar. The se wil l ac t as locating pins for
determining the iBeam's placement.

3. Remov e the adhesi ve b ac king from the iBeam and, hold ing the iBeam upright between your thumb and tw o midd le fin gers, use your index and
little finger s to locate the m atches.

4. Hold the iBeam at a slig ht a ng le a way from the inside of t he g uita r top, a nd, using the slot in o ne e nd of the bottom of the iBeam, locate one of
the protruding matc hes. Rotat e the othe r end of t he p icku p until you find t he o th er p rotruding match with the slot in the other end of th e iBea m.
Then ve ry light ly p ress the adhesive against the bridge pla te with just enough p ressure to hold it in place.

5. Once you have tack ed the pickup into pl ace, inse rt an insp ec tion mi rror into the body to ch eck the placement of th e pickup. After confirming
that it is located correctly, remove the guide pins and press fi rm ly with a l it tl e rock ing motion over the surface of the top of the pickup to secure
it to the bridge plate. B e sure to apply a n equal downward for ce to the top o f the bridge when p ressing up fro m the inside to pre vent d am age to
the guitar.

6. Pl ug in an d tes t t he pi ck up pl acement. If the sound is satisf acto ry (see 7.1: gen eral positioning guidelines fo r a ro ug h d ef inition of this),
proceed t o the preamp installa ti on instructions (section 10). Ho wever, with non-pin bridge gui tars, it is li ke ly that the results wil l be less than
optimum at this position. I f th is is the case, we enco urage you to experiment with alter native placemen ts (see section 9).

8 . i B E A M I N S T A L L A T I O N : C L A S S I C A L G U I T A R S

8.1 General positioning guidelines: The iBeam is a high ly sen siti ve p ickup; therefore, placement is a critical fac tor in pro du ci ng t he outst andi ng

results of which th e iBeam i s capable. A few milli meters in a ny direc tion can have pro found effect s on the quality of the sound. I n short, b ec au se
each guit ar is dif ferent, we can tel l you app roximatel y where the pickup should be pl aced, but we can not prov id e an exac t specification . With
classical gui tars, it is also unlikely that th e fi rst selected spot will be ide al.

The cl as sical iBeam h as a tunn el in the center o f the pic kup designed to clear th e middle fan brace. The tunnel is wide enou gh to all ow for some
lateral m ovement o f th e pickup.

We su gg est that you initially position the pickup so it is lateral ly c entered ove r th e brace and that the entire pickup is offset towa rds (and p arallel
to) the tie bl oc k by 2 to 5 mm. The idea is t o blen d the dire ct string sound with the sound of t he body. Th e more cen tered the pi ck up i s unde r the
saddle, the mo re s tr ing dr ive and "s na p" t he s ound w il l have. Offs et ting t he p ic ku p towards the tie block or e ven towards the sound hole by a few
millimete rs will allow more body sound to mix with the string sound. If you desire more pres en ce from the bass strings and wish to mellow out
the high strings, center the pickup under the bass strings and angle it so the center of the pickup's high string end is eith er i n front or b ehind the
saddle line by some am ou nt. The reverse angle will have more pre sence for the hig h str in gs and les s for bass . If you find that the smal l E string
does not have enough level , offset ting the pickup later al ly toward s it will increase it s volume (see figur e 9).

The op ti mum locati on will d eliver a sound that is foc us ed and ti ght, wi th proper string bala nce and g oo d presen ce. I t will capt ure enough of the
string resonance to be a rticul ate, but will be me ll owed by a full and stron g body resonan ce. Ultimate ly, it w il l accu rately capture the d is tinc t tone
of th e ins trum ent. An unsatisfactor y loc ation wil l often be cha racterized by a woofy or nasal tone, poor string bala nce and a high sensitivity to
feedbac k.

Do not tes t the pickup pl acement without fi rm ly sec urin g the adhesive . With ou t co mple tely sec ur ing th e pickup, the sou nd tes t will produce
unreliabl e results.

8.2 C lassical in stal lation (i niti al placemen t): Most c la ss ical gu itar s are fa n brace d. The m os t common p attern is the Torres pa ttern w ith 5
longitudinal braces. The iBeam is notched in the middle of the pickup to straddle the middle fan brace and will fit mo st Torres-pat tern-braced
guitars. Classical bracing patterns vary, so before you proce ed, check to ensure that there is a total of 3" of clean, flat area between the two
braces on e ither side of the c en ter brace u nder the bridge (see figu re 10).

