mastertech said:
Hi Class-A Specialist,
THE BJT , you want something good for it , certainly Not.....
It suffers from Dreaded Second Breakdown Voltage
It suffers from Negative Temperature Cofficient at High current resulting in thermal runaway, if biasing doesnot implemented with thermal compensation senstivity...
It suffers from low speeds, yields low slew rate...
It suffers from High VCES[saturation voltage] upto 2-3 volts, which hampers it from deliverig rail to rail swings.
It always need a VI limiter in order to function safely in pro-amps[not in hi-end amps]
It yields less damping than Mosfets at a given impendance
The only Good point about BJT is that its very effective to be a small-signal Class-A amplifier with BJT's with small current conductions in VAS, Differential stages, but ALAS, JFET dominates the much of High end market , then where's this BJT stands maybe somewhere , which is ???????
K a n w a r
Well Hi to all the gurus, particularly you Mikeks - you keep defending the tired conventional topology of diff pair - Vas - EF/SF now stating it has the least and only minor shortcomings.
When I highlighted the BIG weakness you tell me RC filters are simple solutions. When I say show me 40dB at 20Hz you disappear from the face of the Earth. So, c'mon show us how simply you can get your conventional topology to match/beat the PSRR of my inherently simpler and considerably better PSRR topology. Here's your opportunity... don't just snipe at the sidelines.
Why is it important? Because this is why my little topology, and my previous Eidetic amplifier (140dB PSRR) was SOOOOOoooo superior to the monster amps! It's simply amazing the detail, the width and depth of the soundstage the sheer delicacy and sweetness of the sound - the detail that resurfaces when the miasma of power supply artefacts is not there.
As soon as my 6" monoblock is ready, I'm happy to challenge any ML, Krell, or Classe or any monster amp fairly and squarely, because I know it's chalk and cheese - and I have science on my side! Likely RRP US$499 ready to go.
Oh and Mikeks here it is again, just in case you can't find it -
Cheers,
Greg
When I highlighted the BIG weakness you tell me RC filters are simple solutions. When I say show me 40dB at 20Hz you disappear from the face of the Earth. So, c'mon show us how simply you can get your conventional topology to match/beat the PSRR of my inherently simpler and considerably better PSRR topology. Here's your opportunity... don't just snipe at the sidelines.
Why is it important? Because this is why my little topology, and my previous Eidetic amplifier (140dB PSRR) was SOOOOOoooo superior to the monster amps! It's simply amazing the detail, the width and depth of the soundstage the sheer delicacy and sweetness of the sound - the detail that resurfaces when the miasma of power supply artefacts is not there.
As soon as my 6" monoblock is ready, I'm happy to challenge any ML, Krell, or Classe or any monster amp fairly and squarely, because I know it's chalk and cheese - and I have science on my side! Likely RRP US$499 ready to go.
Oh and Mikeks here it is again, just in case you can't find it -
Cheers,
Greg
Attachments
Hi darkfenriz,
This is one approach to take but leads to extra complexity. You can regulate at higher voltage all stages from Vas back but it's an extra supply feed /windings/rectifiers/filter C's/wiring, bridge outputs are doubly complex. You end up with either a simple amp and a complex supply trying to compensate for it or a doubly complex amplifier.
I prefer a wholistic approach considering the amplifier and power supply as one - with a low impedance 'noise' source at each supply line trying to intrude on my signal circuits and cloud the output. The simplest topology that keeps this out is then half the battle won, the rest to achieve performance targets.
Cheers,
Greg
This is one approach to take but leads to extra complexity. You can regulate at higher voltage all stages from Vas back but it's an extra supply feed /windings/rectifiers/filter C's/wiring, bridge outputs are doubly complex. You end up with either a simple amp and a complex supply trying to compensate for it or a doubly complex amplifier.
I prefer a wholistic approach considering the amplifier and power supply as one - with a low impedance 'noise' source at each supply line trying to intrude on my signal circuits and cloud the output. The simplest topology that keeps this out is then half the battle won, the rest to achieve performance targets.
Cheers,
Greg
ampguru-
"
Well Hi to all the gurus, particularly you Mikeks - you keep defending the tired conventional topology of diff pair - Vas - EF/SF now stating it has the least and only minor shortcomings.
When I highlighted the BIG weakness you tell me RC filters are simple solutions. When I say show me 40dB at 20Hz you disappear from the face of the Earth. So, c'mon show us how simply you can get your conventional topology to match/beat the PSRR of my inherently simpler and considerably better PSRR topology. Here's your opportunity... don't just snipe at the sidelines.
Why is it important? Because this is why my little topology, and my previous Eidetic amplifier (140dB PSRR) was SOOOOOoooo superior to the monster amps! It's simply amazing the detail, the width and depth of the soundstage the sheer delicacy and sweetness of the sound - the detail that resurfaces when the miasma of power supply artefacts is not there.
As soon as my 6" monoblock is ready, I'm happy to challenge any ML, Krell, or Classe or any monster amp fairly and squarely, because I know it's chalk and cheese - and I have science on my side! Likely RRP US$499 ready to go.
Oh and Mikeks here it is again, just in case you can't find it -
"
wow Greg Ball what an amp, how did you do it? looks like Mikeks
will disappear for a while, youre talking about detail and sheer
sweetness of sound is a result of no power supply artefacts
alone, are you sure?, are you Greg Ball who published an
article on ps in ew, you mention the price of us$499 what power
output are we talking about? keep up the good work,and show
us the schematics and some pics of your new baby
Lets see something different for a change
cheers
"
Well Hi to all the gurus, particularly you Mikeks - you keep defending the tired conventional topology of diff pair - Vas - EF/SF now stating it has the least and only minor shortcomings.
