DonR
Major Contributor
Have to feed the myths somehow.
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Let's stop calling Class D amplifiers "efficient" when they are not.
- Thread starter restorer-john
- Start date
I wonder if those "electrons" are sujejct to the "observer effect" somehow.. Maybe if one don't stare at the watt meter, they calm down a little. But it really hard to observe- such is physics. LOL
D
Deleted member 48726
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Its the „Real man Amp“ argument. Works at any age !
lmao
Hey there.
So i happen to have my first contact with a class d amp. I ordered a Tangent Powerampster II.
Unfortunately my main speakers one woofer died on me after i ordered so now that it arrived i can`t test it with my good speakers to make an informed decision
about sound quality. I only have some „secondary“ Canton Plus Gxl speakers which i have as a reserve for parties etc.
So the Tangent draws around 0,5w in Standby mode , a shy bit under 5 w when its On and idling
and with music playing it is moving between 8.5-10 w from medium to relatively
„too loud for long term comfort“ levels. I just directly connected an ipad for a quick test so it can go a lot louder with a pre amp but even
with the ipad it could go pretty loud with these speakers and i love my hearing
However i am going to send it back as i cant decide how it sounds like with these speakers and don`t know how many weeks my woofer repair will take.
Hope it get`s measured and featured by Amir here at some point but for now i cant wait.
Today my Audiophonics Nc 250 stereo power amp arrived .
I measured it cause your thread made me curious.
Standby: 0.8w
Iddling: 15-isch watts
Music listening at a relatively uncomfortably loud level for long listening but not „deafening“ loud using speakers with 88db sensitivity , consumption moves anything between 15,5 to 18 watts
i had to raise the volume a lot to get consumption higher than 16 watts tbh,
My mosfet power amp rated at 150w at 8 and 225 at 4 ohm consumption is 30+ watt idling.
Did not measure with music cause i have no speakers at the place where my amp is stored.
D
Deleted member 48726
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Your power consumption measurements are not saying anything useful. Only your standby and idling measurements can be compared. For knowing your power consumption while playing music you want to measure with equipment either capable of capturing peaks or measure kWh over a longer period whilst playing music at the level you want to measure at.
Not useful for you you mean. I find it very exciting for my self. Not trying to impress anyone.
i know my measurements are not reference level quality but to me knowing that if i simply leave
amplifier A On for extended periods of time as some times happens, it will consume 15 watts which is half the energy of amplifier B is very useful to know tbh.
I could install 3 extra 5 watt lightbulbs with that energy
On the measuring „peaks“ i cant do this but my device measures KWh. So if i listen it stores how much Electricity went through it.
I also realized how loud a sensitive speaker can go with 2-3 watts. I knew this in theory but its much more exciting to see it in numbers
and hear what 3 watts are.
I would be more than interested to see your measurements. The post asked for us to measure our amps. I did this to the best of my ability and with the means i have
at my disposal.
D
Deleted member 48726
Guest
No. Not useful for measuring power when in use. But useful for measuring standby and idling consumption. That's fine. Just wanted to clarify that the method isn't good enough for measuring when the amp is in use. So when you say things like you know how loud it is with 3 W measured (above idle) it might not reflect how much power is actually used nor how much is going to the speakers.
I hear you. Yeah I don’t completely trust my measuring thingy. It is a simple consumer measuring thing where you can measure you know your refrigerator, etc. consumption it’s not our precision tool or anything special. Was fun. I have started measuring everything in my home. I am getting addicted.
D
Deleted member 48726
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True. I remember when I first got a socket power meter. -Revealed a lot. That was also way before LED lights and flat screen TV's so it actually made a difference and was indeed an eye opener.
This where I am Stil living I feel sometimes. Before led lights. But the best was before my first mobile phone. Though I must admit this little new amps have impressed me a little bit. Today just sold my pre-and power amplifier that I owned for almost 30 years and had it in my closet for five years now hahaha. This Attachment to devices sometimes is utterly ridiculous when I think about it
I missed this thread when it first appeared.
1. I just bought a 3-ton arbor press. In the crate, it weighed 127 pounds. I could not lift it off the ground without serious risk, so I didn't. I told my wife that carrying her over the threshold was a ship that has sailed. So, I'm probably not a customer for a conventional amplifier in the 500-wpc range, at least if it comes with an audiophile-approved transformer.
2. There is a difference between efficiency and thermal management, yet that distinction was conflated by the OP, who should know better. I discount the notion that he was trolling for effect, simply because he never admitted to it.
3. I turn my amps off when not in use. I don't stack stuff around it, and I don't block the case vents.
4. My B&K amps are rated at 125 wpc into 8 ohms, and are conventional A/B amps with linear power supplies. They run in class A at low power, which is why they are A/B amps, to address crossover distortion. Idle power draw is 60 watts. It takes two of those amps to reach the power capability of my NC502MP amp, which is rated at (at least) twice the power output if comparing similar distortion level. That amp draws 23 watts at idle.
5. Vintage A/B amps die frequently enough for a variety of reasons, but they end up taking copious amounts of space in the landfill and so we forget about them. Nobody brags about their longevity, because they are now out of sight. I've owned six A/B power amplifiers. Two of them have failed, one spectacularly, and neither from abuse. I tried to keep one going and managed a repair a couple of times. The notion that they are repairable is sort-of like saying airplanes are repairable. Sure they are, but they are only worth repairing because replacements are so expensive. Nearly anything can be repaired if one is willing to spend more on the repair than the item is worth on the market. That is a separate calculus than the societal value of repairing things rather than disposing of them. (Sidebar: It would take probably half a dozen of my Buckeye amps to fill up as much landfill as one of the B&K's, even if crushed or ground up.)
