AudioCircle

Audio/Video Gear and Systems => Tube-o-phile Circle => Topic started by: OzarkTom on 22 Apr 2018, 06:08 pm

Title: A Tube Article on Selecting Tubes.
Post by: OzarkTom on 22 Apr 2018, 06:08 pm

http://www.audioxpress.com/article/selecting-a-power-tube

Title: Re: A Tube Article on Selecting Tubes.
Post by: FullRangeMan 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

Title: Re: A Tube Article on Selecting Tubes.
Post by: knotscott on 24 Apr 2018, 10:48 am

Thanks for the info

Title: Re: A Tube Article on Selecting Tubes.
Post by: A_shah 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

Title: Re: A Tube Article on Selecting Tubes.
Post by: twitch54 on 27 Apr 2018, 09:35 pm

Thanks Tom ...... :thumb:

Title: Re: A Tube Article on Selecting Tubes.
Post by: FullRangeMan on 27 Apr 2018, 09:47 pm

Quote from: A_shah 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

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.