Digital vs Analog Volume Control, does it matter? Options

[Arnold B. Kruege...]

Your B-stock RX-V371 does have a full warranty, a full B-stock warranty, which is half as long as that of a new RX-V371 warranty (two years, parts and labor). As is common with other brands, cosmetic defects on the faceplate, cabinet, and remote are not covered on Yamaha B-stock units, although their occurrence is probably rare and obviously they don't detract from the electrical performance.

It was appliance store B-stock. A demo that appeared to have never been powered up. Everything was there but the box. The sales documentation was indistinguishable from that for a new, in-box product except for the bottom line price.

[Arnold B. Kruege...]

Doubt it would fail ABX means what, exactly?

Failing an ABX would be my shorthand for saying that it would be audibly different from any other good amp.

Passing an ABX would be to me a failure to find a statistically significant difference in comparison with an ideal device.

Sounds to me like you're saying you believe your AVR will be distinguishable from the more expensive ones.

No, the opposite. I believe that my AVR will be indistinguishable from the more expensive ones.

Sorry for any confusion.

[greynol]

Thanks for the clarification. I am under the impression that most here would consider 20/20 to be a passing test.

If one considers that the null hypothesis is what is being tested then 20/20 would strongly suggest the outcome is indeed a failure.

This post has been edited by greynol: Feb 22 2013, 17:58

[db1989]

I would consider p > 0.05 to be a failed test, given that the results fail to reject the null hypothesis. The device fails to sound different; the user fails to hear a difference.

Saying that failure would be equivalent to an audible difference is confusing and, at best, highly context-sensitive to whether the device that produces a statistically significant result sounds better or worse to the individual tester.

ABX does not necessarily address better or worse, just audibility. Using positive and negative adjectives is bound to lead to misunderstandings, especially when they don’t align well with the usual scientific terminology.

I acknowledge that I’m talking to the inventor of ABX here! I’m not claiming any mistakes, just a potential source of confusion.

[mzil]

Your B-stock RX-V371 does have a full warranty, a full B-stock warranty, which is half as long as that of a new RX-V371 warranty (two years, parts and labor). As is common with other brands, cosmetic defects on the faceplate, cabinet, and remote are not covered on Yamaha B-stock units, although their occurrence is probably rare and obviously they don't detract from the electrical performance.

It was appliance store B-stock. A demo that appeared to have never been powered up. Everything was there but the box. The sales documentation was indistinguishable from that for a new, in-box product except for the bottom line price.

I assumed from your wording you meant you bought a "B-stock Yamaha RX-V371 A/V receiver", they have the half length warranty I was speaking of, no guarantee against blemishes, and should (in theory at least) have a stamp on the box, often red, which indicates that they are B-stock goods with a shorter warranty [although the original warranty card may still be left in the box, as well]. What you bought now sounds more like a "showroom floor model" (at least that's what customers are sometimes told, in truth they could be customer returns). Those, if bought from an true authorized dealer, not a parallel importer, have a full electrical performance warranty from Yamaha as if they were factory sealed A-stock (2 yrs P/L).

[Arnold B. Kruege...]

I would consider p > 0.05 to be a failed test, given that the results fail to reject the null hypothesis. The device fails to sound different; the user fails to hear a difference.

Saying that failure would be equivalent to an audible difference is confusing and, at best, highly context-sensitive to whether the device that produces a statistically significant result sounds better or worse to the individual tester.

ABX does not necessarily address better or worse, just audibility. Using positive and negative adjectives is bound to lead to misunderstandings, especially when they don’t align well with the usual scientific terminology.

I acknowledge that I’m talking to the inventor of ABX here! I’m not claiming any mistakes, just a potential source of confusion.

I confess that I treat online forums as casual conversation, and I'm more careless when I'm posting on them than I am when I'm giving a paper to a professional organization. ;-)

At any rate I don't expect my RX-v371 to sound any different than any of the far pricier and impressively branded stuff that is hanging around the house now or at some other time. I know what's in the box in pretty good detail, and I've read enough tech tests of popular-priced AVRs to believe that most AVRs are pretty blameless.

There is a lot of confusion over the fact that most AVR's can't operate all channels at maximum power concurrently with pure test tones and resistive loads. However as actually used to play music and multichannel source material, that isn't a real-world test. For one thing the worst case music I've ever tested had at least a 6 dB crest factor, which means that it takes 4 channels playing music to equal the average energy of 1 channel playing a pure sine wave with the same peak level.

AVRs are typically used with subwoofers, which further eases the demands on their typically minimalistic power supplies.

Historical perspective: When we did our initial ABX tests of audio amplifiers we were mystified by how insensitive our tests seemed to be to obviously measurable faults. Now something like 20 years on the other side of Zwicker and Fastl and the Perceptual Coder revolution, it all makes sense. ;-)

[Arnold B. Kruege...]

Your B-stock RX-V371 does have a full warranty, a full B-stock warranty, which is half as long as that of a new RX-V371 warranty (two years, parts and labor). As is common with other brands, cosmetic defects on the faceplate, cabinet, and remote are not covered on Yamaha B-stock units, although their occurrence is probably rare and obviously they don't detract from the electrical performance.

It was appliance store B-stock. A demo that appeared to have never been powered up. Everything was there but the box. The sales documentation was indistinguishable from that for a new, in-box product except for the bottom line price.

