Pete,
Thanks for the post! The TAP system was designed for this and if I'd got off my butt and finished it quicker it would have been the first multichannel pre-amp out there as the design began 5 or 6 years ago. It was not origionally for multichannel music like SACD or DVD-A but it was made to do multichannel level control for DSP based crossovers I was brewing up that used multiple DAC's for Low Freq and Mid / High Freq bands.
The TAP system was designed for multichannel and is ready today to use a TAP Base Unit and then plug 3 stereo TX102 based bent units into it for 6 channels total (or 4 units for 8 channels although there are no 8 channel music sources). This would only make any sense in the highest end multichannel SACD system from a cost point of view - it would cost about $4K and even more if silver TX102's were used for the main channels.
To keep the cost af a multichannel system I have a new board in that 'almost done' phase and should have it complete in the next couple of months. This board will plug into the Base Unit and will do the level control for 4 channels. The level control is done using the PGA2310 SS level pot (an improved version of the cs3310 chip Rowland uses in their pre-amps). Despite that it is designed to be a cost effective board it uses things like shunt regulation and OSCON caps - I could not help myself! This 4 channel board allows for up to 4 inputs to each channel. I'm hoping to keep the cost around the 1K mark which would mean a 6 channel system using the TX102's for the main channels and then this board for the additional channels would come in at about 3K or $3350 with silver TX102's for the main 2 channels.
If the Center channel was an exact match to the mains you could use a TX102 for that channel as well but unless it was an exact match I'd think the differences between the TX102 and the PGA level control would be swamped by the differences in the speakers.
I'm afraid puttin all this in one package is not practical due top the size of Parts. The system above would be 3 'boxes' - The Base Unit (with the blue lights) which can be located anywhere in the room, then the Stereo TX102 unit and then finally the 4 Channel Unit. The separate boxes can be placed anywhere as there are no knobs on them and this can help to minimize imnterconnect lengths.
Putting 6 TX102's in a box with a 6 deck switch would work but would be limited as it would not allow for trimming the individual channels levels. This could be done if you had an alternate way of level matching the channels and we could even put a remote control on it.
Many Thanks!
John Chapman
www.bentaudio.com