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Post by adaboy on Oct 3, 2017 18:32:28 GMT -5
So Emotiva, uses a "cheaper" power supply, boast of the benefits of cost savings all around yet raises the prices and cancels all sales on the consumers end?  It still doesn't sit well with me. The negative Stereophile review kinda makes me feel a little better inside. Emotiva got out of their lane, the big boys reviewed it and confirmed that Emo was out of their lane. Emotiva's lack of defense sealed it. |
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Post by leonski on Oct 3, 2017 18:34:18 GMT -5
I'd hold up on this judgement IF Stereophile does a retest with a production sample and fails to confirm the earlier result.
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Post by adaboy on Oct 3, 2017 18:43:45 GMT -5
I'd hold up on this judgement IF Stereophile does a retest with a production sample and fails to confirm the earlier result. While I don't doubt you... Since when does a company give an inferior test model for what may be considered their biggest review? Then to manufacture a better more refined one to the masses??? That seems backwards. |
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Post by leonski on Oct 3, 2017 19:13:32 GMT -5
Agreed 100%. Real bad idea to issue a pre-production sample for full review.
Car mags sometimes test such cars but are CLEAR they have a preproduction sample for an 'impression' drive of probably 20 minutes or so.
And typically under supervision of the manufacturer.
Lonnie made some comments on the TOP of Page #6 of the Stereophile Review thread. He is 'trying to track down' the review sample.
Hopefully somebody had the foresight to jot down the Serial # of the unit shipped to Stereophile.
And likewise, I hope if the 2nd sample is benched, the new and better results are made part of the record.
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Post by AudioHTIT on Oct 4, 2017 0:08:31 GMT -5
I would strongly advise against deciding what audio equipment to buy based on the electric bill ... No one’s suggesting that, and how could we anyway, you don’t think it’s important and Emotive doesn’t supply the information. |
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Post by Jim on Oct 4, 2017 6:04:11 GMT -5
So Emotiva, uses a "cheaper" power supply, boast of the benefits of cost savings all around yet raises the prices and cancels all sales on the consumers end? It still doesn't sit well with me. The negative Stereophile review kinda makes me feel a little better inside. Emotiva got out of their lane, the big boys reviewed it and confirmed that Emo was out of their lane. Emotiva's lack of defense sealed it. I feel like you’re making a lot of conclusions about a power supply based on a Stereophile review. The Big Boys??? |
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Post by Gary Cook on Oct 4, 2017 6:09:13 GMT -5
Seriously, I'm not going to buy an amp solely based on its efficiency, that's just silly. But I may well rule out an amp because it draws too much power when sharing the circuit with the other equipment. Or I might well rule an amp in because it's power draw fits into the circuit profile.
I really don't see any issue with noting an amps power draw while testing it for distortion at the common 1 watt, 20% of its rated power and then at 100%. No extra work involved, since it already has an input signal and a load for those tests. Yes I know that may not be my profile of use, but if it's good enough for distortion then it's good enough for power/efficiency. It's better than nothing which is what we have right now, we just guess, use a rough rule of thumb and hope that it suites our power availability.
For audio I don't care about the power bill, it's such a small portion of the household power usage. It's more that I don't want to spend $big on upgrading circuits if I don't need to.
