I have a Hafler DH-220 amp that has Mosfet output transistors. It has always been described in reviews as having a "tube sound". It was designed by David Hafler as was the Dynaco SV-70 tube amp (from 1958). I am hoping to buy an SV-70 and recondition it with new modern components to see how it compares to the Hafler DH-220. I built the DH-220 amp in 1984 and it remains stock at this point. However laterly I have been listening to the Adcom GFA-545II and am very surprised at its openness and brightness with a beautiful soundstage. I am soon to go back to the DH-220 to see how it compares to the Adcom. The DH-220 may be in need of all of its electrolytics replaced. Thank you this video has helped me understand the mosfet and tube relationship!
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.
High five to you. I just saw your post after my post I built the DH-220 in 1984. It still works and sounds beautiful. I am considering installing one of the Musical Concepts mods to the amp and recapping it where necessary, to their credit it doesn't have many electrolytic capacitors. I also built the DH-110 preamp and also still use it. 👍
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.
@@paulb4661 MOSFETs come in two types: enhancement-mode and depletion-mode. Enhancement-mode MOSFETs are normally off and require a voltage to turn on, while depletion-mode MOSFETs are normally on and require a voltage to turn off. the rest of your assessment is nonsense as well.
@@glenncurry3041 Yesterday, it was fets in general exhibiting the "normally on" characteristic. I'll just wait a couple more, but in the meantime take a look at this excerpt, courtesy of Bob Cordell: " While BJTs require input current to drive the base, mosfets have an almost infininite input resistance at DC. They ONLY require input current to charge and discharge their internal capacitances." from Designing Power Amplifiers, page 322.
As an electrical engineer I've always found the notion of different sound for tube vs BJT vs MOSFET, etc. curious. If the output of the circuit in question is faithfully reproducing the input signal within the audio range with only some degree of amplification the sound should be the same, just louder. That is, if the frequency response is flat across the range of frequencies of interest and harmonic distortion is low and so on, and the waveform is the same on the output as input except for amplitude, where is the brightness or other perceived sound artifacts coming from? I do have an anecdotal story about a double blind test with some PBS engineers and sound difference between the frequency bands used to relay PBS signals via satellite. They felt the sound was different when the transmissions were using C-band versus Ku-band satellite frequencies. Spoiler, the double blind test results were no difference was detectable.
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.
How an amp sounds has more to do with the design and less to do with active device types. I have a 2sc5200-based power amp that I have been trying to replace. It has four pairs of paralleled output transistors per channel. With a good DAC and class A discrete preamp, its midrange is magical. Smooth, detailed, and in-room presence. I replaced it with a class D amp which had a wider soundstage due to dual mono design but the midrange smoothness and clarity didn't come close. One channel of the class d amp died. Next, I replaced it with a Chinese Mosfet amp with a simple circuit based on fake IRFp240 mosfets. It sounded okay but the midrange smoothness didn't come close to the bjt amp. I could never get it's bias right and it sounded great one minute and distorted the minute. I finally killed the Mosfets of the output of one channel while setting the bias current due to the inaccuracy of my multimeter milliamps range. I ended up putting 7 amps through the MOSFETs which damaged them. If they were genuine mosfets, then they would have been fine since they rated for 20 amps of current. None of the Chinese amps can match it, and I think in order to upgrade it, I would have to design and build an amp myself or modify one of the circuits in Bob Cordell's book. Audiophile amps are beyond my reach at the moment.
Interesting. I had one and although I thought it sounded good it didn't sound any better than a few of my other amplifiers whether it be class D or Class A B. I sold it.
@ryanschipp8513 well, it may be the schiit, stellar, kef ref 3 combo - we've (SBITAV) used it a couple of times and it has yielded truly excellent results. What also impresses me about the stellar is the speaker cable run is 15m (usually wouldn't accept that in higher end the set ups) and we don't notice any fall off of impact. We tried some other high end amps against the stellar, none were as tone even and/or smooth as the stellar. We actually a/b test audio equipment - it's extremely tricky but sometimes we yield clear results. The stellar was one such occasion.
