I can't listen to this properly without power. No SE amp I've had will cut it unless it's driving headphones.
#DSOLive Encore: Anne Akiko Meyers: Mason Bates Violin Concerto - YouTube
#DSOLive Encore: Anne Akiko Meyers: Mason Bates Violin Concerto - YouTube
with tubes, the plates are big enough to handle the heat, with ss, dies in the 6mm square size, it is simply not possible without heatsinking...
i have torn down a lot of tv sets and dismantling the sound opt, more often than not, it was a single primary coils and secondary on top of the primary coil, no interleaving so to speak, and yet they sounded very good...
Thanks for sharing. An unknown violin concerto for me.
We should make a difference between power and energy.
I couldn't see any difference to other violin concertos here.
The authority of an intrpretation always comes from enough energy. But there are mostly tube amps on the market, which don't have this authority and therefore cannot deliver an audio image containing energy.
Energy is that what a full bodied instrument like a violin can reproduce in sound waves.
If you don't have enough energy, it will sound like a smaller, not so full bodied, tiny instrument. And exatly thats the case with most amps today. It has nothing to do with the electric power output, you can have an amp with 100+ watt, that lacks energy. And then, everything that you hear lacks that energy. Especially acoustic instruments, with electronic music it isn't audible in the same matter, but it is also.
So what do the music industry do, as they want that energy to be present at home, even with those audio equimpment, that from its nature cannot reproduce enough energy?
Correct, it does manipulating the signal within the recording session, when its being mixed down for the recording format to be released on.
You can hear that very clearly with different recordings. In modern pop music, people want energetic sound. Their gear isn't able to deliver, so they receive and buy records, that have an enhanced mix, which is shifted higher in energetic levels by simply manipulating the sound curces, do a little compression and lift the whole sound to a higher level.
This music sounds full, although it is mostly robbed its dynamic contrasts. In advertising, you can hear that even more. Nearly no dynamics left, the whole music lifted to high levels and manipulated towards more bass, more highs and mostly no midds.
And thats the problem with recordings from those acoustical performances. They fail for being manipulated towards those sounds.
So everyime you play a record with true, acoustic sounds, you think it sounds thin on your audio equipment, you could have a moment and recognise: This record is true to life, but my equipment isn't able to reproduce it with the same energy a solo violin should have, whats wrong with it?
Simple answer: your audio system lacks the ability to reproduce full bodied tones and sound without enhancing the recording in the mix before reproduction.
That is the characteristic of a low level performance audio system.
And it has nothing to do with its price, it just has something to do with the reproduced recording, the recording session (yes, there are even records that lacks this energy right from the start, because the recording session was low quality) and your equipment.
Most equimpment isn't capable of those energy levels to reproduce, most records are simply wrong (in both sides, some lack energy, some are enhanced to death for compensating of bad audio systems, and only very few have the energy on it without being manipulated).
So don't being general and say: this will only sound good with a PP- amp, or that genre is always preferable to audition with a SE amp. Both should be able to perform good, although the PP amp can deliver greater power. But that isn't the same as energy.
You can have an zero point five (0.5) watt SE amp that can deliver enough energy for a solo violin to be reproduced as life recording, in combination with the right speaker.
But obviously its right that this amp cannot perform good on an average 84dB speaker.
For this, you need PP amps.
So, there are many things that could go wrong, when your statement is true. The combination of speaker and amps are bad, the amps are bad and cannot deliver power OR energy, other combinations can be true.
But in general, your statement isn't just correct ant something in your audio system is wrong.
Otherwise, even a SE amp should perform very well with this kind of music.
It has nothing to do with an isolated blame on SE or PP amps in general.
We should make a difference between power and energy.
I couldn't see any difference to other violin concertos here.
The authority of an intrpretation always comes from enough energy. But there are mostly tube amps on the market, which don't have this authority and therefore cannot deliver an audio image containing energy.
Energy is that what a full bodied instrument like a violin can reproduce in sound waves.
