In the old days it was often specified as "sinus power" or "music power" where "music power" was peak power.
Maybe these 600/1200 W was measured as an instant power at the top of the sinus but if you have a THD also at the power level then "sinus power" or "Average" or "RMS" makes more sense to specify. But always best to refer to an international standard the measurements comply with. Then there is no doubt. A speaker is never just 4 or 8 pure ohmic value so a complex impedans is better to use to give a realistic picture of how the amplifier performs. All that should be specified in the standard (e.g., a requirement for the test load used for the measurements).
Then it would be a good idea to have a certified lab to perform these measurements using a specific standard.
Maybe these 600/1200 W was measured as an instant power at the top of the sinus but if you have a THD also at the power level then "sinus power" or "Average" or "RMS" makes more sense to specify. But always best to refer to an international standard the measurements comply with. Then there is no doubt. A speaker is never just 4 or 8 pure ohmic value so a complex impedans is better to use to give a realistic picture of how the amplifier performs. All that should be specified in the standard (e.g., a requirement for the test load used for the measurements).
Then it would be a good idea to have a certified lab to perform these measurements using a specific standard.
I know these things but I assume that Pass Labs means, without any further disclosure of the circumstances as given under their Technical Spefication tab for the X600.5, to be it RMS power from 20Hz to 20kHZ with 1% distortion. That's the standard way for at least 30 years now.
That has been done. I have four pages of each amplifier with graphs like K2 and K3 harmonics (A-A FFT Spectrum of THD Residual) Frequency spectrum at 10 Watts.
I found in a German magazine (Audio June 1998) a review of the X1000 with the same characteristics in the powerenveloppe.
At 8 Ohms 1012 Watts and at 4 Ohms 1218 Watts. (According to Pass Labs it should be 1000 and 2000 Watts)
It always tickles me re: questions asked and answers given when there is potentially an agenda at hand. Your original post seems to have an agenda to it vs. to simply ask a scientific question. You also asked your question in a public Internet forum where the name Pass is pretty well-regarded. So, you got some responses that don't make any real attempt to answer your question.
First, I agree with at least one previous poster, that if you really want to know the answer vs. post what you think are the failings and/or imply false advertising for the amplifier, then the most simple course of action would be to ask the manufacturer if the unit was performing to specifications. Is it working properly to their standards? Then, if it is, you could ask more detailed questions re: your impressions and understanding re: how certain measurements / specifications were obtained. Pass Labs is fairly well-regarded for speed and accuracy of responses and good customer service. My guess, is that if you asked them, you'd get an answer much more quickly than on this forum.
In addition, this may help. You could see if either the max voltage swing and/or the max current delivery is meeting published specs and narrow things down a bit. Again, that's if you really want an answer...which, up to this point, I'm not sure you do.
https://www.passlabs.com/wp-content/uploads/2020/01/x.5_specs_0.pdf
First, I agree with at least one previous poster, that if you really want to know the answer vs. post what you think are the failings and/or imply false advertising for the amplifier, then the most simple course of action would be to ask the manufacturer if the unit was performing to specifications. Is it working properly to their standards? Then, if it is, you could ask more detailed questions re: your impressions and understanding re: how certain measurements / specifications were obtained. Pass Labs is fairly well-regarded for speed and accuracy of responses and good customer service. My guess, is that if you asked them, you'd get an answer much more quickly than on this forum.
In addition, this may help. You could see if either the max voltage swing and/or the max current delivery is meeting published specs and narrow things down a bit. Again, that's if you really want an answer...which, up to this point, I'm not sure you do.
https://www.passlabs.com/wp-content/uploads/2020/01/x.5_specs_0.pdf
Standards?
What standards?????
The only real standard that is at play here, is that someone is not allowed to sell anything with claims that can't be backed-up.
But that definition is so extremely vague and gray that even audiophile network switches are fine apparently.
I just made an inquiry at service@passlabs.com regarding this matter.
I'll keep you posted if interested of course
Kudos. I'm thrilled that you're pursuing it with the manufacturer directly. Thank you for offering to post the progress / outcome. I'm fascinated by how certain specifications / measurements are chosen / performed.
Would it be contradictory for me to hope that your amplifier performing as intended, so that it does not require a repair; and simultaneously hoping that there is a simple misunderstanding re: specifications / measurements?
Cheers
Would it be contradictory for me to hope that your amplifier performing as intended, so that it does not require a repair; and simultaneously hoping that there is a simple misunderstanding re: specifications / measurements?
Cheers
Got a reply from Kent English from Pass Labs Technical Support and he stated:
"Without knowing more of how the test was performed I have no idea. The tewt would presume that the piece had a sold 240 Vac main (not 220 / 230 vac and that the input was either true balanced or if RCA input; run with XLR jumpers in place. See attached. XLR jumpers are frequently lost. "
He did not address to the found German review of the X1000's in 1998 that behaved exactly the same way.
I replied that I will ask the engineer who made the measurements on my two X600.5's, under which conditions he made his measurements.
