Okay. Please note that I have posted repeatedly about my "fantasy amp" project focused on SET and PSET in the 100 watt range.
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Ron’s New System
- Thread starter Ron Resnick
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Okay. Please note that I have posted repeatedly about my "fantasy amp" project focused on SET and PSET in the 100 watt range.
I wanted to make sure that I was not answering your question with the result that a reader could assume mistakenly that I now generally prefer Jadis JA100 over VTL Siegfried II across loudspeakers.
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You seem to be assuming that all of the Jadis amps have the same factory optimization for a certain tube, and the same need for adjustments on different tube swaps. Apparently this is not the case.
In other words, just because the JA30 can take KT90s and EL34s without adjustments does not mean JA200 can accommodate the same. The models designed for KT150s seem to require adjustments for EL34s and KT88s.
I think you have to go amplifier by amplifier and it depends on what tube you are swapping from and to. Without knowing for sure, my impression is that different Jadis amplifiers have different sensitivities to different tubes, and that the higher power amplifiers are more likely to require adjustments for tube swapping from KT120/KT150 to EL34/KT88.
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Why would readers assume that I am talking about anything other than your speakers?? Plus I directed the questions to you and not the "readers". Ron, this kind of pedantic communication makes it hard to discuss with you sometimes.
Sure but focus can change and you have been talking recently about bigger Jadis amps...
People assume things incorrectly very frequently. Perhaps someone is not aware of my whole system thread, and simply sees you asking me "if I prefer Jadis to VTL," and they see me answering "yes."
What is the problem here?
Did you contract audio crankaris too?
I don't know what you're talking about. All I did was make clear that I was answering your question only with respect to Pendragons.
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You know what the word pedantic means, right? Please reflect on how that word might apply when a statement of the obvious is applied in a response some 3200 posts into a thread.
IMO you have to address these questions directly to the manufacturer. Jadis are permanently making small changes to their models and do not tell us about it. Very old Jadis JA200 could use the EL34 just swapping tubes, but at that time they were less powerful than current models.
In fact we know little about the exact differences between a Jadis JA200 made thirty years ago and the current models - their use of mkII, mkIII or mkiV has always been confusing.
Just in the Jadis Defy 7. But there are at less two different versions of the JA200 mkII ...
With plenty of care and knowing the result is not very accurate. The value of the measurement depends a lot on how we handle the PTD-1, because of the glass between the anode surfaces - a special device, working at another wavelength must be used for tubes. However, with some care and experience we can get relative data between tubes measuring the glass temperature at the High emissivity group position.
I also often use it to measure power transformer temperature - an indirect indication of power consumption or the heatsinks temperature in solid state amplifiers.
What are the differences between the two versions?
Not sure, but I have seen Jadis JA200 mkII keeping the same power transformers of the old version and some claiming using different power transformers for optimal use of the KT150. I do not know about the output transformers. The JA 200 will release more heat than the Siegfried II.
the weak spot on EL34s is in the bass, relative to some other tubes. i quite like KT150s combination of tone and extension. it's much better than the KT120 and most KT88s that i've tried. but it also depends on the amp circuit alot.
IMO in order to carry a fair evaluation we should replace the KT88 by two EL34's in parallel ...
If you ever felt so inclined, Ron, and the required modification to enable tube rolling is as simple as a different cathode resistor, a tech could (inexpensively) install a toggle switch or pair of switches to enable you to switch between kt150 mode and el34 mode easily.
It's a good idea and one would think such an expensive amp like Jadis should have done that in the first place. It would also mean boring holes into the chassis which to some owners would be turn-off.