Any downside to Digital power sections?

bubbastain · #1 12-18-2012, 05:29 PM

I read a bunch of threads about different amps with the digital(sorry, Class D) power section and couldn't really find anything that mentions any possible issues or concerns. A few months ago when I was in the market for an amp head, the sales person advised against some of the small lightweight Class D heads. He mentioned something about playing loud for extended periods would overheat it or something like that. Any truth to this? Any downside or possible concerns? Is a Class D watt equal to a SS watt? I really like the Kustom Deep End 300 head I have but when I saw the Kustom KXB500 head(the price and reviews by some of you guys), it made me consider the little 5 pounder.

guy n. cognito · #2 12-18-2012, 05:35 PM

No issues. Lemme guess.....he wanted you to buy a tube head???

Jazz Ad · #3 12-18-2012, 05:41 PM

First thing first, class D is NOT a digital power section. It's all analogic.
They indeed cut off abruptly when they overheat. Typical class A/B amps don't do that. They withstand the additional charge and eventually break.
To avoid going off limits, class D amps tend to come with humongous output powers. It is hard to reach the limits on a 500+ w amp.

**BassIsFun17** · #4 12-18-2012, 05:43 PM

yeahh i think class D power sections are great. I have a GK MB210 combo. and the amp gets plenty loud, but I've blown my speakers and just got them replaced. I hope I don't do it again.

JimmyM · #5 12-18-2012, 05:45 PM

They will never replace my tube gear, but the small amps will darn sure do the job for me and sound excellent when lugging tube gear is impractical.

bubbastain · #6 12-18-2012, 05:56 PM

Quote:

Originally Posted by guy n. cognito

No issues. Lemme guess.....he wanted you to buy a tube head???

Actually, they didn't even have any tube amps. I was in there specifically to check out the Hartke LH500. Ended up liking the DE300 more. Didn't even plug into the small units.

fdeck · #7 12-18-2012, 06:01 PM

I've gotten over the hangup about calling these amps "digital." I've got a Class-D head for those occasions when lugging my other Class-D head is impractical.

Got2SadowskyNYC · #8 12-18-2012, 06:02 PM

I prefer Digital. Loud. Light. Reliable. Super clean and transparent. They take your input and make it louder without any color added.

Got2SadowskyNYC · #9 12-18-2012, 06:06 PM

as far as overheating. I've ran mine HARD for 4 hours straight, outside, in the summer and it's barely warm to the touch. The carpeted top of my cab is hotter than the amp in the back.

bubbastain · #10 12-18-2012, 06:15 PM

Quote:

Originally Posted by Got2SadowskyNYC

I prefer Digital. Loud. Light. Reliable. Super clean and transparent. They take your input and make it louder without any color added.

Just what I want to hear. Thanks

wcriley · #11 12-18-2012, 06:25 PM

Because class D is more efficient, it doesn't generate as much heat as class A/B.

As a result, maybe some of the designers of early class D bass amps scrimped too much on the cooling/ventilating?
It sure hasn't been a problem with any class D amps I own.

rodl2005 · #12 12-18-2012, 06:30 PM

I like em better than yr trad ss amps. Never had a problem with any class D amp. They sound great, are lightweight. Tubes are always my fave, but class D are a fantastic alternative

mattbass6945 · #13 12-18-2012, 06:49 PM

the gallien kreuger mb115 i owned was great. plenty loud, light, dependable. had to sell, but i wouldn't be opposed to buying class d again.

Handyman · #14 12-18-2012, 07:03 PM

The only practical downside to class D amps is that they're significantly more complex than plain old class AB, and you won't be able to drop them off to any old repair shop should the need arise.

That said, I use a Genz Benz Streamliner, and don't see a reason to go back to the old stuff.

ThisBass · #15 12-18-2012, 07:03 PM

Quote:

Originally Posted by Jazz Ad

First thing first, class D is NOT a digital power section. It's all analogic.

But it's PWM.
Pulse Width Modulation.

It's "analogic" but still PWM contains a lot of "0" and "1" at the power stage, and that's a similar meaning like digital.

Red Planet · #16 12-18-2012, 07:16 PM

So what is the difference between a ultra lightweight Class AB amp and a ultra lightweight Digital amp and the same in a Class D amp?

B-string · #17 12-18-2012, 07:27 PM

Class AB is less efficient and produces more waste heat.

Mehve · #18 12-18-2012, 07:56 PM

Class D's had a few teething issues way back, but they're nicely matured by this point.

They've also gotten to the point where different class D's have well-established characters. If you have an idea on what sort of sound you're after, picking the right amp can give you a good headstart on getting there, just like any other family of amplifiers. Lots of threads and posts on all the big names, definitely worth working the search engines on them.

**BassIsFun17** · #19 12-18-2012, 09:42 PM

for the people who've tried class d amps, how much of a difference does the tube preamp section make? for instance, mb500 vs mb fusion 500?

JimmyM · #20 12-18-2012, 09:50 PM

Quote:

Originally Posted by BassIsFun17

for the people who've tried class d amps, how much of a difference does the tube preamp section make? for instance, mb500 vs mb fusion 500?

That all depends on the execution of the tube. In stuff like the SVT 7 Pro and Streamliner amps, a lot. In the case of others where the tube is wired in a starved plate design, it has a little impact but it's less important to the sound. In other words, tube preamps behave pretty much the same in micro power amps (not all micros are class D, BTW) as they do in trad. SS amps.