Kt150

[Marck1973]

Hi,

Was wondering if the new KT150 tube can be fitted in the Ref150?

It is not something I plan to do immediately, but when the tubes need replacing would consider it if Ok to do.

Many thanks
Marc.

[Myles B. Astor]

The KT150 isn't a replacement for a 6550; it replaces an EL34.

[Marck1973]

Agreed, however can it be used in place of the KT120?
Thanks
M.

[Myles B. Astor]

Originally Posted by Marck1973

Agreed, however can it be used in place of the KT120? Thanks M.

No a KT120=6550.

[Harlequin]

Good Morning Mark.

Spec wise the KT150 is not wildly dissimilar to the KT120 , altho perhaps not a straight forward plug n play substitute , I would be surprised were ARC not evaluating this valve , If only for future product development ~

KT150 ~

The plate dissipation is 70 watts
G2 is 9.0 watts,
Cathode current is 275 ma
Filament current is 1.75 -2 amps
Max plate voltage is 850
Screen is 650 volts
Distortion in class A

400v plate
225 v screen
Overall Harmonic Distortion is similar to 6550 at 14%.

KT120 ~

The plate dissipation is 60 watts
G2 is 8.0 watts,
Cathode current is 250 ma
Filament current is 1.75 -1.95 amps
Max plate voltage is 850
Screen is 650 volts

Distortion in class A
400v plate
225 v screen
Overall Harmonic Distortion is similar to 6550 at 14%.

[Marck1973]

Many thanks for clarifying. From above seems unlikely it for would be possible to interchange.
Rgds
Marc.

[Harlequin]

Good Morning ARC Owners .

FYI , Kalvin Dahl's current position on this matter .

"Until engineering tests the KT150s I would not use them in the Ref 150."

It may prove to be the case that the Mains / KT ratio of the Ref 75 might receive sanction , however we may speculate that the Ref 150's 8 x KT / Mains ratio may prove too near the Red Line without major surgery , if at all.

However it would seem prudent to await the 'The Word' from ARC central on this matter regardless of model , especially for units still under warranty .

Jasper.

[Priaptor]

Originally Posted by Harlequin

Good Morning ARC Owners .

FYI , Kalvin Dahl's current position on this matter .

"Until engineering tests the KT150s I would not use them in the Ref 150."

It may prove to be the case that the Mains / KT ratio of the Ref 75 might receive sanction , however we may speculate that the Ref 150's 8 x KT / Mains ratio may prove too near the Red Line without major surgery , if at all.

However it would seem prudent to await the 'The Word' from ARC central on this matter regardless of model , especially for units still under warranty .

Jasper.

It wouldn't surprise me especially when they have a Galileo 150 that will be spec'd out similar to the REF150 using KT150s albeit at 2x the price. I am sure ARC wouldn't want to sanction a similar amp to use KT150s at 1/2 the price. Call me a skeptic but I have seen too much nonsense in this industry to really believe what any of them say.

I can't speak for the REF150, but those of you with the REF75 should (as I was told) run not walk to replace your tubes with KT150s. Amazing difference for the better. I have close to 150 hours on mine on they are marvelous.

[Harlequin]

Originally Posted by Priaptor

It wouldn't surprise me especially when they have a Galileo 150 that will be spec'd out similar to the REF150 using KT150s albeit at 2x the price. I am sure ARC wouldn't want to sanction a similar amp to use KT150s at 1/2 the price. Call me a skeptic but I have seen too much nonsense in this industry to really believe what any of them say.

Indeed Priaptor... Your reasoning mirrors my own conspiracy theory No1. I very nearly offered this up as an option in post #52.

[ariess]

I heard ARC has been testing the KT150's on the VSi75 as a drop in replacement and have liked what they have heard sonically as well as the increase in power. But they have more testing to do before they can sign off on the stability and safety. Apparently the open assembly makes it easier to try out on the VSi75. Can anyone speculate the expected wattage increase? Does anyone have first hand knowledge of the sonic differences with the KT120's?