Why Don't We See More High Current Electronics?


It seems that in looking around for amplifiers and integrated amps that double their power as the impedance is halved (high current), they seem to be in a minority. Is it just more costly to build good-sounding high current electronics and the market demand for them just isn't there, or what?
foster_9
More costly to build, less demand, and bad economy.
I agree with Unsound. Look for a good used Levinson, Threshold or Krell. They are a bargain on the used market.
You only need high current electronics is you have current sucking speakers.
Post removed 
OR, better still
An amp that produces 200 watts into all sorts of wacky loads regardless of impedance
OR
One of those 'double up' amps that fades when confronted with any but a pure resistive load?
I'd say it's because the designers have realized high feedback voltage source design that was popular in 80's and 90's doesn't sound that good. Amp design continues to evolve. The days of low efficiency speakers combined with high powered amp is now gone. Speakers are getting more efficient and there is less demand for high powered amp today.
Jylee,
Bingo! You are absolutely on the mark.Good riddance to the power sucking,high current demanding and low effiency speaker that led to chasing ever higher power amplilifiers(and increased complexity) in an attempt to drive these beast.
Meant to write low efficiency.
Newer Class D and Icepower specifically meet the criteria, are becoming increasingly popular and are more practical for most, and may be undercutting the value of the traditional heavy, power consuming and expensive to build well monster amp, which was always a niche item to start with.

I know in my case I needed the high current, high power amp to drive my larger speakers properly and to the max. I considered Class D or traditional monster amp. I decided to go Class D and have no regrets. Every time I listen, the sound just blows me away.

In general, greater efficiency is the wave of the future. That can mean a more efficient amp to deliver the power and current needed as in Class D or more efficient speakers that require less power and perhaps also current. Either approach or even both in conjunction to some extent can greatly help bring an otherwise under performing system up to par
Here's one more for you:

http://www.atma-sphere.com/papers/paradigm_paper2.html

Why not ask what the relationship is between doubling power and how your ear/brain system hears? The short answer is that you get flatter frequency response, but only with certain speakers. This comes with a price- distortions that the ear is extremely sensitive to. The ear hears these distortions as a variation (coloration) in frequency response! So in a way, you can't win with the explanation of flat frequency response.

The actual fact of the matter is that if you want the equipment to sound like real music (which IMO is the goal of any high end audio system) than some of the design parameters that bring you the ability to double power as impedance is halved may have to be abandoned. So you are seeing that occur, for example there are more manufacturers here in the US of vacuum tube audio products than there was in 1958!
Jylee and Charles1dad, I couldn't disagree with you more. I have yet to hear any of these more efficient speakers that satisfied me.
Mapman, these newer Class D amps with their relatively inexpensive, diminutive dimensions, cool running, high current, high powered prowess just might free up speaker designers from the limitations of meeting the criterion of high efficiency speakers. The future just might be the opposite of what you predicted.
unsound,

Could be.

Regardless of which approach makes more headway, more efficient amps or more efficient speakers efficiency always rules when it comes to doing more for less.

I suspect a consumer has more and perhaps also more cost effective options regarding speakers currently building around a high efficiency amp like a Class D than one does going the high efficiency speaker route, especially if one cares about good full range performance and not giving up the lowest octaves.
Mapman, that depends on what your defining as more and what your defining as less.

I suspect your suspicions are spot on.
I have been considering trying a lower powered tube integrated in my second system where I already have a decent sub and fairly efficient tube friendly speakers (triangle Titus XS) currently driven to good effect at up to moderate volume by a "flea powered" 20 watt vintage Yamaha receiver. A similar 20 watts or so of soft clipping tube power might be a nice step forward. My inefficient but sweet sounding Stax sr-80 electret "earspeakers" I use on that system might benefit as well.
Your Stax "ear speakers" are, ehem, a different can of worms.
"Your Stax "ear speakers" are, ehem, a different can of worms."

No doubt.

They are similar to electrostat and other planar speakers, very inefficient, and require some power (not necessarily current) to drive well.

I do not listen that loud with these though. A 20w/ch or so soft clipping tube integrated could work quite well for these I suspect as well as with the Triangle monitor + sub combo.
They aren't expected to fill a room with sound.
Unsound,
Well what can I say? We just have different taste and hear differently. most of the very best natural sounding systems I`ve ever heard were comprised of high quality but low powered amplifiers with very efficient speakers. Utterly natural/organic music reproduction with disarming realism and presence. That`s my personal experience ,if your ears have led you in a different direction then by all means continue to follow it. Ijust know what`s been better to me that` all.
Best Regards,
Another reason that there may not be as many high current electronics as you might think could be that they are only of concern to "audiophiles" looking to max out performance of there system. Most people get by fine with less than industrial strength SS amplifiers in whatever gear they happen to listen to.

