Class H amp??????

[engtaz]

I have heard of A,B,G but not H. What does Class H do differently.

Thanks

[Face]

http://en.wikipedia.org/wiki/Amplifier#Electronic_amplifier_classes

[venomclan]

I have heard of A,B,G but not H. What does Class H do differently.

Thanks

It is the Happy Class. :D

[disneyjoe7]

Or sounds like HELL class, I stick too A-B classes Thank you.

[engtaz]

Difference between G and H

[Gaara]

Class D rules them all, muwahahaha.

Class G amplifiers are a more efficient version of class AB amplifiers, which use "rail switching" to decrease power consumption and increase efficiency. The amplifier has several power rails at different voltages, and switches between rails as the signal output approaches each. Thus the amp increases efficiency by reducing the wasted power at the output transistors.

A Class H amplifier takes the idea of Class G one step further creating an infinite number of supply rails. This is done by modulating the supply rails so that the rails are only a few volts larger than the output signal at any given time. The output stage operates at its maximum efficiency all the time. Switched mode power supplies can be used to create the tracking rails. Significant efficiency gains can be achieved but with the drawback of more complicated supply design and reduced THD performance.

My take from this is that G switches between a set number of rails to reduce waste and increase efficiency. Class H increases efficiency even more by having a infinite number of rails, and keeps the same efficiency with all power usage levels.

[heiney9]

Don't want to get into an amplifier class arguement. IMO, I don't care for class D, G or H. They have alot of noise issues and switching distortion unless done correctly which is very costly. Class D amps have gotten better but IMO, Class A and A/B amp when well designed leave them in the dust (with exceptions of course). That being said all amplifier designs have there drawbacks, but strictly on a pure sonic level Class A, A/B is hard to beat when done with care using premium components.

H9

[Gaara]

I personally have tried many Class D amps, many class A/AB, one Class A, and one Class H or G. I ended up with IcePower in my main rig with Class A in my PC rig.

I was never a big fan of Class D until I tried IcePower. I have heard some rave that the 1000asp module is the perfect amp, it is now used by many higher end brands like Bel Canto, PS Audio, Jeff Rowland, etc.

I wont really argue one over the other, but alot has changed with Class D. My EVS 500Ms use Class D compared to my Cinenova that uses Class A/AB.

Price is about the same, the EVS500m are 10% of the weight of the Cinenova and maybe 1/4 the size. They run cold as opposed to the Cinenova running warm, have a little less noise even though both are quite, and have no self noise while the Cinenova can have a little at times. Sound quality I would give the nod to the EVS units, more transparent with much better (measurably better) bass.

[mulveling]

So basically, here's a quick summary of mapping known amps to their classes:

The Sunfire amps are all class H.

The older Oulaw M200 monos were class G; they switched rails after 80 Watts (for the last 80-200 Watts). Not sure if their newer monos use this topology. I think the rest of their amps are mostly class AB.

The PS Audio, Bel Canto, Nuforce, stuff is class D (anything using the Icepower modules, plus there are other class D schemes too like the tripath and Nuforce). I've heard good things about the Icepower, though I've heard complaints that the PS Audio stuff (and probably others using these modules) are overpriced considering the parts involved.

The majority of the amps out there, SS and tube, are class AB. Anything over 60 Watts is usually NOT pure class A. There are a few out there, but they're very big and expensive. Some of the AB amps run their first few Watts in class A. An example of this is the Parasound Halo amps - and I like what I've heard from that type of design, so far. But I still like tubes better :)

A few companies have made a name for themselves concentrating more on pure class A designs, like Pass Labs/First Watt and Sugden in the SS world, for example.

[Gaara]

Just one thing, Nuforce doesn't use IcePower, they use their own technology.

[mulveling]

Just one thing, Nuforce doesn't use IcePower, they use their own technology.
You're right; my mistake :)

[tom t]

some soundcraftsmen amps are class h, they are powerfull and reliable and sound good also. i have a 5002 driving infinity 1b bass colums with ease.

[engtaz]

I have Outlaw M200 and I think their a great amp. I also have Adcom 555II and like it also. Some people down G and H and I was looking for reasons why people don't like them, especially when I like my M200.

