Integrated Amp discussion...

[mtrycrafts]

.....
For every interesting article, there is always another that is also interesting, here's one:
https://www.edn.com/design/consumer/4418798/Negative-feedback-in-audio-amplifiers--Why-there-is-no-such-thing-as-too-much
... Just my 0.002 cent.

Interesting that even Doug Self was brought into that discussion.

Are you experiencing negative inflation with that 0.002 cent?

 

[M Code]

There are a handful of USA highly experienced amplifier class A-B design engineers, such as Morris Kessler, Nelson Pass, John Curl, James Bongiorno, Dawson Hadley, Bart Locanthi, Richie Miller and Bob Carver. Through the 70s' and onward, the hi-fi amplifier designs went through multiple cycles as they moved from tubes > solid state, and the advent of digital audio sources stressed the amplifier input & output stages with high dynamic range.. Knowing each of these guys personally I could reiterate various stories as we were heavily involved with their brand/product marketing and amplifiers while each knowing the significant tradeoffs between cost and performance...
However the 1 guy that stands out is Bob Carver, designed/built some of the more successful watts per $ amplifiers for Phase Linear(400 & 700).. Back in the 80s' he had an amplifier face-off challenge with StereoPhile magazine, that provides interesting reading here is the link..

https://www.stereophile.com/content/carver-challenge

I could write a book about my various experiences with each designer, suffice it to say it was most informative, interesting and entertaining experiences.

Just my $0.02..

 

[Matthew J Poes]

Point taken but I think you may be taking that to the extreme. Total is total, if THD is 0.1%, the individual harmonics are not going to be significant compare to one that has 8%. If it is a class AB amps, that 8% THD amp is not going to sound good regardless. I do look at the spectrum graphs as well, some reviews do include them in their bench tests, most don't, unfortunately.

I was intentionally being extreme to make a point but that extreme was based on a real study.

http://www.gedlee.com/Papers/Distortion_AES_II.pdf

See Geddes article looking at actual detection thresholds vs different metrics. Note that one of the THD’s that wasn’t detected as audible was really high.

 

[Mangoman]

Let us know the exact Denon model when you get the chance. The Denon 2800 series were some very well built AVR's with solid amplification. Gene has bemoaned how the build quality of AVR amplification has dropped since then due to having to cram more channels and processing/features in the box without the cost getting out of control.

As has been mentioned above. Figure out your speakers first. Depending on their efficiency, there is a good chance your Denon is a very good device for your needs. I have an AVR-2308ci which has the phono pre-amp built-in. I got it for $65 off Craigslist. Based on comments from @M Code about more recent efforts to reduce AVR costs by using a design life of ~8-10 years, I expect to have a good run with this 11 year old AVR built using very mature standard amp/heatsink design! Since you have no interest in atmos or any of the other latest greatest features, why change?

As for speakers, check out the Martin-Logan electrostatic speakers (BestBuy with Magnolia Room is one place you can hear these) as something that sounds totally different from most other speakers without sounding "wrong". Not saying you will or should prefer them, but something you should check off your list before you buy your "final" speakers!

Where are you located? I wouldn't give out my street address, but if you are near a metropolitan area or simply what state will help us help you. For example, if you are in Michigan, you would do well to visit Jim Salk and check his speakers!
http://www.salksound.com/model.php?model=SS 8

If in the Atlanta Area, I know where you can hear some good speakers in your price range.

Ah! I see you are in (or near) Minneapolis! I only know of one great system in that area, but the speakers are all DIY!

Ok. Got to reply to this finally. Busy with work. The Denon is an AVR 2311 CI.

I think what I am looking for is something more simplistic, and more oomph. Probably does start with the speakers.

I have listened to the BW 800d3 and it was impressive. But not that much more impressive than some of the KEFs I listened to that day. Cool deal though.

I’m in Minneapolis so I tend to listen mostly at Stereoland and at Halston in my metro area. The magnolia guys always push the McIntosh and BWs every time I’m in there.

For reference my Klipsch are RF15 towers and the RW 10 sub. Along with the center and tears that go with that group. Wish the bass was more articulate vs boomy and the speakers had a more in-depth soundstage. I can live with highs that aren’t overly lively but present.

 

[lovinthehd]

Ok. Got to reply to this finally. Busy with work. The Denon is an AVR 2311 CI.

I think what I am looking for is something more simplistic, and more oomph. Probably does start with the speakers.

I have listened to the BW 800d3 and it was impressive. But not that much more impressive than some of the KEFs I listened to that day. Cool deal though.

I’m in Minneapolis so I tend to listen mostly at Stereoland and at Halston in my metro area. The magnolia guys always push the McIntosh and BWs every time I’m in there.

For reference my Klipsch are RF15 towers and the RW 10 sub. Along with the center and tears that go with that group. Wish the bass was more articulate vs boomy and the speakers had a more in-depth soundstage. I can live with highs that aren’t overly lively but present.

