Owner's Manual

Bridged Mode

Bridged operation configures the Left and Right channels to function as a single channel higher

power amplifier to drive a single speaker. When an A 23+ is in Bridged Mode it provides far greater

power output than the sum of its left and right channels’ power output. Please note that in bridged

operation the minimum speaker impedance is 8 ohms. We do not recommend using the A 23+ with a

4 ohm speaker while set to bridged mode.

Bridged/Stereo Mode Selector Switch

Select Stereo for normal operation when the A 23+ will be powering two speakers. Only select Bridged when

an A 23+ will be powering a single 8 ohm speaker.

Note: If the Bridge Mode switch is accidentally set to Bridge while you are using the A 23+

as a stereo amplifier the sound will become very weak and thin.

Speaker Connections for Bridged Mode

When operating in bridged mono mode an A 23+ should only power a single 8 ohm speaker.

Connect the speaker’s positive (+) speaker wire to the A 23+’s right channel positive (+) speaker terminal.

Connect the speaker’s negative (-) wire to the A 23+’s left channel positive (+) speaker terminal.

Correct + and - speaker polarity for bridged mode is shown below the A 23+ speaker terminals.

Bi-Amping is Often Superior to Bridged Mode

Bridging offers a massive power increase but It is often more power than your speakers need or can

safely handle. Bi-amping is an alternative to bridging and many people report greater sonic

improvements. Like bridging, bi-amping will require an A 23+ amplifier for each speaker.

Note: Bi-amping in this context is technically “passive bi-amping” so an external electronic crossover is

not required. The speaker LF and HF terminals still connect to the speaker’s passive crossover

circuits, the difference being that with passive bi-amping the LF and HF crossovers are powered

separately.

Connecting speaker wires for Bi-amping

Bi-amping requires speakers with separate LF (Low Frequency) and HF (High Frequency) input

terminals with removable metal straps or wires. (Some KEF speakers use a rotary switch to join or

separate the HF and LF sections). The left channel of the first A 23+ will power the LF section of one

speaker and this same A 23+’s right channel will power the HF section of the same speaker. The

second A 23+ will connect the same way to the right channel speaker’s LF and HF inputs. When bi-

amping both A 23+’s Bridged switches must be set to their Normal (Stereo) position.

Setting up the input wires for Bi-amping

The A 23+ has an RCA Loop Output jack for each channel. These looping outputs allow the input

signal from one channel to be daisy-chained to the other channel’s RCA Input jack. When bi-amping

you will connect a standard RCA cable from the loop output of the Left channel to the Input RCA jack

of the right channel. If you wish to connect your preamp with balanced XLR connections you will need

to purchase a pair of XLR “Y” cables. You cannot use a combination of a balanced XLR input and

RCA Loop Out to the other channel’s input because the balanced connections will play 6dB louder

than the RCA connections.

Note: Both amplifiers left and right channel gain controls should be set at the same position.