Note: Do not trim the edge s of the
pi ckup if you do not h av e sp ace

fig. 1 0

alternate placement
range (light gray area)

between the brace s for th e p icku p.
This will both ruin the pic ku p and
void th e warranty!

In sta llat ion on cl ass ica l g uit ars
re qui res t hat you re mov e the
saddle, dril l a sma ll hole i n each en d
of the sa dd le slot, and insert guide
pins (match st icks or toothpicks work
well ) to ac t as a refe re nce whe n
pl acin g th e iB eam. The h ole
lo cat io ns will cor re spo nd to the
sm al l s lots in th e b ottom of ea ch
end of the i Be am (se e figure 9). A

bridge bridge

iBeam default position

saddle

(dark gray area)

go od st art ing p lace is to drill the
guid e pin holes so that the iBeam
will be centered un der the E st ri ngs.
You will need an i nspec tion light,
in spect ion mir ror, d rill, 1/16 " dr ill
bit, wooden match stic ks or toothpicks, and a short pencil.

1. Drill a 1/16" hole thro ugh the bridge at both ends of the sa ddle slot. If the guit ar already has a hole in the saddle s lo t for a p ickup, you may be
able to use this as one of the holes. The minimum distan ce between the holes shou ld allow the notch es in each end of the iBeam's ba se to nest
ove r the protruding ma tches or toothpicks that you will in sert as a reference to place the iBeam .

2. Press the matchsticks or toothpick s into the hol es until they just protrude (1/16" to 1/8") into the guitar. The se wil l ac t as locating pins for
determining the iBeam's placement.

3. Remov e the adhesi ve b ac king from the iBeam and, hold ing the iBeam upright between your thumb and two midd le fin gers, use your index and
little finger s to locate the m atches.

4. Hold the iBeam at a slig ht a ngle away from the inside of t he g uita r top, a nd, using the slot in o ne e nd of the bottom of the iBeam, locate one of
the protruding matc hes. Rotat e the othe r end of t he p icku p until you find the o ther p rotruding match with the slot in the other end of th e iBea m.
Then ve ry light ly p ress the adhesive against the bridge pla te with just enough p ressure to hold it in place.

5. Once you have tacked the pickup into pl ace, insert an insp ec tion mirror into the body to check the placement of th e pickup. After confirming
that it is located correctly, remove the guide pins and press fi rm ly with a l it tl e rock ing motion over the surface of the top of the pickup to secure
it to the bridge plate. B e sure to apply a n equal downward for ce to the top o f the bridge when p ressing up fro m the inside to pre vent d am age to
the guitar.

6. Pl ug in an d tes t t he pi ck up pl acement. If the sound is satisf acto ry (see 8.1: gen eral positioning guidelines fo r a ro ug h d ef inition of this),
proceed to the prea mp installation ins truc tions (section 10). Howeve r, with c lassical guitars, it is likely t hat the resul ts will be less tha n o ptimum
at this pos ition. If this i s the case, we encourag e you to expe rime nt with alternati ve placements ( see sect ion 9).

9 . A L T E R N A T I V E P L A C E M E N T S

The adhes ive used to secur e the iBeam is very strong. Once you stick it down , it will increase its gri p over about a week ’s time. If you wish to
experiment with placement, it wil l be easi er befor e the adhesive de velops i ts full s trength. To exp erim ent with placement, begin by o utli ning the
pickup in it s defa ult posi tion w it h a pencil; this will act as a reference of the init ia l loca tion. Next, place three finge rs along the length of the ba ck
side of the pi ck up. Pull f ir ml y with e ven pressure parallel to the guitar top, u ntil t he a dh es ive gives way. Ro ck it up onto one edge and then l if t up
one end to pu ll the adhesive a way from th e br id ge plate. Do not pull up on the cap. Then pull the pickup o ff.

To remov e the adhesi ve f rom the bott om of the pickup, roll it off like carpet. After tack ing the new pad to the bo ttom o f the pickup, use t he e dge
of a p en ci l to p ress t he adhes ive fi rm ly t o the pick up. We’ve incl uded two extra pads in the kit, an d extra pads are available from us i n pack s of 10
for $5. 00. Be sure to inspect the bridge plate for any ad hesive residue before you reposition the iBeam.