Cheers
Gary
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Post by rbk123 on Oct 4, 2017 8:38:55 GMT -5
I don't think I flipped out. I didn't say you flipped out, I said if you go over to that thread you'll see lots of people flipping out because measurement numbers are important to them. |
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Post by rbk123 on Oct 4, 2017 8:56:33 GMT -5
Lonnie made some comments on the TOP of Page #6 of the Stereophile Review thread. He is 'trying to track down' the review sample. They've been "tracking it down" for a couple of weeks now. Hopefully it's not in the same place as the new MC-700 manual Dan promised "in a couple of weeks" back in January. This will probably fall into the same cracks as they have bigger fish to fry, and/or silence may be a preferred response over rebuttal. |
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KeithL
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Post by KeithL on Oct 4, 2017 9:29:26 GMT -5
Agreed..... but the problem remains that the data is actually quite complicated and you need to know how to interpret it. For example, because music is dynamic, knowing the efficiency of the amp at full power with a steady test tone doesn't tell you much about what will happen with music. And, at very low power levels, most of the power consumed is "idle current" - which is sort of like the power it takes to keep the pilot light lit. This idle current will also vary depending on things like ambient temperature, how long the unit has been turned on, and how warmed up it is. Most Class A/B amps, running at full rated power, are between 60% and 70% efficient - but most people, most of the time, run their systems at far lower power levels. To most engineers, this would be sort of like asking how many gallons of gas per hour your car burns while sitting in the driveway idling. And, yes, if you design HYBRID cars that matters quite a bit .... but not to most of us. I sure don't remember seeing that spec for my (purely gasoline driven) Nissan Versa. I can tell you that an XPA Gen3, operating at full power, is going to be somewhere around 60% to 70% efficient. And, idling, a seven-channel amp draws somewhere around 20 watts. Seriously, I'm not going to buy an amp solely based on its efficiency, that's just silly. But I may well rule out an amp because it draws too much power when sharing the circuit with the other equipment. Or I might well rule an amp in because it's power draw fits into the circuit profile. I really don't see any issue with noting an amps power draw while testing it for distortion at the common 1 watt, 20% of its rated power and then at 100%. No extra work involved, since it already has an input signal and a load for those tests. Yes I know that may not be my profile of use, but if it's good enough for distortion then it's good enough for power/efficiency. It's better than nothing which is what we have right now, we just guess, use a rough rule of thumb and hope that it suites our power availability. For audio I don't care about the power bill, it's such a small portion of the household power usage. It's more that I don't want to spend $big on upgrading circuits if I don't need to. Cheers Gary |
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KeithL
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Post by KeithL on Oct 4, 2017 10:18:21 GMT -5
I'm still trying to figure out what the Stereophile review has to do with the power supply...... (the two are actually unrelated). However, about power supplies..... The world moves on..... Cars get better mileage, and have much better acceleration, and better endurance, than horses.... And airplanes cost more, but they're a lot faster than cars, and also a lot safer. Horses are still nice, but, the next time I go to California, I'll either be driving or flying. And, in many but not all applications, switch mode power supplies deliver better performance, cost less, and weigh less, than old-style linear supplies. Performance is important; reliability is important; but wasting money on old technology when there's newer and better technology is... well... wasteful. It really is that simple. (And, yes, both linear power supplies and SMPS can be reliable - or not - depending on how well they're designed and built.) I've also got to sort of vent a little bit here......  Stereophile routinely tests amps that cost tens of thousands of dollars, and whose performance is so inferior to ours that it isn't even funny. However, oddly, nobody wonders who would be dumb enough to buy the $25k tube amp that puts out 35 watts at 5% THD. And nobody suggested that the designer of the $90k a pair amp that actually blew up when Stereophile tried to warm it up to test it "learned his lesson". And neither did anybody comment that "the guy who designed it has been designing amps forever; you'd think he could make one that wouldn't blow up". And, interestingly, we've sold a LOT of XPA Gen3 amps already..... And pretty well everybody seems to agree that they sound downright awesome..... Which is kind of the whole point here. So Emotiva, uses a "cheaper" power supply, boast of the benefits of cost savings all around yet raises the prices and cancels all sales on the consumers end? It still doesn't sit well with me. The negative Stereophile review kinda makes me feel a little better inside. Emotiva got out of their lane, the big boys reviewed it and confirmed that Emo was out of their lane. Emotiva's lack of defense sealed it. I feel like you’re making a lot of conclusions about a power supply based on a Stereophile review. The Big Boys??? |
