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Post by Admin on Jan 9, 2007 13:34:09 GMT -7
It has been brought to my attention from Igor Boros, that the new TS KT-66 aren't really KT-66's at all and the metal base like a 6550 will short the bias voltage if the tube clamp touches them.
Thanks Igor for the heads up.
Pin 1 is tied to the metal base.
Real KT-66 do not have a metal base. This tube looks like a combination of a KT-88 inners, and the outer design of a 6550.
DR.Z
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Post by myles on Jan 25, 2007 12:01:33 GMT -7
As a side note, these are not a real "KT" (kinkless tetrode) design and are more of a blown down 6550. They do not test like a KT66.
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SG123
Full Member
Posts: 221
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Post by SG123 on Jan 25, 2007 17:18:46 GMT -7
Thanks for that, Myles.
I should have suspected as much. I did a head-to-head recently in a Carr Mercury with the Saratov KT66 and the "TungSol" KT66. The T-S stayed cleaner a bit longer than the Saratov. I had to roll of a lot of high end in both of the boost settings (seems like most of the drive comes from the preamp section) so I really couldn't get a fair reckoning of its distortion characteristics. Didn't seem a lot different than the Saratov - in that amp, and using my ears. :-)
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Post by myles on Jan 26, 2007 9:35:28 GMT -7
Thanks for that, Myles. I should have suspected as much. I did a head-to-head recently in a Carr Mercury with the Saratov KT66 and the "TungSol" KT66. The T-S stayed cleaner a bit longer than the Saratov. I had to roll of a lot of high end in both of the boost settings (seems like most of the drive comes from the preamp section) so I really couldn't get a fair reckoning of its distortion characteristics. Didn't seem a lot different than the Saratov - in that amp, and using my ears. :-) On one tube staying cleaner than the other longer .... do both the tubes test the same, that is ... at a given plate voltage and bias is their milliamp output the same? If one tube reads higher than the other than that tube will probably stay cleaner longer. It is like comparing two of the same tube, such as the KT66HP in a #4 rating vs a #7 rating ... the 7 will have more clean headroom.
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Post by solitaire on Mar 29, 2008 10:38:41 GMT -7
Well isn't that as long as there's no retainer or other that potentially could earth the metal base? Greate valve, btw - though not an actual KT-66.
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Post by iggs on Mar 29, 2008 10:58:20 GMT -7
Well isn't that as long as there's no retainer or other that potentially could earth the metal base? Greate valve, btw - though not an actual KT-66. As long as it's not you who connects to the metal base ... ;D OUCH!
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shadco
Junior Member
Posts: 72
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Post by shadco on Sept 18, 2010 9:37:06 GMT -7
Thanks for that, Myles. I should have suspected as much. I did a head-to-head recently in a Carr Mercury with the Saratov KT66 and the "TungSol" KT66. The T-S stayed cleaner a bit longer than the Saratov. I had to roll of a lot of high end in both of the boost settings (seems like most of the drive comes from the preamp section) so I really couldn't get a fair reckoning of its distortion characteristics. Didn't seem a lot different than the Saratov - in that amp, and using my ears. :-) Interesting a have a Mercury and on mine the tone stack is defeated in either boost 2 or 3.
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