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Why do so many prefer the sound of "Class A" amplification vs. "linear" amps?

Chrispy

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I infer that there could be up to 4000 of Ver2. So if that is reasonable then they must be in rare quantity.
I read it more that the original series had SNs starting with 10000 but nothing beyond that. The later version having SNs starting with 6000 I took to mean they didn't expect to make more than 4000 of them....but again no indication of actual production. Hard to know....
 

Doodski

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I read it more that the original series had SNs starting with 10000 but nothing beyond that. The later version having SNs starting with 6000 I took to mean they didn't expect to make more than 4000 of them....but again no indication of actual production. Hard to know....
I searched Canuck Audio mart and Kijiji and I found 2 pair of Apogee panels for sale. That's basically all of Canada unless you are not connected and strapped into the net.
 

Chrispy

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I searched Canuck Audio mart and Kijiji and I found 2 pair of Apogee panels for sale. That's basically all of Canada unless you are not connected and strapped into the net.
I figure there aren't likely a whole bunch that have survived this long in any case. Just curious....
 

Doodski

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I figure there aren't likely a whole bunch that have survived this long in any case. Just curious....
Well. One Dood wanted about $3500 and the other $2800 in Canadian funds for a pair. One guy complained about a slight rattle at elevated volume levels. I read that the drivers last but the adhesive strip between the driver and the surround breaks down and requires replacement.
 

Chrispy

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Well. One Dood wanted about $3500 and the other $2800 in Canadian funds for a pair. One guy complained about a slight rattle at elevated volume levels. I read that the drivers last but the adhesive strip between the driver and the surround breaks down and requires replacement.
Curious if the ribbons were robust, too. A weakness with the similar looking Carver Amazing speakers I had....
 

Doodski

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Curious if the ribbons were robust, too. A weakness with the similar looking Carver Amazing speakers I had....
z apogee  z.png
 

Axo1989

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Where is the spec for BTU's ? :)

Haha. As it happens, Krell do list BTUs (no apostrophes for plural, come on) for Evolution series, which I consider peak Krell (they didn't do BTU for all their products, sadly). We have the first series, and the e-series, which have an additional low current standby mode. They are class A, but with proprietary plateau bias so they don't run hot until they need to. The peak output is instructive (and pretty much what standard class A would put out constantly) and also an indication why we don't have many 900 watt class A amps without power management on offer.

Here's original series 600/1200/2400 and 900/1800/3600 watt (into 8/4/2 Ω) monoblocs (left and right respectively). Remember to multiply by two for stereo.

Screen Shot 2022-10-09 at 10.12.04 am.png


Here's the e series (they are the ones to get, obviously).

Screen Shot 2022-10-09 at 10.11.42 am.png


I've spent a bit of time listening to the baby 400 monoblocs driving Focal Grande Utopia. They do ok.
 
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Paolo

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I commend him on trying. The problem is that he (the father) alternated every single time, never going out of his alternating order. He needed to pull it and re-plug it into the same one a few times to mix it up. The test is basically invalid as the father was helping and just didn't really know what to do except change it when his son told him too. Great attempt, it just needed a bit more to make it "in the home valid". I will not tear it apart but leave it as a botched attempt. But, if he does it again with some minimal advice from me (I try to be helpful) he will get the answer he seeks. He now thinks the results are fantastic and that as he stated, "he is not crazy". If I helped him doing maybe two or three things different he would have seen that he could not reliably tell the difference. Oh well.
Joshua often talks about how well amps and DACs measures. Seems like he looks at ASR, but then magically forget things about proper testing when it’s time to suggest expensive pieces of equipment. Otherwise how can you say to hear differences between the two Topping amps with a straight face?
 

Steven Holt

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no inherent advantage in practical terms for a class A.
I will agree with that. In terms of a pure, clean sound that throws off very little heat, the best amp I own is my topping pa3s. I have prettier amps, but none better.
 

