Class D Amps - Anyone else having second thoughts?

[pablomigraine]

I use Genz Benz amps and I have a component rig powered by the new Carvin DCM1000L. I play in a very loud band, play long sets, gig and tour often, and generally beat the hell out of the power section of whatever I'm using. I can say with absolute certainty that there IS a discernible difference between the class D / SMPS amps and the old class AB Lead sleds. Its a difference I feel more than I hear.

That being said, in my world, the benefits far outweigh the shortcomings, no pun intended. I'm also certain that most players would NOT notice the difference under normal performance loads.

Just as important to note is that, IMHO and as it is with many things, some companies do it way better than others. Standouts in my opinion include Carvin, QSC, Genz Benz and Tecamp.

 

[vinxbass]

I switched over to the Carvin BX500 back in early Feb. 09' and have been very happy ever since. The head performs great, sounds great and Carvin CS is great - can't say enough.

 

[Lync]

Nope. I dig how small/light powerful my Carvin BX500 is, but more so, I really like the tone of the amp.

 

[MetroBass]

Your signature and the tone of your post, indicate your personal preference. However, I submit that in a double-blind test, you (or the rest of us) would not be able to distinguish a Class D from a Class A/B, or other amplifier topology, whether tubes or solid state devices were used. I imply of course proper gain matching.

Listen with the ears, not the eyes or the wallet. Switch-mode power supplies and efficient amplifier topologies are being adopted for much more demanding applications than audio. Their performance isn't even remotely questionable. As with everything else in reality, it is impossible and assinine to generalize to such a high degree.

A well-designed amplifier will sound good regardless of the topology. Choose your price point, weight, tone, and power to suit your preference, but don't miss out on potentially awesome equipment because of an ill-founded prejudice.

I beg to disagree with your first paragraph, second paragraph and last paragraph - that's why I sold my MBs, GBs, and others that I tested.

1. Money never comes into play (you can basically get every piece of middle of the road SS crap for 300-700 dollars - seriously that's not a lot of money in todays world.),
2. Weight no, i'm still young enough and in shape to lug around +80lbs,
3. Tone yes it is a factor - my ears didn't let me down, thank God,
4. lastly power (this shouldn't even be an arguable point) 1W of valve will kill 1Ws of Class D any day of the week. Don't be fooled by the marketing hype around Class D and the increased power you get from 2/4/8 ohm loads. Valves: 1W is 1W whether it's 2/4/8.

I read through many of the posts and it's amazing that "power" and "weight" are the two biggest factors; hardly any rebuttal to tone. So let's either get in shape or get some roadies, who cares what we sound like in the mix.

 

[Kwesi]

I was... until I tried a new cab, lol. I don't think I'm ever go bigger than Class D. They're convenient and sound great so there's really no need for compromise, at least imo.

 

[Interceptor]

I'm a class A/B IE iron conventional power supply guy.

Why? Repairability.

OK, I also prefer the tone of a conventional amp - so screw it, I'll carry one.

I know at least 100 guys who can fix a classic amp. I know about three who can gore on a switching supply and win. That's a very big deal in my mind. There are going to be some very unhappy players when they find out their out of warranty switching supply based amps are destined to be doorstops because they can't be fixed.

I learned my lesson many years ago when I smoked a Standel while on the road. Those things had epoxy potted modules, and unless a shop had modules - repair was not possible. Had to buy an amp to continue and leave the Standel in the truck. That was over thirty years ago and it still irritates me.

 

[agedhorse]

I know at least 100 guys who can fix a classic amp. I know about three who can gore on a switching supply and win. That's a very big deal in my mind. There are going to be some very unhappy players when they find out their out of warranty switching supply based amps are destined to be doorstops because they can't be fixed.

Well, now you know four

Really, switching power supplies are not all that difficult to fix. Class D amps aren't too hard either but usually it's less costly to replace the entire class D section because of the economies of scale when building large quantities.

I repair the old linear stuff too, some of that is harder than SMPS by the way.

 

[vin*tone]

This is a weird conversation. There are A/B amps that are difficult to fix. There are A/B amps that are lightweight. There are A/B amps with bad tone.

I sold my class D shuttle b/c the tone wasn't for me and now own a Mesa WA - win/win. If I didn't have that I would probably be looking at a class D TC elec RH450. I don't care if it's class A, B, W or § - it sounds good.

 

[kesslari]

I beg to disagree with your first paragraph, second paragraph and last paragraph - that's why I sold my MBs, GBs, and others that I tested.

1. Money never comes into play (you can basically get every piece of middle of the road SS crap for 300-700 dollars - seriously that's not a lot of money in todays world.),
2. Weight no, i'm still young enough and in shape to lug around +80lbs,
3. Tone yes it is a factor - my ears didn't let me down, thank God,
4. lastly power (this shouldn't even be an arguable point) 1W of valve will kill 1Ws of Class D any day of the week. Don't be fooled by the marketing hype around Class D and the increased power you get from 2/4/8 ohm loads. Valves: 1W is 1W whether it's 2/4/8.

I read through many of the posts and it's amazing that "power" and "weight" are the two biggest factors; hardly any rebuttal to tone. So let's either get in shape or get some roadies, who cares what we sound like in the mix.

I wonder if I read the same thread you did. I saw a whole bunch of guys say they loved the tone of their ClassD amps. I know I do.

You don't. Film at 11. Either everyone else is crazy, and you're the only guy with taste, or you're crazy, or maybe, just maybe, different people like different tones.
Hard to tell, hard to tell.

 

[fdeck]

Well, now you know four

Really, switching power supplies are not all that difficult to fix. Class D amps aren't too hard either but usually it's less costly to replace the entire class D section because of the economies of scale when building large quantities.

I agree that this is the trend we're headed towards. We will think of SMPS or Class-D power amp modules as "components" that are swapped out in their entirety, just like we swap out integrated circuits rather than prying them open and fixing them.

It seems odd that a lead sled costs less than an equivalent switchmode bass head (e.g., GK Backline 600 vs the 300-W micro heads), but that could be due to the vagaries of global economics and labor markets.

When my switchmode bass head needed a repair (damaged power switch), it cost me less than $10 to mail it back to the maker. Try that with your SVT.

I repair the old linear stuff too, some of that is harder than SMPS by the way.

Same here. But I have noticed that the most frequent repair issues are common to all amp classes, namely the failure of connectors and other electromechanical parts.

 

[Derek Kiernan]

I can say with absolute certainty that there IS a discernable difference between the class D / SMPS amps and the old class AB. Lead sleds. Its a difference I feel more than hear. That being said, in my world, the benefits outweigh the shortcomings, no pun intended.

I often wonder how an 'all-tube' amp without all the lead would sell if it were made, if it had the same tone as a classic amp but dramatically lower weight. I'm not sure there would be a strong market demand.

 

[R Baer]

The Peavey VB-3 does just that.

Invalid Link Removed

 

[Derek Kiernan]

Does anyone own one? I haven't seen reviews for it outside of publications.

 

[xray]

Interesting: I personally haven't been all that impressed with the Class D's I've played through; however, I do believe they have a place in the field and they're definitely lite. I think the big reason the industry has gone in this direction is production, labor and parts costs.

GB / MB / G-K, et al, are all in the business to make a profit - bottom line! So they've used the Class D technology to make a high powered, light weight amps that are affordable to the general public and have a nice entry level price point to take advantage of the profit margin. Most, if not all are made in Asia. Not saying Orange and Ampeg as examples aren’t in the game to make a profit but they have other products to bring the revenue in. The valve stuff is still their marquee high end touring professional rigs (not trying to demean any touring professional musicians on this site – we know who the big boys are)
As someone mentioned earlier they’ve become the disposable amps of our time. Out of warranty repair $$$ or buy a new one? Follows the trend the world is in right now. Apple sells 3M iPads 2M iPhone in two week. What was wrong with the itouches and G3 iPhones that everyone replaced? Landfill!

