I used the original Atma-sphere autotransformer with the MA-1s on my 3.6's and they worked perfectly well. Actually, Paul helped me with the connection as there was an error in the original autotransformer which he knew about.
To this day, the MA-1's with the autotransformer provided the best sound I had from my 3.6's (which I no longer have by the way). Rich, detailed. even balanced and suitably dynamic. The sound was poignant and realistic with proper attack and decay. Not overly damped as in the case of some amplifiers (like the Wolcott 220s which I also had but, were very good amps none-the-less). And, absolutely none of the solid state micro-veil that you never know existed until you hear an amplifier without it. Probably the best way I could describe it is that it was just extremely enjoyable. I really liked the sound.
I have run my Maggies from the Bryston you have but, not though an autotransformer. They sounded pretty darn good with this amp. My guess is that it would not do much for the Maggies since the Bryston is characterized for driving the 3.6 input impedance. The feedback employed within the amplifier tends to de-sensitize the amplifier to varying impedances. The Atma-sphere, with it's virtually non-existent feedback mechanism and higher effective plate impedance, favors a higher load impedance (like 16'ish ohms) for the best match.
I did run the Innersound ESL-300 amplifier with, and without, the autotransformer. The difference is sound was slight at best and, in the end I probably preferred the sound without the autotransformer. But, it was close. This is why I theorize that your Bryston/Maggie combo will will not benefit from the autotransformer in it's output. There may be some aspect to the sound you might prefer but, when taken as a whole I think the extra iron will negate any advantage from better aligning impedances.
To this day, the MA-1's with the autotransformer provided the best sound I had from my 3.6's (which I no longer have by the way). Rich, detailed. even balanced and suitably dynamic. The sound was poignant and realistic with proper attack and decay. Not overly damped as in the case of some amplifiers (like the Wolcott 220s which I also had but, were very good amps none-the-less). And, absolutely none of the solid state micro-veil that you never know existed until you hear an amplifier without it. Probably the best way I could describe it is that it was just extremely enjoyable. I really liked the sound.
I have run my Maggies from the Bryston you have but, not though an autotransformer. They sounded pretty darn good with this amp. My guess is that it would not do much for the Maggies since the Bryston is characterized for driving the 3.6 input impedance. The feedback employed within the amplifier tends to de-sensitize the amplifier to varying impedances. The Atma-sphere, with it's virtually non-existent feedback mechanism and higher effective plate impedance, favors a higher load impedance (like 16'ish ohms) for the best match.
I did run the Innersound ESL-300 amplifier with, and without, the autotransformer. The difference is sound was slight at best and, in the end I probably preferred the sound without the autotransformer. But, it was close. This is why I theorize that your Bryston/Maggie combo will will not benefit from the autotransformer in it's output. There may be some aspect to the sound you might prefer but, when taken as a whole I think the extra iron will negate any advantage from better aligning impedances.