• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Best line stage tube?

What is the best line stage tube?

  • ECC81

    Votes: 5 9.6%
  • ECC82

    Votes: 9 17.3%
  • ECC83

    Votes: 6 11.5%
  • ECC88

    Votes: 30 57.7%
  • ECF80

    Votes: 1 1.9%
  • ECL82

    Votes: 1 1.9%

  • Total voters
    52
  • Poll closed .
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Hello Joshua_G,
You may be on to something when you speak of SET micro-dynamics even if you do have a faraday cage in your hat. SET’s do have some kind of magic. Perhaps it can be defined and measured without distracting from the presence.
Moving on from hypothetical construct, something possible but not defined or measured, up a notch to intervening variable. We are speaking of the psychology of perception here. My first thought was intermodulation distortion caused by power supply impeadance vs. voltage interacting with the signal. Second thought, no I don’t think so, there will be interaction between power supply noise and signal but it is not unique to SET’s. The next thought is something that is measureable and is largely unique to SET’s that is “sonic signature” or the stair stepping of increasing harmonics. The 2nd harmonic is more prominent than the 3rd, the 3rd more prominent than the 4th and higher harmonics trailing into the noise floor. This is musical and fits my bias. Any other ideas? Will we ruin the magic by testing it?
Possible test design:
Build a amplifier with a SET signature and one without. Adjust the Micro-Dynamic level until 70% of the randon subjects can identify the difference between the two amplifiers. Then administer a psychological evaluation instrument to the subjects to get their description of subjective response; open, spacious, warm harsh ect.
A second study could be with an odd harmonic signature amplifier with the same psych follow up test.
Thoughts?
DT
All just for fun!
 
...listen to a well designed SET power amp you will note the extended details and micro-dynamics of the sound, compared to any PP power amp, be it tubes or SS.

Not my dpa300B differential amp - it has far better microdynamics than any SE amp - because for one thing, it doesn't have a whole pile of 2nd harmonic distortion - almost unavoidable in an SE amp. Raise your standards, Joshua.
--------------------------------------------
The tube pole is a joke - no way enough choices. If I had to pick one tube, it would be the 6H30, but prefer a much wider choice range than just one.

The topology is far more important than tube type IME.

Regards, Allen
 
Hello Wavebourn,
Rule of thumb THD is proportional to power output(up to clipping). 3rd or odd harmonics increase in relation to 2nd or even as power decreases. My thought was to fix as many variables as possible and test a typical SET stair step signature and identify subject response. Same with odd order distortion.
Where are you headed?
DT
Just for fun!
 
No it's not. It's his own polemic that is based on personal hypotheses. There is nothing wrong with a good single-ended amplifier and his remarks about about the high end are simplistic generalizations that are way off base.

John

I don't agree with all he says but still it's a fine site. Can't believe you close your eyes to all the good info you can find there just because he criticizes SE amplification. I like SE amps, they have qualities PP amps don't have but hifi- they're not. Not that I care anyway. He also says he could built a SS guitar amp which will sound like a tube one if he wanted to. 😀 But the strangest thing I read was this:

Code:
Negative feedback reduces the hum and hiss of a HiFi valve amp, but has  little to zero effect on reducing audible distortion

It is an interesting site, many good things to read and many whacky comments.

This is possibly OT but I don't remember what the topic was...oh yes, best
line stage tube. A bit silly, isn't it? Sometimes in this forum there's a fever for "best of" threads, people keep forgetting audio is a subjective experience and there will NEVER be an agreement about what it's best. Frankly, best line stage topology would be a better subject.
 
But the strangest thing I read was this:

Code:
Negative feedback reduces the hum and hiss of a HiFi valve amp, but has  little to zero effect on reducing audible distortion

Not so strange. There is a difference between audible and perceivable distortions.

Like, there is a difference between saying, "How well your system sounds!", and "I like how well frogs are singing on your backyard!". Actually, frogs were singing on CD where piano was playing on background of Nature sounds.
 
Hello Joshua_G,
You may be on to something when you speak of SET micro-dynamics even if you do have a faraday cage in your hat. SET’s do have some kind of magic. Perhaps it can be defined and measured without distracting from the presence.
Moving on from hypothetical construct, something possible but not defined or measured, up a notch to intervening variable. We are speaking of the psychology of perception here. My first thought was intermodulation distortion caused by power supply impeadance vs. voltage interacting with the signal. Second thought, no I don’t think so, there will be interaction between power supply noise and signal but it is not unique to SET’s. The next thought is something that is measureable and is largely unique to SET’s that is “sonic signature” or the stair stepping of increasing harmonics. The 2nd harmonic is more prominent than the 3rd, the 3rd more prominent than the 4th and higher harmonics trailing into the noise floor. This is musical and fits my bias. Any other ideas? Will we ruin the magic by testing it?
Possible test design:
Build a amplifier with a SET signature and one without. Adjust the Micro-Dynamic level until 70% of the randon subjects can identify the difference between the two amplifiers. Then administer a psychological evaluation instrument to the subjects to get their description of subjective response; open, spacious, warm harsh ect.
A second study could be with an odd harmonic signature amplifier with the same psych follow up test.
Thoughts?
DT
All just for fun!

What I wrote about SET amps was after I heard one.
It may well have to do with the psychology of perception, I don't know.
I'm retired and I don't have the money to build different amplifiers, I'm trying to gather the money needed to build the amps I need for my audio setup.
Also, I have no idea what to change in an amp in order to change its' microdynamics.
 
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