I do not think that an English AC version of 240 Volts connected to the Continental Europe AC Voltage of 230 Volts would make such a huge difference in power output.
Will see what this German engineer will say about it and probably he has had some more Pass amps (although my experience with Threshold and Pass Labs is that they rarely show up for repairs in service repair stations in contrast with Krell and Levinson) so he can maybe state of this was an incident or always/often the case with these amps.
The difference in mains voltage doesn't make sense. If I understand correctly the test done by the German guy was done in 2015? By then, Germany was already at 230V.
The difference between 240V and 230V is to small.
The difference between 240V and 220V would have made more sense. Assuming that they use a linear power supply. For switching PSU's the input voltage doesn't really matter.
Which brings me to the following question.
Do they still sell these things?
The difference between 240V and 230V is to small.
The difference between 240V and 220V would have made more sense. Assuming that they use a linear power supply. For switching PSU's the input voltage doesn't really matter.
Which brings me to the following question.
Do they still sell these things?
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They all run linear PSU’s with huge amounts of low ESR capacitance.
Nelson himself should be able to give some feedback and shed some light on these measurements. His address is also in the manuals of both PL and FW products.
Yes the tests were made in 2015 and for the serial 18142 the powerratings were 498,3 Watts at 8 Ohm and 721,9 Watts with 1% THD.
For the serial 18143 he powerratings were 499,3 Watts at 8 Ohm and 725,9 Watts with 1% THD.
You also asked about the PFC regulations and I found as already stated that the FTC regulates output power specifications for audio amplifiers in their so called 'Amplifier Rule' under 16 CFR Part 432:
PART 432 - POWER OUTPUT CLAIMS FOR AMPLIFIERS UTILIZED IN HOME ENTERTAINMENT PRODUCTS
Authority: 38 Stat. 717, as amended; (15 U.S.C. 41-58).
Source: 39 FR 15387, May 3, 1974, unless otherwise noted.
§ 432.1 Scope.
(a) Except as provided in paragraph (b) of this section, this part shall apply whenever any power output (in watts or otherwise), power band or power frequency response, or distortion capability or characteristic is represented, either expressly or by implication, in connection with the advertising, sale, or offering for sale, in commerce as “commerce” is defined in the Federal Trade Commission Act, of sound power amplification equipment manufactured or sold for home entertainment purposes, such as for example, radios, record and tape players, radio-phonograph and/or tape combinations, component audio amplifiers, self-powered speakers for computers, multimedia systems and sound systems, and the like.
(b) Representations shall be exempt from this part if all representations of performance characteristics referred to in paragraph (a) of this section clearly and conspicuously disclose a manufacturer's rated power output and that rated output does not exceed two (2) watts (per channel or total).
(c) It is an unfair method of competition and an unfair or deceptive act or practice within the meaning of section 5(a)(1) of the Federal Trade Commission Act (15 U.S.C. 45(a)(1)) to violate any applicable provision of this part.
§ 432.2 Required disclosures.
(a) Whenever any direct or indirect representation is made of the power output, power band or power frequency response, or distortion characteristics of sound power amplification equipment, the following disclosure shall be made clearly, conspicuously, and more prominently than any other representations or disclosures permitted under this part: The manufacturer's rated minimum sine wave continuous average power output, in watts, per channel (if the equipment is designed to amplify two or more channels simultaneously) at an impedance of 8 ohms, or, if the amplifier is not designed for an 8-ohm impedance, at the impedance for which the amplifier is primarily designed, measured with all associated channels fully driven to rated per channel power. Provided, however, when measuring maximum per channel output of self-powered combination speaker systems that employ two or more amplifiers dedicated to different portions of the audio frequency spectrum, such as those incorporated into combination subwoofer-satellite speaker systems, only those channels dedicated to the same audio frequency spectrum should be considered associated channels that need be fully driven simultaneously to rated per channel power.
(b) In addition, whenever any direct or indirect representation is made of the power output, power band or power frequency response, or distortion characteristics of sound power amplification equipment in any product brochure or manufacturer specification sheet, the following disclosures also shall be made clearly, conspicuously, and more prominently than any other representations or disclosures permitted under this part:
(1) The manufacturer's rated power band or power frequency response, in Hertz (Hz), for the rated power output required to be disclosed in paragraph (a) of this section; and
(2) The manufacturer's rated percentage of maximum total harmonic distortion at any power level from 250 mW to the rated power output, and its corresponding rated power band or power frequency response.
§ 432.3 Standard test conditions.
