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Post by Boomzilla on Sept 14, 2020 13:08:39 GMT -5
Yes - high powered amplifiers provide better damping factor regardless of loudspeaker sensitivity.
But... My 12 watt tube mono blocks sounded better regardless of their theoretical deficiencies. And my ears aren't the only ones that thought so.
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Post by Deleted on Sept 14, 2020 14:32:51 GMT -5
Yes - high powered amplifiers provide better damping factor regardless of loudspeaker sensitivity. But... My 12 watt tube mono blocks sounded better regardless of their theoretical deficiencies. And my ears aren't the only ones that thought so. Hey boom! What amps are you using? I created a thread here and looking for recommendations: emotivalounge.proboards.com/thread/57658/tube-amp-recommendations |
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Post by Boomzilla on Sept 14, 2020 14:57:59 GMT -5
Alas, these are one-of Frankenamps. I found two Heathkit monophonic integrated amplifiers at a yard sale & then stripped out the phono-EQ & preamp sections. Replaced all the caps & resistors & what's left is 12 watt mono power amps. To my knowledge, nobody else has any exactly like these. I must also give credit to audiobill who generously coached me through a few of the oddities of the conversion. Nevertheless, on a good day, these little imps are really, really GOOD sounding! What makes them so spiffy? Well, it isn't flat frequency response, nor is it any ability to play at auditorium levels. They also have a tendency to hum if you don't have the power cords plugged into the same socket as the preamp. They also have an order of magnitude more background noise than any solid-state amplifier. And the amps are not at their best with 4-ohm speakers. But despite these flaws, they have dynamics much better than the average amp (tube or solid-state). They also have micro-dynamics that most other amplifiers just can't get right. And finally, they are super detailed. You can hear into the recording more deeply than other amps I've owned & heard. So within their limitations, they're awesome. But they're DEFINITELY not "jack of all trades." |
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Post by Boomzilla on Sept 15, 2020 9:09:59 GMT -5
Hi @shimei A passing comment about tube amplifier burn-in. I have noticed, that on multiple vacuum tube power amplifiers, the sound of the amp changes considerably during the first 50 hours (or less) of use. Changes how? With a brand-new, never turned on, vacuum tube power amplifier, the first few hours of use sound significantly different. The "new" amplifier sounds FAR more dynamic, and significantly less linear (in terms of frequency response). With those dynamics come a shocking amount of detail that the amplifier may never display again during its service life. This makes the "new" tube amplifier sound significantly more transparent than it will later. Once the power amplifier has some running time (anywhere from 10 to 50 hours of use), the frequency response becomes more linear, but at the expense of dynamics and transparency. This is (usually) NOT a subtle change. The amplifier may still sound "good," but never again like it did when it was brand new. Why is this so? Initially, I hypothesized that the resistors and capacitors were changing their sound during the "burn-in" period, but I've never found a single solid-state power amplifier that displayed this magnitude of change. So I'm left to speculate, instead, that it's the output tubes themselves that cause this. Why not the driver or splitter tubes? Because tube preamplifiers (in my experience) don't exhibit this phenomenon, or at least not to the same extent. This theory would be easy to test - Get a new tube power amp, let it burn in until the initial "bloom" had passed, and then plug in a brand new set of output tubes. Unfortunately, I've not taken the opportunity to test this. I've also noticed that the greater the number of output tubes, the greater the audible change that occurs during the "burn in" period. A tube power amplifier with, for example, eight or even four output tubes per channel exhibits this phenomenon to a significantly greater degree than an amp with only two output tubes. In fact, I'd almost propose a strong inverse correlation between the number of output tubes and how good the amplifier will sound once fully broken in. The very best sounding tube amplifiers that I've owned have all had two and only two output tubes. Of course, this limits the ultimate output wattage available, but to my mind, I'd rather have better sound than more watts. I've also noticed that some amplifier circuitry is more highly prone to the "burn in phenomenon" than others. My Heathkit mono amps, for example, still sound close to new despite the time that I've put on them. They use but two output tubes per channel. The Vacuum Tube Audio M-125 mono block amplifiers, on the other hand, came with four output tubes (the amps have the capability of being run with four output tubes at 125 Watts or two output tubes at 60 Watts). With four tubes, and despite their initially excellent sound, once fully broken in, I found that the thrill was gone. In fact, one of my friends labeled them "the worst-sounding tube amplifiers he'd ever heard." I sold the amps to an audio amigo without bothering to try the amps in their "two-tube output mode." I now wish I'd tried them with only two output tubes - I bet they'd have sounded significantly better! And that concludes my tube power amplifier contemplations. YMMV Boomzilla PS: audiobill - Your thoughts? |
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Post by Deleted on Sept 15, 2020 9:50:23 GMT -5
Hi @shimei A passing comment about tube amplifier burn-in. I have noticed, that on multiple vacuum tube power amplifiers, the sound of the amp changes considerably during the first 50 hours (or less) of use. Changes how? With a brand-new, never turned on, vacuum tube power amplifier, the first few hours of use sound significantly different. The "new" amplifier sounds FAR more dynamic, and significantly less linear (in terms of frequency response). With those dynamics come a shocking amount of detail that the amplifier may never display again during its service life. This makes the "new" tube amplifier sound significantly more transparent than it will later. Once the power amplifier has some running time (anywhere from 10 to 50 hours of use), the frequency response becomes more linear, but at the expense of dynamics and transparency. This is (usually) NOT a subtle change. The amplifier may still sound "good," but never again like it did when it was brand new. Why is this so? Initially, I hypothesized that the resistors and capacitors were changing their sound during the "burn-in" period, but I've never found a single solid-state power amplifier that displayed this magnitude of change. So I'm left to speculate, instead, that it's the output tubes themselves that cause this. Why not the driver or splitter tubes? Because tube preamplifiers (in my experience) don't exhibit this phenomenon, or at least not to the same extent. This theory would be easy to test - Get a new tube power amp, let it burn in until the initial "bloom" had passed, and then plug in a brand new set of output tubes. Unfortunately, I've not taken the opportunity to test this. I've also noticed that the greater the number of output tubes, the greater the audible change that occurs during the "burn in" period. A tube power amplifier with, for example, eight or even four output tubes per channel exhibits this phenomenon to a significantly greater degree than an amp with only two output tubes. In fact, I'd almost propose a strong inverse correlation between the number of output tubes and how good the amplifier will sound once fully broken in. The very best sounding tube amplifiers that I've owned have all had two and only two output tubes. Of course, this limits the ultimate output wattage available, but to my mind, I'd rather have better sound than more watts. I've also noticed that some amplifier circuitry is more highly prone to the "burn in phenomenon" than others. My Heathkit mono amps, for example, still sound close to new despite the time that I've put on them. They use but two output tubes per channel. The Vacuum Tube Audio M-125 mono block amplifiers, on the other hand, came with four output tubes (the amps have the capability of being run with four output tubes at 125 Watts or two output tubes at 60 Watts). With four tubes, and despite their initially excellent sound, once fully broken in, I found that the thrill was gone. In fact, one of my friends labeled them "the worst-sounding tube amplifiers he'd ever heard." I sold the amps to an audio amigo without bothering to try the amps in their "two-tube output mode." I now wish I'd tried them with only two output tubes - I bet they'd have sounded significantly better! And that concludes my tube power amplifier contemplations. YMMV Boomzilla Much appreciate your input Boom! |
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KeithL
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Post by KeithL on Sept 15, 2020 11:50:54 GMT -5
I'm going to chime in here... because I happen to be in the area. You're quite correct... and the reason for this is two-fold: First, vacuum tubes actually DO change considerably during their first few hundred hours of operation. Things like the surface characteristics of the cathode, and even the composition of the "vacuum" in the tube, actually change quite a bit. These things change quite significantly over the first few hours of use... And, even after the first few hundred hours, they continue to change gradually throughout the life of the tube... And, yes, the changes are more extreme with big power tubes - which tend to carry more current and run hotter. (Many of the changes involve various things boiling off of, or soaking out of, hot surfaces and contaminating the so-called vacuum inside the tube.)
(Others involve changes in the surfaces themselves, both because of things that leave them, and things that are absorbed by them.)
Also note that a good designer is going to account for this... And, if the circuitry is likely to change, will design it to function optimally over the largest portion of its life. (Unless, of course, they're designing for "most 'wow' factor when you first get it home".)
Second, because of the sorts of circuits used in most tube amplifiers, the electrical characteristics of the tubes have more effect on how they sound. Most of the types of circuits used on modern solid state amplifiers are specifically designed to be unaffected by the characteristics of the actual components used.
A good solid state amplifier is designed to sound neutral - and part of that is for it NOT to be affected by the "sound" of individual components.
(You won't hear anyone discuss "how NPN transistors sound vs PNP transistors" and, lately, you won't even hear much talk about how FETs sound.)
In contrast, the sound of tube circuitry tends to be affected by the type of tube you use, and the performance characteristics of specific types. For example, most people who like tubes recognize that they do add coloration; and, for example, triodes tend to introduce a different type of coloration than pentodes. (And, yes, many designers of tube circuitry do deliberately design circuitry that emphasizes rather than de-emphasizes these performance differences.)
I would also be remiss if I didn't point out that we humans also have our own version of burn-in related to "perceptual accommodation". What this means is that, when something sounds different than what we're used to hearing, we find the novelty both noticeable and notable. Then, as we "get used to it", we fail to find it as interesting or noticeable, and it simply starts to sound "normal". So, if the initial "novelty" was what we found pleasing or exciting, then it does indeed "begin to fade over time" (in our perception; independent of reality). But we tend not to notice gradual changes...
That's why, when something ages slowly over time, we tend not to notice the change... But we do tend to notice the sudden change when we replace it with a new one that restores the original performance... Hi @shimei A passing comment about tube amplifier burn-in. I have noticed, that on multiple vacuum tube power amplifiers, the sound of the amp changes considerably during the first 50 hours (or less) of use. Changes how? With a brand-new, never turned on, vacuum tube power amplifier, the first few hours of use sound significantly different. The "new" amplifier sounds FAR more dynamic, and significantly less linear (in terms of frequency response). With those dynamics come a shocking amount of detail that the amplifier may never display again during its service life. This makes the "new" tube amplifier sound significantly more transparent than it will later. Once the power amplifier has some running time (anywhere from 10 to 50 hours of use), the frequency response becomes more linear, but at the expense of dynamics and transparency. This is (usually) NOT a subtle change. The amplifier may still sound "good," but never again like it did when it was brand new. Why is this so? Initially, I hypothesized that the resistors and capacitors were changing their sound during the "burn-in" period, but I've never found a single solid-state power amplifier that displayed this magnitude of change. So I'm left to speculate, instead, that it's the output tubes themselves that cause this. Why not the driver or splitter tubes? Because tube preamplifiers (in my experience) don't exhibit this phenomenon, or at least not to the same extent. This theory would be easy to test - Get a new tube power amp, let it burn in until the initial "bloom" had passed, and then plug in a brand new set of output tubes. Unfortunately, I've not taken the opportunity to test this. I've also noticed that the greater the number of output tubes, the greater the audible change that occurs during the "burn in" period. A tube power amplifier with, for example, eight or even four output tubes per channel exhibits this phenomenon to a significantly greater degree than an amp with only two output tubes. In fact, I'd almost propose a strong inverse correlation between the number of output tubes and how good the amplifier will sound once fully broken in. The very best sounding tube amplifiers that I've owned have all had two and only two output tubes. Of course, this limits the ultimate output wattage available, but to my mind, I'd rather have better sound than more watts. I've also noticed that some amplifier circuitry is more highly prone to the "burn in phenomenon" than others. My Heathkit mono amps, for example, still sound close to new despite the time that I've put on them. They use but two output tubes per channel. The Vacuum Tube Audio M-125 mono block amplifiers, on the other hand, came with four output tubes (the amps have the capability of being run with four output tubes at 125 Watts or two output tubes at 60 Watts). With four tubes, and despite their initially excellent sound, once fully broken in, I found that the thrill was gone. In fact, one of my friends labeled them "the worst-sounding tube amplifiers he'd ever heard." I sold the amps to an audio amigo without bothering to try the amps in their "two-tube output mode." I now wish I'd tried them with only two output tubes - I bet they'd have sounded significantly better! And that concludes my tube power amplifier contemplations. YMMV Boomzilla Much appreciate your input Boom! |
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Post by Boomzilla on Sept 15, 2020 11:57:21 GMT -5
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klinemj
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Post by klinemj on Sept 15, 2020 13:28:14 GMT -5
But we tend not to notice gradual changes... That's why, when something ages slowly over time, we tend not to notice the change...But we do tend to notice the sudden change when we replace it with a new one that restores the original performance... This is very true...I've also noticed this with projector lamps (mine is due!) and shock absorbers (in cars). You never know how bad they got until you replace them! Mark |
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Post by audiobill on Sept 15, 2020 14:25:21 GMT -5
Boom, agree with @keithl as to frequency response.
