Transient Attack and Amp Design


I have observed with my new McCormack DNA-1 Deluxe (CJ Rev. 1 upgrade) that the transients are significantly better than my previous amps. Everything from classical, rock, and jazz has, for lack of a better term, better rythm and transients. (Granted, I have only owned mid-fi amps like Marrantz, Rotel, and Sunfire.)

I was wondering if the McCormack amp design explains the reason. It has eight caps on each output board instead of just one large cap for each channel. Maybe that means there is just more storage capacity? In any event, the amp is a heck of a lot more responsive than what I have heard in the past.

Is the multi-cap board topology more conducive to better transients or is this benefit dependent on the skill of the amp designer regardless of board layout?
jragsda

Showing 2 responses by jragsda

02-16-09: Shadorne
Transients require large amounts of near instantaneous current without the voltage in the power supply dropping. Essentially the bigger a power reservoir you have the better an amplifier can cope with transients. It matters less how the power is stored (a capacitor bank or a couple of large capacitors compared to the total amount of stored energy).

Your comments point to what I suspected. Now does the transistor proximity to the storage cap(s) make a difference? McCormack puts the caps close to output(?) transistors rather than a considerable circuit distance as I saw in my sunfire and marrantz amps. Or are we talking nanoseconds and thus it is not a significant consideration?

BTW, thanks for everyone's comments thus far!
Steve, at the risk of gushing, I am honored that you have responded to my thread. Kudos on an outstanding, musical amplifier in the DNA-1.

In the old Stereophile review (noted above in this thread), your DNA-1 design is noted for its treatment of distortion spectra. Here are JA's comments:
The Test CD also features signals with distortion spectra representing "tube"-type THD, "solid-state"-type THD, and a mixture of harmonic and subharmonic distortion typical of a planar speaker driven at high levels. My experience with generating the signals for the disc using the Audio Precision System One Dual Domain suggests that the situation is more complex than RH describes. While the DNA-1 does have some upper partials present, these are not isolated but are accompanied by the lower partials in an almost regular descending series. This is typical of tube amplifier performance, tending to sound smooth and "fat" rather than grainy.—John Atkinson
I suspect, but have not read, that you have departed from the "tube" distortion spectra approach in your later designs, notably the DNA-500. Is this so? If so, would you please comment as to your reasoning?