Revox AGORA B MKII User manual

nd/ox
Agora B MKII
Af;ora B Slim Line
Operating Instructions

IMPORTANT
WARRANry
PACKING MATERIAL
Protect your speakers from exposure to excessive heat and mois-
ture. Carefully read Section 1 (setup) before you installthe speak-
ers.
The powered speaker should be connected to the (pre-)amplifier
before it is connected to the AC outlet.
It is important to follow the instruction in Section '11 (AC power
connection).
Please note that the warranty is only valid in the country in which
the equipment has been sold. We also would like to draw your
attention to the fact that the warranty becomes null and void if
unauthorized modifications or unprofessional repairs are made.
Warranty cards for equipment sold in Swiüerland or Austria are
issued directly by the authorized dealer. For equipment sold in
France you will find the warranty card inside the packing. This
card must be completed and signed by your authorized REVOX
dealer. ln the Federal Republic of Germanv, in the USA, and in
most other countries a special warranty card supplied with the
equipment This card is located either inside the packing or in a
plastic pouch attached to the outside of the packing. lf this card is
missing please consult your REVOX dealer or your national
REVOX distributor.
Please retain the original box for reuse in case your equipment
ever needs to be transported The packing material has been
especially designed to protect your valuable equipment from
shock in transit.
Vorsicht: Das Gerät ist in ausgeschaltetem Zustand (STANDBY) nicht von der Stromzuführung getrennt
Attention: Cet appareil n'est pas separe du r6seau lorsqu'il est ddclench6 (STANDBY).
Warning: This unit is not separated from the mains supp y when swltched o1f (STANDBY).
Attenzione: Ouesto apparecchio non ö separato dal a rete quando interruttore Ö spento (STANDBY)
Precauciön: Este aparato no estä separado de la red cuando estä apagado (SfANDBY).
Waarschuwing: ln uitgeschakelde toestand (STANDBY) s het apparaat nlet gesche den van de netspanning.
Advarsel: Apparaten er ogsaa hvis lukket (STANDBY) undet strom
Huomio: Huo matta slltä, että virta on katkaistu laitteesta (STANDBY). sitä ei ole eristetty sähköstä.
Forsildig: Selvom strommen ikke er pa i apparatet (SIANDBY). sa er det ikke skilt fra strom
Varning: Oaktat om strömmen är avbruten i apparaten (STANDBY), sa är den ända kopplad med ström.

Table of contents
sEcTtoN 1Page
2
G enera L
Content of packing 3
3
3
AC power connection
Setup
sEcTroN 2Synopt cal sketch
Pilot lamps
Connection to the preamplif er or amplifier
sEcTtoN 3Connection versions
sEcTtoN 4Technical data
sEcTroN 5Block diagram

sEcroN 1
General ln conventional passive speakers the frequency range is allocated to the indivi-
dua I speaker chässis by passive frlters implemented with coils and capacitors
The ohmic resistance inherent to these coils as well as the resistance of the
connecting cable beh/,/een the amplifier and the speaker have a detrimental
influence ön the damptng factol i. e. it becomes much more difflcult for the
amplifier to control the speaker diaphragm movement.
ln powered speakersthe frequency spectrum is split before the.power amplifi
erä. ln this case the crossover networks can be implemented with low loss
components (amplifiers). One power amplifier each is assigned to the bass,
midänqe, and treble. These power amplifiers are installed in a speaker hous-
lnq (heäce the desiqnation "powered"). This arrangement results in short,
loürlloss connectioni bet,veen the power amplifiers and the corresponding
speaker chassis. The damplng factor is known and controllable
Cone type speakers generally have an asymmetrical deflectlon of the dia-
phraqm. thris means that the travel of the moving coil is not identica I in the d i-
iectiön toward the maqnet and away from the magnet. The diaphragm ofthe
bass soeakers oerform the qreatest deflection. This is the reason why this
asvmmetrv is most perceiväble in bass speakers. ln the powered speaker
AGORA B MKll/AGORA B SLIM LINE, the only feasible solution to this prob
lem has been chosen, the so-called push-pull operation of a pair of identical
bass speakers of which one is installed in the housing in a conventional man-
ner thö other, however, with the magnet system facing the outside. ln thisway
the asymmetries of the speakers are mutually compensated. The diaphragm
movement of the two bass speakers is rigidly coupled to the output signal of
the bass amplifier by an interlocking control system. Frequency response
errors and high-ordei sympathetic reaonance of the housing, which occur in
passive and powered systems without interlocking control, are now a thing of
the past.
The input sensitivity of the AGORA B lvKll/AGORA B SLIM LINE powered
soeakärs can be switch selected so that it can be matched either to a tuner/
preamplifier combination (e. g. REVOX B286) or a tuner/power amplifier c^om
bination (e. g. REVOX 8285). In various power amplifiers (e. g. REVOX 8250)
and receiveis it is possible to open the path betu/een the preamplifier and the
oower amolifier. ln this case the AGORA B I\lKll/AGORA B SLIM LINE can be
bonnected to the preamplifier output of the correspond ing unit. Direct connec-
tion to source units with variable output level (e.9. REVOX CD 8226) is also
feasible.
Thepowered speakerAGORA B MKll/AGORA B SLIM LINE is. of course. also
compatrble with REVOX equipment of older series. Your dealer will gladly
advise you.
Protective circuits prevent overheating of the built-in power amplifiers and
protect the midrange speaker and the Nveeter from overloads.

