For some reason my reply did not get posted. I am using a PS Audio GCA 250 on my mid/bass panels. I will move it to the ribbons. I am expecting to get Wyred monos for the mid/bass panels. Underwood HiFi is selling a multi-channel version, which would be great if I didn't already own the PS. |
No, the 80w is the power it consumes in "standby" mode, i.e. leaving it on all the time without use is like burning an 80w bulb for energy consumption.
The specs of 500w are accurate in that module for those amps, if you take notice, the power output of all the ICE amps are almost identical, 100-125w for the smaller, and 500-550w for the larger, all in 8 ohms.
They control bass very well.
They run very cool, even after heavy use, all 3 I had have done this, both the smaller and larger power amps.
They would work well for Maggies, or any other low efficiency speaker. |
It is not standby power. Smaller module 200ASC has FTC power listed as 55W (standby is about 10W). Icepower cannot run with maximum power for a long time but you don't need it because "average music power" is in single percents of peak power. Also B&O spects are very conservative - please read what I found on another forum:
"Originally posted by dmfraser
I operated a sample 1000ASP on the bench delivering 350W average of pink noise into a 4 ohm load for over one hour with no additional heatsink and the metal case stayed below 55°C.
However, higher levels would make the power supply voltage go down to act as a thermal compensation. Much nicer than just shutting down.
However, with 1214W of sine wave, partly into clipping, after about 35 seconds, the output level would drop to about 600W by the protection circuitry. Remember this is with no additional heatsink.
The 200ASC, I was able to operate with sine wave at 100W into 4 ohms continuously. Turning it up, with sine wave, the module would shut down at about 214W.
However, with pink noise at 100Waverage and a 6 db crest factor, the 200ASC would run all day without shut down, until I was tired of tying up one of my Audio Precisions with it. It would also run all day with music, driven hard where the output limiter was set to a peak limit of 210W maximum. That is, the limiter would allow small amounts of clipping. Driven so the limit light in our external optical limiter was on essentially continuously."
Icepower has even more serious limitation of maximum power at higher frequencies (to protect output chokes) but again it's not important since high frequencies in music carry very little power and the tweeter (and your ears) cannot take more than 10% of the speakers maximum power anyway. |
Koestner is right.These amps should use cooling,if under demand for larger power.My friend noticed this in specs in the datasheet ICE files (page 21 or near).
Kijanki is right,too.I believe these amps still can reproduce music with (very) big dynamic changes faithfully.Power demand only happens from time to time.
But nevertheless,it is not true 1000W/4 Ohm.It just can reach this from time to time.But more is actually not needed for music reproduction.
Does anyone know of a similar test with Hypex modules?In their datasheet it does not say for how long they can sustain rated power. |
My Channel Island D200 amps (which uses Hypex) are rated per FTC rule. Early serial numbers had a problem, noted in the Stereophile review, which limited output, but this was fixed as reported in a followup review. My Carver ZR1600 amps are Tripath based, and they are also spec'd per FTC rule. It has a fan: the CID200 does not. Neither amp gets even warm when playing loud into 4 ohm MG1.6s. |
My GCC250 runs warm in a poorly ventilated space ONLY if I hammer it as loud as it'll go for as long as I can stand.
Other than that, reasonably cool, good dynamics and response.
Since I gave up listening to sine waves and pink noise sometime in the mid/late '70s, the FTC limit is not exactly germain.
Besides, are maggies known for sheer loudness? If mine go much over 98->100db in my listening room, I'd be surprised.
If you want louder, buy a louder speaker. |
If you're using an ICEPower amp to blast 110dB sine waves continuously, then you had better cool it, but if you play music with your amp, then don't worry about it.
Dave |
Oh fuddlebud. I am running my 1 ohm speakers at .3 ohm for the time being, as a foil resistor on the right speaker is malfunctioning and I am bypassing it. My class D amps are fitted with the 250A ICE modules. The highs are to drool for. The amps are room temperature. |
Muralman1, can you please elaborate the sound from the icepower and the highs in particular?