It's only the audiophile camp, a small niche itself, that is concerned with things like high current, high efficiency, tube amps, etc.

I will say though that within that niche, tube gear and high efficiency speakers to go along seem to be experiencing a renaissance and cutting into the high current SS amp/lower efficiency speakers domain compared to the recent past, so that would have to have some effect on how much of any particular design one sees.

I think Atmasphere is a big force behind this, at least on this site. He apparently makes some very nice gear, believes strongly in what he does and is a verbal champion of the approach, so kudos to him and the others who have helped breath some life back into the paradigm!
Atmasphere,
You stated basically that you think the goal of any high end audio system is to have the equipment sound like real music. I think many would agree with this approach. However, given the great variety of recording quality, doesn't this imply that the system will impart some level of coloration to make one's whole collection sound like real music? What do you think of the approach that equipment should be as true or faithful to the recording as possible, ie, as neutral and transparent as possible? Great recordings will sound great but lesser recordings, not as good.
Charles1dad, I couldn't agree more.
Well, in my experience I haven't come across high current amplifiers that double down and sound anything less than stellar. If an amp cannot double down I'll pass on it...why limit your choice of speakers due to challenging impedance loads and such?
Hack, remember that a high current amp will decrease power into higher loads. There are limitations in either case. Choose your speakers and amplify them appropriately.
I just did a quick search to see what amps double down and found the following do , Ayre , Classe , Edge ,luxman , Marantz , Simaudio , Tenor and some Levinson and Parasound , probably lots of others . As others above have said I don't think that aspect is very important , even in a large room and at lease braking levels .
As others above have said I don't think that aspect is very important , even in a large room and at lease braking levels .
Tmsorosk (System | Threads | Answers | This Thread)
Well, I'm of the opinion that it matters based on what I've experienced in my system using speakers that had an uneven impedance curve.

Relating back to what Unsound stated in his previous post, the reduced power output into higher loads (lower impedances if I'm reading Unsound correctly) from an amp that does not double down (double power as impedance is halved) resulted in a sound that was always "bright" because less power was being delivered by into the mids and bass frequencies than the treble frequencies. Therefore, there was a higher decibel level in the highs than in the mids and bass. The difference was not large, and it probably wasn't noticeably measurable on a Radio Shack decibel meter, but the results were clearly audible on my speakers that had an uneven impedance curve.

Once I drove them with an amp that doubled down, the sound was evened out and the speakers no longer sounded "bright".

FWIW...
So far the efficient Class D amps I've tried have not presented the clarity, bass weight, and refinement with the (somewhat difficult load) speakers I own now. (I need some power and current damn it!). So I continue to look at Class AB designs. But I'm not interested in a 125 lb behemoth either; just a reasonably priced high current amp(less than 3k ) that doesn't take 2 people to lift and isn't old as the hills and in line to be re-capped soon. An amp with good sonics too.
...I'm not interested in a 125 lb behemoth either...
Foster_9 (Threads | Answers | This Thread)
You'll find that the best high current amps (tube or solid state) have the largest transformers, and are therefore heavy. The higher the power output the heavier the amp. There's really no way to escape it.
Maybe a 80-90 lb amplifier but not much more.
Tvad , you may be comparing apples to oranges . The new amp is likely quit different in design , there may be other reason's it dosn't sound bright other than just the double down aspect . Is the output the same on both amps into an 8ohm load . Size of transformers can have a great effect too . I guess if an amp is well under powered for the situation doubling into 4ohm would likely help . Glad your happy with your new amp though .
03-15-11: Foster_9
Maybe a 80-90 lb amplifier but not much more.
I think my Pass Labs amps (XA-30.5 and XA-60.5) weighed about 60 lbs per chassis. The XA-30.5 leaves Class A at 60wpc peak power, and the XA-60.5 leaves Class A at 120wpc peak power.
03-15-11: Tmsorosk
...there may be other reason's it doesn't sound bright other than just the double down aspect.
Could be, but I'm sticking with the double down aspect. The details of it are thoroughly explained in "The Complete Guide to High End Audio" by Robert Harley.

