New tubes in Rogue M-180 Monoblocks


I understand the M-180s now ship with the KT-120 power tubes, instead of the KT-80. You can also simply replace the KT-80 with the KT-120 if you already own these amps. I'm curious whether anyone has done it and what their impressions are as far as the difference in sound. Is the over $300 upgrade worth it?
actusreus

Showing 4 responses by daverz

I've been running KT-120s in my M-180s for about 6 months. I'm still using the 12A*7 tubes that the amps shipped with.

Yes, I'd say it's worth it. My comments at the time I did the replacement were:

"They just give you more of everything: more treble, more colors, more drama. As happy as I was with the original sound of the Rogues, I always wanted a bit more texture and warmth on massed strings, and the KT-120s give you that."

Also, from what I've read, the KT-120 is a more robust tube than the KT-90. Depending on usage, I'd expect to have to replace 1-2 KT-90s a year (and a fuse blows when the tube blows). I haven't had a KT-120 blow yet, but only more time will tell.
"08-29-12: Tobes

That seems like very poor longevity/reliability from the KT90 tubes - unless you're running the amps 24/7?"

The amps do get heavy use from morning until evening every day. But I also forgot to mention that the KT-90s were biased at 40 mA as per the manual. When I called Rogue to ask about the KT-120s, they said that their new recommendation was 35 mA, and that's what I've had the KT-120s at since I installed them.

I no longer have a full complement of KT-90s, so I can't do a re-evaluation of them. But I've never felt dissatisfied with the KT-120s.
Actusreus, I don't remember who I talked to at Rogue. Maybe he thought I was asking about a Cronus. I'll try calling them on Tuesday to get some clarification.
Thanks for the update, Actusreus. I've already had the 120s biased at 40mA for a couple days now. Perhaps it's my imagination, but the sound is perhaps a bit more present.