[cfrizz]

I suspect it's the snob factor kicking in again.;)

[heiney9]

I suspect it's the snob factor kicking in again.;)

To be frank, the Outlaw mono's are very, blah. I'm sure they are good for HT but for a serious 2-ch system, IMO they are very bland. And Cfrizz how did you like that Rotel digital amp you listened to? For me it's a matter of better sound not snob appeal.

Christ, I'm still running a 20 year old Adcom and most here would turn their noses up at. I am amazed how good it still sounds. But I have yet to find anything that wasn't a lateral move unless I step it up a couple notches to gear more oriented to 2 ch. reproduction, which mean more $$$.

CFrizz, I love you to death, but everytime someone talks about moving up the audio chain you shout about snobbery.;) That maybe true for some but I think a majority are looking that next level of sound. Some are content some are not. But just because one is not content doesn't mean they are a snob.

The better amp designs and boutique brands like Pass Labs, Monarchy, Levinson, Jolida, Manley, BAT, TAD, Classe, Belles, etc. all bring the goods in spades over more common stuff. As always in this hobby YMMV.

Have a great safe weekend everyone.

H9

[Danny Tse]

I am currently using a Technics HT receiver from the mid 90s, which has a Class H+ power amp section, as my headphone amp. It sounds great driving speakers as well.

[RuSsMaN]

Class A, all the way.

[dudeinaroom]

I am currently using a Technics HT receiver from the mid 90s, which has a Class H+ power amp section, as my headphone amp. It sounds great driving speakers as well.

Scrap that technics, I had a late 90's with the class H+ circuitry, and was dumb founded when I went to Adcom/Denon combo, and floored When I used an Adcom Pre with The Adcom amp.

[mhardy6647]

As Russ says: Hard to beat Class A (no switching, no crossover, maximal linearity) as long as you can afford the electric bill :-)

[disneyjoe7]

I bitch about my electric bill so A-B for me.

[mhardy6647]

My everyday is EL84 push-pull Class AB, ca. 14 wpc.

[Zero]

Mhardy - One of my highlights of hi-fi in 2007 has been the very affordable Vista Audio i84 integrated amplifier that specs similar to what you mentioned above. It is an EL84 push pull amp that operates in class A for the first 8 watts, and switches to A/B mode for the remaining 7 (15 total).

Good shtuff.

[mhardy6647]

:-)

I don't think it is possible to make a bad sounding EL84 amp, PP or SE, pentode or triode mode, class A or AB.

Here's a SE pentode example...

http://img.photobucket.com/albums/v223/mhardy6647/AF4inaction0222.jpg
http://img.photobucket.com/albums/v223/mhardy6647/AF-4rfront.jpg

Sorry! We were talking about Class H. That was Soundcraftsmen, wasn't it?

[Face]

I know the newer MaC amps are A then A/B, I can't find any info on what my older stuff is, 7270, 2125, 2105, and 250.

[heiney9]

I know the newer MaC amps are A then A/B, I can't find any info on what my older stuff is, 7270, 2125, 2105, and 250.

As has been stated before there are very few pure class A amplifiers over about 30-50 watts. I'm sure all your MaC's were of the A/B variety.

As an example the Pass Labs XA160 is 160 watts pure class A and it retails for $18K and adds about $100 a month to your electric bill at idle. :D :p

H9

[mhardy6647]

2105 and 250 were AB; the others likely were, too.
AB basically, and generally means, Class A up to some operating point, then class B. Practically speaking, it means the output devices are biased "a little bit on, but not full on".

http://sound.westhost.com/class-a.htm
http://www.duncanamps.com/technical/ampclasses.html
http://sound.westhost.com/amp-sound.htm

[cfrizz]

:D That's why I put in the little winky H9!:D I have nothing against anyone moving up to better sound, I just don't like it when they start putting down the gear they started out with like it is some bastard stepchild!

As for the Rotel digital amps. I didn't like the 1077 100wpc 7 channel amp. But I was hard put to tell the difference between the 200wpc regular amp & the 500wpc 2 channel digital Rotel!

No doubt with extended listening I might have been able to tell a difference. But for the short time I listened I was satisfied with it.

