Engl E670 - Power Amp Output A: A1, A2, Impedance Selector

74 IMPEDANCE SELECTOR B
75 POWERAMP OUTPUT B: OUTPUT B1
76 POWERAMP OUTPUT A: OUTPUT A2
77 IMPEDANCE SELECTOR A
Impedance selector for .Use thisrotary selector toset the overall
power amp output impedance for the two speaker outs B1 (75) and B2 (73). Your
options are 4,8, and16 ohms. Theselected impedanceapplies to boththe B1and the
B2 outputs! That means if one cabinet is connected to and another to
, their actual overall impedance and the impedance setting selected on the
ampmustmatch!
Impedance table for two cabinets connected in parallel:
(|| stands for a parallel circuit)
16 ohms || 16 ohms -> 8 ohms overall impedance: OK;
the correct selector setting is 8 ohms.
8 ohms || 8 ohms -> 4 ohms overall impedance: OK;
the correct selector setting is 4 ohms;
4 ohms || 4 ohms -> 2 ohms overall impedance: definitely not OK;
not an option because 2 ohms lies below the 4-ohm minimum;
16 ohms || 8 ohms -> 5.3 ohms overall impedance: not recommended;
the closest selector setting would be 8 ohms, but the output power
would not be distributed equally to the two cabinets!
16 ohms || 4 ohms -> 3.2 ohms overall impedance, not recommended;
the closest selector setting would be 4 ohms, but the output power
would not be distributed equally to the two cabinets!
8 ohms || 4 ohms -> 2.6 ohms overall impedance: definitely not OK,
not an option because 2.6 ohms lies below the 4-ohm minimum.
Thisis B1jack,whichiswiredinparallelto .Aspeakermustbe
connected to this or the B2 jack - or in parallel mode, to both - for the Speaker A/B
switching option tobe enabled. The power ampsignal is routedto outputsB1 andB2
when isactivated.
Use (74)toset the impedance for thespeaker connected to this
output or the overall impedance when two cabinets are connected to and
.
This is A2 jack, which is wired in parallel to . A speaker must
be connected to this or the A1 jack - or in parallel mode, to both - to switch the amp
from Standby to ON. The power amp signal is routed to outputs A2 and A1 when
isdeactivated.
Use (77)to settheimpedancefor the speakerconnectedtothis
output orthe overall impedance when two cabinets are connected to and
.
Impedanceselectorfor .Usethis rotary selector to setthe overall
power amp output impedance for the two speaker outs A1 (78) and A2 (76). Your
optionsare4, 8, and 16 ohms.The selected impedance appliesto both the A1and the
Poweramp Output B
Output B1
Output B2
PowerampOutputB's B2
SpeakerA/B
ImpedanceSelectorB
Output B1
B2
Poweramp Output A's A1
SpeakerA/B
ImpedanceSelector A
Output A2
A1
PowerampOutputA
27