Thank you |
Let's take cymbal crashes for instance. My system breaks the metallic splash into its separate shimmering wavelengths the same way a prism breaks white light into it's rainbow waves. Unlike other class D amps, mine has a hefty power supply that supports huge dynamic swings. |
The H2Os aren't the only Class D amps with "hefty power supply".
Dave |
Dcstep, I meant to most other class D amps.... There have been too many modules in a box amps around. |
Muralman1...My CI D200 amps have a "hefty" linear power supply, but I doubt that this sort of power supply is essential to a good power amplifier. Performance of the power supply is what matters; not how it is mechanized. Perhaps your experience with switching power supplies is limited to poorly designed ones that are sometimes used to reduce costs. A well designed regulated switching power supply does not need the huge capacitors that seem to turn you on. In fact, adding capacitance will often degrade such a power supply, as I once discovered. It turned into an oscillator!
In my field of work we need a 30 volt DC supply to power our equipment. When I began this work, decades ago, we used a slightly-modified welding supply which stood on the floor and weighed well over 100 pounds. You would have loved it! Although we later used smaller "bench" type power supplies, they were also brute force unregulated supplies because the chief engineer, although a genius in some regards, was in the dark ages about power supplies. He retired. Now we use a thoroughly modern supply which is 2-high rack mount in size. It performs better, and costs a lot less, which you, as a taxpayer, should appreciate. |
Eldartford, There is lots and lots of capacitors in the H2O. The big ones supply
clean power, and defeats ripple. The smaller ones fast fire this energy when
needed. Note that none of these caps are in the signal path.
It is a proven fact that the digital power supply ICE modules are not good for
high audio use. They are instituted in mass productions of popular electronics. |
Muralman1 - SMPS are regulated (line and load) while linear power supplies are not. They also operate at non-audible frequency that is easy to filter out while 120Hz is not. They also respond faster to load demands than linear supplies because of inductance of huge electrolytic caps (unless you use expensive slit foil caps). In fact class D is controlled SMPS. Reviewers of icepower amps like Bel Canto S300 (SMPS on board) praised behavior at max power and heavy orchestral pieces (holding coherence, imaging etc).
Size of power supply is not an indication of its quality. Small 1" Dia toroidal transformer in SMPS can cary at 100kHz as much power as huge toroidal transformer at 60Hz.
As for your statement:
"It is a proven fact that the digital power supply ICE modules are not good for
high audio use. They are instituted in mass productions of popular electronics."
- I like to mention that highly praised Jeff Rowland's Capri preamp has switching power supply. |
Muralman1. I respectfully hope you are wrong - Yesterday I bought a 5 channel icepower amp.
As history has proved many times, not always, but many times that we humans tend to be skeptical when it comes to a new... technology, as in this case.
I will not argue with anybody because this is not my field and what I know is what I read or experiencs my self, and I until then I won't comment.
But: "It is a proven fact that the digital power supply ICE modules are not good for
high audio use. They are instituted in mass productions of popular electronics."
if it is a fact, can you prove it? |
ICE module amps even 1,000 watts into 4 Ohms only get warm to the touch. My amps are on 24/7 as at idle they only draw 1/4 the power of a Light Bulb. |
I believe an ICE amp will melt about 32 degrees Fahrenheit : ) |
My Rowland Continuum 500 integrated amplifier idles around 120-degrees F. Jeff says that's due to the power factor correction not the ICEPower units.
Dave |
Muralman1 said:
"It is a proven fact that the digital power supply ICE modules are not good for
high audio use. They are instituted in mass productions of popular electronics."
Those using Rowland, Spectron, Bel Canto, etc. in high end systems would disagree that anything such thing is a "proven fact".
Dave |
Look you guys, it's like this. Class D is analog. This is true. A digital switching power supply is not. It shuts power off and on. Analog power supplies provide a constant energy source the analog module can draw from.
