so bob at eruotubes says... (mark IV tube question)

[JimAnsell]

that you can use kt66's in the middle two sockets on mark IV's.
is this realistic?
anyone tried it?

 

[dmt]

I use ALL KT66's in my Simul-Satellite (read: Mark III Green Stripe Simul-Class)

 

[JimAnsell]

I use ALL KT66's in my Simul-Satellite (read: Mark III Green Stripe Simul-Class)

you use them in both amps?
how do they sound compared to regular 6l6's?

 

[Shep]

i think rabies might use something like that..

 

[Boogiebabies]

Don't use a true KT-66 in the outer sockets. It's a 25 Watt tube, but a GT KT-66HP draws way too much bias. I tried a # 5 and it pull -68 ma and I quickly shut it down. They run just fine in the inner sockets. This amp was a C+ with 483V at the plates with the factory bias at -46V. It may be possible on a MK IV as they may run as low as 440V under load.

 

[Paul Secondino]

Don't use a true KT-66 in the outer sockets. It's a 25 Watt tube, but a GT KT-66HP draws way too much bias. I tried a # 5 and it pull -68 ma and I quickly shut it down. They run just fine in the inner sockets. This amp was a C+ with 483V at the plates with the factory bias at -46V. It may be possible on a MK IV as they may run as low as 440V under load.

Just to put a exclamation point on that, don't use KT66 in the outer sockets because they run too hot. 8)

If you're fortunate enough to get colder ones that will run at no more than 42 mA or so , it would be ok but that is pretty close to the max limit.

 

[Boogiebabies]

Don't use a true KT-66 in the outer sockets. It's a 25 Watt tube, but a GT KT-66HP draws way too much bias. I tried a # 5 and it pull -68 ma and I quickly shut it down. They run just fine in the inner sockets. This amp was a C+ with 483V at the plates with the factory bias at -46V. It may be possible on a MK IV as they may run as low as 440V under load.

Just to put a exclamation point on that, don't use KT66 in the outer sockets because they run too hot. 8)

If you're fortunate enough to get colder ones that will run at no more than 42 mA or so , it would be ok but that is pretty close to the max limit.

Exactly. 42ma would be about 75% of max plate dissipation and leave a little room for rising. I've got two spare quads of the GT KT66HP and I would be happy to see how they react in the simul sockets on a MK IV.
I will divulge that I have to run them in the SLO as a 25W tube and 60% MPD or they start to glow after a few minutes. That's at 490 plate volts.
It would also be interesting to see what they draw in tweed power.

 

[Dr. Tweedbucket]

I ran KT88s in my Dual rec per his website :lol: :lol: ...... sounded pretty huge ! :twisted: