Class D Amps

[jazztonebass]

Lots of buzz around the ultra lite Class D amps in the marketplace. Been doing my due diligence and have found much enthusiasm for the Tone Hammer, Puma, Mark Bass, GB, etc....

Undeniably, they make a lot of sense for the gigging bassist. The portability is very attractive.

Question is... is there a sacrifice tonally for the convenience of the package. Do they lack girth and fullness? What, if any, are the sacrifices here?

I want to believe!

[KJung]

No compromises at all. These heads have been around for years. All bass heads sound different. There a midrange voiced 'heavy heads', and there are small heads that hammer huge down low. There is not 'class D' sound IMO and IME. And, more importantly, the SMPS power supplies (which is really what makes 'small heads small') have significantly improved over the last 6 or 7 years.

The only thing they won't do is sound like an all tube amp pushed hard. Of course, neither will a 40 pound version of a solid state head.

[CL400Peavey]

Originally Posted by jazztonebass

Lots of buzz around the ultra lite Class D amps in the marketplace. There seems to be a lot of enthusiasm for the Tone Hammer, Puma, Mark Bass, GB, etc....

Undeniably, they make a lot of sense for the gigging bassist. The portability is very attractive.

Question is... is there a sacrifice tonally for the convenience of the package. Do they lack girth and fullness? What, if any, are the sacrifices here?

No they do not sacrifice tone. What can be said, and this is for every amp topology, is that well implemented amps sound better than poorly implemented amps.

Not every tube (class A) amp sounds the same, and the same goes for SS class A/B amps as well. This extends to Class D amps as well. There are some that are very good, and some that are lack luster. There are also a lot in the middle that appeal to some, but not to others.

[Tuned]

Class D amps are generally very neutral and accurate, which means they don't add any flavor either, so you want a good preamp. IMO the preamps in micro amps leave much room for improvement, but if you find one you like they're the holy grail.

[jumblemind]

Originally Posted by Tuned

Class D amps are generally very neutral and accurate, which means they don't add any flavor either, so you want a good preamp. IMO the preamps in micro amps leave much room for improvement, but if you find one you like they're the holy grail.

You mean the Class D amps that you have tried. None of this can be attributed to the fact of being Class D. The Aguilar TH amps, for example, are anything but "neutral" and flavorless.

[KJung]

Originally Posted by Tuned

Class D amps are generally very neutral and accurate, which means they don't add any flavor either, so you want a good preamp. IMO the preamps in micro amps leave much room for improvement, but if you find one you like they're the holy grail.

Don't mean to dog you, but any pure power amp is 'neutral and accurate'. Also, there is no relationship between preamp design and 'micro amps'. You can pair any preamp with any amp design. Gain structure and hi passing can result in PA power amps of the same or different topology to sound a bit different with the same preamp though.

Again, I understand that power tubes being pushed into distortion is a special case of 'topology', and kind of a different thing.

And, of course, just like in traditional power supply driven amps (that can be any 'class' of amp... A/B, D, H, whatever), there are HUGE variations in 'honesty of power rating (i.e., power delivery at all frequencies within the amps range, distortion levels, etc.), and on a less cynical note, voicing designs the designers make that result in 'big versus tight' low ends, bright versus organic top ends, massive upper treble versus top end attenuation. Very little of this has anything to do with class of power amp.

[kevteop]

I've found the tube pre side of the GB Shuttles is actually pretty nice. I wasn't expecting that - I thought I'd be getting an amp that just did 'clean', but it gets nicely warm and full-sounding if you bias towards the tube side of the preamp.

My general feeling is I should've got a class D head years ago.

[onosson]

Originally Posted by jazztonebass

I want to believe!

Just do it! Your shoulders and back will thank you later...

I've been through tons of heads in my 25+ years playing bass, some tube, most solid-state, and recently class D. Nothing is lost in terms of tone and performance, and much is gained.

[Biggbass]

None that I have found.

[Jebberz]

Best tone I ever had from an amp is now with a class-D Genz-benz amp. So small, so powerfull and so good sounding, I'm still amazed at each gig and rehearsal.

[KrisHayes]

Have owned an Ampeg PF-500 and an Orange Terror Bass 500, and I can definitely say nope! Bassists are in a fantastic spot right now. Now if they can only fit EL34's in a lunchbox-sized guitar head...