If you don't have enough energy, it will sound like a smaller, not so full bodied, tiny instrument. And exatly thats the case with most amps today. It has nothing to do with the electric power output, you can have an amp with 100+ watt, that lacks energy. And then, everything that you hear lacks that energy. Especially acoustic instruments, with electronic music it isn't audible in the same matter, but it is also.
So what do the music industry do, as they want that energy to be present at home, even with those audio equimpment, that from its nature cannot reproduce enough energy?
Correct, it does manipulating the signal within the recording session, when its being mixed down for the recording format to be released on.
You can hear that very clearly with different recordings. In modern pop music, people want energetic sound. Their gear isn't able to deliver, so they receive and buy records, that have an enhanced mix, which is shifted higher in energetic levels by simply manipulating the sound curces, do a little compression and lift the whole sound to a higher level.
This music sounds full, although it is mostly robbed its dynamic contrasts. In advertising, you can hear that even more. Nearly no dynamics left, the whole music lifted to high levels and manipulated towards more bass, more highs and mostly no midds.
And thats the problem with recordings from those acoustical performances. They fail for being manipulated towards those sounds.
So everyime you play a record with true, acoustic sounds, you think it sounds thin on your audio equipment, you could have a moment and recognise: This record is true to life, but my equipment isn't able to reproduce it with the same energy a solo violin should have, whats wrong with it?
Simple answer: your audio system lacks the ability to reproduce full bodied tones and sound without enhancing the recording in the mix before reproduction.
That is the characteristic of a low level performance audio system.
And it has nothing to do with its price, it just has something to do with the reproduced recording, the recording session (yes, there are even records that lacks this energy right from the start, because the recording session was low quality) and your equipment.
Most equimpment isn't capable of those energy levels to reproduce, most records are simply wrong (in both sides, some lack energy, some are enhanced to death for compensating of bad audio systems, and only very few have the energy on it without being manipulated).
So don't being general and say: this will only sound good with a PP- amp, or that genre is always preferable to audition with a SE amp. Both should be able to perform good, although the PP amp can deliver greater power. But that isn't the same as energy.
You can have an zero point five (0.5) watt SE amp that can deliver enough energy for a solo violin to be reproduced as life recording, in combination with the right speaker.
But obviously its right that this amp cannot perform good on an average 84dB speaker.
For this, you need PP amps.
So, there are many things that could go wrong, when your statement is true. The combination of speaker and amps are bad, the amps are bad and cannot deliver power OR energy, other combinations can be true.
But in general, your statement isn't just correct ant something in your audio system is wrong.
Otherwise, even a SE amp should perform very well with this kind of music.
It has nothing to do with an isolated blame on SE or PP amps in general.
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I tend to prefer SE to PP when you don't need to push the amplifier over 1/4 of it's capacity. Else I prefer a PP.
Right now I use a pair SE 808 (8-10w) on 112db eff. Midrange horns and a pair of PP SETH PP 2A3 (7-8w) on my 113db eff. horns tweeters.
I can swap the PP on the mids and the SE on the tweeters and the differences is negligeable. The PP test better when measured but not by much if I measure at a realistic power level for my use.
I'm not sure SE vs PP is that different, in my case it's all DHT tubes and the amplifiers barely have to push half a watts when I'm feeling wild and the characters are very similar.
At this efficiency SE is simpler and cheaper on the tubes and even if pushed quite loudly, i don't see any impact on the sound over PP. Noise level can be an advantage on PP but you can bring a SE to under 1mv of ac noise if you know what you do.
Horns and SE are certainly a good match, specially if you don't have to pad down the horns.
Right now I use a pair SE 808 (8-10w) on 112db eff. Midrange horns and a pair of PP SETH PP 2A3 (7-8w) on my 113db eff. horns tweeters.
I can swap the PP on the mids and the SE on the tweeters and the differences is negligeable. The PP test better when measured but not by much if I measure at a realistic power level for my use.
