Yamaha Integrated Amplifiers Quality and Affordability Unite!

[Schurkey]

I already linked you a detailed article about how the impedance switch works and why its there.

No. You linked me to an article that defines various electrical terms, discusses speaker impedance, how it's measured, how it "used" to be rated, and how it varies with frequency.

NOWHERE does it explain what the impedance switch DOES, and why some amplifiers/receivers have one while others do not.

NOWHERE does it explain what trade-offs are made that require the switch to be employed at all.

That article is not as informative as it could be, and of no real benefit in this discussion.

The Yamaha has NO problems driving 4 ohm speakers other than your distrust based on the misunderstanding of the switch and how Yamaha rates their amplifiers.

I do not "misunderstand" the switch. I freely acknowledge that I have NO understanding of the switch.

I further have little understanding of why Yamaha apparently chooses to under-rate the output power, and not provide a 4-ohm FTC rating at all, considering that the amp is apparently fully-capable of operation into a 4-ohm nominal load. This is not misunderstanding, this is Yamaha being deliberately misleading--although I cannot fathom what they're gaining from it.

Good luck buying a new Phone or HDTV as they are all made overseas.

Inductors and transformers are usually built by underage workers in China for pennies on the dollar. A sad but true reality.

Thank you for agreeing with my point about the destruction of (North) American industry. The further point I'd make is that it seems like you're trying to assert that just because manufacturing certain product segments are extinct in the US, we should willingly accept the imports. I accept them because I'm forced to, not because that's what I actually want.

Slaverey was a sad-but-true reality, but taking action against slavery was the right thing to do.

Lots of stuff will change, when I'm Emperor.

I said my concerns about this product were the Country of Origin, and the current/impedance capacity. Let's wrap-up the political side of this thread. I'd like to know what the impedance switch DOES, whether it's sonically transparent, and why Yamaha needs it (rather than just building the amp more robustly.) In other words, is the existence of the impedance switch prima facie evidence of excessive cost-cutting?

 

[gene]

No. You linked me to an article that defines various electrical terms, discusses speaker impedance, how it's measured, how it "used" to be rated, and how it varies with frequency.

NOWHERE does it explain what the impedance switch DOES, and why some amplifiers/receivers have one while others do not.

NOWHERE does it explain what trade-offs are made that require the switch to be employed at all.

That article is not as informative as it could be, and of no real benefit in this discussion.


I do not "misunderstand" the switch. I freely acknowledge that I have NO understanding of the switch.

I further have little understanding of why Yamaha apparently chooses to under-rate the output power, and not provide a 4-ohm FTC rating at all, considering that the amp is apparently fully-capable of operation into a 4-ohm nominal load. This is not misunderstanding, this is Yamaha being deliberately misleading--although I cannot fathom what they're gaining from it.

Thank you for agreeing with my point about the destruction of (North) American industry. The further point I'd make is that it seems like you're trying to assert that just because manufacturing certain product segments are extinct in the US, we should willingly accept the imports. I accept them because I'm forced to, not because that's what I actually want.

Slaverey was a sad-but-true reality, but taking action against slavery was the right thing to do.

Lots of stuff will change, when I'm Emperor.

I said my concerns about this product were the Country of Origin, and the current/impedance capacity. Let's wrap-up the political side of this thread. I'd like to know what the impedance switch DOES, whether it's sonically transparent, and why Yamaha needs it (rather than just building the amp more robustly.) In other words, is the existence of the impedance switch prima facie evidence of excessive cost-cutting?

My article clearly states what the switch does. It's steps down rail voltage to derate max power so the amp does not exceed a certain temp (65 deg C) when driving a 4 ohm load. They do this to get the UL rating. Most Amps don't have a 4 ohm UL rating hence no swich. The bigger amps that have 4 ohm rating have more heatsink area to not need the switch. You should never use the switch in the low setting unless you're UL running the certification.

This doesn't mean the yamaha can't drive 4 ohm loads.

Unless you can confirm Yamaha is using slave labor to make their products I'd suggest you drop such a claim as it borders on libel.

 

[KEW]

Schurkey, not sure how you missed it, but this post was for you!

http://forums.audioholics.com/forums/threads/yamaha-integrated-amplifiers-quality-and-affordability-unite.94534/page-2#post-1082681

This switch adjusts the circuitry inside the amplifier for either maximum current drive or maximum voltage

 

[Schurkey]

My article clearly states what the switch does. It's steps down rail voltage to derate max power so the amp does not exceed a certain temp (65 deg C)

Please present the paragraph in your article that states what you've just said. I cannot find anything like what you've said after reading that article three separate times. I did a word-search, the words "step" (as part of "steps down") "rail", and "derate" do not appear in the article, neither does "exceed" or "65" as in 65 degrees. I even tried "thermal" as part of "thermal protection". Nope. I tried "power" and got some hits, but none are valid in the context of reducing power supply voltage. Even if you didn't use the exact phrase as you've posted here, I should have found something similar...if it existed.