[KJung]

Originally Posted by KrisHayes

Have owned an Ampeg PF-500 and an Orange Terror Bass 500, and I can definitely say nope! Bassists are in a fantastic spot right now. Now if they can only fit EL34's in a lunchbox-sized guitar head...

Have you seen the Mesa Trans-Atlantic

[seamonkey]

The title says "Class-D amps" but it's actually about heads.

For pure amp part - class-d or class-ab - sound the same. In audio world they both far exceed human hearing.

Power supplies, if engineered correctly - sound the same.

The pre-amp part of the head varies immensely. The pre-amp is where all the tone comes from. Mostly.

Given a class-d or class-ab all heads need to have limiters and feedback. This affects how things sound at extremes. Extremes is a fringe case, and too much focus is put on it.

Heads = big difference in sound from one to the next.
Feedback/Limiter = difference but fringe case.

Amps sections = Class-D, Class-AB - transparent
Power Supplies = Transparent

Walk in an blind test. There's no compromise or trade-offs as far as sound goes.

[KrisHayes]

Originally Posted by KJung

Have you seen the Mesa Trans-Atlantic

Those aren't EL84's in there? Sure sound like 'em!

[jazztonebass]

Originally Posted by seamonkey

The title says "Class-D amps" but it's actually about heads.

For pure amp part - class-d or class-ab - sound the same. In audio world they both far exceed human hearing.

Power supplies, if engineered correctly - sound the same.

The pre-amp part of the head varies immensely. The pre-amp is where all the tone comes from. Mostly.

Given a class-d or class-ab all heads need to have limiters and feedback. This affects how things sound at extremes. Extremes is a fringe case, and too much focus is put on it.

Heads = big difference in sound from one to the next.
Feedback/Limiter = difference but fringe case.

Amps sections = Class-D, Class-AB - transparent
Power Supplies = Transparent

Walk in an blind test. There's no compromise or trade-offs as far as sound goes.

yes... you are right. I am inquiring about heads. Just wondering if there is any sacrifice inherent with a Class D power section regardless of the pre-amp characteristics/design.

[KJung]

Originally Posted by KrisHayes

Those aren't EL84's in there? Sure sound like 'em!

I think so.... if I read the back panel of the amp correctly on the website.

[pfschim]

Originally Posted by jazztonebass

yes... you are right. I am inquiring about heads. Just wondering if there is any sacrifice inherent with a Class D power section regardless of the pre-amp characteristics/design.

I think it was summed up very well in an earlier post.

the amp topology/power supply stability aspect of an amp should be pretty straight forward and transparent. In the primary performance range (i.e. not the extreme ends of usage) it will be the preamp that will/should provide the actual "sound" of the amp. Also, you get what you pay for, so with cheaper implementations you will probably be taking a greater gamble with any amp technology.

from my reading of this topic here on TB, I'd say that unless you are really seeking the old school "power tubes driven to compression" sound, you really do not give anything up with a Class D power amp, unless the design is low quality, or has been cheaped out by the manufacturer, and even then, the risk is more in reliability, rather than sound/tone.

good luck

[NYCbassist]

Carvin BX500 is an great 500 Watt Head good down to 2 Ohms. Endless (almost too much) choices for EQ/Tone adjustment. This is my pick in the Bang for the Buck category.

[mystic38]

This +1

You simply cannot should not make any generalisations about amplification of clean tones and amplifier topology... an amp of any topology can be designed to be "neutral" ie have a 1n:1 relationship to the input. Amp designers delberately color the sound to the preference of their intentions.

Originally Posted by CL400Peavey

No they do not sacrifice tone. What can be said, and this is for every amp topology, is that well implemented amps sound better than poorly implemented amps.

Not every tube (class A) amp sounds the same, and the same goes for SS class A/B amps as well. This extends to Class D amps as well. There are some that are very good, and some that are lack luster. There are also a lot in the middle that appeal to some, but not to others.

[KrisHayes]

Originally Posted by KJung

I think so.... if I read the back panel of the amp correctly on the website.

Right... I'm saying if they could figure out a way to make an EL34 lunchbox sized amp...