I've got a Defy 7 Mkl with 6550's. I wanted to try KT88's but was warned by a Jadis dealer, it's risky on the trans...
KT120 Tube compatibility w/ Jadis Defy 7 Amp MK 1
Hi, I have an original Jadis Defy I just acquired for I liked its sound very much. However, I don't have any users manual or schematic for the serial #445. Could anyone help by sending a .pdf or electronic copy.
Also, there is a new tube out for the KT88/6550/KT90/EL34 socket line called the KT120. It is the most powerful tube of all of them.
I would like to replace all of the current (12) 6550B tubes with the new larger KT-120 Tubes by Tung Sol (which has a plate dissipation of 60 watts, making it the most powerful tube in the 6550/KT88/KT90 family, or approximately 10 more watts/tube vs. KT90 . Also, when used at the parameters found in existing 6550/KT88/KT90 circuits, the Tung-Sol KT120 is impervious to overload, delivering peak power with extreme reliability and long tube life). Another note regarding universal replacement/compatibility is that the glass envelope of the KT-120 tube is 1/2" taller than other KT88 cousins to accommodate the larger internal plate structure and larger control grid cooling fins, which won't present a problem. However, a word of caution is given regarding the KT120's small increase in current vs. the next most powerful KT88 or KT90 (close in current draw), wherein they say the filament of this tube draws 1.7A to 1.95A, or 0.1 Amp to 0.35 Amp (100 to 350 mA) more current than a KT88 at 1.6 amp; so they say to be safe and recommended to check with your amp manufacturer to make sure the Jadis Defy 7 filament transformer will or can handle the increase in current (at 0.1 to 0 .35A/tube and if you have a quad that is 0.4-1.4A total additional current draw with normal current of 1.6A/tube) without any transformer mods. Will this small increase in current for the Jadis Defy 7 filament transformer be able to handle this increase draw in current required of the Tung-Sol JT120?
Any help answering this technical question would be greatly appreciated and I would gladly pay for a owners manual/schematic for this 100wpc push-pull configured amp design.
Also, there is a new tube out for the KT88/6550/KT90/EL34 socket line called the KT120. It is the most powerful tube of all of them.
I would like to replace all of the current (12) 6550B tubes with the new larger KT-120 Tubes by Tung Sol (which has a plate dissipation of 60 watts, making it the most powerful tube in the 6550/KT88/KT90 family, or approximately 10 more watts/tube vs. KT90 . Also, when used at the parameters found in existing 6550/KT88/KT90 circuits, the Tung-Sol KT120 is impervious to overload, delivering peak power with extreme reliability and long tube life). Another note regarding universal replacement/compatibility is that the glass envelope of the KT-120 tube is 1/2" taller than other KT88 cousins to accommodate the larger internal plate structure and larger control grid cooling fins, which won't present a problem. However, a word of caution is given regarding the KT120's small increase in current vs. the next most powerful KT88 or KT90 (close in current draw), wherein they say the filament of this tube draws 1.7A to 1.95A, or 0.1 Amp to 0.35 Amp (100 to 350 mA) more current than a KT88 at 1.6 amp; so they say to be safe and recommended to check with your amp manufacturer to make sure the Jadis Defy 7 filament transformer will or can handle the increase in current (at 0.1 to 0 .35A/tube and if you have a quad that is 0.4-1.4A total additional current draw with normal current of 1.6A/tube) without any transformer mods. Will this small increase in current for the Jadis Defy 7 filament transformer be able to handle this increase draw in current required of the Tung-Sol JT120?
Any help answering this technical question would be greatly appreciated and I would gladly pay for a owners manual/schematic for this 100wpc push-pull configured amp design.
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- 28 posts total
- 28 posts total