Like tubes, FETs are in an on state normally and external signals control that flow relatively linearly. They go into a compression when over driven. Even order harmonics. Bipolars are switches that are normally off and turn on when a signal is fed to them. They can be forced into linear ranges. They clip when driven to max and cause odd order, harsher harmonic distortions.
Like vacuum tubes, fets can be considered to be voltage controlled devices, opposite to current driven bipolars, but this an over-simplification. Only J-fets can be considered as normally on, the rest of your assessment is nonsense as well.
There are two main types of output MOSFETs, there are "audio" MOSFETs. Traditionally, most class-AB designs use lateral MOSFETs that have a positive temperature coeficient because they are very easy to work with (no need for complicated bias circuits with temperature sensors), with a low and predictable gate threshold voltage, however these FETs have a relatively high on-resistance compared to BJTs and the more familiar switching FETs. The downside of these designs is that power is wasted due to the high on-resistance and peak current delivery is limited. It is possible to design a linear amplifier using switching FETs, which have incredibly low on-resistance and high gain, however these have a negative temperature coeficient and, since the gate threshold voltage is both higher and varies dramatically (2 to 4 V) between batches, are tricky to bias and thermal runaway has to be prevented with temperature sensors, as it does for BJTs. However the reward is that it is possible to design an amp with incredible peak current cabability. Some such designs use a "auto-bias" system to continuously measure and regulate the bias.
One interesting element for me is how audiophiles become commodity investors. Drive US 101 in Santa Clara County, California and observe the names of component producers. Purveyors are in different states of buying power with different goals in the global market, affording a window on their pricing strategies and marketing. Some audio companies are a miniscule fraction of their parent company's revenue while for others it is the only game. My system is a mix.
More nonsensical audio lore from Paul. MOSFETs can work well into the 100s of kilohertz (and even higher). MOSFETs have a frequency response more than high enough to sound as bright as you like. The frequency response of a circuit is much more a function of how that circuit is tuned than whether a MOSFET or bipolar transistor is used. There are many reasons why you might choose a bipolar transistor over a MOSFET, but achieving a bright sound isn't one of them.
The issue you are conveniently forgetting is their tendency to oscillate and inter-domain capacitance, hence large value gate resistors and compensation, which defeats this advantage in majority od cases.
Merry Christmas to you Paul & the whole PS Audio family. I am the proud owner of a P10 regenerator since 2016 - enough to feed a pair of VTL Deluxe 300 tube monoblock amplifiers. They do not have the typically "sickly sweet" sound of tubes, but rather a dynamic sound, of course although bass is tight, doesn't quite match the best of solid state there.
I am very interested in learning how an audio power amplifier is made to be stable at low ohm loads, like 2ohms or 1ohm. In car audio amps, 2ohm stable & even 1ohm stable amps are fairly common. In home audio, below 4ohms seems to be considered impossible.
Hi Sir.. How is the total impedance of a speaker box calculated? Before network crossover or after crossover? Will crossover play any major role in total impedance of a 2way or 3ways speaker system? Love from India (Gangadhar G)
I'm curious about Darlington Array. What exactly is it? Is it a fet? Is it bipolar? I seem to have a vague memory that they were popular in old amps from the 70s & 80s. Am I wrong?
@jesiscott6048 I understand that part. I've seen the diagram. There is also a triple darlington array. I'm not an electronic engineer however & so I don't know exactly what the Darlington transistor is in it's type. How much power can it produce? Could 4, 6 or 8 of them be used in series or just 2 or 3?
It's all on a continuum what you like. Some people love the ultra revealing a magico speakers. Personally too much clarity in your face sounds good for one song and then it's too sterile. I like tube amps myself. The problem is tubes get a bad rap. Most people's budgets can only afford basic tube amps that do not cost much maybe 3k to 10k in price. For that level lot of negatives with tubes. Solid state at cheaper levels tend to have less issues so the perception is they are more stable and better. When you get into more expensive tube gear there is no comparison the tubes outshine easily for realism and feeling the music. When younger many want pounding sound that is clean. When you get older people tend to enjoy feeling the music more and getting lost in it. There is an art to building equipment for the anticipated outcome and a Mosfet is just one piece in tons of parts that make component do its thing.
