Great discussion. I knew all of this, but it really crystalized it for me. I like massively oversized linear power supplies, with chokes for filtering and film caps for small signal sections and as bypass caps for the power section. In my limited experience all of this will take a well designed circuit up a notch in performance.
Thank you for making this much clearer in my mind now. So the Transistor or Triode Tube control or modulate the power flowing through it from the Power Supply. The Varying AC Signal Source Varies The Flow of Power through The Amplifier Circuit in Direct Proportion to the Varying Signal on the Base to create Gain on the Output Circuit that has a Waveform that copies the Signal on the Base but simply makes it larger by controlling the Power flowing through the Amplifier from the Power Supply. Now it makes perfect sense why Paul says they pay so much attention to having a Very Clean Stable Power Supply with as little Noise as possible.
The guy who asked the question basically answerd the question himself, very true what paul said as well, transistors and vavles/tubes are just that a valve, controlling current flow to your load from a small signal source input on the base/grid, and the power supply is an importent factor meaning having the current available when demanded like water pressure from a tap, a transistor doesnt amplify it just controls current flow from the power supply, hope it makes sense, im not great at typing
As you know the first computers were done with tubes. It filled a room and was a tiny fraction the number of valves that the smallest processor has today controlling your refrigerator. And it would only run a few days before a tube would need to be changed.
For those mechanically inclined, the hydraulic steering or brakes of an automobile work the same way conceptually. The hydraulic pump is the power source, the steering wheel or brake are the small signal being amplified.
How many times does the point need to be made, that it is the quality of the DC, after rectification and smoothing that is important, and not the AC entering the box? I think Paul knows this, but keeps trying to imply that it is the AC from the wall outlet that matters, to the extent that a power regenerator is needed. Of course he wants to sell them!
Had a car with a battery dial on the dashboard. Fitted a 400 watts amplifier and a large Subwoofer. Turning up the music caused the battery dial to drop 20% on the bass beats 😅
I did not understand the concept until I study deeply the design of carvers first amplifiers. That was my aha moment 💡 thinking 🤔 💭 when I figured all these great amplifier designers we’re doing nothing more than modulating a power source. That got me studying in learning about power sources why some are better than others. Then that got me going down the rabbit hole of linear amplifier’s. And class A amplification.. weather was done with tubes or transistors. I was then addicted and caught the fever for building class A amplifiers and pre-amplifiers
I would just have to push back a little again to say that while it's okay to think of amplification this way (power supply quality certainly matters a lot), most amplifier distortion is introduced by the "valves" and the topology characteristics of the amplification circuits. Also, gain (not maximum signal level limited by supply) is of course determined by the amplifier circuitry, not the supply.
@@user-od9iz9cv1w - I know there are times that I can make a circuit sound better with the same power supply - but a good power supply. So yes, it all matters. And yes, I design stuff.
Well yes, to an extent depending on the area of the circuit. Like adding a "quality" fuse holder or power switch does nothing to alter sound quality provided it does not restrict current flow. But what does define a quality component? An engineering data sheet by the component manufacture like you get from the established electronic component manufactures? Or the marketing hype by some garage operation placing new labels on otherwise low quality off-shore components? Capacitors for example. Slit the original plastic sleeve off and heat shrink on a new label with all the audiophile voodoo attached?
@@andydelle4509 Agreed. Pretty hard to tell from specs and marketing BS. Certainly specs can weed out unacceptable candidates, but still trial and error to see if there is any sound improvement. So I look to see what my trusted sources say to narrow the field. For example, the I/V resistor in my DAC. Its just a 60ohm 1/4W resistor. Lots of people say it does not matter. Others swear by Audio Note original tantalum. Some like Riken carbon. Its only a couple of resistors. So I experiment. Penny metal film are fine. But the AN and Riken are bad. I try some $10 each Caddock TFS stuff and its much better. Then I make my own non inductive wire wound using manganin. This, the cheapest solution of all is clearly the best.
Wish you would have stated the basic limitations and properties of transformers as well, since they are just like all other devices that only convert the available power to a mathematical equivalent, minus losses, of course. And in special cases reduced overall power at equivalent voltage.