Am I reading the correct article? I begin to wonder. I'm reading this one:
http://www.audioholics.com/audio-amplifier/impedance-selector-switch-1

Is there a Page 2 that I haven't found? (The last sentence of the article is "The opposite is true for Class D amplifiers, some of which choke when presented with low impedance dips at high frequencies because of potential interactions with their output filter."...right?)

This doesn't mean the yamaha can't drive 4 ohm loads.

I eagerly await your bench-test.

Unless you can confirm Yamaha is using slave labor to make their products I'd suggest you drop such a claim as it borders on libel.

You cannot quote a passage written by me accusing Yamaha of using slave labor, because I have never accused Yamaha of doing that. You could quote me as saying that slave labor is improper, that slave and child labor is still practiced in various countries. For the most part, my outrage is directed against the Communists--China in particular; you'll recall that I said Malaysia is a step UP from China in terms of acceptability.

I'm perfectly happy to continue a politically-centric conversation especially if I can provide further clarification of my position; but I think I've said all I really need to about it. Let's go back to the need for the impedance switch. What is UL demanding that can't be met without the switch? Is UL certification a requirement for home electronics? Why don't all amps have a selector switch?

 

[anamorphic96]

You where linked two bench tests and reviews and you still maintain these Yamaha amps are not comfortable into 4 ohm loads. What more do you need ?

 

[Steve81]

Is there a Page 2 that I haven't found?

Yes.
http://www.audioholics.com/audio-amplifier/impedance-selector-switch-1/amplifier-and-power-supply-basics

and a page 3
http://www.audioholics.com/audio-amplifier/impedance-selector-switch-1/what-is-ul-csa-actually-testing

From page 2:

What the "low impedance" setting accomplished (except for the Yamaha RX-Z11) was to step down the rail voltage fed to the amplifier by the secondary of the power transformer. The unfortunate side effect was clipping at a much lower power level as seen in the tabulated test results. The low switch setting appears to limit the maximum available current draw on the transformer to about 1/3rd (Onkyo TX-NR5007) as much as the high setting so that it would be able to play continuously (at a significantly reduced power level) during the UL/CSA certification testing while generating significantly less heat.

There is no set derating number that manufacturers use as far as I can tell. I surmise that they calculate the maximum power their receiver can deliver at a certain distortion level while still maintaining a low enough temperature so that it will pass UL / CSA certification, deeming it safe to operate into 4-ohm loads. This value depends greatly on how well the amplifier can dissipate heat which is a function of heatsink area and ventilation and also the VA rating (Volts time Amperes) of the power transformer and how much actual power the amplifier can deliver before failing. Realize that the power transformer is wrapped up tight and into a ball. In most cases, manufacturers don't heat sink them but some do add a cooling fan which turns on during high current demands to cool off the power supply. They do put resettable fuses and heat sensing switches inside to prevent them from burning the enamel off the windings. The "low" setting of the switch is providing some protection to the power transformer from blowing up under a continuous maximum power condition into 4-ohm loads, but so is the overload protection circuitry that causes the receiver to shut down if driven into clipping for more than a few seconds in either impedance mode. The low impedance setting is also killing amplifier headroom and maximum available power which will send more distorted and clipped signals to your loudspeakers.

 

[highfigh]

No. You linked me to an article that defines various electrical terms, discusses speaker impedance, how it's measured, how it "used" to be rated, and how it varies with frequency.

NOWHERE does it explain what the impedance switch DOES, and why some amplifiers/receivers have one while others do not.

NOWHERE does it explain what trade-offs are made that require the switch to be employed at all.

That article is not as informative as it could be, and of no real benefit in this discussion.


I do not "misunderstand" the switch. I freely acknowledge that I have NO understanding of the switch.

I further have little understanding of why Yamaha apparently chooses to under-rate the output power, and not provide a 4-ohm FTC rating at all, considering that the amp is apparently fully-capable of operation into a 4-ohm nominal load. This is not misunderstanding, this is Yamaha being deliberately misleading--although I cannot fathom what they're gaining from it.


Thank you for agreeing with my point about the destruction of (North) American industry. The further point I'd make is that it seems like you're trying to assert that just because manufacturing certain product segments are extinct in the US, we should willingly accept the imports. I accept them because I'm forced to, not because that's what I actually want.

Slaverey was a sad-but-true reality, but taking action against slavery was the right thing to do.

Lots of stuff will change, when I'm Emperor.