Amplifiers are not supposed to sound lively, nor sound calm nor warm, nor have any kind of sound. The are not an audio processor or filter. if an amp has a sound then its faulty or poorly designed IMO. I know that's blasphemy but its true, they are simply supposed to amplify voltage and current without altering / distorting / filtering the input signal content in any way, and the fact is most quality amps do exactly that. As an Amp manufacturer however, you cant get way with not having opinion on the "sound" of your amp because Audiophiles actually beleive they can tell the difference on an ultra low distortion amp. its delusion. Speakers on the other hand DO very much have a "sound"
Yes agree, but in actuality amps can sound different and especially when you reach clipping level tube amps can soft clip the signal with better sounding even harmonics. Personally I prefer an amp to have no or little perceivable sound to it with enough dynamic range to completely avoid clipping.
@ Yes I have compared amps and observed some differences. But my honest opinion is those differences are mostly also measurable if using the right method of measurement.
Says who? This is an opinion. This boomer logic to think amps “shouldn’t” have a sound is hilarious. Some people buy tube amps or mosfet amps typically because they like that type of sound it produces. It does sound different. To many this sounds better than other solid state devices. These are just facts.
Every component has a sound to it. Dead neutral or the appearence of it is also a particular flavor. There is also the case of: dead neutral compared to what???
@@ChicagoRob2 Nelson pass doesnt know what a good amp is, his designs are actually quite bad. i would never buy or recommend anything with his name on it
@@ChicagoRob2 stereophile is a hoax, 99% esotheric bs. all reviews are paid reviews. their only purpose is to to make you buy overpriced audiophoolery stuff like gold coated optical cables and such because some old reviewe legen says its sounds sooo much better when you use this 10000$/ft cable. its all a big scam
Paul, why do you have a shitty NAD device on top of this stand? I don't know how other devices are assembled and which components are used in them, but this NAD is definitely a piece of overpriced crap in terms of assembly and parts quality. Shoulda remove a '0' from it's price.
@@alex_stanley Because NAD always were a crappy company. Maybe their design WERE developed in Canada or somewhere in Europe, but electronic part of it always were assembled in China. And in terms of quality it always was pure garbage.
“ Bah Humbug “ Merry Christmas 🎄🎁 🎉 To All of Pauls Garden Gnomes Gremlins Drive By Comments Goon Squad and Don’t Forget His Bromites and Cheers to Your Big 👂Ears👂 Paul in The Mysterious World 🌎 inside Paul’s Head Where His Ceiling Fan That Rotates Backwards By His Wind Mill Where The Ocean Waves Hit The Rocks How In The World Did We Get This Far Without The Lip Smacking Little Paul Bunyan….I Mean Onion 🧅 and His Many Layers of Audio Babble …..Plug it In Turn It Up and Who Cares What The Neighbors Think 🤔 What a Wonderful Day It Is in Pauls Neighborhood of Audio Lunacy 😮 Where Only The Great Incongruous Salvador Dali Could Make Sense of Pauls Esoteric Contemporaneous Subjective 😮 Audio Horse 🐎 Exhaust So Scratch Your Heads And I Would Love ❤️ To Hear Paul Read Just One Letter from a Female Audio File Not Just The Usual Tripe From Pauls Boys Club of Audio Cripples So Happy New Year 🎊 To All That We Love and All That We Hold Dear Peace To All 😊
Thanks for another year of sharing your insights and wisdom, Paul! Happy holidays to the entire PS Audio family!
Merry Christmas and happy new year to the entire PS Audio family.
Like tubes, FETs are in an on state normally and external signals control that flow relatively linearly. They go into a compression when over driven. Even order harmonics. Bipolars are switches that are normally off and turn on when a signal is fed to them. They can be forced into linear ranges. They clip when driven to max and cause odd order, harsher harmonic distortions.
Like vacuum tubes, fets can be considered to be voltage controlled devices, opposite to current driven bipolars, but this an over-simplification. Only J-fets can be considered as normally on, the rest of your assessment is nonsense as well.
There are two main types of output MOSFETs, there are "audio" MOSFETs. Traditionally, most class-AB designs use lateral MOSFETs that have a positive temperature coeficient because they are very easy to work with (no need for complicated bias circuits with temperature sensors), with a low and predictable gate threshold voltage, however these FETs have a relatively high on-resistance compared to BJTs and the more familiar switching FETs. The downside of these designs is that power is wasted due to the high on-resistance and peak current delivery is limited.
