As I said, even with such nice monitors I still hear sound of monitors amplified by amps. I don't hear sounds as if they are alive. That's the problem between your theoretical conclusions and my practical experience.
Hello Sy,
I just reread Jones 3rd Edition section on test method and results for medium mu tubes. Perhaps we see your inspiration to use D3A tubes. All the tubes were tested at 8ma and 19.5V RMS output. The results show an order to things at the test conditions. I think that there is still room for us DIYers to play with the “lesser” tubes.
I bought a box of 9AU7’s for a dollar each. I also bought a box of 6BK7’s that I have used for line output buffers. Also in the stash is a box of 12SN7’s mostly WWII vintage JAN RCA in the plain cardboard packaging of the time. They are all fun to play with. I have been playing with 5763 transmitter tubes as power output tubes, could be junk.
DT
I just reread Jones 3rd Edition section on test method and results for medium mu tubes. Perhaps we see your inspiration to use D3A tubes. All the tubes were tested at 8ma and 19.5V RMS output. The results show an order to things at the test conditions. I think that there is still room for us DIYers to play with the “lesser” tubes.
I bought a box of 9AU7’s for a dollar each. I also bought a box of 6BK7’s that I have used for line output buffers. Also in the stash is a box of 12SN7’s mostly WWII vintage JAN RCA in the plain cardboard packaging of the time. They are all fun to play with. I have been playing with 5763 transmitter tubes as power output tubes, could be junk.
DT
You see correctly. Morgan gave me two of them to duplicate his test setup. Before I wired things up, I stuck a D3a into mine (CCS plate load, LED bias) to check its distortion spectrum, just for fun. I thought my test equipment was broken! I asked him if he had measured them before doing his 6SN7 work. He responded, no. I suggested that he had put the wrong tube on the bottom of his mu follower.
I dont know about mathematical models, but in real life higher plate voltages require lower currents and higher negative bias voltages that lead to island-effect, when each gap between grid wires act as a separate deevice in ray deflecting mode, lots of them in parallel. I don't think how it can be more linear than in case of traditional usage.
I know nothing of mathematical models of valves, I can barely handle LTSpice, but the sims are consistent with what you say
+B=650V i=6mA Vgk=-13V THD=0.074%
+B=800V i=4.5mA Vgk=-17V THD=0.058%
I will try to explain following the approach suggested by SY in post # 6, by using curves of post#49
Sorry, but are the only ones I have on hand.
On curves mu vs. I, at low Vak, clearly sees that as decreases the electron cloud, mu increases, reaching a maximum, and from there begins to weigh secondary emission, then mu decreases.
When Vak increases, the electron cloud is increasingly weak, whereas secondary emission is increasing, and mu decreases.
At high levels of Vak, mu tends to be linear, and its slope tends to decrease, then distortion decreases.
You may not like my physical interpretations, but I'm just a TV repairman.
+B=650V i=6mA Vgk=-13V THD=0.074%
+B=800V i=4.5mA Vgk=-17V THD=0.058%
I will try to explain following the approach suggested by SY in post # 6, by using curves of post#49
Sorry, but are the only ones I have on hand.
On curves mu vs. I, at low Vak, clearly sees that as decreases the electron cloud, mu increases, reaching a maximum, and from there begins to weigh secondary emission, then mu decreases.
When Vak increases, the electron cloud is increasingly weak, whereas secondary emission is increasing, and mu decreases.
At high levels of Vak, mu tends to be linear, and its slope tends to decrease, then distortion decreases.
You may not like my physical interpretations, but I'm just a TV repairman.
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In my childhood I read how to increase the gain of a small signal triode reducing the filament voltage.
How to explain this in a not fanciful way?
Or will that in this hemisphere the laws of physics are reversed, or the books are written the other way around? Or am I reading the wrong books?
How to explain this in a not fanciful way?
Or will that in this hemisphere the laws of physics are reversed, or the books are written the other way around? Or am I reading the wrong books?
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Actually for natural sound like frogs, surround is much better. It also has an advantage in reducing influence of room acoustic on resulting sound.
Thank you Mr. Theoretician, I will follow your advice!
Which surround sound processing would you recommend for particular frogs?
You see correctly. Morgan gave me two of them to duplicate his test setup. Before I wired things up, I stuck a D3a into mine (CCS plate load, LED bias) to check its distortion spectrum, just for fun. I thought my test equipment was broken! I asked him if he had measured them before doing his 6SN7 work. He responded, no. I suggested that he had put the wrong tube on the bottom of his mu follower.
Hey Sy,
That is an excellent tale, thanks for sharing. The process and fellowship is half the fun!
DT
If memory works was a Loftin-White amp and valve was a 12AX7, but in a DHT the effect is almost the same.
Is this the not fanciful explanation? The deepest nature of triode?
Can be described in two words.
I am speaking of the same in the whole thread, but as I said before, it seems, in this hemisphere the laws of physics are reversed or people from the other hemisphere does not see what is happening in this, perhaps for some unknown relativistic effect.
What's in a triode addition to the interactions of electrons?
electron-electron, electron-electrodes, electron-fields
Am I missing something?, Cosmic rays?, Gravitation?, The wave-like nature of electron?, Virtual particles?
How can it be denied that the electron cloud decreases the gain of the triode?
The starved filament operation reduced thermionic emission, then the electron cloud decreases, then increases the gain of the triode.
Is this fanciful?
How can it be denied that secondary emission also reduce the gain of the triode?
No need 1MeV to have secondary emission, around 4ev is sufficient.
The electrons emitted by the anode can be absorbed again, because the anode is positive, but have less energy, part of it is dissipated as heat, as result, the gain of the triode decreases.
Is this fanciful?
Hi DualTriode
Thanks for your feedback.I hope not me vain.
Of course they are right, but do not own the truth, almost from the beginning, when I say the same in a different way, I am fiercely attacked.
It is also true that it has all been done before, and the theory and mathematics is all in old books, but seem to forget.
It is also true that we can't see that electron cloud or hold in our hand, neither distortion, but we can talk about it.
I've said before, my knowledge is limited, and do what I can, after all I'm just a TV repairman.
Best regards
Johann
Thanks for your feedback.I hope not me vain.
Of course they are right, but do not own the truth, almost from the beginning, when I say the same in a different way, I am fiercely attacked.
It is also true that it has all been done before, and the theory and mathematics is all in old books, but seem to forget.
It is also true that we can't see that electron cloud or hold in our hand, neither distortion, but we can talk about it.
I've said before, my knowledge is limited, and do what I can, after all I'm just a TV repairman.
Best regards
Johann
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Well I'll quote one of England's most famous footballers, George Best on this one: "I spent a lot of money on women, drink and fast cars, the rest I just squandered"
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