I'd definitely settle on new speakers/sub(s) before worrying about the electronics (but would possibly move on from the 2311).

 

[Matthew J Poes]

Ok. Got to reply to this finally. Busy with work. The Denon is an AVR 2311 CI.

I think what I am looking for is something more simplistic, and more oomph. Probably does start with the speakers.

I have listened to the BW 800d3 and it was impressive. But not that much more impressive than some of the KEFs I listened to that day. Cool deal though.

I’m in Minneapolis so I tend to listen mostly at Stereoland and at Halston in my metro area. The magnolia guys always push the McIntosh and BWs every time I’m in there.

For reference my Klipsch are RF15 towers and the RW 10 sub. Along with the center and tears that go with that group. Wish the bass was more articulate vs boomy and the speakers had a more in-depth soundstage. I can live with highs that aren’t overly lively but present.

For bass, I think you might find that the best bass will come from a multitude of quality subs appropriately sized for your needs. My preference is three. The reason is that if you place the subwoofers strategically around the room, you can dramatically reduce the effects of modes and other reflection based distortions.

Gaining the capacity to measure also helps with getting them setup correctly. Boominess is often caused by a response with big peaks and cancelations. The peaks cause ringing along with emphasis of those note. EQ can help but is not a perfect solution. Sometimes your seat just happens to be in a null and moving the sub might fix that only to mess something else up. Multiple subs tends to provider a larger sweet spot for the low frequencies and provides a better pallete on which to eq.

 

[AcuDefTechGuy]

I have listened to the BW 800d3 and it was impressive. But not that much more impressive than some of the KEFs I listened to that day.

That’s the salient point.

If the ultra-expensive speakers don’t sound that much better than the less-expensive speakers you like, then the ultra-expensive speakers aren’t worth the extra money.

You would know for sure because you have listened to those expensive speakers.

 

[KEW]

Maybe I'm just a dinosaur about audio amplifiers, but I still can't get past the fact that the Hypex measurements must be done with AES17 brick wall filters. I'm fine with Class D amps in my subwoofers (since they're used with a low-pass filter anyway) ,but I just can't get comfortable feeding that ultrasonic crap to my over-priced tweeters. Or has there been a Class D innovation introduced I'm not aware of?

That’s a measurement issue more than a practical one. Your talking about switching noise of ~300mv at 450khz. Your tweeter won’t reproduce that nor will it likely damage them. The inductance and capacitance is the cables and tweeter coil should itself dampen that quite a bit. I guess it isn’t a problem that concerns me.

At what frequencies is the AES17 filter effective?
Help me understand why noise at 450kHz would need to be filtered from measurements. If the noise is only at 450kHz, it seems reasonable to discount them from the measurement as irrelevant due to frequency.

 

[Mikado463]

That’s the salient point.

If the ultra-expensive speakers don’t sound that much better than the less-expensive speakers you like, then the ultra-expensive speakers aren’t worth the extra money.

You would know for sure because you have listened to those expensive speakers.

and that too is the 'salient' point, for if he new of the two speakers and their respective price points going in chances are(perhaps) his pre-listening biases lessened the heard differences to where he minimized the difference. Whereas someone who couldn't care less about the $$ differential could do just the opposite and claim the 'night and day' proclamation ........

 

[Irvrobinson]

At what frequencies is the AES17 filter effective?
Help me understand why noise at 450kHz would need to be filtered from measurements. If the noise is only at 450kHz, it seems reasonable to discount them from the measurement as irrelevant due to frequency.

AES17 filters are supposed to be 60db down above 24KHz. See:

https://www.ap.com/technical-library/selecting-appropriate-aes-17-pre-analyzer-filters-for-the-2700-series-analyzers/

Hypex specifies the 20KHz brick wall filter when doing measurements, as does every other Class D amp I'm aware of, but I admit that I don't follow this field very closely, nor have I seen unfiltered measurements to compare filtered measurements to.

 

[Kvn_Walker]

How happy are you with the Klipsch sound? You could spring for a pair of RF-7 III's well within your budget if that tonal quality is something you'd like to keep. Most likely you'd be able to find a pair of those to demo, since Klipsch is very mainstream.

For that same price ($3400/pr) there's also the Canton A45, but since only 3 pairs are left in the country there's likely no way you could hear them first. I will say that my one Canton experience was amazing, and I only had the bottom-of-the-line GLE towers. Many members of this forum have Canton Chrono and Vento speakers and can't praise them enough. But it's a 180 degree sound from the "in your face" Klipsch experience.

 

[AcuDefTechGuy]

and that too is the 'salient' point, for if he new of the two speakers and their respective price points going in chances are(perhaps) his pre-listening biases lessened the heard differences to where he minimized the difference. Whereas someone who couldn't care less about the $$ differential could do just the opposite and claim the 'night and day' proclamation ........

How dare you! I’m the only one here allowed to use the word “salient”!