Vacceo

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I will agree with that. In terms of a pure, clean sound that throws off very little heat, the best amp I own is my topping pa3s. I have prettier amps, but none better.
In fact, smaller and cooler means better to build active speakers and in general, friendlier to work with.
 

jim1274

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We used Energy Pro22, Energy Reference 22 and the KEF 104.2 and did a listen both in the repair shop and at home because 2 of us techs bought and used the same class A amps at home. The Pro22 and the Reference 22 are revealing speakers in that they sound good with a average amp but if using a really good amp they perk up and come alive. I wish I still had the class A amp in mind because with all the excitement in the magazines of the time, all the listener tests and my own tests showed that it is a very smooth amp. Almost tube like. I suspect the amp is colored but if it is they did a wonderful job of smoothing things out and making it a high power class A.

I could not resist replying to this, about the only reference to the Energy 22 on the forum. I have and still use 2 pairs of the Reference Conn floor standing version, and just recently purchased a Benchmark AHB2 and pulled the 22s and and 3 other Speakers into the living room for a little speaker shoot-out. I always played the 22s with pretty good amps and they sounded good, but nothing near the level of an AHB2—forgot how good these could sound. The first time I heard them at a boutique joint in Chicago (1984) in a proper acoustically listening room with SOTA front end, I was mesmerized. This session using the Bemchmark like a flashback to 1984—second your comment on really good amp making them sing. My room acoustics are pretty good, but it’s not like that finely tuned demo room, so maybe not the same exact magic of 1984. I don’t remember much of the front end beyond a Linn turntable to play our MFSL albums brought with (and some CD’s they had—didn’t get my first CD player until 1985)
 

Ricardus

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I could not resist replying to this, about the only reference to the Energy 22 on the forum.
I had a pair of Pro 22's that I bought in 1988 and I ended up putting them into a dumpster when I moved 18 months ago. I think one of the tweeters only needed ferro-fluid but I had no more room in my U Haul so I left them behind.
 

jim1274

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I had a pair of Pro 22's that I bought in 1988 and I ended up putting them into a dumpster when I moved 18 months ago. I think one of the tweeters only needed ferro-fluid but I had no more room in my U Haul so I left them behind.

Good thing they weren’t the floor stander Ref Conns…the Pro Monitors you get a pass—I recently did the same after pulling the drivers from a pair for spares. That’s the one downside to 22s—the tweeters need “maintenance”. Not sure how many other speakers have/had tweeters that need ferro-fluid periodically replaced? I just fairly recently had the tweeters for 2 pairs refurbished. With fresh fluid and fully restored to new OEM spec, they can still sing. I have had a lot of speakers come and go here, but still use and enjoy my 22s. There is a guy who still services and rebuilds the drivers if anyone out there wants to keep theirs going:


Great guy and great service from my experience. Not cheap to rebuild, but worth every penny to restore a 22 to new performance.
 

Ricardus

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Good thing they weren’t the floor stander Ref Conns…the Pro Monitors you get a pass—I recently did the same after pulling the drivers from a pair for spares.
Yeah, I used to dream about getting the Reference series. They served me faithfully for many decades. I actually blew a tweeter back in the late 80s and Energy sent me a replacement.
 
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jim1274

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Yeah, I used to dream about getting the Reference series. They served me faithfully for many decades. I actually blew a tweeter back in the late 80s and Emergy sent me a replacement.

Good to hear that. I was getting worried other forum members would just do eye-rolls and think that old geezer is still stuck in the early 80’s. I’m just trying to contribute, and bet if someone came across cheap or free broken ones, they would be surprised what a few hundred bucks invested in tweeter restoration to as new would sound like. If anyone lives in Canada, they probably could find a pair fairly easy—seems like a lot more were sold their given country of origin.

Just for the heck of it, I checked eBay and Canuck Audio Mart and prices have gone up a fair amount in last 10 years. None for sale now on EBay, but a really nice looking pair of the monitors sold for $399, but no tweeter “refreshing” noted, so not a particularly good deal. The large stand mount Monitor version uses the same drivers, but the floor mount with larger displacement digs a bit deeper and looks better. Canuck Audio Mart has a few 22s, but $850 for the Ref Conn floor model like mine with fresh tweeters. Not that I don’t think they are worth it, but no longer in bargain territory..or maybe so…. Also saw a pair of the monitors with original stands in good condition with rebuilt tweeters for $400, a good price to me. Good thing they are not close to me or I probably could not resist myself…
 
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