I said my concerns about this product were the Country of Origin, and the current/impedance capacity. Let's wrap-up the political side of this thread. I'd like to know what the impedance switch DOES, whether it's sonically transparent, and why Yamaha needs it (rather than just building the amp more robustly.) In other words, is the existence of the impedance switch prima facie evidence of excessive cost-cutting?

What do you mean "Let's wrap up the political side of this thread."? That was all you.

 

[gene]

Please present the paragraph in your article that states what you've just said. I cannot find anything like what you've said after reading that article three separate times. I did a word-search, the words "step" (as part of "steps down") "rail", and "derate" do not appear in the article, neither does "exceed" or "65" as in 65 degrees. I even tried "thermal" as part of "thermal protection". Nope. I tried "power" and got some hits, but none are valid in the context of reducing power supply voltage. Even if you didn't use the exact phrase as you've posted here, I should have found something similar...if it existed.

Am I reading the correct article? I begin to wonder. I'm reading this one:
http://www.audioholics.com/audio-amplifier/impedance-selector-switch-1

Is there a Page 2 that I haven't found? (The last sentence of the article is "The opposite is true for Class D amplifiers, some of which choke when presented with low impedance dips at high frequencies because of potential interactions with their output filter."...right?)



I eagerly await your bench-test.


You cannot quote a passage written by me accusing Yamaha of using slave labor, because I have never accused Yamaha of doing that. You could quote me as saying that slave labor is improper, that slave and child labor is still practiced in various countries. For the most part, my outrage is directed against the Communists--China in particular; you'll recall that I said Malaysia is a step UP from China in terms of acceptability.

I'm perfectly happy to continue a politically-centric conversation especially if I can provide further clarification of my position; but I think I've said all I really need to about it. Let's go back to the need for the impedance switch. What is UL demanding that can't be met without the switch? Is UL certification a requirement for home electronics? Why don't all amps have a selector switch?

You have been given many examples of Yamaha products tested into 4 ohm loads. I have explained many times the function of the switch and why its there. I can show you sources, test results, etc, but I cannot learn these things for you.

You may not be saying Yamaha is using slave labor but your implying anything built in China is. You've made your point many times about your views on China but I don't care to hear it any more, especially in this thread and being typed on your chinese made computer. Take it elsewhere.

 

[Schurkey]

Holy crap. The Mother Lode:
From your own article:
http://www.audioholics.com/audio-amplifier/impedance-selector-switch-1/what-is-ul-csa-actually-testing

It is this action being taken by the manufacturers which are playing "specsmanship" with the numbers instead of making the best engineering compromise and publishing both sets of numbers (power into 8 AND 4-ohm loads) for their customers. Until we as consumers demand more complete information from amplifier manufacturers, they will count on our ignorance and optimize their amplifiers for one load (8-ohms for example) and by virtue of the cost/performance analysis decide that the lower power setting needed to secure UL/CSA certification won't preclude their selling the products if the consumer is never going to ask the question, "and what about power into a 4-ohm load?".

and

Why Do Some Receivers NOT Have the Impedance Selector Switch?
There are three reasons actually, with one being the most common with respect to consumer A/V gear as we discuss below:

• The receiver in question has a large enough power transformer, output devices and heatsink area to properly dissipate heat under full 4-ohm power tests (very uncommon, I can count the number of multi channel A/V receivers on one hand that do and still have fingers left over)
  
• The receiver is NOT rated for 4-ohm loads at all (most common)

That's EXACTLY what I've been arguing--and taking flack for!

1. Yamaha isn't publishing a 4-ohm FTC spec, which made me doubt the capacity of the amp to properly-power a low-impedance load.

2. The impedance-matching switch is a cop-out that replaces proper engineering, no doubt with cost-cutting as the ultimate motivation. Conversely, an amp with "enough" power supply, "enough" heat-sink, "enough" output stage--in other words, APPROPRIATELY ROBUST--doesn't need an impedance-matching switch.

3. The consumer is not served by failing to publish 4-ohm (and lower) ratings when there's a great plenty of 4-ohm nominal speakers.


As for the politics, yes I was the first to ask COO, but YOU, Gene, were the one who said it didn't matter--and opened the door to me elaborating on why it DOES matter.

Ok, I get the hint. I'm done with this thread.

My thanks to Steve81 for links to the Page 2 and Page 3 that clarified so much--and which I was utterly unable to find on my own.

My thanks also to Gene, who wrote a considerable share of my own argument in his own words, five years before we got to this thread.

 

[PENG]

My thanks also to Gene, who wrote a considerable share of my own argument in his own words, five years before we got to this thread.

