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Rogue M180 replacement tubes

So last night as I powered off my amps, a terrible squeal came out of thr left speaker. I haven't had a power tube go in some time but my recollection is that the horrible noise I heard is an early sign of tube failure. Seems like I'm going to be in the market for some new tubes! Wondering what other power tubes people have tried in thr M180s and what your experience has been. 

To tell you a little more about my system my pre is a Rogue RP-7 and my s l eaters are Vandersteen Quatro Woods.  While the speakers aren't super efficient, they also have a powered sub so the amps don't have to work that hard as they're not driving the woofers, just tweeter mid and mid bass. Most of what I've read is that the KT120s the amp comes with are most people's favorite because the bass really tightens up but for me, that likely won't change much. Wonferinf if people have different 120s they like other than the stock tung sols or if there are 88s or 90s that people are partial to. 

rmdmoore
mulveling's avatar
mulveling
1,932 posts
 

Several of us in the Rogue group over on FBook have discovered that we actually prefer KT88 over KT120 in the bigger Rogue amps. My direct experience is with Apollos, but M180 should be similar. The KT88 midrange is better, and that’s where the Rogue amps need help - they can be a bit dry here. Triode mode doesn’t really touch it, but a good KT88 does.

KT120 will indeed improve bass slam, but that’s where the Rogue amps are inherently strong - they don’t need help here! Now on some of VAC’s amps we can have a bit of the opposite problem, and I prefer KT120 over KT88 there.

Gold Lion KT88 are excellent. EH KT88 are also good, just a different flavor - perhaps better tuned to "rock", while the GL are more refined.

The EH KT90 these amps used to ship with are a bit bright and not very "tubey" sounding. They are worse than either KT120 or KT88, unless your system is dark and needs a lift.

500homeruns
13 posts
 

@mulveling 

That is some really great insight!

I will definitely go with the Gold Lion KT88’s for power tubes. Any other recommendations for the remaining tubes in the Rogue monoblocks?

rmdmoore OP
168 posts
 

I was using NOS clear tops in the 12au7 positions and a Telefunken smooth plate 12ax7. Stellar.

hiend2's avatar
hiend2
438 posts
 

Mullard, GE 5751 Black plate.

jafox
1,460 posts
 

@mulveling Much appreciation from you on your detailed contributions on the preferences of the tubes for the Rogue Audio amps. You mention in this thread the preference of the KT-88 to bring on some midrange magic over the KT-120 which makes the Rogues sound dry. But in another thread, you state that you prefer the KT-66 over the KT-88 for even more of that magic.

Can you share here what your estimate is for the power output of the Apollo amps with each of the three tube types and what would be the bias current setting for each of these three tubes in the Apollo.

John

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