It is possible to design a linear amplifier using switching FETs, which have incredibly low on-resistance and high gain, however these have a negative temperature coeficient and, since the gate threshold voltage is both higher and varies dramatically (2 to 4 V) between batches, are tricky to bias and thermal runaway has to be prevented with temperature sensors, as it does for BJTs. However the reward is that it is possible to design an amp with incredible peak current cabability. Some such designs use a "auto-bias" system to continuously measure and regulate the bias.
I like the sound of bipolar for bass and mid-bass frequencies and V-FETs for treble. That's one of the reasons I tri-amp.
I had an amp (VSP Labs Gold) that had MOSFETs in its output stage that I really liked as it definitely sounds more tube like.
Merry Christmas from Germany to you all and a very big Thank you to Paul and his team for his amazing work and your dedication to HiFi-crazy people 😊
One of the best amp I've heard Stellar 300!!
I threw an akm schiit dac in the chain
Perfection
Merry Christmas to all you music and hifi lovers ❤🎉
And to you as well..... and Paul and PS Audio.
One interesting element for me is how audiophiles become commodity investors. Drive US 101 in Santa Clara County, California and observe the names of component producers. Purveyors are in different states of buying power with different goals in the global market, affording a window on their pricing strategies and marketing. Some audio companies are a miniscule fraction of their parent company's revenue while for others it is the only game. My system is a mix.
More nonsensical audio lore from Paul. MOSFETs can work well into the 100s of kilohertz (and even higher). MOSFETs have a frequency response more than high enough to sound as bright as you like. The frequency response of a circuit is much more a function of how that circuit is tuned than whether a MOSFET or bipolar transistor is used. There are many reasons why you might choose a bipolar transistor over a MOSFET, but achieving a bright sound isn't one of them.
The issue you are conveniently forgetting is their tendency to oscillate and inter-domain capacitance, hence large value gate resistors and compensation, which defeats this advantage in majority od cases.
Merry Christmas to you Paul & the whole PS Audio family.
I am the proud owner of a P10 regenerator since 2016 - enough to feed a pair of VTL Deluxe 300 tube monoblock amplifiers.
They do not have the typically "sickly sweet" sound of tubes, but rather a dynamic sound, of course although bass is tight, doesn't quite match the best of solid state there.
I am very interested in learning how an audio power amplifier is made to be stable at low ohm loads, like 2ohms or 1ohm. In car audio amps, 2ohm stable & even 1ohm stable amps are fairly common. In home audio, below 4ohms seems to be considered impossible.
Could it be that there is a Bluesound node in PS audio system? I myself use it as my transport and love it. Merry Christmas!
Hi Sir.. How is the total impedance of a speaker box calculated? Before network crossover or after crossover? Will crossover play any major role in total impedance of a 2way or 3ways speaker system?
Love from India (Gangadhar G)
Total impedance is calculated before the crossover and varies with frequency. Yes, the crossover also affects the overall impedance.
Mmmmm...... one of my favourite topics 😊.!
I'm curious about Darlington Array. What exactly is it? Is it a fet? Is it bipolar? I seem to have a vague memory that they were popular in old amps from the 70s & 80s. Am I wrong?
A Darlington circuit is two transistors connected in series.
@jesiscott6048 I understand that part. I've seen the diagram. There is also a triple darlington array. I'm not an electronic engineer however & so I don't know exactly what the Darlington transistor is in it's type. How much power can it produce? Could 4, 6 or 8 of them be used in series or just 2 or 3?
What you do is my dream job. I got into music which lead me to music production and now I’m an electrical engineer. Are you hiring ?? lol 😂
It's all on a continuum what you like. Some people love the ultra revealing a magico speakers. Personally too much clarity in your face sounds good for one song and then it's too sterile. I like tube amps myself. The problem is tubes get a bad rap. Most people's budgets can only afford basic tube amps that do not cost much maybe 3k to 10k in price. For that level lot of negatives with tubes. Solid state at cheaper levels tend to have less issues so the perception is they are more stable and better. When you get into more expensive tube gear there is no comparison the tubes outshine easily for realism and feeling the music. When younger many want pounding sound that is clean. When you get older people tend to enjoy feeling the music more and getting lost in it. There is an art to building equipment for the anticipated outcome and a Mosfet is just one piece in tons of parts that make component do its thing.
Well said. For me a transparent triode amps are the way to go.
🎄Merry Christmas to all the staff at PS Audio!🎄
The fabulous.... "Mosfet Mist"
Happy Solstice and Happy New Year.