Decades ago when I last bought my audio equipment I was looking at Carver and Soundcraftsmen. The Carver was (I think) bipolar and clearly had a bright high end. The Soundcraftsmen (which I still own) were MOSFET and had a smoother top end. At 73 I don't know if I would still hear the difference. A different question - Who or what AI translates your letters? Or are they all english speakers? Love you videos, go ahead and ramble on. Thanks
There were different configurations for the layout of the circuitry of MOSFETs. Darlington configuration was popular back in the early 80’s. I am not familiar with what all that means for difference in sound.
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)
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.
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.
@mitchtaylor6512 Not in mass market. I don't count class D amps. If you get into boutique amps that cost a lot, then yes, but they are boutique. I'm left to believe that 2ohm & especially 1ohm stable amps can't be produced at an affordable price for the mass market. I've chatted with Schiit Audio & was told 2ohm loads are not recommended.
@@adambrown8867you can drive a low impedance load with a lot of amplifiers if you don't turn the volume too high. Most car audio amps run a lower output voltage than home audio amps, that's one of the reasons they can drive low impedance. I also don't think many of the car audio amplifiers actually have as much power as is stated.
I have a friend who says his tube amp stimulates all the family pets, and that jazz fusion night (thursdays) has become almost impossibly to manage. Is this an issue with Class D ? Thank you ever so.... ..
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.
That's very poetic, but the real reason is that MOSFETS are faster and you need that to switch at ultrasonic frequencies, far above the 'top end' audio.
I love my PS Audio S300 (dual mono) for my PS Audio FR5 speakers (like u see in Paul's video) in bi-amped (S300 powers the low pass, NAD C298 powers the high pass). My video: th-cam.com/video/-WbVsly1X0w/w-d-xo.html source=Apple Music lossless
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.
@@markmeridian3360 "The standard approach to controlling parasitic oscillations in mosfets is to employ gate stopper resistors in series with the gate of the device. These resistors are placed very close to the gate terminal of the mosfet. the resistors tend to kill the speed of the mosfets and to damp out resonant circuits that may be formed by inductance operating in conjunction with gate capacitances. Unfortunately, the practice of using gate stopper resistors discards one of the big advatages of the power modfets, namely their speed." Bob Cordell; Designing Audio Power Amplifiers, page 329.
@@paulb4661 Phony strawman argument. You don't have to just use a gate resistor. It's possible to control unwanted oscillations with RC damping, minimizing parasitic inductance (good circuit board design), or even by using ferrite beads on the gate lines. Carefully selecting gate drive circuit characteristics can stop unwanted oscillations without impacting circuit performance. Remember, we're only talking about 20 kHz max.
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???
why not just use Purifi Eigentakt and you don't need any artificial distortion added, eh? perfect linearity, more than enough power, ultra low distortion
@@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
“ 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 😊
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.
Thanks for another year of sharing your insights and wisdom, Paul! Happy holidays to the entire PS Audio family!
I have a Hafler DH-220 amp that has Mosfet output transistors. It has always been described in reviews as having a "tube sound". It was designed by David Hafler as was the Dynaco SV-70 tube amp (from 1958). I am hoping to buy an SV-70 and recondition it with new modern components to see how it compares to the Hafler DH-220. I built the DH-220 amp in 1984 and it remains stock at this point.
However laterly I have been listening to the Adcom GFA-545II and am very surprised at its openness and brightness with a beautiful soundstage. I am soon to go back to the DH-220 to see how it compares to the Adcom.
The DH-220 may be in need of all of its electrolytics replaced.
Thank you this video has helped me understand the mosfet and tube relationship!
Merry Christmas and happy new year to the entire PS Audio family.
Paul. I just ran across your channel and appreciate your common sense approach.
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.
Thanks for explaining Paul.