When I highlighted the BIG weakness you tell me RC filters are simple solutions. When I say show me 40dB at 20Hz you disappear from the face of the Earth. So, c'mon show us how simply you can get your conventional topology to match/beat the PSRR of my inherently simpler and considerably better PSRR topology. Here's your opportunity... don't just snipe at the sidelines.
Why is it important? Because this is why my little topology, and my previous Eidetic amplifier (140dB PSRR) was SOOOOOoooo superior to the monster amps! It's simply amazing the detail, the width and depth of the soundstage the sheer delicacy and sweetness of the sound - the detail that resurfaces when the miasma of power supply artefacts is not there.
As soon as my 6" monoblock is ready, I'm happy to challenge any ML, Krell, or Classe or any monster amp fairly and squarely, because I know it's chalk and cheese - and I have science on my side! Likely RRP US$499 ready to go.
Oh and Mikeks here it is again, just in case you can't find it -
"
wow Greg Ball what an amp, how did you do it? looks like Mikeks
will disappear for a while, youre talking about detail and sheer
sweetness of sound is a result of no power supply artefacts
alone, are you sure?, are you Greg Ball who published an
article on ps in ew, you mention the price of us$499 what power
output are we talking about? keep up the good work,and show
us the schematics and some pics of your new baby
Lets see something different for a change
cheers
Hi Mastertech,
"youre talking about detail and sheer
sweetness of sound is a result of no power supply artefacts
alone, are you sure?"
No not alone, of course there are other factors but this is as important. Given an otherwise good design, non-attention to PSRR can be THE major limiting factor. A prime example is Douglas Self's series, where, with all the machinations, the single biggest improvement came when he tried a regulated PS - the distortion dropping from > 0.03% to 0.006% - remember this was in an already honed amplifier, many designs are worse! How many on this forum have said that his amplifiers, true conventional topology, honed, doesn't sound any good!
The article (pictured) "Audio Distortion - Holy Grail Located" I wrote pre my 1990 Eidetic amplifier. It was the reality.
Cheers,
Greg
"youre talking about detail and sheer
sweetness of sound is a result of no power supply artefacts
alone, are you sure?"
No not alone, of course there are other factors but this is as important. Given an otherwise good design, non-attention to PSRR can be THE major limiting factor. A prime example is Douglas Self's series, where, with all the machinations, the single biggest improvement came when he tried a regulated PS - the distortion dropping from > 0.03% to 0.006% - remember this was in an already honed amplifier, many designs are worse! How many on this forum have said that his amplifiers, true conventional topology, honed, doesn't sound any good!
The article (pictured) "Audio Distortion - Holy Grail Located" I wrote pre my 1990 Eidetic amplifier. It was the reality.
Cheers,
Greg
Attachments
amplifierguru said:Well Hi to all the gurus, particularly you Mikeks - you keep defending the tired conventional topology of diff pair - Vas - EF/SF now stating it has the least and only minor shortcomings.
When I highlighted the BIG weakness you tell me RC filters are simple solutions. When I say show me 40dB at 20Hz you disappear from the face of the Earth. So, c'mon show us how simply you can get your conventional topology to match/beat the PSRR of my inherently simpler and considerably better PSRR topology. Here's your opportunity... don't just snipe at the sidelines.
Oh and Mikeks here it is again, just in case you can't find it -
Cheers,
Greg
Hello Greg,
Dont you know that our Beloved friend "Mikeks" is extremely good at "Theoratical Works" as well as "Short Word Posts", therefore it is impossible for him to encounter with you on the basis of "Real World Practical Analysis", Secondly , I had never seen his posts more than a Few words.....Maybe he uses short words to describe his big intentions....
Cheers,
K a n w a r
Hi Andrew T,
Kanwar and I are on excellent terms. I think I have shown off my topology enough that many would be able to complete a practical unit - if not, they are quite welcome to contact me for a complete kit with schematic, instructions and PCB populating guide as per my website. They are very keenly priced with highly matched and quality components - my contribution to the DIY community.
I find it sad to see so many wanting to copy yesterdays overbuilt dinosaur amps at great expense/waste. I doubt they've ever heard really transparent audio. I guess some people really are more absorbed by hype than science.
Cheers,
Greg
Kanwar and I are on excellent terms. I think I have shown off my topology enough that many would be able to complete a practical unit - if not, they are quite welcome to contact me for a complete kit with schematic, instructions and PCB populating guide as per my website. They are very keenly priced with highly matched and quality components - my contribution to the DIY community.
I find it sad to see so many wanting to copy yesterdays overbuilt dinosaur amps at great expense/waste. I doubt they've ever heard really transparent audio. I guess some people really are more absorbed by hype than science.
Cheers,
Greg
Somewhere I heard that power Fets have a neg temp. coefficient as opposed to the BJT's positive were Vbe turn on reduces with temp increase, as a Fet heats, Vgs turn on becomes larger. Is this correct, or just with certain types like hexfets, or lateral. Or am I in deep left field on this? Now I have not much experience with power fets for audio or linear functions, so I'm a bit cloudy on the specifics of this subject. Temperature compensation whould be a factor in this "killer amp" would it not? Or is it biased class B. (being sarcastic of course)
(being sarcastic of course)- Status
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