6. Suggesting strategies for improving existing devices with poor heat management would be less...incendiary. I used this purpose-designed supplemental cooling fan when I was running two B&K amps in the same system:
Should we be identifying how something like these might be used for any amp that has thermal management that needs improving? One advantage to a cheap-but-cheerful sheet-metal case is that modifying it causes no real heartburn, at least after the warranty is up.
Rick "preferring solutions" Denney
1. I just bought a 3-ton arbor press. In the crate, it weighed 127 pounds. I could not lift it off the ground without serious risk, so I didn't. I told my wife that carrying her over the threshold was a ship that has sailed. So, I'm probably not a customer for a conventional amplifier in the 500-wpc range, at least if it comes with an audiophile-approved transformer.
2. There is a difference between efficiency and thermal management, yet that distinction was conflated by the OP, who should know better. I discount the notion that he was trolling for effect, simply because he never admitted to it.
3. I turn my amps off when not in use. I don't stack stuff around it, and I don't block the case vents.
4. My B&K amps are rated at 125 wpc into 8 ohms, and are conventional A/B amps with linear power supplies. They run in class A at low power, which is why they are A/B amps, to address crossover distortion. Idle power draw is 60 watts. It takes two of those amps to reach the power capability of my NC502MP amp, which is rated at (at least) twice the power output if comparing similar distortion level. That amp draws 23 watts at idle.
5. Vintage A/B amps die frequently enough for a variety of reasons, but they end up taking copious amounts of space in the landfill and so we forget about them. Nobody brags about their longevity, because they are now out of sight. I've owned six A/B power amplifiers. Two of them have failed, one spectacularly, and neither from abuse. I tried to keep one going and managed a repair a couple of times. The notion that they are repairable is sort-of like saying airplanes are repairable. Sure they are, but they are only worth repairing because replacements are so expensive. Nearly anything can be repaired if one is willing to spend more on the repair than the item is worth on the market. That is a separate calculus than the societal value of repairing things rather than disposing of them. (Sidebar: It would take probably half a dozen of my Buckeye amps to fill up as much landfill as one of the B&K's, even if crushed or ground up.)
6. Suggesting strategies for improving existing devices with poor heat management would be less...incendiary. I used this purpose-designed supplemental cooling fan when I was running two B&K amps in the same system:
Should we be identifying how something like these might be used for any amp that has thermal management that needs improving? One advantage to a cheap-but-cheerful sheet-metal case is that modifying it causes no real heartburn, at least after the warranty is up.
Rick "preferring solutions" Denney
I am not sure when thermal management was introduced, but the original post related to the power dissipated at idle being no better than most other amps. Which is often true, depending upon how the other amps are biased.
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Also, to be fair I think John pointed out some pretty lazy design factors/decisions relating to the thermal management in some modern Class D amplifiers. Pretty basic stuff. OK, possibly easily rectified with a drill and/or added fan. Fact is they are still poorly designed units and this shouldn't be necessary. The thread does seem to be inherently more about quiescient power draw and thermal management, than the actual efficiency of Class D tho... Which I actually found fairly enlightening tbh.
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To listen to music: I turn on the amp (as all other things that are needed)
When I stop listening: I turn off the amp (as all other things that are needed)
What exactly whas the question (esp. facing climate change)?
When I stop listening: I turn off the amp (as all other things that are needed)
What exactly whas the question (esp. facing climate change)?
Ze Frog
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How outrageous that an electrical product uses electricity.
The most inefficient Class D are likely the ones with power bricks that obviously waste energy even if disconnected at the amplifier end. The amplifier itself is actually efficient especially as more power is demanded. Too be honest though, in the interest of safety and being cautious, any kind of power brick etc should be turned off when not in use anyway.
The most inefficient Class D are likely the ones with power bricks that obviously waste energy even if disconnected at the amplifier end. The amplifier itself is actually efficient especially as more power is demanded. Too be honest though, in the interest of safety and being cautious, any kind of power brick etc should be turned off when not in use anyway.
I don't doubt it a bit, and there have been some excellent examples of bad thermal management here on ASR. I meant it when I said I was not sure when thermal management was introduced, should have clarified that I was not surprised that it was, but was just looking at the John's first post.
Specsmanship is as much a part of marketing class D as anything else. Most components do not provide a chart show how efficiency varies with power, from which many folk might realize their class D amp is not much if any better than class AB at their average power levels. I think that was @restorer-john 's main point.
My 1980's vintage Quad 606 tends to run quite cool, and is reliably to this day.... I did have it serviced about 15 years ago, to replace ageing caps (preventative), and raise the input level, as it was previously at 0.5V and I had it raised to 0.7V as per the later Quad 707 - which makes it slightly easier to match to AVR pre-outs (!)
It remains an excellent sounding amp - and handles difficult speakers with aplomb - where many current amps still fail to, and most AVR's also continue to fall short.
No intention to add it to landfill here.... and it has also maintained its market value admirably - If I decide to move it on, it would add its fair share to my audio "kitty". (But I'm too fond of it to do that)
So yeah - there are plenty of examples of excellent vintage AB's that still do a great job day in day out after 40 years service... (well strictly speaking, the Quad is a current dumping design.... but it best fits into the AB category - just like everyones favourite Benchmark AHB1 - which is a close relative of the current dumping design too )
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