Now reposition the pick up. If the sou nd is satisfactory, proceed to the preamp installation ( sectio n 10). I f not, repeat this se ct ion as needed until
you fin d th e proper location .

1 0 . P R E A M P I N S T A L L A T I O N

This preamp is d esigned for si des that a re .09 0” to .165” thick a nd rea so nably flat o r co nvex. The skir t of the bezel may bottom out o n guit ars that
have especially thin or concave sides. This w il l prevent the bezel fro m seating completely on the guitar ’s side. I f this happ en s, place the provid ed
fiber washe rs over the p rotruding ends of the screws (inside of the guitar body) to spa ce the preamp dow n into the guitar.

The bezel is made of a special mat er ia l that may be cold-for me d by hand and can be easil y made to conform to the cur vature of t he guitar side.
Simply bend t he bezel by han d until it fits to the guitar side without a ny gaps. I t may help to o ver-bend the beze l slightly in spots u ntil it lies

flush on the guit ar side's surf ace.

1. Once th e bezel has been formed, drop it into the existing cutout and scre w
the 4 p rovided scre ws into t he holes unti l they prot rude into the guitar about
1/16”. Do not enlarge th e holes i n the g uita r! If you enlarge th e holes, the
screws wi ll n ot be able to hol d th e bezel in plac e to position the pre am p.

fig. 11

2. P lug the pickup and stra pj ack harness into the end of the preamp.

3. Insert a battery into the battery compartme nt (obser ve polarity!) and push
the batter y compart me nt into the unit u ntil it click -loc ks into p la ce. Inser t the
preamp into the guitar through the sound hole and place it into the opening
in the bezel fro m in side of the guitar. Wiggle it ar ou nd unt il the screw ends
find the corresponding slot s i n the chassis. Cente r the preamp laterally (alon g
the length of the si de) in the beze l and star t the screws into the plastic. Ho ld
the preamp firmly against the s ide so t hat it d oe s no t “w al k” as you tighte n the
screws. Bef ore you tighten the scre ws completely, be sure that the b attery
compartment does not bind against the bezel whe n you open and close the
compartment.

Do n ot ove rtight en the screws! T his will cause th e beze l ends to l if t from the
side. Excess ov er tighte ni ng m ay even cau se the screws to cut through the
bezel. It is helpful to watch the edge of the bezel as you tighte n; stop when it
seats nicel y against the wood.

4. Secu re the wire s in side of t he guitar with t he self-s tick wire p latform s
provi ded.

1 1 . U S E R ' S G U I D E

11.1 Co ntrols:

Caution : Do not re move the batter y fr om the preamp while plu gged in!

1. P hase Button: Th is i nverts the freq uenc y ph as e (see section 11.3).

fig. 12

1

click-lock battery
access -- press to

release

2

4

3

5

g u i t a r

2. Bat te ry Acc es s and Battery Gauge Light: D epress and rel ea se the u pp er
panel to acc ess the battery compar tmen t. When the batter y light dims, it will
be necess ary to r ep lace the batter y.

3. Volume Slid er: Th is adjusts the prea mp volume.

4. Garret t N ul l Notch Filte r: Th is knob is used to canc el gu it ar bo dy resonance
feedbac k (s ee sec tion 11.4).

5. Treble and Bass Controls: These sliders adjust the level of high and low
frequency output.

11.2. Prea mp Gai n Trim : T he gain control is located on the ba ck side of the
preamp. It is factory-set to ave rage level s. You ma y turn th is trimmer wi th a
small screw dr iver if you’d l ik e your output to be l ouder or quieter.

How to tell if you’ve gone to o far: if you he ar distort io n, it’s too high; turn it
down. If you hear his s, it’s t oo l ow ; t ur n it up.

11.3 Phase: Phase is a t im e relationship between two vibratin g obje cts, in t his
case a guitar and a spe aker. The phase rel ationship bet ween the sp eaker and
the g uitar at feedback f requencies wi ll va ry with t he distance between the
gu it ar and the lo udspe aker. Depe nd ing on the ph ase determ ined by th e
distance bet we en t he g ui tar and the spe aker the se fre qu en cies wil l ei ther
reinfor ce (add) or cance l (subtract).