I would add, I consider a transidtor to be a current amplifier and a valve (tube) to be a voltage amplifier, broadly speaking. Paul is right that the PSU design is key to the overall, which is why finding a "HiFi" fuse for sale at £4,500 drives me nuts. If your PSU is good, the fuse will make no difference. Hence my view, if you find changing your mains cable or _mains_ fuse (internal LV rail fuses different argument) made a difference, take you amp out back, beat it with a stick, pour petrol on it, burn it, mock it loudly, and then bury it, because it's obviously junk.
So, the takeaway is, the power supply voltage has to be matched with the impedance of the drivers, if you want "dynamic" sound? The higher ohm the speakers, the higher voltage input amplifiers you need.
Bingo! But why then are "single ended" tube amps so low in output power? Could they be larger? If a tube is acting as a valve, what is the advantage of a 300B over a KT88 or EL34?
I'm gonna guess and answer because of heat (or wasted amplitude). A tube can only handle a set amount of amplitude. Putting more power in turns the valve into a welder,which is bad. Now I am having visions of a very large tube with a huge grid that can expend the energy across a greater surface which makes me curious to know if it was ever attempted.
@@jimh1021 There have been a few huge and outrageous tube audio amplifiers built, using exotic transmitting type tubes--even some using mercury vapor. Though they're not commercially practical, a web or YT search will find some. @Ross Warren 's question has a complex answer, but points to why the valves do matter (including solid state ones), and matter very much indeed. Obviously the excellent BHK amplifiers that PS Audio sells as its flagship models encompass far more more than optimized power supplies.
@Hastings Piper Yes, triodes like the 300B have desirable transfer characteristics in terms of distortion and ease of use, as do JFETs. Thanks for agreeing here that all amplifiers are not mostly power supplies of varying quality. Class D amps are another category that throws that premise out the window. Amplifier performance is mostly about these "valves" (as Paul refers to them), whether solid state or tube, and how they're used in the amplifier section.
@Hastings Piper it would be interesting for an electrical engineer or technician such as Skunkie Design Electronics to do a tear down of say a Willsenton R300 single ended 300B amp and find out about the transformers used. I'm mainly looking at a Willsenton R8 (not single ended but push-pull EL34 or KT88) one day for some fun. Thank you for that great explanation regarding valves.
This is why so many units in the 70s and early 80s were judged based on weight, because it meant it had a hefty power supply. Try that with Class D amps!
Actually, the power supply in a class D can be the exact same big and heavy one that AB amps use. What you're actually thinking is if it uses a switch mode power supply. It isn't the class D amps that make the weight, it's the designer's choice of power supplies.
Because power supplies are so important that is where Bob Carver invested a lot of his time by improving class G in his "magnetic field coil" amplifiers then with his " tracking down converter " (the first class H) power supply. Neither design was affected by noise or sags in line voltage. Both designs could deliver a lot of current to low impedance speakers and were quite light weighing only a fraction of equally powerful amplifiers and were super energy efficient. BTW he had already shown that he could design great sounding amplifiers with the Phase Linear 700 , the most powerful and best sounding of it's day.
I still use a M-500(t) Carver amp. Had it recapped and refurbished to even better than new specs. I can drive some big 4-ohm speakers to crazy volumes with that thing.
@@rosswarren436That's a Great amplifier , Many people got Carver amps to drive Magnepan speakers and even some new amps can't drive them . See the New Record Day review of Magnepan .7 speakers.
The Carver Magnetic Field amplifiers are what we call an "engineering exercise" in the electronics industry. An interesting application of alternate engineering theory but has no practical benefit over existing technologies and may even be deficient. The Carver Magnetic Field amplifier used a regulated power supply by phase chopping the line AC input to the power transformer. Basically a Home Depot wall light dimmer - same technology. Now I have much professional respect for Bob Carver and he has done a lot to advance consumer audio technology. But this product had side issues caused by his unique power supply design. It has never been duplicated in high end audio amplifiers so that should tell us something.