I'm not sure SE vs PP is that different, in my case it's all DHT tubes and the amplifiers barely have to push half a watts when I'm feeling wild and the characters are very similar.
At this efficiency SE is simpler and cheaper on the tubes and even if pushed quite loudly, i don't see any impact on the sound over PP. Noise level can be an advantage on PP but you can bring a SE to under 1mv of ac noise if you know what you do.
Horns and SE are certainly a good match, specially if you don't have to pad down the horns.
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And what efficiency have your woofer for those horns?
Thats relevant, not the efficiency of the horns alone, because the woofers have most often less efficiency and that means your horns have to be damped to play with them in combination.
I have 99dB woofers, but of course my horn has more. But its just irrelevant, I have to damp the horn because of the woofer.
So the complete system has 99dB, even if the horn has much more. It could never be more efficient than the least efficient part of it.
So if Dave's "kink" in the hysteresis curve of a transformer is the cause of mal-formed signals passing through, why are transformers all the rage as recording "signal massagers" and how does a product like Sophia Electric's "Magik Box" work?
How does that all connect back to an SE amp that uses an OPT? Also, do autotransformer type OPTs count as well in terms of signal voicing in a desirable way? The old car radios with the one big germanium output transistor used those - Class A, autotransformer coupled to the speaker.
How does that all connect back to an SE amp that uses an OPT? Also, do autotransformer type OPTs count as well in terms of signal voicing in a desirable way? The old car radios with the one big germanium output transistor used those - Class A, autotransformer coupled to the speaker.
More misunderstanding on your part. I did not mean SET heater with hum bucking pot. It is PP, heaters fed from AC winding with ground center tap. AC across heaters of opposing tubes has the same phase and amplitude, so it is common mode.
Your sentence "AC heat generates intermodulation..." is not intelligible. Could you explain it better? The symmetry of a differential stage, with matched gm, current source, and symmetric transformer, is as perfect as it could be. The composite plate characteristics of a differential stage are straight lines, regardless of control grid voltage, large or small.
The measurements you posted do not prove anything. To prove the point, you have to do measurements in the SAME PP amplifier, first with AC heaters, and then with regulators.
Battery heating is golden standard. With battery internal resistance in milliohms, all signals across filaments are effectively shorted. It sounds good. Isolating each filament is Coleman standard (pretty clumsy one), not golden standard.
I am not bashing your regulators. They are great - in SE amplifiers. They are not needed in PP, where AC heating worked fine since late 1920s. The IMD is your scare invention, not convincingly supported by measurements.
In a single ended amp the transformer is used in a linear part of the cirve ine 1st quadrant. DC on the output pushes it up there, but now the OPT has to be gapped, much larger, and harder to get bandwidth out of.
dave
When I finished building my SE tube amp I hooked it up to my single driver speakers and heard what I thought was hum. But as I put my ear closer it was the amp whispering. It was saying, play the Cramps, play the Misfits, play Kraftwerk, play Bauhaus, play The Legendary Pink Dots, play Billie Holiday, play Louis Armstrong, play Roy Orbison, play Sun Ra, play Bach, play Tchaikovsky. I did and much more, my tin ears reveled in its beauty.
Signal is applied grid-cathode. In a *directly heated* tube the cathode is the filament. If this filament is heated with AC, the varying voltage along the heater interacts with signal voltage to cause intermodulation, with 50/60hz as one term, not usually harmonically related to the music.
Thanks, Dave. So in class A, conduction never stops; in a SE OPT, magnetization never reverses.
Now effects on DHT using 60 Hz is hard to imagine. The cathode emission is actually modulated by the 60 Hz? Like putting the audio through a "ring modulator" with 60 Hz on the modulating input?
Obviously, you need another amplifier so you can heat the DHT cathodes with the same music signal you're playing through the amp! Get some nice squared term 2nd harmonic generator going on there. So what if it isnt "easy"? Causes a bit of delay? Gives you a great "black" background? By the sounds of it, neither are batteries or individual regulators for each tube's filament.
