I like the look of this....
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DIB said:
If I'm right, with Class G topology and a £1k price tag, it is (as Vlad so eloquently put above), worth slobbering over.
plastic penguin
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I've loved the look of Creek stuff since I had the Evo2 amp on home dem. They are stylish without that 'look at me' glossy s### you get with some makes -- I can imagine that'll sound cracking with PMC TB2is.
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jonathanRD
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one of the suggested speaker pairings is the new Epos K2, but it will be interesting to see/hear what the active version of the K2 is like *unknw*
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jonathanRD said:
It is well reported that the Epos K2's will eventually come as active speakers with Creek amplification modules. Could be a very nice sounding combo if they 'float your boat'.
The look of the new amp does appear decidedly 'Naimish' as pointed out previously but I like it and, depending on pricing, it will hopefully sell very well for them.
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What has caught my attention is that the although the 100A boasts double the power than the 50A, its power supply is only a bit bigger—300W vs 250W.
Maybe they found out that the 50A was over specified?
Maybe they found out that the 50A was over specified?
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unsleepable said:
In a test the 50A had indeed good current supply and was only marginally less (or equally, I can't exactly remember but could dig it out) than either the 5350 or Destiny. Power was however not much higher than quoted.
A 300W transformer does seem on the limit of the minimum for a quoted 100w/channel 8ohm rating though.
As far as I know, Creek tend to meet (if not exceed widely) their specifications in tests.
regards
drummerman said:
Comparing with other similarly-specified amps, a 300W power supply (500W max power consumption) does indeed look very small.
For example, the new Arcam A39 is also class G and being a 120W per channel amplifier (just 20% more) it has a max power consumption of 1kW (double).
An amp can push, let's say, 500Wpc at 10% Total Harmonic Distortion, but the manufacturer will only rate it at 100Wpc at 0.1% THD. This is because 1% THD and more is considered clipping (amplifier voltage rails sagging).
500W or 1kW maximum power consumption does not mean its going to burn constantly all that power, like a Class A amp would do. These are Class G. The Creek has maximum of 500W total power consumption specified, which means at its absolute best, with high THD, it will give large short bursts, sucking in 250W per channel. The Arcam A39 claims 1kW, meaning it can burst as much as 500Wpc at high THD. Subwoofers run with very high THD all the time and human hearing is not very discernable and they can get away with it. So these excess distorted watts are not wasted.
Now how can a 300W transfomer have 1kW consumption? Simply, it can't. Not even for short bursts. But the power caps will provide this stashed energy and recharge and deliver again when needed next. Remember, music is not linear power user, it depends on gain, frequency and duration. Most of the time there is not much low bass at very high gain, lasting longer than few seconds. The transformer's job is to keep the caps charged and if the music is asking more than the PSU can keep up, yep, clipping time. Voltage rails will sag.
So how do they compensate for this serious situations? This is where Class G saves the day. Amplifier with Class A topology will burn 25-50% of all its power in heat. Class AB, 50-75%, Class D 80-90% and Class G is somewhere between AB and D. So Class G is very efficient, it wont waste 50% of the PSU potential into heat. This is why they can forget the old rule for Class AB amps where the transformer needs to be 2.5 times larger than the rated power output and Class A 5 times, even 7 times larger.
Basically due to their efficiency, these Class G amplifiers will manage to charge their caps sufficiently fast from a small power transformer without any occurances of clipping at rated output.
What I don't understand is how it sucks 500W or 1kW from the socket. Any technical minds care to help and explain?
500W or 1kW maximum power consumption does not mean its going to burn constantly all that power, like a Class A amp would do. These are Class G. The Creek has maximum of 500W total power consumption specified, which means at its absolute best, with high THD, it will give large short bursts, sucking in 250W per channel. The Arcam A39 claims 1kW, meaning it can burst as much as 500Wpc at high THD. Subwoofers run with very high THD all the time and human hearing is not very discernable and they can get away with it. So these excess distorted watts are not wasted.
