Gold Lion kt77 bias help?

[bigaudioscotto]

Hey Guys,

I am going to swap in a pair of Gold Lion KT77 for SED EL34
and running in Triode.I am running 424v plate and 35v cathode on SED.
what kind of plate and Cathode voltages should I be looking to
get for getting the Max out of the Gold Lion KT77?

Scott

 

[bigaudioscotto]

KT77 Bias Help ?

So I put the Gold Lion KT77 in and am getting 434v on plates and 33v on cathodes which comes to 22 watts of plate dissipation.
do I need to get more voltage on the cathodes say 36v ?
I have 620r on the cathodes so maybe try 560r any thoughts guys?


Scott

 

[bigaudioscotto]

anybody help?

 

[H E Pennypacker]

What should they be biased at? How does it sound now? What amplifier?

 

[nigelwright7557]

If I remember correctly I think the bias on my EL34's was 19 volts.
I used a cathode resistor to get a bias.

 

[bigaudioscotto]

I am not sure what best bias is for these.
they sound real warm but a bit compressed and sluggish on the bottom end.
I am using these in this amp. with 12au7 drivers and KT77 power.
DIY Single-Ended KT88 / 6L6 / EL34 / 6CA7 Tube Amplifier

What should they be biased at? How does it sound now? What amplifier?

 

[H E Pennypacker]

Here is the datasheet if you don't already have it.
http://www.google.com/url?sa=t&rct=...evvNIb_ohOr9NybhEvyRW1g&bvm=bv.59026428,d.b2I

 

[bigaudioscotto]

Yeah I saw that thanks. I am running in triode and just not sure
what kind of voltage would be best for these.
the SED that I have been using had 424v plates and 35v cathode and sound
great. putting these in I get 434v plate and 33v cathode.

Here is the datasheet if you don't already have it.
http://www.google.com/url?sa=t&rct=...evvNIb_ohOr9NybhEvyRW1g&bvm=bv.59026428,d.b2I

 

[MikeR]

I don't know what is the optimal bias point for that tube but you are in the right ballpark. Just listen to it for a number of hours to see if the tubes break in and the sound changes.

Don't go chasing cathode resistor values right now. It could be that tube is just not right for you but give it some time.

 

[bigaudioscotto]

Thanks for the feedback.

I don't know what is the optimal bias point for that tube but you are in the right ballpark. Just listen to it for a number of hours to see if the tubes break in and the sound changes.

Don't go chasing cathode resistor values right now. It could be that tube is just not right for you but give it some time.