To be frank, the Outlaw mono's are very, blah. I'm sure they are good for HT but for a serious 2-ch system, IMO they are very bland. And Cfrizz how did you like that Rotel digital amp you listened to? For me it's a matter of better sound not snob appeal.

Christ, I'm still running a 20 year old Adcom and most here would turn their noses up at. I am amazed how good it still sounds. But I have yet to find anything that wasn't a lateral move unless I step it up a couple notches to gear more oriented to 2 ch. reproduction, which mean more $$$.

CFrizz, I love you to death, but everytime someone talks about moving up the audio chain you shout about snobbery.;) That maybe true for some but I think a majority are looking that next level of sound. Some are content some are not. But just because one is not content doesn't mean they are a snob.

The better amp designs and boutique brands like Pass Labs, Monarchy, Levinson, Jolida, Manley, BAT, TAD, Classe, Belles, etc. all bring the goods in spades over more common stuff. As always in this hobby YMMV.

Have a great safe weekend everyone.

H9

[mhardy6647]

I just don't like it when they start putting down the gear they started out with like it is some bastard stepchild!
umm... I still have, listen to, and appreciate mine. Yamaha CA-610II, T-550 tuner, and Polk Monitor 7A speakers. Listening to "A Prairie Home Companion" on that stuff as I type this, in fact.

[Yashu]

Class A wins whether tubed or solid state. However, the recent developments with the new class D variations (H is basically higher tech D right?, why not call it D?), "class T" or AKA Tripath chip", are pretty exciting. Right now they don't have the power to match the big amps, but maybe the technology will grow. They are certainly more effcient than a class A amp of the same power, and from what I hear, they sound pure, fast, and extremely detailed.

The weird thing is, class B and AB amps these days can be built well enough to hang with the big boys, but remain efficient, making the Tripath amps almost left to re-invent the wheel... their main advantage so far has been their size and cost.

I also like the Tripath and other D varients because there is not much room for innovation with A or B... We have pretty much reached the limits in terms of classic amplifier design.

[Gaara]

Class A wins whether tubed or solid state. However, the recent developments with the new class D variations (H is basically higher tech D right?, why not call it D?), "class T" or AKA Tripath chip", are pretty exciting. Right now they don't have the power to match the big amps, but maybe the technology will grow. They are certainly more effcient than a class A amp of the same power, and from what I hear, they sound pure, fast, and extremely detailed.

The weird thing is, class B and AB amps these days can be built well enough to hang with the big boys, but remain efficient, making the Tripath amps almost left to re-invent the wheel... their main advantage so far has been their size and cost.

I also like the Tripath and other D varients because there is not much room for innovation with A or B... We have pretty much reached the limits in terms of classic amplifier design.

Class H isn't Class D, from what I am reading Class H uses a more efficient power supply but can feed a amp that is Class A, A/AB, D or whatever else.

As for Tripath there are higher output designs, Bel Canto comes to mind with their Evo Line which was 100wpc+. They used Tripath for a few different models until they dumped the technology for cheap better IcePower.

[Yashu]

IcePower, I have heard of it. Sounds pretty interesting and I was trying to find some info on bel canto's website but there isn't really anything.

I think you are right about the class H. I always felt that the D in class D was for digital, and so digital switching PSUs and dynamic rails based on that, well... anyway, I probably got carried away with trying to deal with the fact that every tiny improvement to amp design needs a new letter ;)

[Gaara]

If you want info on T vs Icepower there was a good review on 6moons about it, Srajan used the older evo line in one of his setups and upgraded to new Icepower amps by Bel Canto did a nice comparison btwn the two.

If you want info on Icepower just do a google for it, it is created by B&O. Most of the modules (asp ones) come with the power supply built in, all the manufacturer needs to add is jacks and they are all set.

If you want more info you could also look at different brands that utilize IcePower now such as: Bel Canto, PS Audio, Red Dragon, Murano, D-Sonic, EVS, H20, Jjaz, Jeff Rowland, Acoustic Reality, Wyred 4 Sound, Rotel...just to name a few.

[Zero]

If you were curious to try out class "T" (Tripath), I'd suggest you look at the Red Wine Audio Signature 30 - or better yet, the new Signature 30 version 2.0.