Now how can a 300W transfomer have 1kW consumption? Simply, it can't. Not even for short bursts. But the power caps will provide this stashed energy and recharge and deliver again when needed next. Remember, music is not linear power user, it depends on gain, frequency and duration. Most of the time there is not much low bass at very high gain, lasting longer than few seconds. The transformer's job is to keep the caps charged and if the music is asking more than the PSU can keep up, yep, clipping time. Voltage rails will sag.
So how do they compensate for this serious situations? This is where Class G saves the day. Amplifier with Class A topology will burn 25-50% of all its power in heat. Class AB, 50-75%, Class D 80-90% and Class G is somewhere between AB and D. So Class G is very efficient, it wont waste 50% of the PSU potential into heat. This is why they can forget the old rule for Class AB amps where the transformer needs to be 2.5 times larger than the rated power output and Class A 5 times, even 7 times larger.
Basically due to their efficiency, these Class G amplifiers will manage to charge their caps sufficiently fast from a small power transformer without any occurances of clipping at rated output.
What I don't understand is how it sucks 500W or 1kW from the socket. Any technical minds care to help and explain?
There are other issues too, some power supplies are far more efficient than others, look what a M-CR610 squeezes out of a 50VA supply for example.
Point of order though, short burst capability is almost entirely a function of the capacitor size rather than the power being drawn from the mains. Massive peaks can be produced providing the psu has time to recover and 'refill' the capacitors.
If the peaks come too often and the psu can not fill the caps up quickly enough the maximum voltage (rail voltage) drops, this is power supply 'sag'. Just to be clear, the 'sag' will cause the amplifier to clip early, well below it's rated power.
Judging the right transformer rating and balancing that with the correct amount of capacitor 'storage' is part of the designers art, it can be done in diferent ways but it is essential it is done right.
Power supply capabilities are a very useful guide to the power and performance of the amplifier, but there is a little more to it than seems obvious.
Point of order though, short burst capability is almost entirely a function of the capacitor size rather than the power being drawn from the mains. Massive peaks can be produced providing the psu has time to recover and 'refill' the capacitors.
If the peaks come too often and the psu can not fill the caps up quickly enough the maximum voltage (rail voltage) drops, this is power supply 'sag'. Just to be clear, the 'sag' will cause the amplifier to clip early, well below it's rated power.
Judging the right transformer rating and balancing that with the correct amount of capacitor 'storage' is part of the designers art, it can be done in diferent ways but it is essential it is done right.
Power supply capabilities are a very useful guide to the power and performance of the amplifier, but there is a little more to it than seems obvious.
A description of Class G:
"It's an operating mode that employs tiered devices in the output stage, operating at different voltage levels, and is thereby much more efficient, producing much less heat on typical dynamic program. This saves on heat generation, for a given power output capability, and thus gives the design engineer an extra heat budget that he can choose to spend in various other ways, for a given chassis package having a given heat dissipation capability.
How does this class G work, and why is it more efficient? In a conventional power amplifier, say the ubiquitous class AB type, there is only one voltage rails for the power output stage. This rails voltage represents the absolute maximum that the power amplifier can output (and, incidentally, some internal circuit losses reduce this a bit). The output devices in the power output stage act merely as gates or valves, letting out some portion of this rails voltage to your loudspeakers, this portion depending on the varying instantaneous signal level (which in turn depends on the varying program and of course on your volume control setting). So some portion of the rails voltage is let out by the output stage gate/valve to your loudspeakers - but what happens to the rest of the rails voltage that is not let out? Simply speaking, that remainder must be dissipated internally by the amplifier's output stage, dissipated as heat.
