A Tube Article on Selecting Tubes.

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FullRangeMan

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Re: A Tube Article on Selecting Tubes.
« Reply #1 on: 22 Apr 2018, 10:43 pm »
Nice article, thanks for post.
The currrent KT90 EH or Ei are a perfect sub for the KT88 with lower price than the famous 88, unfortunately 90 midrange is not so rich as 88 but bass is stronger.

Anyone have experience how long are the EH KT90 time life in a conservative Class A1 circuit?
Thanks
« Last Edit: 24 Apr 2018, 07:17 pm by FullRangeMan »

knotscott

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Re: A Tube Article on Selecting Tubes.
« Reply #2 on: 24 Apr 2018, 10:48 am »
Thanks for the info
« Last Edit: 27 Apr 2018, 05:02 pm by knotscott »

A_shah

Re: A Tube Article on Selecting Tubes.
« Reply #3 on: 27 Apr 2018, 09:29 pm »
Can someone explain to me what is the difference between biasing the power tubes and balancing the input or out put tubes like 12AU7 which needs to be done by a Tech using a voltmeter ? I always thought one can change  the small tubes, 12AU7  on a power amp  without requiring any biasing , however My understanding is that the QuickSilver M60 that I have may require "balancing by a Tech using a voltmeter , if I want to roll tubes ?
 :scratch:
A_shah

twitch54

Re: A Tube Article on Selecting Tubes.
« Reply #4 on: 27 Apr 2018, 09:35 pm »
Thanks Tom ...... :thumb:

FullRangeMan

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Re: A Tube Article on Selecting Tubes.
« Reply #5 on: 27 Apr 2018, 09:47 pm »
Can someone explain to me what is the difference between biasing the power tubes and balancing the input or out put tubes like 12AU7 which needs to be done by a Tech using a voltmeter ? I always thought one can change  the small tubes, 12AU7  on a power amp  without requiring any biasing , however My understanding is that the QuickSilver M60 that I have may require "balancing by a Tech using a voltmeter , if I want to roll tubes ?
 :scratch:
A_shah
Usually these small tubes have fixed or auto bias.
I would like see what the builder had to say on it.
Sure the owner manual may say something on it.