My present amps don't double down and they aren't solid state. I replaced the speakers that required that type of amplification.
...to add a pertinent detail. When I was experimenting with amps that doubled power as impedance is halved, I auditioned or owned four amplifiers...all at different price levels and build quality. In each instance, these amps produced balanced sound whereas amps that did not double down produced sound that was "bright".

The amps that doubled down were: Bel Canto REF1000 MK II monos, Belles 150A Reference monos, Pass XA-30.5, Pass XA-60.5 monos.
Although I always have the greatest respect for opinions expressed by Ralph (Atmasphere) and Grant (Tvad), and I almost always find myself in agreement with both of them, in this case I think that their posts are commingling two separate issues.

ANY amp having negligibly small output impedance, such as most solid state amps, WILL double the amount of power that is delivered into a halved load impedance, PROVIDED that it is operated within the limits of its maximum voltage, current, power, and thermal capabilities. That is a matter of basic electrical engineering principles. If in fact Harley disagrees with that he is wrong.

Most, and perhaps nearly all, tube amps will not do that, BECAUSE their output impedance is not negligibly small.

All of that is essentially a separate issue from the one I believe Emerson (Foster_9) was asking about, which I believe concerns whether or not the MAXIMUM power ratings of a solid state amp are twice as much for a 4 ohm load as compared to an 8 ohm load.
03-15-11: Tmsorosk
...there may be other reason's it doesn't sound bright other than just the double down aspect.
I suspect this is correct.

Best regards,
-- Al
Okey-dokey. I'm bowing out.
Al, I always welcome your posts. The "PROVIDED" you provided is the operative word.
Hack, remember that a high current amp will decrease power into higher loads. There are limitations in either case. Choose your speakers and amplify them appropriately.
Foster,

Sorry to hear your still fighting bass and other issues. Your case is a tough one to get a handle on because I know you've tried so many things, including subs, and still have not yet scored completely.

Even if everything is matched well electronically, room acoustics and individual preferences still come into play in determining what sounds good.

Maybe a near field setup of some sort might be the best approach if you can get to that kind of setup in your room.

My best guess is the thing you need new most is a new room. Unfortunately, that is one of the hardest things to have to deal with.

My wife's very lively sun room, 12X12 with a cathedral ceiling, lots of windows and a hard tile floor is that way. What sounds spot on other rooms never quite gels completely in there. Generally there is too much bass and imaging and soundstage is not totally up to snuff. Fortunately for me that is only an auxiliary listening location so I am able to live with what I get there, though I have not given up on trying to get it perfect.
Wow, Map,
That would appear to be an awful space. Headphones, anyone?
I had some MG-1s in a 10x10 room with an 8' flat ceiling. now THAT was terrible. I had to swap the speakers L/R (they are marked) to make is sound right.
Current matters when you're driving difficult loads, and as Tvad mentioned, there's no real drawback. I value systems as follows: source=>preamp=>amp=>speakers. There's a ton of excellent speakers that are hard to drive (I've owned Apogee's, Eminent Technology, Celestion 700's, etc)and of course many excellent speakers I'd like to fool with at some point. I don't want my speakers telling me what amp I should use... I'm not sure why anyone would think this is not a sensible approach.
Peterayer, we agree on that- all the system can do is reproduce the recording as accurately as possible.
Hack, a high current amps prowess might be lost on a speaker with a 16 Ohm impedance.
Mapman, thanks for the sentiments. The beat goes on. I'm still looking for the high current amp in the used market that better matches my speakers and fits my amplifier profile:

clarity with bass weight and refinement
Not extremely heavy: 50-90lbs at most- bad back
amp w/higher input impedance is required for my Cary SLP 05
high current - doubles down - 100-300 wpc
not over $2k
known for quality sonics
Mirage OMD28 speakers
In a tough room like my wife's sun room, options to achieve "perfect" sound are limited.

1) minimize the imperfections through tweaking and learn to live with it
2) have the room professionally analyzed and based on findings, do some combination of treatments and/or signal processing using a graphic or parametric equalizer
3) rely on near field listening
4) headphones

For 2, a newer possible variation these days that might prove effective is doing the needed signal processing in the digital rather than analog domain. That provides more flexibility and precision in whatever processing might be needed.

Ironically, directly below my wife's sunroom is my office where my gear lives and often serves as my main listening room. This is also 12X12, however I have not had problems getting whatever speakers I put in there to sound spot on.