After all these years, my Hafler DH200 which I built from a kit, still works after more than 30 tears.
High five to you. I just saw your post after my post I built the DH-220 in 1984. It still works and sounds beautiful.
I am considering installing one of the Musical Concepts mods to the amp and recapping it where necessary, to their credit it doesn't have many electrolytic capacitors.
I also built the DH-110 preamp and also still use it.
👍
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 😊
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.
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.
@@paulb4661 MOSFETs come in two types: enhancement-mode and depletion-mode. Enhancement-mode MOSFETs are normally off and require a voltage to turn on, while depletion-mode MOSFETs are normally on and require a voltage to turn off. the rest of your assessment is nonsense as well.
@@glenncurry3041 Yesterday, it was fets in general exhibiting the "normally on" characteristic. I'll just wait a couple more, but in the meantime take a look at this excerpt, courtesy of Bob Cordell: " While BJTs require input current to drive the base, mosfets have an almost infininite input resistance at DC. They ONLY require input current to charge and discharge their internal capacitances." from Designing Power Amplifiers, page 322.
@@paulb4661 To YOU yesterday was "Only J-fets can be considered as normally on". SAD! Just learn to acknowledge when you are wrong.
As an electrical engineer I've always found the notion of different sound for tube vs BJT vs MOSFET, etc. curious. If the output of the circuit in question is faithfully reproducing the input signal within the audio range with only some degree of amplification the sound should be the same, just louder. That is, if the frequency response is flat across the range of frequencies of interest and harmonic distortion is low and so on, and the waveform is the same on the output as input except for amplitude, where is the brightness or other perceived sound artifacts coming from?
I do have an anecdotal story about a double blind test with some PBS engineers and sound difference between the frequency bands used to relay PBS signals via satellite. They felt the sound was different when the transmissions were using C-band versus Ku-band satellite frequencies. Spoiler, the double blind test results were no difference was detectable.
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 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.
How an amp sounds has more to do with the design and less to do with active device types. I have a 2sc5200-based power amp that I have been trying to replace. It has four pairs of paralleled output transistors per channel. With a good DAC and class A discrete preamp, its midrange is magical. Smooth, detailed, and in-room presence. I replaced it with a class D amp which had a wider soundstage due to dual mono design but the midrange smoothness and clarity didn't come close. One channel of the class d amp died.
Next, I replaced it with a Chinese Mosfet amp with a simple circuit based on fake IRFp240 mosfets. It sounded okay but the midrange smoothness didn't come close to the bjt amp. I could never get it's bias right and it sounded great one minute and distorted the minute. I finally killed the Mosfets of the output of one channel while setting the bias current due to the inaccuracy of my multimeter milliamps range. I ended up putting 7 amps through the MOSFETs which damaged them. If they were genuine mosfets, then they would have been fine since they rated for 20 amps of current.
None of the Chinese amps can match it, and I think in order to upgrade it, I would have to design and build an amp myself or modify one of the circuits in Bob Cordell's book. Audiophile amps are beyond my reach at the moment.
One of the best amp I've heard Stellar 300!!
I threw an akm schiit dac in the chain
Perfection
Interesting. I had one and although I thought it sounded good it didn't sound any better than a few of my other amplifiers whether it be class D or Class A B. I sold it.
@ryanschipp8513 well, it may be the schiit, stellar, kef ref 3 combo - we've (SBITAV) used it a couple of times and it has yielded truly excellent results. What also impresses me about the stellar is the speaker cable run is 15m (usually wouldn't accept that in higher end the set ups)
and we don't notice any fall off of impact.
We tried some other high end amps against the stellar, none were as tone even and/or smooth as the stellar.
We actually a/b test audio equipment - it's extremely tricky but sometimes we yield clear results. The stellar was one such occasion.