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Post by geebo on Oct 4, 2017 10:46:55 GMT -5
I'm still trying to figure out what the Stereophile review has to do with the power supply...... (the two are actually unrelated). However, about power supplies..... The world moves on..... Cars get better mileage, and have much better acceleration, and better endurance, than horses.... And airplanes cost more, but they're a lot faster than cars, and also a lot safer. Horses are still nice, but, the next time I go to California, I'll either be driving or flying. And, in many but not all applications, switch mode power supplies deliver better performance, cost less, and weigh less, than old-style linear supplies. Performance is important; reliability is important; but wasting money on old technology when there's newer and better technology is... well... wasteful. It really is that simple. (And, yes, both linear power supplies and SMPS can be reliable - or not - depending on how well they're designed and built.) I've also got to sort of vent a little bit here...... Stereophile routinely tests amps that cost tens of thousands of dollars, and whose performance is so inferior to ours that it isn't even funny. However, oddly, nobody wonders who would be dumb enough to buy the $25k tube amp that puts out 35 watts at 5% THD. And nobody suggested that the designer of the $90k a pair amp that actually blew up when Stereophile tried to warm it up to test it "learned his lesson". And neither did anybody comment that "the guy who designed it has been designing amps forever; you'd think he could make one that wouldn't blow up". And, interestingly, we've sold a LOT of XPA Gen3 amps already..... And pretty well everybody seems to agree that they sound downright awesome..... Which is kind of the whole point here. I can attest to that. My XPA-2 Gen 3 sounds great. No regrets whatsoever replacing two XPA-1Ls with it. And it runs way cooler in my enclosed rack, too. |
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Post by AudioHTIT on Oct 4, 2017 11:10:02 GMT -5
To most engineers, this would be sort of like asking how many gallons of gas per hour your car burns while sitting in the driveway idling. In my opinion for an audio engineer that would be poor analogy, while a car is getting 0MPG idling in the driveway, an amplifier can drive a speaker to listenable levels while ‘virtually’ idling, up in the 70-80 dB area for most speakers while the amp is putting out a 1/10th of a Watt — much listening is done in this first Watt range. I have pushed for idle power because it’s relevant not only for amplifiers, but for all equipment, hence it would allow us to compute the steady state draw of our systems. Again it only requires the tester to read the current draw without a signal applied, and publish it. I also fully support Gary’s additional measurements at standard power outputs to more completely evaluate efficiency. |
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Post by Jim on Oct 4, 2017 12:30:43 GMT -5
I think that SMPS vs old iron is like....... analog vs digital, tube vs solid state, burn in, break in... etc.
I don't think that a forum debate is going to change the opinion of anyone who is steadfast in their position.
SMPS has replaced heavy toroids in almost everything, that's just progress...
Good clean power isn't determined simply by the PS topology.
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Post by leonski on Oct 4, 2017 14:40:16 GMT -5
I don't think I flipped out. I didn't say you flipped out, I said if you go over to that thread you'll see lots of people flipping out because measurement numbers are important to them. My Bad. Sorry, I misunderstood your post / intent: Not to say I DON'T flip out once in a while! |
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hemster
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...still listening... still watching
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Post by hemster on Oct 4, 2017 19:10:45 GMT -5
... Good clean power isn't determined simply by the PS topology. ... ^What he said! It's like saying that a great photo is determined simply by its megapixels.  |
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klinemj
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Official Emofest Scribe
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Post by klinemj on Oct 4, 2017 21:08:57 GMT -5