For high powered IcePower, thus far the best I've come across is the H2O Signature 150 (no info on the WWW yet as its not en' production). There's no drop and plop or small modifications going on here. Full DC output (no switching about it)... and nearly a completely custom circuit. Good shtuff.

Ok, this has become nothing more than a plug for two pieces I have a fondness for.... ah well, whats done is done, and I had fun doin' it. :)

[Vr3MxStyler2k3]

I think the worst sounding amp I've heard was the Soundcraftman my Dad had...

Thing was pure power, Class H ---

Sounding like someone was talking through a quilt... no detail, just raw, blah sound...

Definitely wasnt the speakers since the almighty 1.2TL was on the forefronts ;)

But very unimpressive

[Yashu]

Red Wine audio... I have been thinking about them lately... I have this high quality extremely well regulated 12v DC PSU, and I thought his 12v DC gear would be cool to mess around with. I don't think I could use battery power, the charging, the hazardous waste, but I don't know of many other "audiophile" components that accept 12v DC. If they have a tripath amp, I need to check that out.

EDIT: $1500 bucks is a little much. Haha, maybe the Trends would be a more sensibly priced playtoy.

[mulveling]

Just a personal preference...but regarding RedWine audio - I find it hard to take seriously a company that offers a $250 ipod mod that *requires* a special cable (with a capacitor) to not cause damage to your equipment. Oh, and they'd love to recommend the special $380 cable or $500 special home dock from the even more hard-to-take-serious company they're partnered with :p

It'll run you nearly $1000 for an ipod plus their imod plus their best imod home dock package. $600 Jolida JD100 on agon, anyone (used Sony scd-777es, Meridian 507, the list goes on...)? Not saying anything about their amps, but I'd exercise caution by the association... I know the good audio toys usually ain't cheap, but throwing that kinda money at an ipod??

BTW, the current PS Audio Icepower amps sound really good - I've briefly heard the 250. There are occasionally good deals for them on agon that pop up (saw a $1100 for the 100 not too long ago), and in those cases they're a good buy. However, I'd have a hard time playing the dealer premium to a company that really spouts the marketing/electronics voodoo BS like that.

Basically, there are a lot of audio companies out there that thrive/depend on consumer ignorance. Polk Audio, by providing the forum and website they have here, has risen well above all that BS. Hooray for Polk :) Don't know why I felt like ranting about this all of a sudden...

[mhardy6647]

Just a personal preference...but regarding RedWine audio - I find it hard to take seriously a company that offers a $250 ipod mod that *requires* a special cable (with a capacitor) to not cause damage to your equipment. Oh, and they'd love to recommend the special $380 cable or $500 special home dock from the even more hard-to-take-serious company they're partnered with...

Basically, there are a lot of audio companies out there that thrive/depend on consumer ignorance...

People spend more than that kind of money to buy wires to hook hifi components together :-P

[mulveling]

People spend more than that kind of money to buy wires to hook hifi components together :-P
It's one thing to drop $$$s on cords to connect an excellent source to a great preamp or integrated...it's another thing entirely to drop $$$ on cords for a system with an ipod source.

Currently I have a paltry 0.5% - 1% of my system invested in the cables...though eventually I would like to upgrade to something along the lines of Audioquest Panther/Jaguar/Columbia. It's not too odd on head-fi to see people have disproportional investments on cables with an ipod source - that's just wrong IMO.

[mhardy6647]

I really fail to see the difference -- the über-tweak mentality is what it is.

Enough of the digression... cheers!

[Yashu]

I think he is saying that the performance of an ipod would make high end cabling a moot point (would you want to add resolution to distortion?). However, I don't know... I don't know how good an ipod is since I don't have one. I have messed with one... but I found out that you need iTunes just to copy music to the thing... Apple has become the new Sony. Luckily it was a gift for someone else so they had to deal that junk software not me :) I thought it would be a simple matter to fill it with some music before I gave it to him (my father... he likes to take walks), but you actually have to do it through iTunes for some reason, and once they (I made some high bitrate mp3s of his favorite albums) were on there, half of them would not play after the first 10 seconds.