@@andydelle4509 How can you say it had no practical benefits it kept the voltage rails constant regardless of load or variations in line voltage (no need for a PS Audio power regen unit) and as stated were light weight and energy efficient had lots of headroom for transients and could drive speakers that most other amps in it's price range could not. The only downside was if you were right next to it in a quiet room you could hear a slight transformer buzz (due to the triac pulses) that was not audible at most listening positions or when music was played. No one else copied it because of patent issues While others have tried to copy his class H designs no other class H amp is truly load invariant able to double output power down to 1 ohm like his Sunfire Signature amps. I should also note that I know how his class G (with the triac) and H (where the rails were kept 6v above what was needed at that instant in time) designs worked. Also note I started my EE degree but never finished due to the job market at the time and finances and became a technician instead and am now retired.
@@leekumiega9268 yes, I've put it up against newer amps and it holds its own. I've seen no reason to upgrade, hence my getting it refurbished. My only purchase one day might be a tube amp "for fun". I note some have said the reason it isn't as prevalent today is: "A linearly tracking (class H) power supply is a much more complex beast than one that "just" switches the voltage rails (class G). It is a lot harder to design and make stable, both in fundamental amplifier stability and in keeping supply modulation under control when the supply is intentionally varying (bias circuits, not just gain stages, are more complex). But switching the rails also leads to issues with bias stability, amplifier stability, and need for careful transient control, so class G is not a panacea. At the end of the day, class D offers higher efficiency and a more straight-forward design, albeit with its own set of challenges and tricks. And the "linear analog" crowd probably wants "pure" class AB so marketing gets involved..." And, "Emotiva XPA-2 is a class H. Class H adds cost and complexity. Also, in the audiophile world (where people will actually pay) people seem to want the old-style power supply. Now that we have sites like this (Audio Science Review), which would help class H power become better known, we are benefiting from lower cost class D."
When listening to my integrated amp in class AB mode only the power supply gets warm. When I switch to class A mode both the power supply and the power transistors get very warm. I don't hear the difference between the two modes.
Why do people look for problems buying 4 ohm speakers that are allowed to dip well below that by law, by a certain %. There was a highly touted cable on the market which could ruin your equipment. Then there's vintage amps which could be leaking DC and ruin your speakers. There are speakers and speaker drivers that have been know to catch fire etc. etc.
Nope, it was just transistors. There were portable tube radios, made until about the very early 60s, that usually required two batteries, one of which was a high voltage battery.
I can see why a tube could be called a valve but isn't a transistor just a switch, which can either open or close but not pass varying current? I am talking a single transistor not banks of them.
Both tubes and transistors act as valves. Either of them can act as switches if you want, and either of them can continuously vary their output if you want. It just depends on the type of circuit you put them in.
Okay. Now I am calling it. defiantely Trolls at work!...".Master electrician" asks how transistors work, "electrical engineers" doesn't know speakers are AC, random incensed by a quiet "bye"!
"".Master electrician" asks how transistors work," - why does that seem weird to you? Not many people know how a transistor really works, even those people who use them.
Having two separate power supplies means that when you drive one channel hard, the power in the other channel is not affected. It was and still is a great design. They can also handle certain speakers (such as the Polk SDA speakers) that put unusual loads on the amplifier.
Quite frankly I thought Harman Kardon these days was just indifferent Samsung products with inflated price tags. With them been mainly Bluetooth speakers and soundbars.
Do you really need a Masters Electrician Degree to operate a stereo..🤔😀 What kind of stereos are you people buying. 😳😀 I have never bought a stereo that had a warning label on it. “Electronic Engineering Degree required to operate this Stereo”
I have a 5 pin balanced interconnect. It is way louder than when I use an RCA interconnect cable. I've read where it can be 4 db louder with a balanced interconnect. It is the better connection and connector. I better get to bed. The church has a new audiophile experience awaiting for parishoners in the back pews.
because power is proportional to square of voltage at constant current, doubling the output voltage with everything else the same means 4x power output from original also expressed as 10 log(4) = +6.02dB, mind you this is the output power comparison, SPL depends on transducer device (i.e. speaker sensitivity) and the listening room characteristics