So Emotiva, uses a "cheaper" power supply, boast of the benefits of cost savings all around yet raises the prices and cancels all sales on the consumers end? It still doesn't sit well with me. The negative Stereophile review kinda makes me feel a little better inside. Emotiva got out of their lane, the big boys reviewed it and confirmed that Emo was out of their lane. Emotiva's lack of defense sealed it. Emotiva did comment on this at Emofest. We asked directly. They said the Stereophile had an early version which was changed prior to production. They called this to Stereophile's attention and the magazine went ahead and published without commenting about that. Mark |
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Post by Gary Cook on Oct 5, 2017 0:21:20 GMT -5
Agreed..... but the problem remains that the data is actually quite complicated and you need to know how to interpret it. For example, because music is dynamic, knowing the efficiency of the amp at full power with a steady test tone doesn't tell you much about what will happen with music. And, at very low power levels, most of the power consumed is "idle current" - which is sort of like the power it takes to keep the pilot light lit. This idle current will also vary depending on things like ambient temperature, how long the unit has been turned on, and how warmed up it is. Most Class A/B amps, running at full rated power, are between 60% and 70% efficient - but most people, most of the time, run their systems at far lower power levels. To most engineers, this would be sort of like asking how many gallons of gas per hour your car burns while sitting in the driveway idling. And, yes, if you design HYBRID cars that matters quite a bit .... but not to most of us. I sure don't remember seeing that spec for my (purely gasoline driven) Nissan Versa. I can tell you that an XPA Gen3, operating at full power, is going to be somewhere around 60% to 70% efficient. And, idling, a seven-channel amp draws somewhere around 20 watts. Hi Keith, I'm sure you, at the very least, sit in while a power amp is on the test bench, would it be that big of an ask for at the same time it to be tested at say the common 1 watt, 20% of its rated power and then at 100%? Would there be any extra work involved? It seems such a simple thing to me that may well be of some use to customers and potential customers. Cheers Gary |
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Post by AudioHTIT on Oct 5, 2017 1:14:12 GMT -5
... And, idling, a seven-channel amp draws somewhere around 20 watts. If that’s true I would be touting it. Because of this post I measured my XPA-7 G2 again today. I think the XPA-7 is arguably the closest toroidal amp to a seven channel G3, both are rated at 200 WPC with all 7 channels driven, with 2 channels however the G2 produces over 500 WPC, compared to the G3’s 300 WPC x 2. I plugged the XPA-7 into my Furman PL-PLUSDM which has a readout of either voltage or current, and let the amp sit for about 20 minutes (nothing else was plugged in). The current settled at about 1A, while the voltage read 124V. The Furman’s readout gets down to 0.1A increments, but I don’t know the rated accuracy, since it’s a nice round number let’s say my G2 is idling at about 120 Watts. This would gives us a 100 Watt difference between the G2 and G3 at idle (or over a 500% difference!), I think that’s pretty significant. Could you give us an actual measured of idle on the XPA-7 G3? |
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Post by leonski on Oct 5, 2017 2:13:48 GMT -5
Kill-A-Watt meter. 20$ from Amazon. All questions answered. My Panamax has voltage and current meters which I wouldn't give you the cost of a local call for. Measuring high power amps sounds simple. But a few things are involved. You'll need a 7 channel dummy load. Amp rated to 200 watts? Load should be maybe 3x the expected maximum load. Power resistors are inexpensive and you'll need some 10ga wiring and connectors, not to mention a caged 'case' for safety and ventilation. Make sure your AC for the room is up to snuff! You'll also need an Industrial Strength Variac. This to maintain line voltage TO the amp. This ensures real reading and you KNOW going in that most persons power line will 'sag' some so they may not get what YOU get on the bench. The example I link has 17% 'one star' ratings AND though rated as 20 amp, has only 15 amp outlets. I'd skip to the REAL Variac 'brand' which goes nearly 1000$ for what I'd have on MY bench. www.amazon.com/Electronix-Express-16VA520T20-Variable-Transformer/dp/B006NG9OTI/ref=sr_1_3?ie=UTF8&qid=1507187156&sr=8-3&keywords=variacThan meters, scope, signal generator and MORE. Meters get Calibrated on a annual basis, as does the scope and signal generator. |
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It still doesn't sit well with me. The negative Stereophile review kinda makes me feel a little better inside. Emotiva got out of their lane, the big boys reviewed it and confirmed that Emo was out of their lane. Emotiva's lack of defense sealed it.