Now, with typical dynamic program (music, film soundtrack, etc.), the instantaneous program signal level is far below its maximum peak output for most of the time, and thus is also far below the power amplifier's maximum peak voltage output for most of the time. This means that, for the majority of the program's varying amplitudes, and for the majority of the time, only a tiny fraction of the rails voltage is let through the output stage gate to your loudspeakers, and the remaining large fraction of the high rails voltage causes pressure on the output stage gate, forcing this gate to expend energy (and dissipate the resulting heat) holding back the high voltage/pressure from these high voltage rails in this output stage.
To understand this better intuitively, consider as an analogy that exit tube at the base of Hoover dam, which can shoot a stream of water for hundreds of feet. Consider the gate valve that closes or opens this exit tube to varying degree. There's tremendous water pressure on this gate valve, precisely because the Hoover dam is so high, just like the rails voltage being high on a power output stage. Now imagine that you had to do the work of holding that gate valve partially open, to varying degrees, say by holding your 'very large' hand palm over part of the exit tube, thus holding back some portion of that tremendous water pressure.
If you held your large hand over most of that exit tube, letting out only a small stream of water (like letting out only a small signal to the loudspeaker), you'd still have to fight to hold back most of that tremendous pressure in the exit tube, coming from the high dam above (like the high voltage rails) - and fighting to hold back water against this pressure would be hard work, causing you to burn calories and sweat (to dissipate the excessive heat generated in your body by this hard work). Conversely, if you moved your hand palm off to the side, so as to let most of the water flow freely out of the exit tube (like letting a large signal out to your loudspeakers), you'd then scarcely feel any pressure on your palm at all, since all the pent up pressure from the dam above would be going into pushing huge amounts of water out the exit tube (driving your loudspeakers), and you'd scarcely have to do any work, so you wouldn't get hot nor have to break a sweat to dissipate heat.
This example is analogous to the typical power output stage operating with the typical single, high voltage rails. When the signal amplitude output to your loudspeakers is small, compared with the amplifier's maximum output amplitude capability, then the output stage gate valve has to do a lot of work, to 'hold back' that tremendous pressure/voltage from the single high voltage rails, to keep it from being output to your loudspeaker, and all this work generates heat that then must be dissipated. It probably seems counterintuitive to think that a power amplifier would have to work hard, in order to merely push out a small signal into your loudspeakers. But this dam analogy helps us to view the situation differently, as instead pertaining to holding back most of the high pressure/voltage from a high dam or a high rails voltage, and to the work that must be done, and consequent heat that is wastefully generated, even when only a small signal is output.
Everyone wants power amplifiers to have lots of rated power output capability (indeed, this numbers game is overvalued as a selling point). But, to get a higher maximum rated power output capability, one needs to raise the rails voltage, and that increases the pressure on the output stage gate valve by making the dam higher, which in turn makes the output stage work harder to hold back this higher voltage/pressure and keep it from getting out to your loudspeakers, and this harder work creates more wasteful heat to be dissipated, which then forces the chassis heat dissipation package to be made larger and thus more expensive.
In any given amplifier chassis package, there are limits on how much heat can be dissipated (long term), hence limits on how much heat can be generated by the circuit, therefore limits on how high a rails voltage can be allowed. When making an expensive monoblock power amplifier, the design engineer can always make the single channel chassis a little bigger and a little more expensive, in order to be able to raise the rails voltage and thus claim a higher spec for that vaunted maximum power output capability. But in a multichannel power amplifier, and certainly within the modest size constraints of a multichannel receiver, the chassis package's modest heat dissipation capability cannot be substantially increased, so there is a severe limit on the allowable maximum for rails voltage - at least with the conventional configuration, where the output stage works off a single high rails voltage.