For purposes of performing the tests necessary to make the disclosures required under § 432.2 of this part:
(a) The power line voltage shall be 120 volts AC (230 volts when the equipment is made for foreign sale or use, unless a different nameplate rating is permanently affixed to the product by the manufacturer in which event the latter figure would control), RMS, using a sinusoidal wave containing less than 2 percent total harmonic content. In the case of equipment designed for battery operation only, tests shall be made with the battery power supply for which the particular equipment is designed and such test voltage must be disclosed under the required disclosures of § 432.2 of this part. If capable of both AC and DC battery operation, testing shall be with AC line operation;
(b) The AC power line frequency for domestic equipment shall be 60 Hz and 50 Hz for equipment made for foreign sale or use;
(c) The amplifier shall be preconditioned by simultaneously operating all channels at one-eighth of rated power output for one hour using a sinusoidal wave at a frequency of 1,000 Hz; provided, however, that for amplifiers utilized as a component in a self-powered subwoofer system, the sinusoidal wave used as a preconditioning signal may be any frequency within the amplifier's intended operating bandwidth that will allow the amplifier to be driven to one-eighth of rated power for one hour;
(d) The preconditioning and testing shall be in still air and an ambient temperature of at least 77 °F (25 °C);
(e) Rated power shall be obtainable at all frequencies within the rated power band without exceeding the rated maximum percentage of total harmonic distortion after input signals at said frequencies have been continuously applied at full rated power for not less than five (5) minutes at the amplifier's auxiliary input, or if not provided, at the phono input.
(f) At all times during warm-up and testing, tone loudness-contour and other controls shall be preset for the flattest response.
[39 FR 15387, May 3, 1974, as amended at 65 FR 81240, Dec. 22, 2000]
§ 432.4 Optional disclosures.
Other operating characteristics and technical specifications not required in § 432.2 of this part may be disclosed: Provided:
(a) That any other power output is rated by the manufacturer, is expressed in minimum watts per channel, and such power output representation(s) complies with the provisions of § 432.2 of this part; except that if a peak or other instantaneous power rating, such as music power or peak power, is represented under this section, the maximum percentage of total harmonic distortion (see § 432.2(d) of this part) may be disclosed only at such rated output: And provided further,
(b) That all disclosures or representations made under this section are less conspicuously, and prominently made than the disclosures required in § 432.2 of this part; and
(c) The rating and testing methods or standards used in determining such representations are disclosed, and well known and generally recognized by the industry at the time the representations or disclosures are made, are neither intended nor likely to deceive or confuse the consumers and are not otherwise likely to frustrate the purpose of this part.
Note 1:
For the purpose of paragraph (b) of this section, optional disclosures will not be considered less prominent if they are either bold faced or are more than two-thirds the height of the disclosures required by § 432.2.
Note 2:
Use of the asterisk in effecting any of the disclosures required by § 432.2 and permitted by § 432.4 shall not be deemed conspicuous disclosure.
[39 FR 15387, May 3, 1974; 39 FR 17838, May 21, 1974]
§ 432.5 Prohibited disclosures.
No performance characteristics to which this part applies shall be represented or disclosed if they are not obtainable as represented or disclosed when the equipment is operated by the consumer in the usual and normal manner without the use of extraneous aids.
§ 432.6 Liability for violation.
If the manufacturer or, in the case of foreign made products, the importer or domestic sales representative of a foreign manufacturer, of any product covered by this part furnishes the information required or permitted under this part, then any other seller of the product shall not be deemed to be in violation of § 432.5 of this part due to his reliance upon or transmittal of the written representations of the manufacturer or importer if such seller has been furnished by the manufacturer, importer, or sales representative a written certification attesting to the accuracy of the representations to which this part applies: And provided further, That such seller is without actual knowledge of the violation contained in said written certification.
Long post, just a link would be nicer 🙂
Anyway, that is interesting, because that's fundamentally different than EN61000-3-2
Meaning that Pass Labs is not compliant with EN61000-3-2.
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1. I believe in data presented by manufacturer, especially having complete files for 600.5 in front of me - claims are well founded in construction facts
2. What's the point of using Pass Labs DiyAudio platform for resolving technical issues, when official PL contact is sole logical thing to take?
3. If really "This is a professional working for decades in the field of highendaudio repairs" is in case, why you didn't ask him to check what is wrong with amps? They are not new, and who knows what their history is .....
2. What's the point of using Pass Labs DiyAudio platform for resolving technical issues, when official PL contact is sole logical thing to take?
3. If really "This is a professional working for decades in the field of highendaudio repairs" is in case, why you didn't ask him to check what is wrong with amps? They are not new, and who knows what their history is .....
Tick a box.
1. Please help me my second hand purchase doesn't perform as expected and I want someone with deep pockets to blame.
2. Please help me I've just paid for a service and the results aren't as i expected and I want someone with deep pockets to blame.
3. Please help me I don't understand that full rated power only occurs when amp is used at the intended mains voltage and frequency, operating with the correct service manual parameters and using the balanced inputs or balanced inputs shorted.
Let's hope it's no 3.
1. Please help me my second hand purchase doesn't perform as expected and I want someone with deep pockets to blame.
2. Please help me I've just paid for a service and the results aren't as i expected and I want someone with deep pockets to blame.
3. Please help me I don't understand that full rated power only occurs when amp is used at the intended mains voltage and frequency, operating with the correct service manual parameters and using the balanced inputs or balanced inputs shorted.
Let's hope it's no 3.
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