McIntosh MA12000

The mcintosh_ma12000 driver controls the McIntosh MA12000 hybrid integrated amplifier over its native RS232 protocol fronted by a serial-to-IP bridge. One GEM device represents the amplifier; there are no zones — the MA12000 is a single-zone unit.

What's supported

Power, volume (0-100), mute, input selection (1-17), Output 1 / Output 2 speaker switching, balance, per-input trim, EQ, mono, meter and tube lights, display brightness, headphone HXD crossfeed, and MM/MC phono trim are all controllable. The amplifier pushes status updates automatically (it re-enables status feedback on every power cycle), so most attribute changes appear in GEM without polling. A 60 s safety resync re-reads power, volume, mute, input, and both speaker outputs as a backstop; every other setting (balance, trim, EQ, lights, brightness, phono) relies on the amp's automatic push.

Prerequisites

• Serial-to-IP bridge (Brainboxes, Global Cache, etc.) wired to the MA12000 RS232 jack with a DB9-F to 3.5 mm TRS cable (e.g. SF Cable D935-06: Tip = TXD, Ring = RXD, Sleeve = GND).
• Bridge serial port set to 115200 8N1, no flow control (the amp also supports 57600 / 38400 / 19200 / 9600).
• Bridge running in raw TCP mode (not telnet), with a stable LAN IP (DHCP reservation or static).

Setup

1. Cable the MA12000 RS232 jack to the bridge.
2. Configure the bridge to expose the serial port as raw TCP at 115200 8N1.
3. System → Devices: add a device with driver mcintosh_ma12000. Set:
   • ip — LAN IP of the bridge
   • port — TCP port the bridge maps to that serial port
4. Save and enable. On AC connect the amp emits its model, serial number, and firmware version banner — the driver captures these into the model, serial_number, and firmware_version device attributes automatically.

Attributes

Device — required

Attribute	Type	Description
ip	string	LAN IP of the serial-to-IP bridge.
port	int	TCP port on the bridge that mirrors the RS232 serial port.

Device — optional

Attribute	Type	Default	Description
monitor_interval	int (ms)	60000	Safety resync cadence. The amp pushes updates on every change; this is a backstop. A value that is not a positive number uses the 60000 default; anything under 1000 is raised to 1000. If the amp sends nothing for three resyncs in a row (bridge up, amp unplugged), the cadence doubles each time up to 5 minutes and returns to normal as soon as the amp is heard again.
max_volume	int (0-100)	60	Hard cap applied to discrete volume commands. volume_up / volume_down are not clamped since they only step by 1%. Protects against accidental loud levels on this very high-output amp.

Reflected device attributes

The driver mirrors the following onto the device as state changes:

Attribute	Type	Source
power_state	string	on / off
volume	int	0-100
mute	bool
input	int	1-17
input_label	string	Resolved label (BAL1, UNBAL3, MM PHONO, etc.)
output1, output2	bool	Speaker output switching
balance	int	-50…+50 (left negative, right positive)
input_trim	int	-12…+12 (0.5 dB steps)
eq	bool
mono	bool
meter_lights	bool
display_brightness	int	1 (dimmest) … 4 (brightest)
headphone_hxd	bool	Crossfeed; only effective with headphones plugged in
headphone_state	string	unplugged / plugged / no_jack
phono_resistance	int	1=50Ω 2=100Ω 3=200Ω 4=400Ω 5=1000Ω (MC only)
phono_capacitance	int	1=50pF 2=100pF 3=150pF 4=200pF 5=250pF 6=300pF 7=350pF 8=400pF (MM only)
status_feedback	bool	Whether the amp is pushing unsolicited status updates

Input map

Index	Input
1-2	BAL1, BAL2
3-8	UNBAL1 … UNBAL6
9	MM PHONO
10	MC PHONO
11-12	COAX1, COAX2
13-14	OPTI1, OPTI2
15	USB
16	MCT
17	HDMI (DA2 module only)

Commands

Command	Args	Notes
power_on / power_off / get_power	—
volume	volume (0-100)	Absolute level. Clamped server-side to the max_volume attribute (default 60).
volume_up / volume_down / get_volume	—
mute_on / mute_off / get_mute	—
output1_on / output1_off / output2_on / output2_off	—	Speaker A / B switching.
input	input (1-17)	See input map.
input_up / input_down / get_input	—
balance	balance (-50…+50)
balance_left / balance_right / get_balance	—	Step in single increments.
input_trim	trim (-12…+12)	Absolute per-input trim in 0.5 dB steps; persists per source.
input_trim_up / input_trim_down / get_input_trim	—	Step the active input's trim up/down by one increment.
eq_on / eq_off / mono_on / mono_off	—
meter_lights_on / meter_lights_off / tube_lights_on / tube_lights_off	—
display_brightness	level (1-4)
headphone_hxd_on / headphone_hxd_off	—	Headphones must be plugged in.
phono_resistance	index (1-5)	MC PHONO must be the active input.
phono_capacitance	index (1-8)	MM PHONO must be the active input.
trim_menu_close	—	Closes the front-panel trim menu (else it times out).
status_feedback_on / status_feedback_off / query_all	—

For input, balance, input_trim, phono_resistance, phono_capacitance and display_brightness, a value that is missing, blank, not a whole number or outside the range shown is refused with an error and nothing is sent to the amp. input and input_trim also accept the amp's own U / D step letters and balance accepts L / R. volume is different: an unreadable value sends 0, and every value is held under max_volume.

Every readable setting also has a matching get_… query — get_output1, get_output2, get_eq, get_mono, get_meter_lights, get_display_brightness, get_headphone_hxd, get_headphone_state, get_phono_resistance, get_phono_capacitance — that fetches its current value on demand. query_all asks the amp to report the status of every setting in one shot.

Known quirks

Power-off rejects most commands

While the amp is in standby, every command except PWR returns (ERROR - Invalid Command). The driver only polls non-power state when power_state is on.

• The amp turns its status feedback (STA) on automatically at every power cycle, so unsolicited updates are the norm.
• phono_resistance (TPR) only works while input is MC PHONO; phono_capacitance (TPC) only works while input is MM PHONO. They return an Invalid Input error otherwise.
• Power-on takes ~15 s; commands sent during warm-up are buffered and acted on after.
• tube_lights_on / tube_lights_off switch the tube lighting, but the amp reports no tube-light state back, so GEM never reflects their current status. The meter lights, by contrast, do report (meter_lights).
• The driver keeps the link alive with a get_power query every 60 s — the one query the amp answers while in standby — so an idle socket stays connected even with the amp off.

Troubleshooting

Symptom	Check
Every command returns Invalid Command	Amp is in standby. Send power_on first.
No volume / input updates appear in GEM	Confirm the bridge is in raw TCP mode (not telnet) and the serial settings are 115200 8N1.
Phono resistance / capacitance command rejected	TPR requires MC PHONO selected; TPC requires MM PHONO selected.
Model / serial / firmware never populated	The banner is only emitted when the amp is power-cycled at the AC mains while the bridge is connected. Power-cycle the amp once after wiring.
Connection drops when the amp sits idle	The driver already pings the amp every 60 s. If a firewall or NAT still idles the socket, add a ping_interval attribute (ms) on the device row and lower it.

Related documentation

• Devices — add and configure the amplifier (this driver creates a single standalone device, no zones).
• Subsystems — the AV subsystem the device is placed in.
• Commands — the command grid and Test runner for the power, volume, input, and trim commands above.
• Device Types — the av_receiver / amplifier classification the driver hints.