KeithL
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Post by KeithL on Feb 10, 2023 11:04:01 GMT -5
I do want to clarify a few things here.... First of all, for Class A/B amplifiers, the maximum efficiency, at whatever impedance the amp is optimized for, is about 70% (and usually a bit lower for other load impedances). However, if you want to include Class-D amplifiers in the discussion, those actually can reach efficiencies in the 80% to 90% range... A switching power supply is also VERY efficient. However, to be fair, even a linear power supply is quite efficient - as long as it is unregulated. It's adding linear regulation to a power supply that really cuts down its efficiency. (This is why you don't see regulated linear power supplies on power amps. It's only really practical to regulate a big power supply if it's an SMPS. ) However I do feel a need to chime in about comments like "40 pound transformers" and "1200 watt transformers".... The physical size and weight required for a transformer is determined by many things - including the frequency it operates at. For example, in case you didn't know, the switching power supply we use in our XPA Gen3 amplifiers has a 2.5 kW transformer in it (that's 2500 watts).
But, because it runs at a much higher frequency, it is a lot smaller, lighter, and more efficient, than a transformer capable of far less power running at 60 Hz.
This is one of the major benefits of switch mode power supplies. It's not a great analogy... But comparing a linear power supply to a switcher is like comparing a big old diesel tractor to a sports car with twin turbochargers... Denon/Marantz used to have a "70% guarantee" on power, meaning that in a 5-ch, all channels driven configuration their AVRs would deliver at least 70% of the 2-ch power rating. Not sure they still follows this self-imposed rule. I am afraid we'll have to wait for Audioholics or AVS to run actual tests. It is also true that in a real listening situation the chances to drive all channels simultaneously at their rated power is virtually nil. Disclosing such rating though, would help in assessing the power supply capability. Unless the amp requires a 120 / 20 amp service.....you are limited as to possible maximum output power. That power is long term input power MINUS an efficiecy penalty of maybe 50%, give or take. Long term 15amp service is only 1400 or so watts, long term AFTER deducting the 20%. 20 amp service just ups the game, but not the essential outcome. This is why more efficient 'D' amps are gaining ground and 'switcher' PS has some advantages as well......But still and all? You're up against the wall of Physics. ALL 15 channels driven @4ohms? 50 or 60 per would be all you could EVER expect. |
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KeithL
Administrator
Posts: 10,261
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Post by KeithL on Feb 10, 2023 17:37:58 GMT -5
Actually putting the power supply in a separate chassis has advantages and disadvantages - besides costing a lot more. The main advantage is that you can "keep the AC power out of the audio section". This can make life easier with 60 Hz power (because hum gets into things rather easily)... And with a SMPS (because noise can also be an issue there)... And, of course, if the entire thing is too heavy to lift comfortably, it makes handling easier... However there are also significant down-sides... It means longer cable runs between the power supply and the rest of the circuitry... This means more wire resistance... This isn't like the interconnects between a preamp or processor and a power amp...
You need big heavy wires and connectors between the power supply and the power amplifier output stages...And you're still going to need extra filtering and decoupling on the "audio chassis"... And those wires and connectors add resistance, and the possibility that they will come loose, as well as adding cost and complexity in general. And now you have the extra difficulty of maintaining a really solid ground between two chassis... (Implementing an effective grounding scheme can be tricky in one chassis.... it's far worse with two separate ones.) All in all, unless you really NEED to do it, for example if the whole thing is just too heavy to put in one chassis... Splitting everything into two boxes tends to be more trouble than it's worth... Well, the MR-1 is almost there, with a 1,000VA transformer. Not many knobs, though 😆 Here's an example of a multi-piece component. This is the EXTREME end of things...... I heard these at a show and after about 1/2 hour, they shut them down since the room was getting hot enough to cook roast beef....AC at the hotel was hopeless. www.passlabs.com/products/xs300/Pass makes this and a smaller one. 2 large PS and a pair of Driver stages....each with over 100 output devices. EACH Channel is two pieces totaling about 300lb......so you'll need not 'A' friend, but a team of guys to help move this stuff, than enough Pizza to choke an NFL team while doing setup.....and don't forget a dedicated circuit for each amp. they IDLE at 900 watts, which as it turns out, is ALL HEAT..... |
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Post by leonski on Feb 10, 2023 18:25:22 GMT -5
Actually putting the power supply in a separate chassis has advantages and disadvantages - besides costing a lot more. The main advantage is that you can "keep the AC power out of the audio section". This can make life easier with 60 Hz power (because hum gets into things rather easily)... And with a SMPS (because noise can also be an issue there)... And, of course, if the entire thing is too heavy to lift comfortably, it makes handling easier... However there are also significant down-sides... It means longer cable runs between the power supply and the rest of the circuitry... This means more wire resistance... This isn't like the interconnects between a preamp or processor and a power amp...
