[c12mech]

I've pretty much decided to build a β22.  What I have not decided is whether to spend the extra money and go balanced.  Is there any point to going balanced without a balanced source.  I will eventually get a balanced dac and am looking into a good sacd player with balanced outputs.  Is there any reason I cannot start with a 2 or 3 channel amp and add the 4th later?  AS far as the power supply goes, it is recommended to use a separate power supply board for each channel with the balanced version.  Does that mean a separate transformer as well or can I use a transformer with a higher amp rating for multiple channels? I plan to use separate cases for amp and power supply.

 

[Armaegis]

If you start with a 3-channel active ground config, you will have to change the ground channel into a regular amp channel which involves changing a few caps and resistors. It may be easier just to go from 2 to 4. You can use just one power supply to power all 4 boards as long as it has enough juice. The separate supplies is recommended for speakers, but not necessary for headphone usage.
 
I myself am doing a 3-channel build where all my boards are regular amp boards, but I'm also attempting a weird "active balanced ground" topology inspired by Jan Meier.

 

[c12mech]

I forgot to mention it will be used for some small full range speakers that I am working on for my office.  That's the reason I asked about multiple power supplies.  I will most likely start with the 2 channel version and add 2 more for balanced as I get the money.  The case will be built for balanced from the get go.

 

[Armaegis]

For a full wacky setup...
- 4 b22 boards
- two s22 boards and two transformers
- balanced speaker output
- balanced headphone output
- dual single ended passive ground headphone outputs

 

[c12mech]

Quote:

For a full wacky setup...
- 4 b22 boards
- two s22 boards and two transformers
- balanced speaker output
- balanced headphone output
- dual single ended passive ground headphone outputs

 
That's a little more involved than I was thinking but it would be cool.  Seems that with a couple of selector switches and some extra wiring it could be done.  Something for me to think about. 

 
 

 

[Armaegis]

Actually it shouldn't be too complicated. You essentially build two independant sets of 2-board b22s. Then when you smoosh it all together, you just have to add the extra hookups for the balanced inputs, balanced headphones, and speakers.