I agree you should thank him, but if you read everything with open mind you will see that what he wrote was useful and professional, yours on the other hand show lack of understanding (not totally, just to be fair). One example: you seem to think just because the speaker's impedance could dip to 4 ohms, you need the receiver to be rated 4 ohm, that is not necessarily true for many reasons. There are speakers that dip to 3 ohms or lower, but 3.X ohm dips are not uncommon at all, so do we insist on manufacturer's to rate their amps for 3 ohms and below?

Even high end amps such as McIntosh, probably among the few that are still designed and built in the USA, has adopted some sort of limiters or auto-transformers (model dependent) and rate their amps for lower impedance with more or less the same output, i.e. no double down rating, not even close. On the bench they will likely still produce more watts into a lower impedance load if you don't change tap though.

Gene's articles talked about not just test lab style "ratings" but also real world practical scenarios where most receivers and amps are used for HT and music, not continuous sine waves/pink/white noises all day long. Some receivers cannot even maintain the same output at impedance much below 8 ohms, such as 6,4 ohms or slightly below, but mid range and above Yamaha receivers typically have no trouble doing that as shown on test benches. This thread is about a stout integrated amp that Gene has indicated the subject amps can do well in he 4 ohm department even though they do not provide a test lab style rating. I understand why you feel "done with this thread.." but please re-read the whole thing and try to understand what others are saying. There are more than one side of a story.

 

[3db]

You where linked two bench tests and reviews and you still maintain these Yamaha amps are not comfortable into 4 ohm loads. What more do you need ?

A shrink perhaps?

 

[RichB]

I wasn't actually saying the differences can't be heard and I should have made that clear. The amplifier measurements don't show dynamic phase variations with music- only a couple of tests use more than one frequency and even then, it's pure sine or square wave. I don't even know if someone has designed something to compare complex waveforms at the input and output, but I think it's time for that.

A comparator testing the input versus output would be ideal to determine performance.

Eventually, I will buy a machine to listen to my system for me

- Rich

 

[udp]

Quick question on these amps -- I have just purchased R55Ti speakers from EmpTek, and am looking for an amp to pair them with. I am deciding between the S501 and S701, and will mostly be using streamed music (FLAC) through a Raspberry Pi + Pi-DAC+ to the analog inputs. Will I notice the difference in power/features between these two amps? It's a huge difference in cost (~2x), and my first system. The room is 30' X 10', and I will never be driving these all that loud.

 

[gene]

Quick question on these amps -- I have just purchased R55Ti speakers from EmpTek, and am looking for an amp to pair them with. I am deciding between the S501 and S701, and will mostly be using streamed music (FLAC) through a Raspberry Pi + Pi-DAC+ to the analog inputs. Will I notice the difference in power/features between these two amps? It's a huge difference in cost (~2x), and my first system. The room is 30' X 10', and I will never be driving these all that loud.

The R55s are relatively easy load to drive. Save your money, get the S501 and add a sub down the road to increase bass extension below 50Hz. A small ported 10" sub will really do wonders to this system more so than a beefier amp.

 

[udp]

The R55s are relatively easy load to drive. Save your money, get the S501 and add a sub down the road to increase bass extension below 50Hz. A small ported 10" sub will really do wonders to this system more so than a beefier amp.

Gene, thank you -- you have relieved me of analysis paralysis. As the speakers are Internet only, I couldn't audition them with both amps. The subwoofer out was a reason I went for the yamaha's, and now I have a start on saving for the sub.

 

[gene]

The EMPs are a good overall sounding speaker that play very loud and clean but they don't have much bass below 50Hz. Coupled with a nice sub, you will get fullrange sound so it's a good investment to get that sub when you can.

 

[udp]

Gene,

Other than the S-10 from EmpTek (which looks like a nice sub), any other recommendations on subwoofers that would pair well with my R55's but would also have a high quality-to-cost ratio?

 

[3db]

Rythmik LV12-R or the F12 are great subs. I own the former and use it for mainly for HT and for classical music. Great sounding sub. .The servo feedback really keeps them stable during bass heavy passages.

 

[Tom._White]

OK, I've got what is likely a dumb question about these integrateds. I noticed in the article, a picture of the front of one of the units. From what I could see, there is not a lighted display?

So, how do you know just how hard you are driving these, if you don't have a readout showing what the volume is set at?

I don't listen to my music very loud, but I do like to know where I am on the volume control.

 

[anamorphic96]

OK, I've got what is likely a dumb question about these integrateds. I noticed in the article, a picture of the front of one of the units. From what I could see, there is not a lighted display?

So, how do you know just how hard you are driving these, if you don't have a readout showing what the volume is set at?

I don't listen to my music very loud, but I do like to know where I am on the volume control.

There is a little notch on the volume control.