I think this debate relates well to Class A vs. Class AB. Sure, there are very good sounding class AB amps out there, but I believe most folks would say the class A amp sounds more natural. |
Muralman1...Your "analog" power supply also switches power on and off. On when the incomming AC voltage waveform is greater than the voltage the capacitors are at, so that the diode conducts. Off most of the time. Because this switching is at low frequency the resulting ripple requires a filter with large (expensive) capacitors and/or inductors. And a big heavy (expensive again) transformer.
An analog power supply can certainly perform very well, as I am sure is the case with your favorite amp. But it is a "brute force" approach, and hardly appropriate technology in context of a modern digital amplifier. |
I'm not looking currently, but I strongly suspect the next amp I buy for my current power hungry speakers will be Ice or Class D at least. |
Eldartford, Yes, the analog power supply acts like bagpipes in the energy is pumped in as to need. Also, this being a low frequency switching one may believe that it would be much more audible than the much quicker switching of the digital PS ICE module. Only it isn't. there is no ripple for reasons you noted. Yes, it is expensive, but put in practice, it is worth the expense.
The H20 company also has inexpensive amps using the switching power supply. they are great sounding, just not as sweet and easy as their bigger brethren. |
well, two days ago I indeed bought a class d amplifier with 5 modules, three of them are 525w.
I am really looking forward to the arrival.
With all the respect I don't buy muralman1 claims because he did not give a practical explanation of his thoughts.
I believe in evolution and time will tell me pretty soon wether it is a whorthy solution. As far as I am concerned the fact that class d amplification is greener it's already worth a try. |
Any professional reviews out there that compare the sound of a digital switching power supply to analog?
I only care about the sound and would have to be convinced before paying a premium for more expensive technology that may or may not make a difference. |
Guidocorona is a "professional" reviewer, writing for TAS. You can read his reviews of various Rowland components here on A'gon.
Of course, the best test for an individual is to listen for themselves.
Dave |
"Your "analog" power supply also switches power on and off."
"Also, this being a low frequency switching one may believe that it would be much more audible than the much quicker switching of the digital PS ICE module."
Exactly. That was the reason for Jeff Rowland to put switching power supply in Capri preamp (efficiency not needed here) and using batteries previously.
Jeff Rowland's Continuum 500 is one of the best integrated amps and it has SMPS - certainly not "mass production of popular electronics" - just look at the price tag.
I think that technical reasoning and showing examples won't make any difference. H2O owned by Muralman1 has linear power supply and he believes that's the only solution. If his H20 would use switching power supply he would claim just the opposite. It is not a criticism - just observation. |
Vince's (Muralman) mantra i.e. H2O, non-oversampling cd, home made speaker cables, and Apogee Scintilla is the same today as it was 2 years ago.
Leave him be. |
Audiofeil, I have new speakers and a new DAC in the mix now. Things never stay the same in my system. They just get better. |
Well congratulations on the change Vince.
It must have been difficult to improve on the Scintilla. I owned both Calipers and Duetta Signatures; both are very very fine speakers.
Bill |
Kijanki, thanks for repeating my quote out of context. The 250A ICE module is getting clean power, and lots of it. There is no switching noise. |
Muralman1 - I don't know what context was that. You stated that digital power supply ICE modules are instituted in mass production of popular electronics - could you provide us with example of popular mass produced electronics with ICE module in it? (I don't know of any). The smallest ICEpower I know with built in switching power supply 200ASC has great reviews in products such as Rowland model 102, Bel Canto S300, M300 etc. I also mentioned before that great sounding Jeff Rowland Continuum 500 has switching power supplies as well as Capri preamp. Reading your post one would thing that serious electronics has linear power supplies and mass production has switchers because they, as you stated, "are not suitable for audio". How do you know that? Do you know something that Jeff Rowland doesn't? Could you clarify what was the context of your statement - maybe I'm missing something. |
Kijanki...Don't kick him when he's down!! |
ü Bang & Olufsen ICEpower a/s doubled its turnover from DKK 50 to DKK
100 million while the result improved by DKK 28 million from DKK 2 mil-
lion during the 2004/05 financial year to DKK 30 million in 2005/06.
