OK, What's the Final Verdict on Class D?

[agedhorse]

again, your Crest's specs says that CD3000 draws 7 amps a 1/8 of its rated power output, and at around 45 lbs, and althugh i think that its a great amp, i wouldn't consider it to be a 'lightweight' amp by today's standards.

Thanks John!

Of course, it's preposterous to think that this amp draws 7 amps while delivering 3000 watts continuous and even more misleading where fourstrigburn says he measured it... no way. It draws slightly more than 30 amps at rated output of 3000 watts RMS. Now, take the 1/8-power FTC duty cycle derating and it's closer to 7 amps (adding in the proper derating and power factor figures).

 

[R Baer]

Thanks John!

Of course, it's preposterous to think that this amp draws 7 amps while delivering 3000 watts.

If it really does do this, then I no longer see the need for us to explore nuclear fusion as an energy source. Just plug millions of these amps into the power grid and all our energy problems would be solved.

 

[MikeBass]

I think some of you are missing the beauty of class D amps. While some have given these technical formulas why they can or can't, they are forgetting class D amps seems to break ohms laws and traditional train of thought due to it's design. The spec's are real as I tested it myself (at least the amperage draw ). My class D amp will put out up to 3000 watts and use only 7 or so amps and weigh less than 45lbs and are efficient. Sorry if that goes against your engineering degree but I play them not design them. Rock on...

Point me to who makes your cabs that will handle that 3000 watts of power.
I'm kinda interested.......
And how do they (class D amps) break Ohms law? Again, just curious.
And you measured this how- amperage draw at 3000 watts???

Not arguing with you or being a smart-a$$. Just would like to hear you speak more into you facts that you base your statements on....

 

[xray]

I believe Class D amps are here to stay and will only get better. Even if they add two pounds in the evolution process they're still a great technological asset. Personally, I have a small class D amp and a big tube amp (who cares what the brands are) and I love them both. At home the Class D gets more love just because it's easier to dial in without my wife screaming from the top of her lungs. The beast gets plenty of love as well but in bigger venues. However, the class D is extremely portable and because of shear portability finds itself being thrown in the back seat to jam sessions quite often.

So my take on this analysis is they both have a place in the bassist's world!

 

[basscooker]

bravo, x-ray. being a chef i agree that everything has its place (misen en place). i have always had solid state rigs and when you transport your gear alot, portability eventually wins. yeah, we can all agree to disagree when tone comes into play (tube vs not), but i'll take my gb shuttle over that tube head that's bigger than my first apartment and weighs as much as my fridge. and by the way i don't get burnt moving it after i play it.

 

[xray]

That's not a technical reason.

Technical: (since your question keeps changing since your OP)

AMPS with Pre/Power sections with TUBES sound way better than any Class D amp built today. Once the Class D amps can truly emulate a pure tube tone they'll be more popular, but will never replace an all tube amp.

 

[agedhorse]

If it really does do this, then I no longer see the need for us to explore nuclear fusion as an energy source. Just plug millions of these amps into the power grid and all our energy problems would be solved.

Yeah, sign me up for some shares in the Perpetual Motion Corp.

 

[Passinwind]

Yeah, sign me up for some shares in the Perpetual Motion Corp.

Link Removed

 

[Munjibunga]

You lost me where I made it bold. What I mean is, I get the arithmetic behind it all, what I don't understand is the correlation of the volts/amps and how they apply to each other.

watts = volts times amps

amps = watts divided by volts

 

[sixway]

I've never had the pleasure of owning an all tube head such as the SVT, but played through one for the first time late last year at a large venue through an 8x10 cabinet, and can see why they are the standard (for the most part) on tours and large stages. The sound was huge, warm, and surrounded me with bass goodness!

I've also had the same experience with my Walter Woods 1000w Stereo head running through my AccuGroove El Whappo Jr., and the AG Tri-112 chained in for large gigs, and it sounds huge and warm as well, and allows me to dial in just a bit more bite if I want it. And over the years I've spent hard-earned money to have a bass rig that has quality and reliability built in, has the ability to dial in a multitude of bass tones, and is easy to load in and out.