You need big heavy wires and connectors between the power supply and the power amplifier output stages...And you're still going to need extra filtering and decoupling on the "audio chassis"... And those wires and connectors add resistance, and the possibility that they will come loose, as well as adding cost and complexity in general. And now you have the extra difficulty of maintaining a really solid ground between two chassis... (Implementing an effective grounding scheme can be tricky in one chassis.... it's far worse with two separate ones.) All in all, unless you really NEED to do it, for example if the whole thing is just too heavy to put in one chassis... Splitting everything into two boxes tends to be more trouble than it's worth... Here's an example of a multi-piece component. This is the EXTREME end of things...... I heard these at a show and after about 1/2 hour, they shut them down since the room was getting hot enough to cook roast beef....AC at the hotel was hopeless. www.passlabs.com/products/xs300/Pass makes this and a smaller one. 2 large PS and a pair of Driver stages....each with over 100 output devices. EACH Channel is two pieces totaling about 300lb......so you'll need not 'A' friend, but a team of guys to help move this stuff, than enough Pizza to choke an NFL team while doing setup.....and don't forget a dedicated circuit for each amp. they IDLE at 900 watts, which as it turns out, is ALL HEAT..... That's why I went to the Edge Of The Cliff with my example. Total for the XS300 amp....all four pieces for a stereo amp, goes nearly 600lb and EACH channel needs a dedicated circuit..... And yes, a CHEAP and non-robust solution will be an accident waiting to happen when connection of PS to AMP is made. Maybe sell the amp with a choice of 2 foot, 4 foot or 6 foot (or whatever) umbilical which is a dealer installed piece. ONE end...the PS end, maybe, is hard wired to the beefiest terminal block you can find. I'd use nickel over silver crimp connectors, maybe. We used such when connecting diffusion pumps....which ran at very elevated tempretures and high current. No other connector would last. And I'm afraid that for a very high power'd amp? You're gonna need bigger wire......Which makes flexibility a problem. The 2-box solution is to be reserved, as Keith notes, for when NOTHING else will do. Heat sinking for 100 output devices ran in class 'A' is going to be a problem almost no matter what.....Unless you live north of the Arctic Circle..... |
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Post by cwt on Feb 10, 2023 23:53:17 GMT -5
Personally, I'd rather like to see a multichannel AVR (or even amp) designed and specified with the rated power over 3-ch (for LCR use), over 8 Omhs, all channels driven, possibly with the ability to double the power over 4 Ohms and all other channels dedicated to surround duty designed and rated for lower power. In any case, kudos to Emotiva for specifying power also with all-channels driven. That says a lot about the overall capability of the power supply and its ability to sustain dynamic peaks in a real life scenario. Its interesting to note how others are shoehorning amp channels in without a very large chassis . Anthem mrx1140 is close to your specs with 5 x 140w a/b channels for the bed and 6 x 60w class D for the back surrounds and heights The 1140;s main 5 channels dont come close to doubling output into 4 ohms like a good class d would however  Audioholics says i wonder if Emo considered a MR1 stacked with multiple PA1 monoblocks [sadly discontinued] although the twin rail power supply is almost as efficient as class D . Coud be just a matter of fitting the psu and everything in there .. |
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Post by MusicHead on Feb 11, 2023 0:23:29 GMT -5
Personally, I'd rather like to see a multichannel AVR (or even amp) designed and specified with the rated power over 3-ch (for LCR use), over 8 Omhs, all channels driven, possibly with the ability to double the power over 4 Ohms and all other channels dedicated to surround duty designed and rated for lower power. In any case, kudos to Emotiva for specifying power also with all-channels driven. That says a lot about the overall capability of the power supply and its ability to sustain dynamic peaks in a real life scenario. Its interesting to note how others are shoehorning amp channels in without a very large chassis . Anthem mrx1140 is close to your specs with 5 x 140w a/b channels for the bed and 6 x 60w class D for the back surrounds and heights The 1140;s main 5 channels dont come close to doubling output into 4 ohms like a good class d would however Audioholics says i wonder if Emo considered a MR1 stacked with multiple PA1 monoblocks [sadly discontinued] although the twin rail power supply is almost as efficient as class D . Coud be just a matter of fitting the psu and everything in there .. Very interesting design by Anthem. In truth, it would be very difficult to have 5 channels capable of doubling power over 4 Ohm (ideal amplifier). Much easier doing it on 2-ch, not impossible over 3. One of the Schiit amps can (2-ch) |