There are so many class D auto amps out there I don't care to track down what is inside them.
Here is one that admits it uses ICE.
http://www.caraudiomag.com/0607_cae_alpine_pdx_4150_amplifier/index.html |
I'm not down, Eldartford. Not by a long shot. :) |
Audiofeil,
My new speakers are True Sound Works Apogee Scintillas with precision panels, and new specially engineered ribbons giving the Scintilla greater presence.
My new DAC is an Audio Note 2.1 highly enhanced by Henry HO, of H2O, so that it doesn't resemble stock Audio Note DACs. |
Muralman1 - I don't recognize this module. It is probably made by B&O for car market and not the home audio. In addition it is in application that always uses switching power supplies - no linear to compare with.
Yes you'll find switchers in every piece of modern mass market electronics but you'll also find linear supplies there. Should I conclude that linear supplies are not suitable for audio? It is important to understand that class D amp including your H2O is switching mode power supply with varying reference voltage. Do you really thing that B&O would put mass market power supply "not suitable for audio" in their best amps or you believe that good SMPS cannot be designed for audio? Again your H2O is switching power supply.
Switching power supplies have improved over the years as much as class D amps (because it's the same thing). They operate at zero-voltage, zero-current switching with very little noise that is non audible and easy to filter out. Many manufacturers are still sticking to old fashion "no brain needed to design" linear power supply probably believing that switchers are worse but it is really funny that they produce class D amps.
Jeff Rowland switched all his production to class D with switching power supplies. He even uses switchers in preamps and he released only great products in over 20 years. Maybe your audio experience or expectations are higher than mine but if it's good enough for Jeff Rowland is good enough for me. |
Kijanki, If it were so funny for amp builders to use analog power supplies. You sure got that backwards. There is nothing that switches in an analog power supply. Nothing. It does not switch. It is like I said. The big caps hold a whole lot of reserve, and the small caps are there to fast feed the module.
B&O makes the A series modules so that talented builders can put their knowledge into improving the product. |
Muralman1 - I said it's funny because they think power supply should not switch but the amp itself should - and both of them are the same thing.
On the other hand I don't think they are THAT stupid and have some purpose in mind. The obvious one is that a lot of buyers, like you, still believes in linear power supplies.
If you can come up with any technical reason against using switching power supplies in audio - please let me know. |
Here's one. The digital power supply is noisy. My amp builder makes amps of
both modules. The newest module has cut distortion and noise by half. They
gave this module a different designation. There is a built in noise and distortion
filter in the module. It has to be there.
The analog power supply is just that. It operates just like class A in that it
contains all power that the module needs under any load and any loudness. It is
not an amp.
The ICE amp is analog, and not digital. Read their white papers. |
Muralman - I don't know how many times I have to repeat that - CLASS D IS SWITCHING POWER SUPPLY. Switching itself does not make class D or SMPS digital. Both of them are exactly the same thing.
There is very little noise in properly designed SMPS (my Rowland 102 has 110dB S/N).
Noise is at non audible frequency
This frequency is easy to filter out (that's why Rowland uses it in preamps instead of linear
AS for linear power supply - it is not class A. Class A is an active regulated supply while linear PS in neither active nor regulated (line and load). It produces 120Hz ripple in-spite of huge number of capacitors. There are good and bad realization of each technology but the fact is that linear one is unregulated. |
Kijanki, B&O would find your notion the modulation process is the same as the switching power supply unit insulting, or more likely, hilarious.
Henry Ho, an advanced electronics engineer is quite capable of creating a power supply that has no measurable ripple or other distortions. The 250A module is built to accept any power supply. My sound is proof enough.
