I'm definitely in that 'what works for me' campNick wrote: ↑Wed Aug 12, 2020 12:52 pm
With respect Steve, you seem to be tilting at windmills, reality is what it is, and its just lucky that we can model it with maths at all else we would still be in the dark ages. Its not as it is there to frustrate you, but you can chose to be happy with what works or worry over what you probably don't need to know. Most of us just try to find the level of interpretation that works for us and does what we need.
New SE With Triode Mode KT120/150
#271 Re: New SE With Triode Mode KT120/150
The tube manual is quite like a telephone book. The number of it perfect. It is useful to make it possible to speak with a girl. But we can't see her beautiful face from the telephone number
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#272 Re: New SE With Triode Mode KT120/150
Tilting at Windmills - sounds like a Shed 7 song that never made in on to an album
#273 Re: New SE With Triode Mode KT120/150
Just a nit-pick on what Nick said - ESR for a capacitor does vary with frequency as it is dependent on the dissipation factor and that is frequency dependent - this is separate from the ESL.
A good discussion of capacitors and audio is on the Rod Elliot site https://sound-au.com/articles/capacitors.htm.
ciao
James
A good discussion of capacitors and audio is on the Rod Elliot site https://sound-au.com/articles/capacitors.htm.
ciao
James
#274 Re: New SE With Triode Mode KT120/150
Yep, I was wondering if I should mention the extra perfect LCR components across the perfect cap and decided that that way lay madness, but you are of course correct.JamesD wrote: ↑Wed Aug 12, 2020 4:21 pm Just a nit-pick on what Nick said - ESR for a capacitor does vary with frequency as it is dependent on the dissipation factor and that is frequency dependent - this is separate from the ESL.
A good discussion of capacitors and audio is on the Rod Elliot site https://sound-au.com/articles/capacitors.htm.
ciao
James
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#275 Re: New SE With Triode Mode KT120/150
I think any discussion of capacitors and audio promotes madness...
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#276 Re: New SE With Triode Mode KT120/150
And I don’t know much about algebra, or what a slide rule is for, so I’ve no chance.
As Nick has advised. I’ll keep to doing what works for me.
Sgt. Baker started talkin’ with a Bullhorn in his hand.
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#277 Re: New SE With Triode Mode KT120/150
Yer but no but yer but the frequency is 100hz
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
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#278 Re: New SE With Triode Mode KT120/150
Or isn’t it that simple?
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
#279 Re: New SE With Triode Mode KT120/150
and maybe change your user name to Don QuixoteCressy Snr wrote: ↑Wed Aug 12, 2020 5:27 pm As Nick has advised. I’ll keep to doing what works for me.
Sorry, I couldn't resist!
#280 Re: New SE With Triode Mode KT120/150
Don't forget the harmonics.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
#281 Re: New SE With Triode Mode KT120/150
And the noise/signalling on the mains that gets through the trannie and rectifiers....
And the signal that finds it way back into the psu...
And the ground/earth noise...
and
and
and....
And the signal that finds it way back into the psu...
And the ground/earth noise...
and
and
and....
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#282 Re: New SE With Triode Mode KT120/150
" and and and and and and and and and and and and end.. "
As Arthur Lee sang.
As Arthur Lee sang.
"Once you find out ... the Circumstances ; then you can go out"
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#283 Re: New SE With Triode Mode KT120/150
Sorry it’s late was woken by a friend whose little girl getting taken to Jimmy’s and then you’re lying awake. It’s certainly true you can hear the microphonics in the Power supply capacitors playing the music in standard SE.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
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#284 Re: New SE With Triode Mode KT120/150
I brought a pair of grey-glass KT66s out of hibernation to tryout, and the results were encouraging.
At the bias settings I had, they were being over dissipated slightly, but I only had them in for a short time; just long enough to figure that correctly configured, in terms of dissipation and OPT impedance, they would be good.
One change of cathode resistor value to bring the dissipation under 25W, one change of rectifier valve to drop the HT a bit, to make doubly sure, and one rewire of the OPTs for 5K later, we have quite a little performer on our hands.
OK, so these KT66 are not the earlier VT75s (I could have wept when I heard those) but they come in at a highly respectable second place. MH4 driving KT66 is a good combination.
#285 Re: New SE With Triode Mode KT120/150
If you didn't mind a top cap /change of base there are a few other valves that may come close to the vt75, early vt75a to start. I'd need to look at my books, but I dont have with me at the moment.
The tube manual is quite like a telephone book. The number of it perfect. It is useful to make it possible to speak with a girl. But we can't see her beautiful face from the telephone number