Digital Amplifier Questions


I've been wondering the following:

1. Do digital amps benefit from being left on 24/7in the same way the ss amps do?

2. Is plugging a digital amp into a different outlet as your preamp as crucial compared to a ss amp?

3. Do digital amps have small transformers? If so, is distancing equipment from one another less important? (My peachtre Nova Pre/220 look best stacked)

4. When upgrading power cords on a digital amp, do you look for cords that do well with digital gear like your preamp and dac, or do you still go for a beefy cord?

I apologize ahead of time for my ignorance on the matter! Thanks!
b_limo
Xt explained it pretty well I would say.

THe Wikipedia article is a good one and highlights key advantages and disadvantages of each.

The main advantage of Class D is its efficiency, and often a resulting smaller package. Class D amps are a practical alternative in cases where a large heavy and expensive monster class A or class A/B amp would be needed for best results otherwise due to speaker power and current demands. Its a common case these days that smaller inefficient speakers with extended bass are designed to fit tighter quarters. A Class D amp fits this need well. Some good quality 250 w/ch Class D amps with decent current delivery capabilities can be had for less than $1000 these days. Most smaller ineffficient speakers capable of extended bass in larger rooms will likely benefit sonically from teh extra power and current.

In my case I find the high power Class Ds to be uniquely capable of driving the larger OHM speakers that I like, hence my enthusiasm over that pairing in particular. They also benefit my smaller Dynaudio monitors compared to other higher power SS amps I have used in the past, but the benefits are greatest whenever more power and current out of a smaller more efficient package is what the doctor ordered.
B_Limo, in a lot of cases, the answer is... "It depends"... But here are some specifics as they have applied to class D amp I have used... ROwland M312, Merrill Veritas monos, Belcanto REF100M and REF500M, Rowland M925.

Q: Leave on 24/7?
A: Yes, in all cases... Takes at least 24 hours of playing time for all class D amps in my test set to reach peak performance after being off for a spell.

Q: Plug in its own AC circuit?
A: It depends.... Amps with high degree of power supply isolation like Rowland M925 do not inject much noise back into the AC line, others do. In all cases, you may get slightly better dynamics by plugging power amps in a dedicated outlet.

Q: Stacking or not.... RF leaks?
A: It depends again on degree of isolation... Newer amps like Rowland M925 and Merrill Veritas do not leak RF... Try moving an FM radio on top of them... You will not hear any additional hash on the radio... IMO stacking is OK with these... Both amps are based on Hypex NCore NC1200 modules.

Q: What power cords?
A. Use high current capable power cords... with class D amps, instant current swings/transients can be huge. Do not use analog cords for low power applications, nor old style "digital" cords like the old Shunyata VX.... They will "caramelize" the sound. Note that some cable manufacturers might have today new styles of digital-ready PCs that handle high current class D amps... E.g. Check with the Shunyata factory for their recommendations.

Let me know if you have further questions. G.
One other thing I would note about Class D amps is that they typically seem to have very high damping factors. That will play well with larger speakers taht can benefit with more control of the driver movements as a result of the high damping factor. My large OHm F5s use a 12" walsh style driver known to benefit from high damping in terms of bass control and articulation and that is in fact the result.

Due to high damping, Class D amps can come off as somewhat lean in other speakers. That is the case with my smaller Triangle monitors in particular. I have those set up accordingly to compensate and the results are still quite top notch. My Dynaudio monitors are more in between. I like the clean taut articulate bass that results with them as set up (see my system pics) but I could easily see where some might consider the sound a bit too lean despite the fact that the bas is all there and very detailed and accurate. it just won't be shaking the rafters, at least on most recordings.
OK Guido, now you've accelerated my desire to add a pair of pangea ac9 cords to my amps to go with the AC14ses on my line level gear.

I guess it never ends. :^}
B, I think excellent recommendations from Guidocorona. I know he has a big interest in Class D amps and probably has actually heard and spent time comparing the most of just about anyone I am aware of in these parts.