Enter the class G output stage configuration. The basic concept of class G is quite simple. Class G simply has more than one voltage rail, and the plural rails are set at different voltages. The output stage uses only the lowest voltage rails when outputting small signals to your loudspeakers, and then changes to use higher voltage rails only when the instantaneous signal level rises enough to warrant this change. To return to our analogy, that's like having two dams as water sources. When you only need to output a small stream of water, you use a farmer's shallow pond with a small dam, so it's very little work for you to hold back and control the small water pressure (like small rails voltage) coming from a hole at this dam's bottom, and you don't work up much of a sweat doing this easy work (you don't generate a lot of heat that needs to be dissipated). Then, only once in a while, you need to output a big burst of water, but only for a brief time. So you quickly switch to using Hoover dam as your water source, and you can then output that large but brief peak burst of water.
Admittedly, during your use of Hoover dam, you are working very hard holding back and controlling the much higher pressure/voltage, so you are temporarily generating heat at a very high rate. But, and this is the crucial but, if the need for these large bursts only occurs a small fraction of overall time, and if each large burst is brief in duration, then your overall average work output over the moderate to long term will be low, and thus generation of heat that needs to be dissipated will be low. In point of fact, virtually all program we listen to, via audio power amplifiers, does have this blessed characteristic, of having an average level much lower than the peak level, and of having the peaks occur only occasionally, and of having peaks that are each brief in duration. Thus, on average, the work you do or a power output stage does, and the heat you or the power output stage generates and must dissipate, is not much more than it would be if you were using the small pond with the small dam all the time.
When the output stage outputs a signal whose level at that moment is low, then the output stage only has to act as a gate valve for the lowest voltage rails, so it only has to do the work of holding back this lower voltage/pressure, which is far easier work than having to hold back the high voltage/pressure from a high rails voltage, so far less heat is generated.
Again, this heat efficiency advantage for class G depends on the fact that virtually all the program we listen to does indeed have an output level that stays below the lower rails voltage most of the time, hence also has an average output level below this point, with only occasional peaks that are brief in duration (thus, any given single peak does not last long enough, and any series of peaks is not temporally dense enough, to severely impact the chassis' heat dissipation package, which functions over the long term).
Incidentally, class G can be made even more efficient, with even less heat generation, by simply making the voltage lower on the low voltage rails, i.e. a smaller fraction (say one fourth rather than half) of the voltage on the high voltage rails. This works so long as the lower rails voltage is above the average program level - which is easy to accomplish, since the average level of most program material is merely 1/10 the peak level or even less.
Thanks to class G's heat efficiency, the designer suddenly has a substantial heat budget surplus to play with (which was previously needed to support a given conventional class AB power amplifier having single rails voltage, but now with class G no longer needs to be accommodated as a constraint). The designer can make use of this gift, this new heat budget bonus, in many ways. He could make his product package smaller and less expensive. He could increase its rated maximum output power capability. He could accomplish some other sonically beneficial design moves. Or he could engineer a customized mixture or blend of these various benefits."
"It's an operating mode that employs tiered devices in the output stage, operating at different voltage levels, and is thereby much more efficient, producing much less heat on typical dynamic program. This saves on heat generation, for a given power output capability, and thus gives the design engineer an extra heat budget that he can choose to spend in various other ways, for a given chassis package having a given heat dissipation capability.
How does this class G work, and why is it more efficient? In a conventional power amplifier, say the ubiquitous class AB type, there is only one voltage rails for the power output stage. This rails voltage represents the absolute maximum that the power amplifier can output (and, incidentally, some internal circuit losses reduce this a bit). The output devices in the power output stage act merely as gates or valves, letting out some portion of this rails voltage to your loudspeakers, this portion depending on the varying instantaneous signal level (which in turn depends on the varying program and of course on your volume control setting). So some portion of the rails voltage is let out by the output stage gate/valve to your loudspeakers - but what happens to the rest of the rails voltage that is not let out? Simply speaking, that remainder must be dissipated internally by the amplifier's output stage, dissipated as heat.
