3124+
3124mb+
3124+ / 3124mb+ Mixer
Features
Uses API 2520 Op Amp
Classic Console Circuit
Four XLR Mic Inputs
Four1/4”Un-BalancedInputs
Front Panel Polarity Switch
Front Panel 20dB PadSwitch
Front Panel Mic / Line Switch
Front Panel 48V Power Switch
Output Clips at +30 dBm
Boththe3124+andthe3124mb+aredesignedwith
theprofessional engineerin mind,giving thehigh-
est possible quality 4 channel Mic Preamp and
with the 3124mb+, an audio mixer, while keeping
the size and price at a reasonable level. Several
3124mb+mixerscanbelinked toincreasethenum-
ber of bussed channels. Both models are equally
athome in the controlroom, the studio,a news or
recordingtruck,atthehouseconsole,onthestage,
direct-to-DAT, or at the artist’s disposal for the
sourceof hismusic.
Themodel3124+utilizesthesame microphonepreampcircuit
thatisused in all API consoles. ItusestheRE-115K mic input
transformerandthesame output transformer thatisusedinall
APIequalizers. Allfourmicinputs ofthe3124+andthe3124mb+
arepowered byaninternal48 voltphantompowersupply, front
panel switchable for each channel. Also provided is a front
panel20dBpad switch that effectsboththeMicand Line in.
Themodel3124+ can provide up to65dBof gain to anoutput
clip level of +30 dBm. The Hi-Z front panel input goes directly
to the op amp, allowing a low level input such as a guitar or
bass to be amplified without a matching transformer or direct
box. ThisHi-Zinputcantakeinputlevelsashighas +22, mak-
ing it perfect for keyboards and other high level devices. The
rear output is an XLR connector.
TheModel3124mb+ is a 3124+withtheadditionof a complete
stereomixer. Inconjunctionwiththegain control of the 3124+,
the 3124mb+ adds a stereo panner with a level control, and a
post“fader”auxsend. Thestereopanners and the aux sends
arebussed tomasteroutputcontrols andthentothe rearpanel
jacks. Astereo aux return isprovided to return effectsorcas-
cadeadditionalmixers formoreinputs. Theuniqueaux return
pot acts like a panner to balance the left/right signal, yet stay-
ing stereo. It can also be used as a mono return. A standard
3124+ can be further expanded to an “mb” at the factory. Sev-
eral options for the “mb” include a discrete unbalanced stereo
outputoradiscrete balanced stereo output.
8301 Patuxent Range Rd. Jessup, MD 20794 Phone (301) 776-7879 Fax (301) 776-8117 [email protected] 