Anyway, that is not really the point... I am sure there are plenty of happy ipod users... and so it makes sense to try and bring these people into the world of audiophilia.

[Zero]

Mulveling,

As time goes by, I’ve adapted to the practice of remaining silent whenever I read or hear something I do not particularly agree with – especially when it comes to hi-fi. Frankly, I enjoy life without the back and forth banter. Usually, nothing is learned and at best, both parties agree to disagree. Still, I’ve got some time to kill so I will curve from the usual routine and make a few points.

Applying meaningful modifications to the Ipod circuit is not an easy task, mostly due to a lack of space. The latest Ipod variant has a circuit that is even less hospitable than before. This cable had to be devised because that critical capacitor could not fit inside the chassis of the Ipod. To implement this, the connector has to be custom, meaning that your off the shelf cords will no longer ‘fit’. Like many other things in this hobby, it is a compromise. However, this proprietary connector comes with a very good cable when you buy the iMod – and I am confident that Vinnie will be more than happy to supply a stock cord without a sales pitch - should you lose it.

As an aside; the concept of the Ipod could yield some of the best digital on the planet. An extremely small circuit – virtually no jitter/laser read errors – extremely stable platform that far surpasses the best transports available today, not to mention great storage space and off-the-grid power, those small devices could deliver giant performance if someone had the money to front such a product.

In a bout of irony, consumer ignorance is relative. You mention the PS Audio ice powered amplifiers as a counter-example to Red Wine Audio. Yet here, PS Audio is doing what everyone else is; riding the wave of class D and maximizing profits. They use nearly a stock ICE circuit, inexpensive parts, a very cheap switching power supply, and wrap it all up in an inexpensive case with high quality connectors and charge you a grand (referring to the A-100). You want to talk about premiums eh? I have nothing against PS Audio. They have a rich history and produce many great products. However, I am not the kind to avoid calling a spade a spade.

Polk Audio’s website and forum has not done a thing to separate themselves from the pack. Their products, consistency, customer support, and insight is what makes Polk a success. This mostly un-moderated forum has surfaced no less BS than others of its size and activity.

Given past experiences and general odds – I’m sure you will wake up tomorrow feeling the same way about Red Wine Audio as you did at the time of your post. That’s alright – I’m not here to make you love or hate anything. I’m just making a counter post to tell the other side of the story. As usual, it’s up to the reader to make of it what they will.

Cheers, and enjoy those Tannoy’s.

[Gaara]

I recall the same being said about the Squeezebox when some members were asking about it, it was described as just a toy and something that wouldn't last. Now I know many members use them as their main sources paired with a good DAC, I know I do.

It seems that many newer products are not embraced by the members of Club Polk. In the recent Icepower thread Russ was talking about newer technologies stating that none of them are hifi. When I asked about Icepower a few months ago I got very little in the way of response, now there is more input but still very little.

As for the RWA units I have a lot of respect for Vinnie, I would love to experience one of his amps but it would be incompatible in my system. The I-Mod is a very interesting idea and like Zero I don't understand why people put them down. Part of my goal in my system is to get the shortest signal paths, I want the purest sound possible. The I-mod seems like a logical choice for a high quality source as you don't have to worry about power supply issues, the signal path is extremely short, and there are less issues with jitter and optic problems. I first was skeptical about using a SB3 and once I started I couldn't believe I took so long to do so, I haven't touched a CD in weeks.

Many other forums rant and rave about PCs as being the ultimate sources, and the few times it comes up on Club Polk it seems to be gawked at. This is just another example of a new fad in 2ch listening that is popular in other forums but hasn't seemed to take hold here. I find it sad that things are changing in many ways but to be able to discuss these innovations I have to venture outside of club polk.

[I-SIG]

I've read thru this thread to make sure I did miss anything.....

Anyway, those that are shunning the use of an iPod or other similar device as a source either haven't tried one or didn't rip your music into a lossless format.

From what I've been able to experience one needs those 6moons "golden ears" to tell a difference between losslees and a quality CDP, especially at the level of equipment most of us are using.

Wes

[RuSsMaN]

They aren't, yet. If you would take time to think that all posts responding to you, aren't necessarily ABOUT you, you might be able to see the real intent.

