Goodness ....
Three stage amps are worse than a really good two stage DC amp.
I built my first 2A3 DHT amp in 1982, with audio reviewer Neil Levinson, Fanfare Magazine. . Designed my first DHT amp in 1983.
The best test equipment is located on either side of your cranium, GOD given, called "ears" here in the USA.
Betcha your chokes are all over 20 Ohms DCR. Maybe you will experiment and learn in the future. From the way you talk, there is likely no helping you.
Easy for me to see. You are lost .
Jeff
Three stage amps are worse than a really good two stage DC amp.
I built my first 2A3 DHT amp in 1982, with audio reviewer Neil Levinson, Fanfare Magazine. . Designed my first DHT amp in 1983.
The best test equipment is located on either side of your cranium, GOD given, called "ears" here in the USA.
Betcha your chokes are all over 20 Ohms DCR. Maybe you will experiment and learn in the future. From the way you talk, there is likely no helping you.
Easy for me to see. You are lost .
Jeff
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Your preference for a two stage over a three stage is your opinion. Of course you're entitled to your opinion. Both can perform well, but I'm entitled to my opinion as well, which is the result of a lot of testing and listening.
I built my first amp in the 60's, with my Dad. He previously ran a production line at EAI. They designed and built analogue computers based on vacuum tubes. I started doing my own designs in the early 70's, while working in a high end audio shop in NJ. The owner was an engineer at Bell Labs. The shop was well staffed and equipped.
Good test equipment is that which is reliable, consistent, well maintained and properly calibrated. Your ears (most of the planet calls them ears as well), are only a pickup device, whose calibration drifts constantly based on temperature, humidity and barometric pressure. Aging doesn't improve them. The gray matter between does the rest, and is also subject to constant calibration errors due to mental state, recent food/drink intake, weather conditions and is easily distracted. As a result, I'll use proper test equipment first, followed by a lot of listening sessions over time.
Choke DCR, 20 ohms is not a magical specification. Do you also consider the DCR in the output transformer? How about other specs such as inductance and the ability to saturate magnetically?
Finally, I'm not lost. I only got lost once driving in Brussels back in the 90's. Regardless, you're not qualified to provide me with any help or assistance.
We should simply leave it at that.
Regards, KM
I built my first amp in the 60's, with my Dad. He previously ran a production line at EAI. They designed and built analogue computers based on vacuum tubes. I started doing my own designs in the early 70's, while working in a high end audio shop in NJ. The owner was an engineer at Bell Labs. The shop was well staffed and equipped.
Good test equipment is that which is reliable, consistent, well maintained and properly calibrated. Your ears (most of the planet calls them ears as well), are only a pickup device, whose calibration drifts constantly based on temperature, humidity and barometric pressure. Aging doesn't improve them. The gray matter between does the rest, and is also subject to constant calibration errors due to mental state, recent food/drink intake, weather conditions and is easily distracted. As a result, I'll use proper test equipment first, followed by a lot of listening sessions over time.
Choke DCR, 20 ohms is not a magical specification. Do you also consider the DCR in the output transformer? How about other specs such as inductance and the ability to saturate magnetically?
Finally, I'm not lost. I only got lost once driving in Brussels back in the 90's. Regardless, you're not qualified to provide me with any help or assistance.
We should simply leave it at that.
Regards, KM
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Of course some engineers design effects boxes, either because they prefer them or because they believe their customers may prefer them. Perhaps I should have made it clear that I was speaking of hi-fi, not general audio.bigun said:
I guess designing by recipe is what people have to do when they can't find their calculator. I would give that a 'U' grade.drlowmu said:
More recipes, but at least there is now no pretence of sound reproduction. Instead, the amplifier is supposed to add "FUN" to the music. I prefer my "FUN" to be created by the musicians.
You should have added a smiley if humour was intended. 'kmaier' is flying the US flag so why do you suspect he is in Europe?
The really sad thing about such humour is that there are fanboys and newbies out there who might think you are being serious and offering sound advice about amplifier technology.
I am really curious to see the rest of the system in ITS room. If this 2A3 SET is the best possible amp there must be some serious troubles going on.
Sorry drlowmu your mystical approach was almost the standard practice in some specialised DIY magazines back in the early 90's when most people still didn't know anything about valve/tube amplifiers. So the "Charleston" amplifiers were kings because they were simple and mostly "self adjusting". It's out of fashion nowadays. The reason why they become so popular is trivial: a common person with no technical know-how can only assemble few components that do not require any other effort or knowledge to make it work safely and decently, can only swap components and see what he gets. This will have a double useful result:
1) He will believe he can "design" an amplifier (because if I change the value of a capacitor or a choke it's a new design!) and so a new member of the community joins in;
2) He will spend a lot more money than he would normally do when buying a proper well engineered off-the-shelf product.
Granted!
Sorry drlowmu your mystical approach was almost the standard practice in some specialised DIY magazines back in the early 90's when most people still didn't know anything about valve/tube amplifiers. So the "Charleston" amplifiers were kings because they were simple and mostly "self adjusting". It's out of fashion nowadays. The reason why they become so popular is trivial: a common person with no technical know-how can only assemble few components that do not require any other effort or knowledge to make it work safely and decently, can only swap components and see what he gets. This will have a double useful result:
1) He will believe he can "design" an amplifier (because if I change the value of a capacitor or a choke it's a new design!) and so a new member of the community joins in;
2) He will spend a lot more money than he would normally do when buying a proper well engineered off-the-shelf product.
Granted!
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On an ultimate amplifier, one less stage is always better, because each stage you employ is a opportunity for the signal to be further degraded. Less, is more.
Yes, I own Tektronics scopes, etc, but the final judge is always the ear, listening to music.
20 Ohms, or less, IS magical. It was the very first thing my first audio mentor, Bob Fulton told me about doing a DHT amp, in 1982. He knew !! Over 20 Ohms and you have messed the amp up. I prefer under 10 Ohms, this last ten years. My pictured amp uses 7.8 Ohms plus 8.1 Ohms in series, so I have 15.9 Ohms DCR , total series resistances, due to the chokes. It flies !!
LOL, I was born and raised in Trenton, NJ.
I am surprised you don't have the intellectual curiosity to ask for the two EE's compilations on power supplies. Yes, KM, we can end it here.
Have a good day.
Jeff
Fulton Musical Industries - Biography
You constantly contradict yourself because in your amplifier the signal is far more degraded by that bad power supply. IMD is not something I would like to hear from an "ultimate" amplifier. Too much less is worse!😀
How does one amplifier CREME another, is this something we should add in specifications:
CREME FACTOR........ 20 dB
What if a person used 470uF across the stage at the end of the supply. There's the 20 ohms at 20Hz without necessarily passing the signal through the power transformer?
This is a specific figure, does it relate to a specific amp? What, within this amp does that 20 ohms work with or against that makes it special?
It may be possible to capacitor couple and make things worse but that doesn't have to happen, does it?
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I read somewhere that somebody on this forum who had a dc-coupled amp found that they preferred the sound to cap-coupled - OK, that's a matter of opinion still, but what was interesting to me was that they reported that using a MOSFET source-follower to drive the grid of the power tube gave the same 'sound' as dc-coupling.
I think I have already explained. If it is not clear for you that's a double proof!!!!
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