The point here is, both of these heads in a sense represent the best of their design worlds, are reliable, and will - and have - shown their ability to last for years. I've owned my WW since late 2002, and will admit it failed within the first three months. Walter replaced a part from his parts supplier that was from a defective batch (hey, it happens to ALL companies at times), and I've been pushing my amp hard since then. I don't carry a backup for it, and it's not let me down since the fix. I've blown up my share of speakers since then though!

As long as whatever amp you're playing through is built with quality parts, it should last for years. Walter's SS, Class-D style amps have been proving it for quite awhile now, and I feel it's taken a lot of years for other companies to approach the wattage and quality of his amps, and make them affordable through production numbers. I paid a lot of money for it's power, reliability, and portability features, and am not inclined to sell it off anytime soon. Part of my reasoning for this is I've been following all of the other Class-D manufactures for some time now, and reading the reviews here, to see what brands and models will rise to the top and stay there.

I am a tad concerned about repairing my WW after Walter passes on, but there are a lot of amps out there over the years that have gone obsolete one way or another, and ways are found to keep them running if they are valued enough by the owner. I'm sure I'll be able to find a technical genius to help me when the time comes. Besides, I've always been a classic kind of guy, preferring to maintain and restore what lasts and appeals to me.

More can be... but 'nuff said.

 

[lowphatbass]

Point me to who makes your cabs that will handle that 3000 watts of power.
I'm kinda interested.......
And how do they (class D amps) break Ohms law? Again, just curious.
And you measured this how- amperage draw at 3000 watts???

Not arguing with you or being a smart-a$$. Just would like to hear you speak more into you facts that you base your statements on....

I'm not going to argue physics either, I do know that watts don't always mean volume and paper means nothing.

As far as cabs that handle 3000 watts, I find that running ample headroom is beneficial not just in terms of tone, but it also helps extend speaker and amp life. I can't prove anything scientifically but I've never blown a driver by overpowering, only underpowering. IMO, 3000 watts is not overkill for any cabinet(s)(you don't have to use all of it) and probably ideal for any cabinet compliment rated at 1000w or higher.

 

[KJung]

I'm not going to argue physics either, I do know that watts don't always mean volume and paper means nothing.

As far as cabs that handle 3000 watts, I find that running ample headroom is beneficial not just in terms of tone, but it also helps extend speaker and amp life. I can't prove anything scientifically but I've never blown a driver by overpowering, only underpowering. IMO, 3000 watts is not overkill for any cabinet(s)(you don't have to use all of it) and probably ideal for any cabinet compliment rated at 1000w or higher.

I would doubt you've ever blown a driver by 'underpowering'. Maybe a tweeter if you really cranked up a 100 watt solid state amp so loud that your ears were bleeding and the amp was in full clip mode.

If you feel you need 3000 watts to sound good, then of course, go for it. Makes little sense to me. I can't even push my little 500 watt amps into power amp limiting while slapping at high volumes with a 12 piece band. Maybe I should practice more

 

[Implosion]

Isn't headroom just a fancy word for excessive power you are never going to use?

 

[lowphatbass]

I would doubt you've ever blown a driver by 'underpowering'. Maybe a tweeter if you really cranked up a 100 watt solid state amp so loud that your ears were bleeding and the amp was in full clip mode.

If you feel you need 3000 watts to sound good, then of course, go for it. Makes little sense to me. I can't even push my little 500 watt amps into power amp limiting while slapping at high volumes with a 12 piece band. Maybe I should practice more

Like I said, watts don't always mean volume. You're 500w amp must be nice and loud, I've been castrated by 120w amps so I don't doubt it one bit.
I've got nothing scientific to state about under-powering or blowing speakers. I can tell you that I don't like damaging or replacing drivers so I tend to remember the relative specifics involved when it's happened to me.

 

[KJung]

Like I said, watts don't always mean volume. You're 500w amp must be nice and loud, I've been castrated by 120w amps so I don't doubt it one bit.
I've got nothing scientific to state about under-powering or blowing speakers. I can tell you that I don't like damaging or replacing drivers so I tend to remember the relative specifics involved when it's happened to me.

