“ Musical, warm sounding and
authoritative. My best work.”
DAN D'AGOSTINO
Founder, and Chief Designer of Dan D’Agostino Master Audio Systems
Thank you for purchasing the Momentum amplifier. I’m eager for you to hear it, because
the Momentum amps have been a special labor of love for me.
Everybody was thrilled with the original Momentum monoblock and stereo. And I was
really happy with them, too—I thought they were the best amp I’ve ever made. Still, even
though some thought the Momentum amplifiers might be as good as an amplifier could
get, I couldn’t stop tinkering with it. As I developed more amps using the circuit concepts
I developed for the Momentum monoblock and stereo, I kept getting more ideas for how
I might make the Momentum amps just a little bit better. One by one, I tried them all out,
and kept notes how they affected the amp’s sound and performance.
The result of all that testing is the M400 and S250. One change is obvious: The monoblock
is rated at 400 watts, up from the original 300 and the stereo is rated at 250 watts, up
from the original 200. This increase came not from any particular desire on my part for
more power, but more as a natural result of the improvements I made.
I started by replacing the original transformer with a new, ultra-quiet 1800VA unit. Right
off the bat, this gave me 20 percent more power to work with. I then upgraded the driver
stage—the transistors that interface the gain stage with the output stage. I switched to a
fully complementary design, with separate transistors for the positive and negative halves
of the audio signal. This nearly doubled the current capacity. I then expanded the output
stage to make the most of all this additional energy potential.
The result is an amp that accomplishes something I wasn’t sure was possible: The
M400 and S250 sound even richer and more authoritative than the original Momentum
monoblock and stereo. I hope you agree.
As with every product that bears my name, the M400 and S250 are built by hand in our
Arizona factory, literally just steps away from my workbench. Because we keep such a
tight control on the manufacturing process, we can use techniques others can’t—such
as through-hole construction, which sounds better and lasts longer than surface-mount
construction.
Thank you again for your support, and I hope you enjoy your new amplifier as much as I
enjoyed designing it!
Sincerely,
The Team from Dan D’Agostino Master Audio Systems