However, the real magic of tubes imo has to do with the imaging and soundstaging they are capable of, and also imo result from the output transformer/ speaker interface.
The only solid state amp I've heard that does this really well is my McIntosh MC452, which of course uses an autoformer.
I'll also add that this characteristic doesn't show up in spec sheets, ASR "tests" or other measures prized by "objectivists".
@keithl will explain this away as "distortion" but is real to me and many, many others. And worth every penny.
Very easy these days to build an amp that measures well, another thing entirely to make one that sounds great.
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Post by Boomzilla on Sept 15, 2020 15:10:21 GMT -5
This is very true...I've also noticed this with projector lamps (mine is due!)...You never know how bad they got until you replace them! Mark Hi klinemj - I noticed the same thing with my Epson projector. I found, however, that if I used the Spears & Muncil disk roughly every six months to recalibrate for bulb wear, that the performance remained on a fairly consistently high plane until the bulb finally went to projector bulb purgatory. The overall brightness may have declined some, but with recalibration, the change in dynamic range and color temperature was minimized. Boom |
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Post by Boomzilla on Sept 15, 2020 15:16:05 GMT -5
...However, the real magic of tubes imo has to do with the imaging and soundstaging they are capable of, and also imo result from the output transformer/ speaker interface. The only solid state amp I've heard that does this really well is my McIntosh MC452, which of course uses an autoformer. I'd agree with this, Bill, and also throw in "dynamics." My tube amplifiers sound more dynamic than any of my SS ones. I'll also add that this characteristic doesn't show up in spec sheets, ASR "tests" or other measures prized by "objectivists"...Very easy these days to build an amp that measures well, another thing entirely to make one that sounds great. I'd have to agree with you again, Bill. Some things we don't seem to have tests for yet. Amen to "measures great / sounds bad." I throw in (again) the example of the '70s Technics stereo receivers claiming virtually unmeasurable distortion (achieved via absolutely massive amounts of negative feedback) that sounded like glass breaking - but they measured really, really well! |
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Post by audiobill on Sept 15, 2020 15:53:07 GMT -5
While on a roll, one other thing :
If most of your listening is, say, to the Grateful Dead 1977 bootlegs or the 19th remastering of Stairway to Heaven, none of this matters at all.
Only real acoustic instruments recorded in a good space are capable of revealing the nuances we’re talking about.
Rock Off!
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Post by Boomzilla on Sept 15, 2020 16:01:07 GMT -5
While on a roll, one other thing : If most of your listening is, say, to the Grateful Dead 1977 bootlegs or the 19th remastering of Stairway to Heaven, none of this matters at all. Only real acoustic instruments recorded in a good space are capable of revealing the nuances we’re talking about. Rock Off! Hmmm... I might have to disagree with you on this one, Bill. There are lots of synthesized music tracks that exhibit depth, width, and sometimes startling effects. Off the top of my head, I can think of the album "Waiting for Columbus" by Little Feat. Their cut "Dixie Chicken" is stellar. The live version of "On the Border" by Al Stewart is a similarly good example. Come to think of it, listen to "Soy Yo" by Bomba Estéreo or the entire "Immaculate Collection" by Madonna. You may or may not like the music, but these tracks all have "nuances" that are worth hearing, and a good amplifier magnifies the effects. |
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Post by audiobill on Sept 15, 2020 16:02:47 GMT -5
Yes, Little Feat is a notable exception as all Nawlin’s tunes! I bought that album in 1971 or thereabouts.
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Post by pedrocols on Sept 15, 2020 16:11:02 GMT -5
Photography will be very dull and boring without filters and different lenses and so is music without Tubes.