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Post by leonski on Feb 12, 2023 20:04:45 GMT -5
Its interesting to note how others are shoehorning amp channels in without a very large chassis . Anthem mrx1140 is close to your specs with 5 x 140w a/b channels for the bed and 6 x 60w class D for the back surrounds and heights The 1140;s main 5 channels dont come close to doubling output into 4 ohms like a good class d would however Audioholics says i wonder if Emo considered a MR1 stacked with multiple PA1 monoblocks [sadly discontinued] although the twin rail power supply is almost as efficient as class D . Coud be just a matter of fitting the psu and everything in there .. Very interesting design by Anthem. In truth, it would be very difficult to have 5 channels capable of doubling power over 4 Ohm (ideal amplifier). Much easier doing it on 2-ch, not impossible over 3. One of the Schiit amps can (2-ch) Except for 'specsmanship', very few actual perfect voltage source amps exist... And while my buddies in the Magnepan camp sometimes tout that as the 'ideal'........the real need is for plenty of power...pure and simple. The ability to drive the not-difficult but low sensitivity of such panels is where you want to be. |
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Post by akcorr on Feb 13, 2023 9:48:12 GMT -5
So I did eventually ended up swapping HDMI Ports with my BD player and also set the display type in the settings of my Roku Ultra device and in my limited testing everything working as expected! No more drops in signal!
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Post by AudioHTIT on Feb 13, 2023 10:11:32 GMT -5
… i wonder if Emo considered a MR1 stacked with multiple PA1 monoblocks [sadly discontinued] although the twin rail power supply is almost as efficient as class D . Coud be just a matter of fitting the psu and everything in there .. I thought the same thing, though the B&O modules are surely long gone, maybe something similar. |
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Post by leonski on Feb 13, 2023 13:47:42 GMT -5
First? The 'D' OUTPUT can be quite efficient at higher powers. A conventional 'linear' power supply......Big transformer / rectifier / caps is also, in the unregulated type, quite efficient.
The 'rail' type PS? Can go ether way. Switchers have other advantages.....In most cases the output stage governs overall efficiency.
The B&O modules with on-board PS can be 85% PLUS efficient.....at full power.....dropping at lower powers.....With NO output? And just 'on' with the housekeeping power? ZERO efficiency.
B&O rates 'from plug to speaker'...not a bad idea.
As a replacment for the B&O modules?
I'd suggest a look at the NCore line.......
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Post by cinegreg on Feb 22, 2023 16:19:36 GMT -5
Received my MR-1 and wired it all up. I'm running into an issue with the NVIDIA Shield. When I power up the MR-1 and the Shield it only locks to the signal about once every three or four attempts. Interestingly, the MR-1 does seem to recognize it as the input name changes from HDMI3 to H3-SHIELD. But no signal.
All other connected inputs (Apple TV 4K, Playstation 5, Nintendo Switch) work just fine.
Another minor nit, when doing the channel test tones, no sound plays to the sub, but it is definitely attached and responds as expected during normal sound playback.
Any thoughts on the NVIDIA Switch connection/sync lock issue?
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Post by doc1963 on Feb 22, 2023 16:55:24 GMT -5
Received my MR-1 and wired it all up. I'm running into an issue with the NVIDIA Shield. When I power up the MR-1 and the Shield it only locks to the signal about once every three or four attempts. Interestingly, the MR-1 does seem to recognize it as the input name changes from HDMI3 to H3-SHIELD. But no signal. All other connected inputs (Apple TV 4K, Playstation 5, Nintendo Switch) work just fine. Another minor nit, when doing the channel test tones, no sound plays to the sub, but it is definitely attached and responds as expected during normal sound playback. Any thoughts on the NVIDIA Switch connection/sync lock issue? Have you done a “cold” (unplug the power) reboot of your Shield…? Like the AppleTV (or any other streaming box, STB or DVR), it never truly powers off unless AC is removed from it for a few minutes. EDID is stored at the hardware level where a simple “shutdown” or “restart” has no effect. Those functions are more for the OS. If you haven’t already, give that a try… |
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Post by marcl on Feb 22, 2023 18:40:19 GMT -5