I’m liking Mesa’s stuff a lot more these days – please tell me it’s not Class D.

 

[xray]

Actually, if he'll oblige I have a couple of questions for the GB Engineer:
1. Why doesn't GB make an all tube amp?
2. Why design the shuttle series with a single 12x pre?

 

[calebbarton]

I'm a class A/B IE iron conventional power supply guy.

Why? Repairability.

OK, I also prefer the tone of a conventional amp - so screw it, I'll carry one.

I know at least 100 guys who can fix a classic amp. I know about three who can gore on a switching supply and win. That's a very big deal in my mind. There are going to be some very unhappy players when they find out their out of warranty switching supply based amps are destined to be doorstops because they can't be fixed.

I learned my lesson many years ago when I smoked a Standel while on the road. Those things had epoxy potted modules, and unless a shop had modules - repair was not possible. Had to buy an amp to continue and leave the Standel in the truck. That was over thirty years ago and it still irritates me.

+1

There is virtually noone in my town who will work on a SS amp. The few who do charge millions of dollars to do it. That being said I need to learn how.

 

[Bob Lee (QSC)]

I don't happen to own a class D amp yet, but I would have absolutely no qualms at all about using a good one, especially one designed by agedhorse, Pat Quilter, or any other exceptional designer.

Tone? If you even half know what you're doing you can dial in the tone you want on any good amp, regardless of its class of amplifier circuitry.

 

[agedhorse]

Same here. But I have noticed that the most frequent repair issues are common to all amp classes, namely the failure of connectors and other electromechanical parts.

Don't forget pilot error...

 

[agedhorse]

Actually, if he'll oblige I have a couple of questions for the GB Engineer:
1. Why doesn't GB make an all tube amp?

We do... but not in the bass market. We have 3 tube amps in our guitar line for years that have been successful and also very reliable. In fact, we probably have as much or more experience with all tube platforms than most other manufacturers since we do both guitar and bass amps.

One problem (from a manufacturer's perspective) with an all tube bass amp is that they end up being large, very heavy and expensive if you want to sell a reliable product.

The other problem is the marketplace tends to be very focused on a specific platform such as the SVT. If it's not an SVT they are not interested. That's a tough nut to crack. Look at the variety of manufacturers who have introduced an all tube amp only to discontinue it within a short time frame.

The players have for the most part spoken, They are interested in compact, high performance and lightweight. That is why the industry is headed that way.

2. Why design the shuttle series with a single 12x pre?

The Shuttle was focused on a specific player, one who was looking for a simple, straight ahead amp that was small, lightweight, inherently tone-friendly and powerful enough to gig with. It also had to come in at a reasonable price.

We have a lot of experience with all tube preamps, from our guitar amp section we have expended thousands of hours developing viable tube circuitry for guitar and bass but we will see what the market (as a whole) asks for and if the wide-spread interest was there we would certainly consider it. It's not because of a lack of experience. It's really Roger's call, and he's looking at many of the same issues I mentioned above.

 

[Munjibunga]

I beg to disagree with your first paragraph, second paragraph and last paragraph - that's why I sold my MBs, GBs, and others that I tested.

1. Money never comes into play (you can basically get every piece of middle of the road SS crap for 300-700 dollars - seriously that's not a lot of money in todays world.),
2. Weight no, i'm still young enough and in shape to lug around +80lbs,
3. Tone yes it is a factor - my ears didn't let me down, thank God,
4. lastly power (this shouldn't even be an arguable point) 1W of valve will kill 1Ws of Class D any day of the week. Don't be fooled by the marketing hype around Class D and the increased power you get from 2/4/8 ohm loads. Valves: 1W is 1W whether it's 2/4/8.

I read through many of the posts and it's amazing that "power" and "weight" are the two biggest factors; hardly any rebuttal to tone. So let's either get in shape or get some roadies, who cares what we sound like in the mix.

Sounds like your prejudice is well-seated, so I doubt any of the multitude of insightful, technically sound responses in this thread are going to have any significant effect on it.