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Post by Boomzilla on Sept 16, 2020 5:13:20 GMT -5
Hi pedrocols - Have you ever tried your M-125 in "two output tube mode?" I'd be interested to know if you heard a difference. Cordially - Boomzilla |
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Post by Boomzilla on Sept 16, 2020 6:44:27 GMT -5
Time to comment (again) on the marvelous little Emotiva BasX TA-100 integrated amplifier. For its modest price, one gets a better than average DAC, a better than average preamplifier, and a potentially much better than average 90 wpc (4-Ohms) power amplifier, all in a single, compact, and easy-to-love package. The sound is dynamic and cheerful without being harsh. The sound staging isn't the best I've ever heard, but it's still better than average for a solid-state product. This little amplifier has driven every speaker I've hooked up with no fuss, no muss, and no persnicketiness. It just works! For a reviewer, it's a blessing not to have to fight the equipment when trying out new speakers. Unless you have high-efficiency speakers, you won't be playing at auditorium levels, but that's an academic issue for me.
For those of you who do vinyl, the TA-100 has a phono section. For those of you who have good local stations, the TA-100 has an FM tuner. For those of you who listen to headphones, there's a front-panel jack. Again, none of these affect me.
The finish is the ubiquitous blah-black, but Emotiva has chosen that path to follow, and if you want the product, you'll have to live with the cosmetics. I'm hoping that Emotiva will eventually transcend their Henry Ford phase (as Henry once said of his model T - "You can have any color you want, so long as it's black!") but it hasn't happened yet.
Quite honestly, 99% of us could use the TA-100 and never look back. However, those who like loud volumes, who have huge spaces to fill, or who have exceptionally low-sensitivity or low-impedance speakers may occasionally want more watts. And even there, the TA-100 has you covered. Hook up the megawatt power amp of your choice to the TA-100's pre-out jacks and rock on!
The more I use the TA-100, the more I like it. And that's something that I VERY seldom say about ANY audio component! This amp is just so good and in so many ways that it's an absolute no-brainer. Bravo Emotiva!
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Post by novisnick on Sept 16, 2020 9:00:16 GMT -5
Time to comment (again) on the marvelous little Emotiva BasX TA-100 integrated amplifier. For its modest price, one gets a better than average DAC, a better than average preamplifier, and a potentially much better than average 90 wpc (4-Ohms) power amplifier, all in a single, compact, and easy-to-love package. The sound is dynamic and cheerful without being harsh. The sound staging isn't the best I've ever heard, but it's still better than average for a solid-state product. This little amplifier has driven every speaker I've hooked up with no fuss, no muss, and no persnicketiness. It just works! For a reviewer, it's a blessing not to have to fight the equipment when trying out new speakers. Unless you have high-efficiency speakers, you won't be playing at auditorium levels, but that's an academic issue for me. For those of you who do vinyl, the TA-100 has a phono section. For those of you who have good local stations, the TA-100 has an FM tuner. For those of you who listen to headphones, there's a front-panel jack. Again, none of these affect me. The finish is the ubiquitous blah-black, but Emotiva has chosen that path to follow, and if you want the product, you'll have to live with the cosmetics. I'm hoping that Emotiva will eventually transcend their Henry Ford phase (as Henry once said of his model T - "You can have any color you want, so long as it's black!") but it hasn't happened yet. Quite honestly, 99% of us could use the TA-100 and never look back. However, those who like loud volumes, who have huge spaces to fill, or who have exceptionally low-sensitivity or low-impedance speakers may occasionally want more watts. And even there, the TA-100 has you covered. Hook up the megawatt power amp of your choice to the TA-100's pre-out jacks and rock on! The more I use the TA-100, the more I like it. And that's something that I VERY seldom say about ANY audio component! This amp is just so good and in so many ways that it's an absolute no-brainer. Bravo Emotiva! ^^^^ 👍🎶👍🎶 I had the same experience. I’d go as far as to put it up against almost anything dollar for dollar! (I haven’t heard everything) |
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Post by pedrocols on Sept 16, 2020 11:47:01 GMT -5
Hi pedrocols - Have you ever tried your M-125 in "two output tube mode?" I'd be interested to know if you heard a difference. Cordially - Boomzilla For my listening habits I don't hear much difference. I think it also has to do with speakers because switching between pentode and triode mode with my maggies 1.7s in pentode mode sounds much better. However, with my maggies mg12s the opposite is true. Go figure. |
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Post by audiobill on Sept 16, 2020 11:53:28 GMT -5
Boom - Here's a review of the McIntosh MC275 with comments on running in parallel mode like the M125 (they mistakenly call it bridged, which is different). www.youtube.com/watch?v=5uqkxocx0Fs |
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