If you’ve e ver b ac ke d away from a lo ud moni tor to k ee p your g uitar u nd er
control (thinking that increasing t he distance would r educe the loudness) you
were actually altering the phase relationship bet we en your guitar and the
speaker at t ha t feedback f requency. W hat you intu itively did wa s to move your
guitar from “in ph ase” wi th the monitor to “out of phase” at that freq ue nc y. It
was this change in phase that was responsible for the reduction or elimination
of fee dback, not the lowering of volume due to moving away. Moving towards
the monitor m ay have b ee n just as effec tive.

s p e a k e r

fig. 13: phase addition

c o m b i n e d g u i t a r / s p e a k e r

Wavelength s of feedback frequenci es a re ver y lo ng ( figure13). I f th is f requency
is a guitar body resonance, the addition of energy from these two waves will
increase the tot al energy a nd can caus e feed back . When these freq uencies are
generat ed in tim e by one- ha lf wave length apart (see figure 14) they are OUT
of phase and they will subtract (see f igure 15).

If this frequen cy is a gui tar b ody resonance the subt ract ion of energy from
these two wa ves wi ll decreas e the total energ y and can red uce or eliminate
feedbac k. So, to inve rt th e phase at any particular fre quency you can eit he r
move one half wave leng th (4 to 6 feet) away from or closer to the speaker or
just stan d where you are and push the Invert button . It is likely that you w ill
not be exactly i n or o ut o f ph ase at w ha tever frequen cy is troubling you. If you
are physically between in phase and out o f phase you w il l in effect be in
“ne utra l” a nd r eversing phase electronically will have little or no effect on
feedbac k. You may stil l need to “fi ne tune” your position to achieve optimum
cancellat ion.

5. 4 Fee dback : I t is l ike ly that a r oom/s peake r r esona nc e w ill be first to
instigate fee db ac k, energizing the guitar ai r cavity res on ance ( 13 0-160 Hz ) The
guitar top resonance (190-2 40 Hz) is usually the next to g o off. As you incr ea se
the volume these freq ue nc ies usu ally go off succes si vely in order fr om the
lowes t to the highest.

The phase inver t control is your first line of defense against feedbac k. Usually
it is t he ai r c av it y r esona nc e t ha t g oe s o ff firs t. Th e optim um phas e c an
effective ly damp this resonance. To find th e optim um phase raise the volu me
un ti l your gu it ar jus t star ts to feedb ack. Push th e i nver t bu tt on. But be
prepare d, feedback cou ld get inst antly worse! You nev er know if you are in a
good or bad phase until yo u push the button. If t he feedback g ets worse,
inv er t ph ase ag ain and kn ow you have a lready used one of yo ur tools. The o nl y
thing you can do with phase at this poin t is to move around a bit to optim ize
the ca ncellation. Note: Phase is onl y useful as a feedback weapon if you are
relativ ely statio nary. If yo u plan to move around on stage th e Phase control
will be of no benefit unle ss you can push the button e very time you move 4
feet!

fig. 1 4

g u i t a r

s p e a k e r

fig. 1 5: phase cancellation

c o m b i n e d g u i t a r / s p e a k e r

Now that you have “fire d” you r first weap on, are you as lo ud as you need to
be? If yes, you’re don e. If no, then keep raising the volum e until the nex t
resonance (usually the g ui ta r bo dy air r es on ance ) ju st s tarts to go. Slowl y
swee p the fre quenc y with th e no tc h filte r until i t “grabs” an d dam ps this
feed back. Thi s effec t wil l be easy t o detec t and o bviou s as this f ee dback
frequency will instantl y vanish when you hit it. Thi s shou ld tak e ca re of the top
resonance. With the phase and notc h in their optimum positions, you will find
you can play quite a bit lou der without fee db ac k.

When all else fa il s and you stil l are not loud enough you can simply turn d own
the bass and even increase the treble for more “cut”.

The louder you play, the more critical your physical position is relat ive to the
monitors and the more precisely tuned the no tch must be. Also be aware t hat
the guitar feedba ck fre quencies will drif t sl ightly as the guitar is warmed by
your bo dy a nd the stage lights .

1 2 . S P E C I F I C A T I O N S

Size: 4" x 2.6" x 2.5”
Weight (including ba tter y): 6oz
Battery: single 9v
Curre nt consumption: 2. 6mA
Battery life: 200 hrs (alkaline)
Bass +- 6dB @ 100 Hz
Treble: + - 6dB @ 10kHz
Signal to noi se: -90dB un weighted
Input impedan ce: 10 megoh ms
Output impeda nce: 620 ohm s
Notch fil ter: off to 320hz