Now, with typical dynamic program (music, film soundtrack, etc.), the instantaneous program signal level is far below its maximum peak output for most of the time, and thus is also far below the power amplifier's maximum peak voltage output for most of the time. This means that, for the majority of the program's varying amplitudes, and for the majority of the time, only a tiny fraction of the rails voltage is let through the output stage gate to your loudspeakers, and the remaining large fraction of the high rails voltage causes pressure on the output stage gate, forcing this gate to expend energy (and dissipate the resulting heat) holding back the high voltage/pressure from these high voltage rails in this output stage.
To understand this better intuitively, consider as an analogy that exit tube at the base of Hoover dam, which can shoot a stream of water for hundreds of feet. Consider the gate valve that closes or opens this exit tube to varying degree. There's tremendous water pressure on this gate valve, precisely because the Hoover dam is so high, just like the rails voltage being high on a power output stage. Now imagine that you had to do the work of holding that gate valve partially open, to varying degrees, say by holding your 'very large' hand palm over part of the exit tube, thus holding back some portion of that tremendous water pressure.
If you held your large hand over most of that exit tube, letting out only a small stream of water (like letting out only a small signal to the loudspeaker), you'd still have to fight to hold back most of that tremendous pressure in the exit tube, coming from the high dam above (like the high voltage rails) - and fighting to hold back water against this pressure would be hard work, causing you to burn calories and sweat (to dissipate the excessive heat generated in your body by this hard work). Conversely, if you moved your hand palm off to the side, so as to let most of the water flow freely out of the exit tube (like letting a large signal out to your loudspeakers), you'd then scarcely feel any pressure on your palm at all, since all the pent up pressure from the dam above would be going into pushing huge amounts of water out the exit tube (driving your loudspeakers), and you'd scarcely have to do any work, so you wouldn't get hot nor have to break a sweat to dissipate heat.
This example is analogous to the typical power output stage operating with the typical single, high voltage rails. When the signal amplitude output to your loudspeakers is small, compared with the amplifier's maximum output amplitude capability, then the output stage gate valve has to do a lot of work, to 'hold back' that tremendous pressure/voltage from the single high voltage rails, to keep it from being output to your loudspeaker, and all this work generates heat that then must be dissipated. It probably seems counterintuitive to think that a power amplifier would have to work hard, in order to merely push out a small signal into your loudspeakers. But this dam analogy helps us to view the situation differently, as instead pertaining to holding back most of the high pressure/voltage from a high dam or a high rails voltage, and to the work that must be done, and consequent heat that is wastefully generated, even when only a small signal is output.
Everyone wants power amplifiers to have lots of rated power output capability (indeed, this numbers game is overvalued as a selling point). But, to get a higher maximum rated power output capability, one needs to raise the rails voltage, and that increases the pressure on the output stage gate valve by making the dam higher, which in turn makes the output stage work harder to hold back this higher voltage/pressure and keep it from getting out to your loudspeakers, and this harder work creates more wasteful heat to be dissipated, which then forces the chassis heat dissipation package to be made larger and thus more expensive.
In any given amplifier chassis package, there are limits on how much heat can be dissipated (long term), hence limits on how much heat can be generated by the circuit, therefore limits on how high a rails voltage can be allowed. When making an expensive monoblock power amplifier, the design engineer can always make the single channel chassis a little bigger and a little more expensive, in order to be able to raise the rails voltage and thus claim a higher spec for that vaunted maximum power output capability. But in a multichannel power amplifier, and certainly within the modest size constraints of a multichannel receiver, the chassis package's modest heat dissipation capability cannot be substantially increased, so there is a severe limit on the allowable maximum for rails voltage - at least with the conventional configuration, where the output stage works off a single high rails voltage.