Just FYI... but typically when one says 'I have nothing scientific' and just reports 'what they feel is the cause of what happened', that is almost the exact definition of 'being wrong'

Also, remember, cabinet SPL has even more impact on 'headroom' and 'volume' than wattage. The 'power rating' of a cab means almost nothing, and means absolutely nothing regarding the wattage needed to drive it to full power.

 

[lowphatbass]

Just FYI... but typically when one says 'I have nothing scientific' and just reports 'what they feel is the cause of what happened', that is almost the exact definition of 'being wrong'

I completely agree and I completely admit that I may blow speakers when I'm running smaller amps because I turn-up too far because I'm worried about being loud/strong enough because I don't think I have enough watts. Either way I like what I like and my phone keeps ringing.

 

[johnk_10]

Isn't headroom just a fancy word for excessive power you are never going to use?

for me, i would have to say no. when i'm running a SS poweramp. i prefer to have alot more power available than necessary so that i never even come close to approaching the amp's output limit, as i'm not fond of hearing a SS amp clip, or even coming close to it.

 

[Pat C.]

Isn't headroom just a fancy word for excessive power you are never going to use?

Pretty good article on power from Acoustic Image: The purpose of Power.

...[a] transient signal typically lasts a fraction of a second and it does little to increase the average loudness.

[shows a graph of program material]

As you can see, there is an average component to the waveform and there are many transient signals with amplitudes that are considerably higher than the average...

An amplifier reproducing this complex signal has to instantaneously deliver power to recreate the transients without compressing or clipping them. Otherwise, what results is a loss of fidelity and transparency of the amplified signal. So, in the example mentioned above, the amp outputting 40 Watts to reproduce the average level of the signal (90 dB SPL in a moderate sized club) has to output 400 Watts for a fraction of a second to reproduce the full fidelity of the music signal. If the transient is larger than the assumed ten times, more power is required.

 

[MikeBass]

I'm not going to argue physics either, I do know that watts don't always mean volume and paper means nothing.

As far as cabs that handle 3000 watts, I find that running ample headroom is beneficial not just in terms of tone, but it also helps extend speaker and amp life. I can't prove anything scientifically but I've never blown a driver by overpowering, only underpowering. IMO, 3000 watts is not overkill for any cabinet(s)(you don't have to use all of it) and probably ideal for any cabinet compliment rated at 1000w or higher.

His quote clearly states that his amp will put out up to 3000 watts with X amperage draw.
Just curious as to how he measured it and if he was actually pushing 3000 watts and into what.

You want to discuss headroom/cab SPL etc....I will until we're both blue in the face.

He also mentioned class D breaking ohms law.

Hey, I just want to have a question answered.

Watts generally give you an idea of what to expect. I too don't 100% believe in under/over powering a cab (or 6).
And headroom for clean tone is your friend.

I have 900 watts of micro-amp goodness.
That small percentage of tonal difference (subjective as to good or bad) isn't worth it to me these days for a number of reasons.
A BIG one that is popping up now is freight/shipping/fly costs when doing fly in gigs.
I would love to be able to have a nice rack with a GBE1200. But I have a sweet Pelican case that hold my 9.0 & a few small pedals.
Weighs like 20 pounds.
My other case holds my V-Bass, 25 pounds.

A nice 2-4 space shockmount rack alone weighs as much as both my cases loaded. That drop an amp in there.

Now, watch what the airlines want to charge you for that rack. It's a freight charge.
I carried on my Pelican before.

So, from that perspective, I'm staying small. This fall/winter when our album is released, I may get a GBE1200 racked or double up on 9.0's in a shockrack (one as a spare/back-up) and let the management company worry about it. But for now, I'm good.

 

[agedhorse]

I may get a GBE1200 racked or double up on 9.0's in a shockrack (one as a spare/back-up) and let the management company worry about it. But for now, I'm good.

You don't even need a shock rack with the Shuttles, they are built to tour with a standard rack. They are too light for a shock rack to provide any additional benefit.