My "open box" A12 just arrived from Germany in perfect condition. I've been testing it with my CD player through the balanced inputs and with a Squeezebox Touch through unbalanced analog input. Sounds great! Looks great! I am planning to open it up and shoot a bunch of photos of the guts and post them as I was unable to find much of that online anywhere.
Photo
https://imgdepot.net/image/A12-dark.IKx3d
If you are curious about this amp, ask me! I'll try to answer all questions. I do not have a turntable so I won't be able to answer questions about the phono preamp.
The knobs feel very nice and require only a light touch to turn, with very gentle detentes as they rotate. The volume knob also is used to select items from a menu by pushing in the knob and holding it for a couple seconds. Functions include bass, treble, balance, auto power off time, and several others. Once you have selected a function to change, you make the change by turning the volume knob, push it. You exit the setting by letting it sit for about 5 seconds and it reverts to volume function.
There are two subwoofer outputs with frequency select-able at 75 or 150 Hz. If you study photos, it looks like the switches to select the cutoff frequency are 3 position type. Not so, only two positions- 75 or 150 Hz. There is no high-pass applied to the signal going to the A12 power amp, only low pass out to the sub(s). I have not yet determined if one output corresponds to the A speakers and the other to the B speakers. I have no way to determine the roll-off slope of the low pass filters.
It has a high bias mode that is supposed to bias the power amp stage into class A, but there's no information anywhere I can find that says how much class A power you actually get. I have been running it with the high bias switch off and low to moderate volume levels and can feel a significant amount of heat coming off the top of the amp. After running for a bit over an hour I measure 44C (111 F) on the top of the amplifier.
I connected my TV to the HDMI ARC input and it works fine, with the TV volume control controlling the amplifier volume as expected.
Here's the run down on the remote control: Buttons to control the amp are all located on the lower part of the unit, except the standby button on the top left side.
You can control muting, volume, bass, treble, loudness, balance, input selection, speaker selection, and 3 levels of front panel illumination. There's a button to bypass the tone control circuits, too. Loudness is switched on and off by holding down the DIM/LOUD button for a couple seconds. Speaker selection is activated by holding the SPEAKER/INFO button for a couple seconds. Balance can shift left or right in 1 dB steps up to 20 dB in each direction. Volume moves in 1 dB steps and hits minimum at -95 dB. Bass and treble are adjusted in 1 dB steps over a range of -10 to +10 dB.
One mystery remains... the amp is specced to produce 190 W into 8 Ohms and 280W into 4 Ohms. However, the speaker connections on the back of the amplifier are labeled "A or B: speakers impedance 8 to 16 Ohms, A+B: speakers impedance 16 Ohms". It seems odd to spec the amp for 4 Ohm output but then to say that speaker impedance must be 8 or 16 Ohms. Hmmm. I have seen other photos of the back of the amp that say "A or B: speakers impedance 4-16 Ohms, A+B: speakers impedance 6-16 Ohms". Hmmm. It's having no trouble driving my B&W 703 S3s.
Photo
https://imgdepot.net/image/A12-dark.IKx3d
If you are curious about this amp, ask me! I'll try to answer all questions. I do not have a turntable so I won't be able to answer questions about the phono preamp.
The knobs feel very nice and require only a light touch to turn, with very gentle detentes as they rotate. The volume knob also is used to select items from a menu by pushing in the knob and holding it for a couple seconds. Functions include bass, treble, balance, auto power off time, and several others. Once you have selected a function to change, you make the change by turning the volume knob, push it. You exit the setting by letting it sit for about 5 seconds and it reverts to volume function.
There are two subwoofer outputs with frequency select-able at 75 or 150 Hz. If you study photos, it looks like the switches to select the cutoff frequency are 3 position type. Not so, only two positions- 75 or 150 Hz. There is no high-pass applied to the signal going to the A12 power amp, only low pass out to the sub(s). I have not yet determined if one output corresponds to the A speakers and the other to the B speakers. I have no way to determine the roll-off slope of the low pass filters.
It has a high bias mode that is supposed to bias the power amp stage into class A, but there's no information anywhere I can find that says how much class A power you actually get. I have been running it with the high bias switch off and low to moderate volume levels and can feel a significant amount of heat coming off the top of the amp. After running for a bit over an hour I measure 44C (111 F) on the top of the amplifier.
I connected my TV to the HDMI ARC input and it works fine, with the TV volume control controlling the amplifier volume as expected.
Here's the run down on the remote control: Buttons to control the amp are all located on the lower part of the unit, except the standby button on the top left side.
You can control muting, volume, bass, treble, loudness, balance, input selection, speaker selection, and 3 levels of front panel illumination. There's a button to bypass the tone control circuits, too. Loudness is switched on and off by holding down the DIM/LOUD button for a couple seconds. Speaker selection is activated by holding the SPEAKER/INFO button for a couple seconds. Balance can shift left or right in 1 dB steps up to 20 dB in each direction. Volume moves in 1 dB steps and hits minimum at -95 dB. Bass and treble are adjusted in 1 dB steps over a range of -10 to +10 dB.
One mystery remains... the amp is specced to produce 190 W into 8 Ohms and 280W into 4 Ohms. However, the speaker connections on the back of the amplifier are labeled "A or B: speakers impedance 8 to 16 Ohms, A+B: speakers impedance 16 Ohms". It seems odd to spec the amp for 4 Ohm output but then to say that speaker impedance must be 8 or 16 Ohms. Hmmm. I have seen other photos of the back of the amp that say "A or B: speakers impedance 4-16 Ohms, A+B: speakers impedance 6-16 Ohms". Hmmm. It's having no trouble driving my B&W 703 S3s.