Enter the class G output stage configuration. The basic concept of class G is quite simple. Class G simply has more than one voltage rail, and the plural rails are set at different voltages. The output stage uses only the lowest voltage rails when outputting small signals to your loudspeakers, and then changes to use higher voltage rails only when the instantaneous signal level rises enough to warrant this change. To return to our analogy, that's like having two dams as water sources. When you only need to output a small stream of water, you use a farmer's shallow pond with a small dam, so it's very little work for you to hold back and control the small water pressure (like small rails voltage) coming from a hole at this dam's bottom, and you don't work up much of a sweat doing this easy work (you don't generate a lot of heat that needs to be dissipated). Then, only once in a while, you need to output a big burst of water, but only for a brief time. So you quickly switch to using Hoover dam as your water source, and you can then output that large but brief peak burst of water.
Admittedly, during your use of Hoover dam, you are working very hard holding back and controlling the much higher pressure/voltage, so you are temporarily generating heat at a very high rate. But, and this is the crucial but, if the need for these large bursts only occurs a small fraction of overall time, and if each large burst is brief in duration, then your overall average work output over the moderate to long term will be low, and thus generation of heat that needs to be dissipated will be low. In point of fact, virtually all program we listen to, via audio power amplifiers, does have this blessed characteristic, of having an average level much lower than the peak level, and of having the peaks occur only occasionally, and of having peaks that are each brief in duration. Thus, on average, the work you do or a power output stage does, and the heat you or the power output stage generates and must dissipate, is not much more than it would be if you were using the small pond with the small dam all the time.
When the output stage outputs a signal whose level at that moment is low, then the output stage only has to act as a gate valve for the lowest voltage rails, so it only has to do the work of holding back this lower voltage/pressure, which is far easier work than having to hold back the high voltage/pressure from a high rails voltage, so far less heat is generated.
Again, this heat efficiency advantage for class G depends on the fact that virtually all the program we listen to does indeed have an output level that stays below the lower rails voltage most of the time, hence also has an average output level below this point, with only occasional peaks that are brief in duration (thus, any given single peak does not last long enough, and any series of peaks is not temporally dense enough, to severely impact the chassis' heat dissipation package, which functions over the long term).
Incidentally, class G can be made even more efficient, with even less heat generation, by simply making the voltage lower on the low voltage rails, i.e. a smaller fraction (say one fourth rather than half) of the voltage on the high voltage rails. This works so long as the lower rails voltage is above the average program level - which is easy to accomplish, since the average level of most program material is merely 1/10 the peak level or even less.
Thanks to class G's heat efficiency, the designer suddenly has a substantial heat budget surplus to play with (which was previously needed to support a given conventional class AB power amplifier having single rails voltage, but now with class G no longer needs to be accommodated as a constraint). The designer can make use of this gift, this new heat budget bonus, in many ways. He could make his product package smaller and less expensive. He could increase its rated maximum output power capability. He could accomplish some other sonically beneficial design moves. Or he could engineer a customized mixture or blend of these various benefits."
Class G... boring geek-on-a-budget stuff.
What I plan to do when I get rich (anytime now) is to get one of these Lumenaus Solar Power Systems as a solar power supply, and one of these Pure Class A Boulder Amps, and run 11.1 channel theater room with these Vivid Audio G1 Giya's.
I reckon a 96kWh off-grid system will do the job for 11.1 channel Class A. *scratch_one-s_head*
I was considering wind turbines and generators, but those are noisy. The sun is as quiet as it gets. Might possibly need to move to Australia, otherwise on cloudy days in Europe the voltage rails may sag.
That's the plan. Anyways. Carry on.
What I plan to do when I get rich (anytime now) is to get one of these Lumenaus Solar Power Systems as a solar power supply, and one of these Pure Class A Boulder Amps, and run 11.1 channel theater room with these Vivid Audio G1 Giya's.
I reckon a 96kWh off-grid system will do the job for 11.1 channel Class A. *scratch_one-s_head*
I was considering wind turbines and generators, but those are noisy. The sun is as quiet as it gets. Might possibly need to move to Australia, otherwise on cloudy days in Europe the voltage rails may sag.
That's the plan. Anyways. Carry on.
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