Packing content
AC power connection
Setup
ln additron to these operating instructions and a power cab e with a plug that
fits the AC outlets in your country, the pack ng contains a 12 m screened,
sing e conductor cab e with cinch connectors on both ends. ln additron there
is an adapter for connectiof to a power amp ifier.
Before you connect the spea kers to the AC outlet. make sure that the loca I line
voltage ag rees with the specif cation on the name plate on the powered spea k
er box. Should this not be the case, p ease consu t your dea er.
Do NOT connectthe powered speakerAGORA B N/Kll/AGORA B SLIN/ LLNE
to the AC outlet until it has been connected to the preamp ifier or the power
amplifier
The powered speaker AGORA B lVKll /AGORA B SLIN/ LINE is designed as a
standing box which means that t should be set up on the floor. otherw se the
sound impression wil suffer.
The cooling f ns on the rear shou d be at least 5 cm (2") away from any adja
cent surface so that the heat can be dissipated.
The powered speaker AGORA B MKll/AGORA B SLIN/ L NE has an excep-
tiona Lly large rad at on a ng e which means that it ls not necessa ry to ti t it in the
d irection of the lstener.
Basica lly, each spea ker should be set up in such a way that it rad iates from the
acoustically hard (weakly absorbing) part of the room to the acoustically soft
(strongly absorbing) part of the room.
Strong accentuation of treb e and bass frequencies at the (pre ) amp ifier is not
recommended because the distortion increases and the power handling ca
pacrty is strongly reduced (in some cases the protect ve circuit wrll respond).
REVOX speakers are designed with a neutral sound and therefore do not
require any corrections.
ö@
\*v [--h
q L--ll

sEcroN 2
Synoptical sketch
wrth quick-reference description
of all functions
o
@
-"iJ"* o
11] AC POWER Power inlet
f2l PowER oN/oFF MODE 4 Position rotary switch:
ON: Unit is switched on (standby) as long as it is connected to the AC
power source.
AUTO: The unlt automatica ly starts up from STAN DBY when an input signal is
availabie. lf there is no input signal for approx. 5 minutes. the unit
switches automatical y to STANDBY
DC: Swltch on at > I V DC. switch ofl at < 5 V DC.
Pin assignment: ground [ ] to pin 6
0...30V DC to pin B
At thE REN/]OTE CONTROL INPUT/OUTPUT SOCKCt.
lR: Automatic on/off in conjunction wlth the 8209 subcontroLler.
13] INPUT SELECTOR 4-Posltion rotary switch:
PRE AIVP R: Operation as
connected to
PWR-AMP R: Operation as
connected to
PWR-AIVP L: Operation as
connected to
PRE-AMP L: Operation as
connected to
riqht hand box,
preampLifier output
right hand box,
amplifier output
left hand box.
power amfrlifier output
left hand box.
power amplifier output
[4] REN/OTE CONTROL lN PUT: Connection of the B2O9 subcontroller or input f rom 1st AGO RA Box
with serially connected wiring
OUTPUT: Connecting to the next AGORA with serlally connected wiring
(to REN/OTE INPUT socket)
l5l rNPUT R/L CINCH terminals for audio input signals.

Pilot lamps (LEDs)
Gonnection to the pre-
amplifier or power amplifier
The tv/o LEDS are located on the acoustic baffle on the right-hand side of the
f,r',/eeter. They are also visible when the front cover is installed.
The red LED is alightwhen the powered speaker is connected to the AC power
outlet and if switch l2l is in one of the following positions:
AUTO: The speaker is switched to STANDBY by the automatic on/off crrcuit.
DC: The speaker is switched off ((5VDC).
(lf this external voltage version rs not used, the DC setting functlons in
the same way as "OFF" (STANDBY).
lR: The speaker is in STANDBY mode and operates in conjunction with
the 8209 subcontrol er (connection versron ll).
The green LFD is alight in normal operatlon if switch l2l is in one of the follow-
ing positions:
ON: The speaker is continuously switched on.
AUTO: The speaker is switched on by the automatic on/off circuit.
DC: The speaker is switched on by an external DC voitage ()9VDC).
lR: The speaker is switched on ln conlunction with the 8209 subcontroller
{connection version Jl).
The red and the green LED are alight simuitaneously rf the built- n protective
circuit has responded either because of overheating or because the mid range
speaker or the t\,veeter is overloaded. In the f irst case the power amplifiers are
muted until their temperature has dropped to an admissible level; in the se-
cond case the muting is cancelled after a few seconds.
Before the powered speaker AGORA B N/Kll/AGORA B SLIM LINE can be
connected, it s necessa ry to match the input sensitivity to the d riving amplif ier.
- lf a power am plifier or a receiver is used (e. g. REVOX B2B5), switch [3] must
be in the PWR AMP positlon.
lf a preamplifier or a preceiver is used (e. g. REVOX 8286). switch l3l must
be in the PRE AMP position.
1f a power am plif ier or a recelver is used in which the signal path beh/,/een the
preamplifier and the output stage can be opened (e. g. REVOX 8250), it is
better to connect the powered speal,er to the preamplifier output. (Switch
[3] in PRE AMP position).
A connectlng cable (single-conductor, screened, CINCH connectors on both
ends) is bypacked to the powered speaker AGORA B lVKll/AGORA B SLINI
LINE. lf required by the room size, this cable can be extended up to 35 m
(120feet) without adversely aflecting the quality of the sound reproduction.
lf the speaker is to be connected to a preamplifier equipped with DlN. XLR or
other output sockets, p ease contact your dea er or consult the operating rn-
structions of your preamplifier. Your dealer normally carries sultable adapters
in stock.
The bypacked adapter cable shou d be used for connecting the speaker to a
power amplifier.