Decades ago when I last bought my audio equipment I was looking at Carver and Soundcraftsmen. The Carver was (I think) bipolar and clearly had a bright high end. The Soundcraftsmen (which I still own) were MOSFET and had a smoother top end. At 73 I don't know if I would still hear the difference. A different question - Who or what AI translates your letters? Or are they all english speakers? Love you videos, go ahead and ramble on. Thanks
Merry Christmas to all you music and hifi lovers ❤🎉
And to you as well..... and Paul and PS Audio.
There were different configurations for the layout of the circuitry of MOSFETs. Darlington configuration was popular back in the early 80’s. I am not familiar with what all that means for difference in sound.
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.
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.
Remember those Carver amps that had both voltage and current speaker output taps
Mmmmm...... one of my favourite topics 😊.!
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!
Paul's Made in China speakers are great.
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.
There are quite a few home audio amplifiers that can drive low impedance.
@mitchtaylor6512 Not in mass market. I don't count class D amps. If you get into boutique amps that cost a lot, then yes, but they are boutique. I'm left to believe that 2ohm & especially 1ohm stable amps can't be produced at an affordable price for the mass market. I've chatted with Schiit Audio & was told 2ohm loads are not recommended.
@@adambrown8867you can drive a low impedance load with a lot of amplifiers if you don't turn the volume too high. Most car audio amps run a lower output voltage than home audio amps, that's one of the reasons they can drive low impedance. I also don't think many of the car audio amplifiers actually have as much power as is stated.
I have a friend who says his tube amp stimulates all the family pets, and that jazz fusion night (thursdays) has become almost impossibly to manage. Is this an issue with Class D ? Thank you ever so....
..
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?
It's a BJT configuration, so bipolar.
🎄Merry Christmas to all the staff at PS Audio!🎄
The fabulous.... "Mosfet Mist"
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.
Oll just stick with a hand wired el34 amp with low distortion and wide bandwidth. Sounds like real instruments to me
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 😂
So class D amps have mosfets to tame the aggressive top end. 😂
That's very poetic, but the real reason is that MOSFETS are faster and you need that to switch at ultrasonic frequencies, far above the 'top end' audio.
I love my PS Audio S300 (dual mono) for my PS Audio FR5 speakers (like u see in Paul's video) in bi-amped (S300 powers the low pass, NAD C298 powers the high pass).
My video: th-cam.com/video/-WbVsly1X0w/w-d-xo.html
source=Apple Music lossless
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.
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.
@@paulb4661 Nope. Not even close to being a problem at 20 kHz.
@@markmeridian3360 Since when the tendency to oscillate is, or isn't a problem, depending on the frequency? How many amps have you built?
@@markmeridian3360 "The standard approach to controlling parasitic oscillations in mosfets is to employ gate stopper resistors in series with the gate of the device. These resistors are placed very close to the gate terminal of the mosfet. the resistors tend to kill the speed of the mosfets and to damp out resonant circuits that may be formed by inductance operating in conjunction with gate capacitances. Unfortunately, the practice of using gate stopper resistors discards one of the big advatages of the power modfets, namely their speed." Bob Cordell; Designing Audio Power Amplifiers, page 329.
@@paulb4661 Phony strawman argument. You don't have to just use a gate resistor. It's possible to control unwanted oscillations with RC damping, minimizing parasitic inductance (good circuit board design), or even by using ferrite beads on the gate lines. Carefully selecting gate drive circuit characteristics can stop unwanted oscillations without impacting circuit performance. Remember, we're only talking about 20 kHz max.
Tubes!
Happy Solstice and Happy New Year.
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???
why not just use Purifi Eigentakt and you don't need any artificial distortion added, eh? perfect linearity, more than enough power, ultra low distortion
I was just watching "MOSFETS of Science" last night.
Hey guys i put some honey on my amp circuit, is it gunna be ok
Musks MOSFET amps can overthrow the seppo government😂
Merry Christmas PS Audio and HiFi Gramps. 🎄😊
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
“ 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 😊
GaNFETs are better than both. Oscar Heil invented the FET but failed to patent it.
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.
Why they sound different, fet and bipolar?