Zapco Z-150.6 II — 6-Channel Class AB Car Amplifier

Zapco Z-150.6 II — 6-Channel Class AB Car Amplifier

The Z-150.6 II is a six-channel Class AB amplifier from Zapco's Z-II series, rated 165 watts RMS per channel at 4 ohms, 275 watts per channel at 2 ohms, and 550 watts bridged into 4 ohms per bridged pair. Signal-to-noise is better than 100dB with THD under 0.1%, across a 15Hz to 30kHz bandwidth.

Six channels of Class AB power in one chassis, with the crossover section on each pair set up for a different job.

Three Channel Pairs, Three Roles

Zapco assigned the crossover capability of each pair to the role it is expected to play:

• Channels 1/2 — high-pass only. Intended for full-range use or mids and highs.
• Channels 3/4 — high-pass, full-range, and low-pass positions. Can run highs, or be band-passed for midrange.
• Channels 5/6 — band-pass only, with no crossover mode switch. Low-pass plus a variable subsonic for the bass section.

The detail worth noting is on channels 5/6. The subsonic filter there covers a wide enough frequency range that it can serve as the bottom of a band-pass rather than only as woofer protection — so if a separate amplifier is handling the subwoofer, channels 5/6 can drive midbass drivers instead.

That single design choice is what lets one chassis run a three-way active front stage: highs on 1/2, midrange band-passed on 3/4, midbass on 5/6.

2Ch/4Ch/6Ch Input Switch

An input mode switch selects 2-channel, 4-channel, or 6-channel input, so all six channels can be driven from a single pair of RCA outputs on a head unit. In a factory-source or minimal-preout installation, that removes the need for splitters ahead of the amplifier.

Inputs use Zapco's proprietary RCA connectors with pass-through outputs for daisy-chaining additional amplifiers. Variable gain is provided per channel pair, along with variable bass boost, a port for the optional dash-mount bass control, and power and protect LEDs.

System Application

The Z-150.6 II is built for systems that need many channels from one chassis — a three-way active front stage, or a full-range front and rear plus a bridged bass channel.

At 4 ohms each channel produces 165 watts; at 2 ohms, 275. A bridged pair delivers 550 watts into 4 ohms, and up to three pairs can be bridged, so channel count can be traded for power as the system design requires.

In an active DSP system the onboard filters can be set aside and the crossover work handled upstream, using the amplifier purely for its six channels of output.

Installation Considerations

Four ohms is the minimum load when bridging. Each channel sees half the load bridged, so a 4-ohm bridged load is 2 ohms per channel. Do not bridge into a 2-ohm woofer.

When band-passing channels 3/4 for midrange, the high-pass sets the bottom of the band and the low-pass sets the top. Reversing them produces no output.

Six channels of Class AB power draws real current. Add up the fuse values on the amplifier and size power and ground wire from that total and the run length from the battery. Use the same gauge for ground as power, keep it short, and secure it to clean bare metal on the frame.

Specifications

• Configuration: 6-Channel, Class AB
• Power: 165W RMS × 6 @ 4Ω
• Power: 275W RMS × 6 @ 2Ω
• Power: 550W RMS × 3 bridged @ 4Ω
• Minimum bridged load: 4Ω
• Frequency response: 15Hz–30kHz
• THD: <0.1%
• Signal-to-noise ratio: >100dB
• Ch 1/2: high-pass only
• Ch 3/4: high-pass, full-range, low-pass
• Ch 5/6: band-pass only, low-pass plus variable subsonic
• Input: 2Ch/4Ch/6Ch selector
• Optional: dash-mount bass control (sold separately)

HF Audio Perspective

Six channels in one chassis solves a real problem in a three-way active build — fewer amplifiers to mount, one power and ground run, one set of interconnects.

What determines whether it fits is the channel layout, not the power. Channels 1/2 cannot low-pass, and channels 5/6 cannot run full-range. Map your drivers to those three pairs before committing: if the assignment lines up, this is a tidy way to build a three-way stage from a single amplifier. If it does not, separate amplifiers will give you the freedom this chassis trades away for integration.