The Squeezebox is on my short list, after my 2ch vinyl situation is squared away. There is a Jazz/ Blues station in Paris that's worth it alone!

Tech takes a while to come around. You think the first transistor output devices sounded great? It took a good twenty years before solid state 'came around', and now it's great. The chip / digital stuff will get better - it probably won't take a couple decades, but it will take some time to refine.

Cheers,
Russ

[engtaz]

How did a Class H ????????????? turn into a Ipod / Squeezebox thread? LOL

[disneyjoe7]

How did a Class H ????????????? turn into a Ipod / Squeezebox thread? LOL



I don't know.



But I do agree with IPOD Apple lossless that format is hard to tell which is playing Redbook CD or IPOD.

[Gaara]

How did a Class H ????????????? turn into a Ipod / Squeezebox thread? LOL

My fault, sorry guys. We went from H -> D -> T -> RWA amps -> Imods -> SB3. I shouldn't have gone off on my technology tangent.

[engtaz]

No problem, I posted for a laugh.

[cfrizz]

Well I have been listening to an Ipod & my mp3 player since Friday night. Playing through a Denon receiver outputted through LSI 7 speakers.

And as shocked as I was, it really doesn't sound bad!:eek: :eek: :eek: Nor does it sound bad to my musician brother! So after all this audiophile talk & posturing, it leaves me to wonder what the reality actually is?:)

[Yashu]

I bashed the ipod due to bad UI, proprietary software, and the utter stupidity of not being able to simply mount it as a HD and copy your music there to play... hehe... I cannot comment on the sound quality since I have never hooked one up to my stereo. It plays lossless files so it shouldn't sound too bad.

/OT contribution.

[engtaz]

I bashed the ipod due to bad UI, proprietary software, and the utter stupidity of not being able to simply mount it as a HD and copy your music there to play... /OT contribution.

I agree.

[mulveling]

I have in fact compared a 4G ipod directly to a Meridian G08 in my home system, and it really was that bad. I had a friend over at the time, a DJ - not an audiophile, and we were both shocked at the difference. Beforehand, I'd actually predicted to him that it wouldn't sound that bad - it did. A Zu pivot IC was used to connect the ipod to a Melos SHA-Gold Reference preamp; yes it was docked.

I don't think the difference between a good mp3 encoding and lossless is that great; in fact I doubt I could hear the difference. The problem's in the ipod power supply, digital section, analog output section...there's only so much you can do in a small space.

The G08 wasn't that much better than more modestly priced decent home decks I'd compared it to (Jolida, Bel Canto DAC2, Sony scd-777es, Denon 2910, Denon 3910, Sony scd-777es, some Modwright'd tube players)...and the G08 can't hold a candle to good vinyl.

That's my opinion and I'm sticking to it (for the foreseeable future, at least) :p

Also, I never said msrp'd PS Audio gear offers a good value - in fact I said the opposite. Their marketing BS makes their products sound far more advanced & expensive to build than they actually are. Their stuff happens to sound good, so it's a good deal at a huge audiogon discount. They do seem to rank pretty low on the parts cost to retail price ratio, I definitely agree there.

[Yashu]

On a lark I bought a PS Audio Noise Harvester to plug into the estra outlet in my Ultimate Outlet... well... let me tell you the irony of the thing creating more noise in a buzzing sound than it would ever have a chance to harvest from my power, was not lost on me.

I called PS audio and they told me it was normal for it to do that and that I should maybe tape some foam or something around it to quiet the buzzing. PS Audio wants you to buy half a dozen of them and plug them in anywhere you can... pfft... one is loud enough. Right now plugged it into an outlet in another room... I doubt it helps my stereo any, but the light is nice to watch blink when I go to bed.

Anyway, I understand the sentimant towards PS audio...

[mulveling]

Hah, that is pretty funny about the noise harvester. I guess it both harvests and generates :D
I love how that's "normal" to them, yet there's no mention of it in the marketing.

Let me clarify - the PS Audio power amps I've heard, sound good. I don't think I'd ever get the urge to try a noise harvester.

[Yashu]

Yes, my wife rolled her eyes when I told her what it was... I should trust her instincts.