Once we have gained a lot of experience in auditioning many high-end speakers, I feel that we will have a lot of confidence in determining whether one speaker truly sounds much better than another.

Of course, without a true double-blind test, there will always be bias.

But for our everyday regular life (not a formal publication), I think that’s good enough.

 

[PENG]

How dare you! I’m the only one here allowed to use the word “salient”!

I used that word many years ago when in college specializing in power and motors/generators for a year, though admittedly you may be first in terms of using that word HERE.

 

[Irvrobinson]

How dare you! I’m the only one here allowed to use the word “salient”!

I just thought you were the only person here who *wanted* to use the word "salient". I thought it might be a requirement once you became a professor, since salient is an assertive way of ascribing importance, and I thought you folks had to take training in that sort of thing. ;-)

 

[KEW]

AES17 filters are supposed to be 60db down above 24KHz. See:

https://www.ap.com/technical-library/selecting-appropriate-aes-17-pre-analyzer-filters-for-the-2700-series-analyzers/

Hypex specifies the 20KHz brick wall filter when doing measurements, as does every other Class D amp I'm aware of, but I admit that don't follow this field very closely, nor have I seen unfiltered measurements to compare filtered measurements to.

I certainly understand your concern. If the "side-effects" of the Hypex design are limited to 450kHz, there is certainly no need to limit the measurement at 20kHz. A filter at something like 100kHz would easily eliminate these extremely high frequency artifacts while eliminating any concern of the speaker being subject to undesirable signals.
On the one hand, I have a hard time imagining the many companies that have adopted Class D all colluding to hide some real undesirable effect from these amps, but on the other, why do they want/need a 20kHz filter.
...and on the third hand, if a filter at 20kHz is needed for measurement, why not just add one to the amp so there are no concerns of ultrasonic noise reaching the speaker?
@gene , can you help explain what this is about ... or measure a class D amp to see what happens at frequencies above 20kHz

 

[Irvrobinson]

, if a filter at 20kHz is needed for measurement, why not just add one to the amp so there are no concerns of ultrasonic noise reaching the speaker?

I can't answer your other questions, but I think the filter would have to be right before the speaker terminals, after the output stage, which for high-powered amps would make the filters impractical.

 

[KEW]

I used that word many years ago when in college specializing in power and motors/generators for a year, though admittedly you may be first in terms of using that word HERE.

Actually, that would be in February of 2004, when the beloved and esteemed Audioholic member know as "Guest" eloquently used the term in conjunction with "highly" so as to add emphasis to the salience in question!

Actually, pointing out Sunfire's trade-in program is highly salient specifically b/c of price point.  Some folks over on AVS chose to defend IR if they should choose to leave RDC7 owners high and dry.  Some of us tried pointing out other examples of companies offering upgrades and tradeins on their pre/pros, and one of the most common counter arguments was "well sure, company X can offer a trade in b/c they charge so much for the product.

https://forums.audioholics.com/forums/threads/integra-research-rdc-7-1.1723/page-5#post-8948

 

[Mikado463]

Bob Carver used to be regarded as a 'lord and savior' of the objective crowd many years ago. However, many from that side now believe he has since gone 'rogue' especially when he's peddling stuff like this from his site.

https://www.bobcarvercorp.com/silver-seven

That picture says it all. A horse-drawn wagon going from town to town selling an audiophile tube cure-all designed for any chronic solid-state conponent ailments.

Wow, talk about 'space heaters' !!

 

[PENG]

I certainly understand your concern. If the "side-effects" of the Hypex design are limited to 450kHz, there is certainly no need to limit the measurement at 20kHz. A filter at something like 100kHz would easily eliminate these extremely high frequency artifacts while eliminating any concern of the speaker being subject to undesirable signals.
On the one hand, I have a hard time imagining the many companies that have adopted Class D all colluding to hide some real undesirable effect from these amps, but on the other, why do they want/need a 20kHz filter.
...and on the third hand, if a filter at 20kHz is needed for measurement, why not just add one to the amp so there are no concerns of ultrasonic noise reaching the speaker?
@gene , can you help explain what this is about ... or measure a class D amp to see what happens at frequencies above 20kHz

He did say "Maybe I'm just a dinosaur about class D audio amplifiers............." that is, after I fixed it for him..

 

[KEW]

He did say "Maybe I'm just a dinosaur about class D audio amplifiers............." that is, after I fixed it for him..

...and in fairness to Irv (for those that don't know the history on this),he does not attempt to argue that there is a problem with Class D amps, only that it is a possible concern which he chooses to avoid given there are fine A/B amps available at prices he is willing to pay to avoid living in Class D anxiety!

My personal experience with Class D has been great, but if I had Salon 2's (or whichever model Irv has) with expensive Be tweeters that do play well into the Ultrasonic frequencies, I would probably avoid class D as well. Actually, Focal made that decision on my Solo/Twin6 Be pro-audio speakers. They use a class D amp for the mid-woofer and a class A/B amp for the Be tweeter!