sEcTroN 3
Connection versions
Version I
AGORA B N/K II
(LEil)
ln the following Chapter the term "amplifier" s used to mean power amplifier,
preamplifiel or preceiver.
Basically, there are trr'r'o methods for connecting the REVOX AGORA B lVKll/
AGORA B SLINl LINE speaker to an amplrfier.
AGORA B N/K II
(RtcHT)
The left hand amplifier output is connected by a single-cond uctor. screened
cable to the input socket INPUT L of the left-hand powered box. The INPUT
SELECTOR l3l switch of the lefr-hand box mustbe setto eitherthe PRE AMP L
(preamplifier) or the PWR AMP L (power amplifier) position.
The right-hand channel is cabled analogously. The INPUT SELECTOR l3l
switch of the right hand box must be set to either the PRE AM P R (preamplifier)
or the PWR AMP R (power amplifier) position.
8250

Version ll AGORA B N/ Kll /AGORA B SLIM LINE in the a nciila ry room with 8209 subcon-
troller.
AGORA B MK I]
AGORA B IVK II
The REVOX B209 subcontroller is a high qua lity preamplifier without operator
controls. ltis nsta lled below the AGO RA in place of the base. The volume, the
balance and the tone contro are adjusted with the B20B lR remote control.
The B209 subcontroller features an inputthat is supplied with audio signals by
a preamplifrer located in lhe nain room.
Detailed information concerning the REVOX 8209 subcontroller and the ex-
tended application facilities of the AGORA in conjunction with the B209 sub
controller can be found in the 8209 operating instructions.
8209

sEcTtoN 4
Technical data
AGORA B MKII
Audio data
Bandwidth
(D N 45500) 24Hz 42kHz
Frequency response (- 3 dB) 4AHz.22kHz
Harmonic distortion Ktot Bandw dih
at a d stance of 1ra: 45Hz 2OkHz
wth sound pressure evel82dB SPLmax 0 5%
w th sound pressure evel88dBSPLmax. 1.0%
Achievable
sound pressure level 100 m3 living room, mean reverberat on
rr-r.0r dr.d .ol2r )d. 'r p p6dto-.
s mu taneoLrsly in operation: I]3 dB SPL
Speaker configuration M drange speaker d a.r,.2x220nn
d am 122nn
diam 25 mm
Flux densitiy 2\11I
117
1.1r
Mldrange speaker
Magnetic Ilux Midrange speaker 2x541rrwb
539!Wb
412pWb
Electrical data -&\
*l
lnputs Sens tiv ty for 100 dB SPL at a d stance of 1 m:
sw tch in PRE-Al\/lP pos. 0 35v/47 kohrn
Swtch in PWF AN,4P pos 3.5V/l kohm
Operating modes ON: continuous ON
AUTO on/olfvaaudio
DC: on/off v a DC vo tage
F: on/offva8209
AGORA B SLIM LINE
Switch-ofi delay of the
automatic on/off circuit approx 5 m n
Sensitivity ol the
automatic on/off circuit - PRE-AN/P 0.25 mV
2.5 mV
DC switching thresholds Onr >9V
off:<5V
General data
Power requirements 22A/11AV +10a/a
interna y so der strappab e
50 60Hz
220V:
1 10V: T16A slow T315A slow
Power consümption Standby mode
- Max. (100 dB SPL at 1 m) <7W
400w
Operating environment - Amb enl temperature
Re atve humld ty {D N 40040) +10 + 400c CassF
Weiqht 38.5 kg (AGORA B N4Kl )
43 5kg {AGORA B SL M L NE)
Housing ve.sions Wa nut dark, Ash black,
Pläno varnish b ack or whii-"
Dimensions (WxHxD) 790x386x435mm AGoRA B MKI
1000x334x395mm AGORA B Sl M LNE
Sublect to change
8

sEcTroN 5
Block diagram
V-,
I
v ,
I

sruDElr nd/ox
Manufacturer
Willi Studer AC
CH-8105 Regensdorf/Switzerland
Althardstrasse 30
Studer Revox GmbH
D-7827 Lölängen/Gennany
Thlstrasse 7
Worldwide Distribution
Revox Ela AG
CH-8105 Regensdorf/Switzerland
Althardstrasse 146