By the way, take a look at the graphs provided by B&O. They show a distinct advantage of the A250 over the ASP250. |
B&O developed ICEPower technology with much research and help from their government. B&O uses the units in their mass market systems and also sells them to the likes of Rowland, Spectron, Bel Canto, etc. Some people just stick them into folded metal boxes, but those mentioned add proprietery improvements to integrate them into their own designs.
Yes, switching and digital are two different things. Too bad they didn't call it Class E instead. I think that the "D" confuses lots of people, even though it holds no significance other than being the next letter in the alphabet after A, B and C.
Dave |
Muralman1 - yes it is pretty much the same. I have no idea why you call switching power supplies digital and amplifier analog. Both of them are analog (no discrete values) and both operate with PWM and feedbacks. Modulation process might be different but purpose of power supply is different - input value is constant and feedback keeps output constant. The issue that you raised was noise. Since both operate at the same principle (pulse width modulation) and the same power - noise product of both is the same and very easy to filter out.
Icepower doesn't even bother to filter amplifier's switching noise completely and leaves about 1% on speaker wires. This noise is not audible and can modulate the sound only on non-linear element. Tweeter is potentially one but only if membrane moves (it cannot at such high frequencies). It cannot radiate because it needs hundreds of feet of wire to create 1/4 wave antenna.
There is quite few amps built with 1000ASP module that includes built in SMPS (40 Amperes) and very good reviews.
Let me repeat again - SMPS are regulated (line and load) and can deliver a lot of current - each of 1000ASP modules have its own 40A SMPS.
B&O guys are audio freaks and would never design substandard SMPS to their Icepower modules. I would be happy to discuss it with them if they would find my statements "insulting" or "hilarious". I design electronics (including SMPS) and am familiar with Karsten Nielsen doctorate work.
As for Henry Ho - he might get very low ripple by using a lot of capacitors but you're paying for that and power supply is still completely unregulated same way it was designed more than 50 years ago. Class D was invented during demonstration of response of SMPS. Engineers claimed that SMPS was so fast that it could even play music. Since then SMPS got highly specialized as well as class D. Requirements are different since SMPS is unidirectional and holds constant output voltage but they both got quite sophisticated with a lot of high quality ICs released in recent years. |
Just for the record. Current generation of Spectron amplifiers do not use switching power supplies. I will not go into reasons, sorry. |
Kijanki, thanks for the calm and reasoned response. As much as we want to believe the very talented engineers at B&O made the digital power supply to perfect the sound of their modules, the fact is they did it to shrink the package. There is no doubt the small size of their amps is their strongest selling point. These modules are finding their way into everything from phones to audio gear. Like their business report says, they sold more than a 100 million units last year. Audio amps account for just a tiny fraction of those sales.
Dcstep is entirely right. If you look into your Rowland, you will not see just a module in a box. There is other circuitry there to attenuate the sound to their liking. Same goes for the H2O.
Spectron says they don't use switching power supplies either. He won't say why, but I bet it isn't for conveniences sakes, or some easy way out. |
Ah yes. Then there are batteries. Arguments, anyone? |
Muralman1 - I still don't understand why you keep calling switching power supplies "digital". As for them being suitable only for mass market and not for the audio (your original statement) your Henry Ho (H2O) released two amps with Icepower modules with built-in switching power supplies M250S and M500S. Alleluja!!!
The only other circuitry in my Rowland Icepower amp is tiny input board with differential amp THAT1200. If there are any modds to original Icepower they are probably done at factory level (modds void B&O warranty) and reflect desired "house sound".
Eldartford - Rowland was widely using batteries in preamps and wrote a lot of FAQ about it. Now he switched to SMPS (Capri). If there is any switching noise it would not be able to hide well since Capri's bandwidth is 350kHz. |
Henry Ho has had ASP amps out for years now. They are a cheap offering for people who want the class D sound but can't afford the flagship.
His Fire preamp, a HOT class A design, is pristinely clear and dynamic. I know if Henry thought using an ASP module to create a preamp a good idea, then he would not have gone to the trouble designing a preamp from the ground up. |