Received my MR-1 and wired it all up. I'm running into an issue with the NVIDIA Shield. When I power up the MR-1 and the Shield it only locks to the signal about once every three or four attempts. Interestingly, the MR-1 does seem to recognize it as the input name changes from HDMI3 to H3-SHIELD. But no signal. All other connected inputs (Apple TV 4K, Playstation 5, Nintendo Switch) work just fine. Another minor nit, when doing the channel test tones, no sound plays to the sub, but it is definitely attached and responds as expected during normal sound playback. Any thoughts on the NVIDIA Switch connection/sync lock issue? This is deja-esque ... three years ago when I bought the XMC-2 I discovered that the PEQ didn't work for the subwoofer channels. This was pre-Dirac. So I contacted Emotiva and I was told that the PEQ DOES work but it's the TEST TONE that doesn't work. But hey, I was not USING the test tone, I was using REW to measure and create the filters, and the PEQ filters were not being applied to the subwoofer channel. But Emotiva support insisted that it DID work. Two months later firmware 1.10 was released, including in the release notes the fact that PEQ for the subwoofer channels had been fixed! Just sayin' ... deja ... like, whatever!  |
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Post by cinegreg on Feb 22, 2023 21:03:49 GMT -5
Received my MR-1 and wired it all up. I'm running into an issue with the NVIDIA Shield. When I power up the MR-1 and the Shield it only locks to the signal about once every three or four attempts. Interestingly, the MR-1 does seem to recognize it as the input name changes from HDMI3 to H3-SHIELD. But no signal. All other connected inputs (Apple TV 4K, Playstation 5, Nintendo Switch) work just fine. Another minor nit, when doing the channel test tones, no sound plays to the sub, but it is definitely attached and responds as expected during normal sound playback. Any thoughts on the NVIDIA Switch connection/sync lock issue? Have you done a “cold” (unplug the power) reboot of your Shield…? Like the AppleTV (or any other streaming box, STB or DVR), it never truly powers off unless AC is removed from it for a few minutes. EDID is stored at the hardware level where a simple “shutdown” or “restart” has no effect. Those functions are more for the OS. If you haven’t already, give that a try… Tried that and it did come up, but when I switched inputs and switched back it took nearly 30 seconds for it to return. I did confirm that the Switch is outputting YCbCr 4:2:0 and not 4:4:4 RGB, in case that makes a difference. Will do more experiments over the next few days. On the positive, I've run several audio track tests that I know stressed my previous Onkyo receiver - leading to a harsh sound - and so far the sound out of the MR1 completely blows away the sound from the Onkyo! |
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Post by berniebot on Feb 25, 2023 12:09:04 GMT -5
just got the MR1...so far so good. Infact so far so GREAT! I blows away my old Outlaw separates rig.
Question: When it plays a Atmos track the display says "Dolby Atmos (MAT)" Does anyone know what the "(MAT)" part means?
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Post by cinegreg on Feb 25, 2023 13:57:16 GMT -5
just got the MR1...so far so good. Infact so far so GREAT! I blows away my old Outlaw separates rig. Question: When it plays a Atmos track the display says "Dolby Atmos (MAT)" Does anyone know what the "(MAT)" part means? What's your source? I haven't seen "(MAT)" before. I've seen "(True HD) for my blu-ray sources. |
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Post by kozak56 on Feb 25, 2023 16:01:41 GMT -5
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Post by kozak56 on Feb 25, 2023 16:02:44 GMT -5
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Post by berniebot on Feb 25, 2023 19:01:22 GMT -5
my source is apple TV
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Post by doc1963 on Feb 25, 2023 20:53:03 GMT -5
just got the MR1...so far so good. Infact so far so GREAT! I blows away my old Outlaw separates rig. Question: When it plays a Atmos track the display says "Dolby Atmos (MAT)" Does anyone know what the "(MAT)" part means? Your AppleTV does not bitstream the audio content. By default, it will always decode the source audio internally and send Multichannel PCM out to the audio processor. If the source audio is Atmos, it will also send the metadata. Dolby MAT is the transport mechanism used by the AppleTV (as well as the Xbox and some others) to send LPCM along with Atmos metadata in one container. Some AVRs and/or AVPs will simply display “Atmos” while your MR1 gets a bit more specific by also reporting the incoming carrier (MAT or TrueHD). |
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Post by cinegreg on Feb 26, 2023 10:23:38 GMT -5
My 12-year-old daughter was over this weekend, and when the MR1 powers up, it apparently generates a very high-pitched tone for a few seconds on startup (during the Booting... screen). With all the concerts I attended in my youth I can't hear it anymore, but she certainly can and says it is loud and painful to hear. (She says it is similar to the high pitched "dog whistle" at the end of A Day in the Life on Abbey Road.)
Doesn't seem like the MR1 should be doing that... Is this a known issue?
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Denon/Marantz used to have a "70% guarantee" on power, meaning that in a 5-ch, all channels driven configuration their AVRs would deliver at least 70% of the 2-ch power rating. 
Audioholics says