I assumed from your wording you meant you bought a "B-stock Yamaha RX-V371 A/V receiver", they have the half length warranty I was speaking of, no guarantee against blemishes, and should (in theory at least) have a stamp on the box, often red, which indicates that they are B-stock goods with a shorter warranty [although the original warranty card may still be left in the box, as well]. What you bought now sounds more like a "showroom floor model" (at least that's what customers are sometimes told, in truth they could be customer returns). Those, if bought from an true authorized dealer, not a parallel importer, have a full electrical performance warranty from Yamaha as if they were factory sealed A-stock (2 yrs P/L).

Well yes. You are thinking that B-stock has a fairly narrow meaning, and I've been around retailing long enough to think that B-stock has a fairly broad definition. I've bought a ton of B-stock, held my nose over the warranty situation and almost always laughed all the way to the bank. I see that some formal definitions of B-stock don't include refurbs, but that's not how I was raised!

[mzil]

You are welcome to define "B-stock" however you please, however Yamaha has a clear definition, marks such products appropriately, and the warranty is not the same as A-stock as your original post suggested by the use of the words "full warranty " in terms of both what it covers and the time period length:

The last AVR I purchased (Yamaha RX -V371) was B stock and cost me $118 with full warranty.

What is the difference between A-stock, B-stock, and C-stock Yamaha products

I agree such units are often a good bet, however I wouldn't want anyone reading your post to think that Yamaha B-stock goods have the same full warranty as A-stock. They do not.

[Porcus]

... no wonder the layman thinks that statisticians are a bunch of kooks when a significantly higher-than-normal rate of horse-kick fatalities is counted as a “success”. Well they should have learned by now that a positive HIV test is not positive for you.

[Stephan37]

Wow, thanks for all the input here.

This is what I've learned so far, correct me if I'm wrong.

- Digital volume setting is as good as analogue if not better, but both are audibly fine (you can't hear a difference anyway)

- it's unneccesary that receivers have built in a digitally controlled analog volume setting

- today's AVRs are transparent and buying a cheap one doesn't mean that you are going to loose anything (sound-wise)

So a normal-priced AVR it will be. Thanks again for the enlightenment and your effort.

[Arnold B. Kruege...]

- Digital volume setting is as good as analogue if not better, but both are audibly fine (you can't hear a difference anyway)

- it's unnecessary that receivers have built in a digitally controlled analog volume setting

So much so that TI's web site shows an AVR with just a DSP driving a power amp.

Just guessing, but products being designed in the next few years will drop the analog volume control.

- today's AVRs are transparent and buying a cheap one doesn't mean that you are going to loose anything (sound-wise)

So a normal-priced AVR it will be. Thanks again for the enlightenment and your effort.

That's the message I wanted you to receive.

This post has been edited by Arnold B. Krueger: Feb 23 2013, 18:44

[knutinh]

I do believe that the signal processing software in AVRs differ? There are many ways to map N channels of content to M channels of loudspeakers, and if you want room/loudspeaker correction, that is another differentiatior

[Arnold B. Kruege...]

I do believe that the signal processing software in AVRs differ? There are many ways to map N channels of content to M channels of loudspeakers, and if you want room/loudspeaker correction, that is another differentiatior

Much of the DSP code might be a lot less variable than one might think. A big chunk of the DSP code has to be licensed by people like DTS and Dolby who are pretty sophisticated and careful. They appear to be the developers of much of it. It appears to be primarily distributed through chip manufacturers. Of the major AVR manufacturers, only Yamaha appears to have the technical resources to actually develop this sort of programming in depth.

One major variable among AVRs from various manufacturers and at various price levels is the automated system optimization software, IOW Audyssey, MCACC and YPAO. How this software works can reasonably expected to introduce sonic variations that are easy to reliably detect in a good level-matched, time-synched, double blind listening test. Some of those variations may even have strong random components.

[mzil]

The Marantz I bought recently (over $1000 USD) is rather awkward in how the volume up and down ramp speed varies depending on ...

A slight correction, since I can no loner edit that original post. The Marantz unit I own has no power amp section, so it is not really a receiver. It calls itself an "AV Pre Tuner" but most forum people seem to refer to it as a "prepro".

[knutinh]

Much of the DSP code might be a lot less variable than one might think. A big chunk of the DSP code has to be licensed by people like DTS and Dolby who are pretty sophisticated and careful. They appear to be the developers of much of it. It appears to be primarily distributed through chip manufacturers. Of the major AVR manufacturers, only Yamaha appears to have the technical resources to actually develop this sort of programming in depth.

The codecs themselves probably have reference implementations, compliance tests etc. My guess is that working with them consists mainly of optimizing cycles for a given dsp architecture. It seems that some (typically new/exotic) codecs have license conditions that ensure that they will be included only in more expensive receivers.

The processing after decoding is more open. I believe that there have been a number of "bugs"/undesirable features wrgt e.g. bass management in different receiver products. The user generally just wants things "to work" given an ever-increasing list of possible input formats.

One major variable among AVRs from various manufacturers and at various price levels is the automated system optimization software, IOW Audyssey, MCACC and YPAO. How this software works can reasonably expected to introduce sonic variations that are easy to reliably detect in a good level-matched, time-synched, double blind listening test. Some of those variations may even have strong random components.

As seen e.g. here:
http://seanolive.blogspot.com/2009/11/subj...luation-of.html

Moreover, perceptually motivated level control was a topic when I did my last purchase.

-k

[Arnold B. Kruege...]

As seen e.g. here:
http://seanolive.blogspot.com/2009/11/subj...luation-of.html

Unfortunately that article is now 4 years old and that can be pretty deadly with a fast-moving technology.