Now effects on DHT using 60 Hz is hard to imagine. The cathode emission is actually modulated by the 60 Hz? Like putting the audio through a "ring modulator" with 60 Hz on the modulating input?
Obviously, you need another amplifier so you can heat the DHT cathodes with the same music signal you're playing through the amp! Get some nice squared term 2nd harmonic generator going on there. So what if it isnt "easy"? Causes a bit of delay? Gives you a great "black" background? By the sounds of it, neither are batteries or individual regulators for each tube's filament.
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The issue of B-H curve "non-mononicity" through the zero crossing is sometimes misunderstood. A better way to model the issue is to remember that what's affected is permeability, and that it translates as inductance.
Primary inductance is a parasitic load on the output valves, appearing in parallel to the output transformer's reflected load. So, it's not "directly" in the signal path, and the issue (like several others) disappears completely with an (idealized) zero source impedance from the valves.
FWIW, permeability curves for nickle look considerably different from those for conventional steel. Those old transformer guys actually knew something, although the something wasn't really well passed to future generations.
YOS,
Chris
Primary inductance is a parasitic load on the output valves, appearing in parallel to the output transformer's reflected load. So, it's not "directly" in the signal path, and the issue (like several others) disappears completely with an (idealized) zero source impedance from the valves.
FWIW, permeability curves for nickle look considerably different from those for conventional steel. Those old transformer guys actually knew something, although the something wasn't really well passed to future generations.
YOS,
Chris
Magnetization still reverses, but never goes to or below zero. Idle is set to a spot up on the curve where (hopefully!) the bottom end doesn't get down near zero crossing and the top end doesn't get too badly into the saturation region.
AC heating has an effect on DHTs because they're not a uni-potential cathode, that is, at any instant all parts of the cathode are at different voltages (except twice per cycle of course). So each little bit of cathode has slightly different valve characteristics, and these diversions don't sum to zero. A perfectly linear valve would sum to zero, but perfection is reserved for heaven.
YOS,
Chris
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I understand how it occurrs in SE. But in PP, whatever AC signal appears on one filament/grid, is negated by exactly the same AC signal appearing on the opposite filament/grid. It is similar to cancellation of second harmonic: whatever is produced by one tube is negated by the same distortion produced by the opposite tube.
In addition, since virtual center of the filament is grounded, AC produces no net filament/grid potential, just re-distribution of current density across the filament.
In other words, filament AC is floating, it is not referenced to grid, and thus doesn't produce a grid/filament signal.
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I'm very, very confused by this. Perhaps if it were restated for us slower folks.
Your cancellation argument implies that a matching pair of DHT valves could be connected in parallel, with opposite polarity filament connections, in a single ended (parallel) layout with the same benefit. Or, for big guys like type 304TL, the paired filament halves would have a preferred relative polarity. I hope to be able to test this before the year is out. I hope.
YOS,
Chris
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Chris has understood it perfectly.
Many folks are lulled by the fact that DHT hum can be quite well nulled out at idle. The nulling is in effect the act of locating the centre-tap so that the physical elements AND triode-curves are symmetrical either side of it - if not perfectly, that adjusted by hum-pot to get a best-fit. The more symmetrical, the better the cancellation. With no grid signal, it can get quite close - but not to zero, even with 'easy' filaments like the 2.5V 2A3.
But as the grid swing increases, the operating point sweeps into remoter regions of the triode curves, and here the symmetry breaks down further. Just look at the curves, even for 2A3.
This is the reason why measured IMD increases with input signal amplitude.
With PP, there is more or less cancellation, but again the perfection falls short. This is only to be expected: The gm of each DHT (considered right across the swing) will be mismatched by whole percentage points, and the triode-curves will not match either.
euro21's measurements say it all. The first pic is the 300B-SE with DC heater, the second is the 300B-PP with ac heater:
Sound of 300B SET by Satoru Kobayashi
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Thank you. So is it safe to assume that any distortion that might be caused by the zero crossing is linear and not detrimental to small signals.