There are other differences that I suppose help account for this:

1) I had the ceiling and walls in that room insulated when the house was built so as to have a place to liten without disturbing anyone. It also has a solid wood rather than hollow door for same purpose

2) standard 7' whatever drywall ceiling, actually lower towards rear where there is a conduit so ceiling is not flat

3) rigid concrete foundation floor with very thin but dense industrial grade carpet and padding

So I guess my point is that there is a lot of factors that go into how a room "sounds" and it can be hard to predict without actually hearing it.
Foster,

The Class D/icepower BC ref1000m monoblocks I am using meet all your criteria except for price and power exceeds your stated range at 500w/ch into 8 ohms, which is generally more of a boon than a problem with most large full range speakers built to run all out at higher volumes.

The bass is absolute top notch in my opinion with any kind of music, have not heard anything better in terms of proper weight along with refinement/articulation, at least in my two well tuned rooms (one larger and one smaller). In the sunroom, anything I use that sounds balanced and right in those two rooms tend to go a bit boomy and bass heavy, which clearly indicates that the room is the thing that brings the performance level of an otherwise nicely balanced rig down a notch or two, at least in my case.

I think this is one of the amps that Tvad mentioned above that he has tried and found to deliver properly balanced sound.

I've tried every "good" speaker and amp combo I've owned current and past in that room and always similar results, OK but not great.

I haven't tried my realistic Minimus 7s taht I use over the summer on the deck though! THat might be worth trying! Smaller may be better in a case like this with overzealous room acoustics!
Tvad writes:

Well, I'm of the opinion that it matters based on what I've experienced in my system using speakers that had an uneven impedance curve.

Relating back to what Unsound stated in his previous post, the reduced power output into higher loads (lower impedances if I'm reading Unsound correctly) from an amp that does not double down (double power as impedance is halved) resulted in a sound that was always "bright" because less power was being delivered by into the mids and bass frequencies than the treble frequencies. Therefore, there was a higher decibel level in the highs than in the mids and bass. The difference was not large, and it probably wasn't noticeably measurable on a Radio Shack decibel meter, but the results were clearly audible on my speakers that had an uneven impedance curve.

Once I drove them with an amp that doubled down, the sound was evened out and the speakers no longer sounded "bright".

---------------

Sorry, but this is pretty basic misunderstanding of how amplifiers work. An amp with a low output impedance does not have a frequency response that varies with a speaker's impedance. The key parameter that varies is potential current delivery by frequency before clipping occurs. So for a good voltage-source amp with 100w into 8ohms, if the speaker has a peak impedance of 16 ohms into 4KHz the amp will clip at 50w, and if the lowest impedance occurs at 40Hz with 4ohms the amp will clip at 200w, but the frequency response at 50W will still be flat (within the amp's spec) across the entire spectrum up to 50w.

Trick question - what happens if the speaker is reproducing 4KHz and 40Hz *at the same time*?
As a former owner of VK1000 mono's and many other Pass 600 sized monster blocks I for one don't miss having to place amps of that size any more.

95dB and above speakers driven by an 8 watt 300B SET is as good as it gets for truly refined sound. But if you're not listening to acoustic music, and are of the RR family, then quality of sound isn't what you're after as much as volume of sound. Dare I say it...acoustic rules!

Isn't clipping an even worse consequence than unbalanced frequency response alone?
"But if you're not listening to acoustic music, and are of the RR family, then quality of sound isn't what you're after as much as volume of sound."

That's a very biased perspective.

There is high quality and lesser quality non acoustic music as well. Volume is part of it because that is the nature of the beast but not the whole story by a longshot.

I would argue that it is more costly and difficult to reproduce music that is meant to be loud and powerful accurately and convincingly than it is to reproduce acoustic music that you liten to normally at lower SPLs.

It's a mistake to discount music forms that one does not care for just because one does not care about them. They are forms of music people listen to as much or even more so in practice than others.

That kind of attitude is one way how audiophiles get a bad name.
Yes- audio equipment does not care what kind of music you play on it.

An amp with a low output impedance does not have a frequency response that varies with a speaker's impedance.

That depends on how the speaker is designed. Take a look at
http://www.atma-sphere.com/papers/paradigm_paper2.html

An excellent example is a Sound Lab ESL, but by no means the only example. You can also run into frequency response variation with highly reactive speakers (high efficiency). You have to look at the intention of the designer of the speaker.