I was just watching "MOSFETS of Science" last night.
Amplifiers are not supposed to sound lively, nor sound calm nor warm, nor have any kind of sound. The are not an audio processor or filter. if an amp has a sound then its faulty or poorly designed IMO. I know that's blasphemy but its true, they are simply supposed to amplify voltage and current without altering / distorting / filtering the input signal content in any way, and the fact is most quality amps do exactly that. As an Amp manufacturer however, you cant get way with not having opinion on the "sound" of your amp because Audiophiles actually beleive they can tell the difference on an ultra low distortion amp. its delusion. Speakers on the other hand DO very much have a "sound"
Have you compared different amps in a listening test? Of course well-designed amplifiers /should/ all sound the same but do they, really?
Yes agree, but in actuality amps can sound different and especially when you reach clipping level tube amps can soft clip the signal with better sounding even harmonics. Personally I prefer an amp to have no or little perceivable sound to it with enough dynamic range to completely avoid clipping.
@ Yes I have compared amps and observed some differences. But my honest opinion is those differences are mostly also measurable if using the right method of measurement.
Says who? This is an opinion. This boomer logic to think amps “shouldn’t” have a sound is hilarious. Some people buy tube amps or mosfet amps typically because they like that type of sound it produces. It does sound different. To many this sounds better than other solid state devices. These are just facts.
Every component has a sound to it. Dead neutral or the appearence of it is also a particular flavor. There is also the case of: dead neutral compared to what???
I shoulda paid more attention in Electronics class back in 1976!....But alas it was 1976...lol.
I remember 1976. Ah, great year. The bicentennial and bicentennial quarters. The U.S. attempting to convert to the metric system.
Musks MOSFET amps can overthrow the seppo government😂
Hey guys i put some honey on my amp circuit, is it gunna be ok
bjt's and mosfets sound the same, the difference is just in your head.
Tell that to Nelson Pass.
Yes everything sounds the same.
@@ChicagoRob2 Nelson pass doesnt know what a good amp is, his designs are actually quite bad. i would never buy or recommend anything with his name on it
@@gamerpaddy Two Pass amps made Stereophile Class A recommended components, which is just one indication of what you said is total BS.
@@ChicagoRob2 stereophile is a hoax, 99% esotheric bs. all reviews are paid reviews. their only purpose is to to make you buy overpriced audiophoolery stuff like gold coated optical cables and such because some old reviewe legen says its sounds sooo much better when you use this 10000$/ft cable. its all a big scam
GaNFETs are better than both. Oscar Heil invented the FET but failed to patent it.
Merry Christmas PS Audio and HiFi Gramps. 🎄😊
Paul, why do you have a shitty NAD device on top of this stand? I don't know how other devices are assembled and which components are used in them, but this NAD is definitely a piece of overpriced crap in terms of assembly and parts quality. Shoulda remove a '0' from it's price.
My brother and I both had the same NAD integrated amp back in the '80s, and they both developed intermittent internal connections.
@@alex_stanley Because NAD always were a crappy company. Maybe their design WERE developed in Canada or somewhere in Europe, but electronic part of it always were assembled in China. And in terms of quality it always was pure garbage.
“ Bah Humbug “
Merry Christmas 🎄🎁 🎉
To All of Pauls Garden Gnomes Gremlins
Drive By Comments Goon Squad and Don’t Forget His Bromites and Cheers to Your
Big 👂Ears👂 Paul in
The Mysterious World 🌎 inside Paul’s Head Where His Ceiling Fan That Rotates Backwards By His Wind Mill Where The Ocean Waves Hit The Rocks
How In The World Did We Get This Far Without The Lip Smacking Little Paul Bunyan….I Mean Onion 🧅
and His Many Layers of
Audio Babble
…..Plug it In Turn It Up and Who Cares What The Neighbors Think 🤔
What a Wonderful Day It Is in Pauls Neighborhood of Audio Lunacy 😮
Where Only The Great Incongruous
Salvador Dali Could
Make Sense of Pauls
Esoteric Contemporaneous Subjective 😮 Audio
Horse 🐎 Exhaust
So Scratch Your Heads
And I Would Love ❤️ To
Hear Paul Read Just One
Letter from a Female Audio File Not Just The Usual Tripe From Pauls
Boys Club of Audio
Cripples
So Happy New Year 🎊
To All That We Love and All That We Hold Dear
Peace To All 😊