Rogue M180 replacement tubes

@jafox Mulveling is super helpful and gave me great advice as well when I started this thread. I ended up going with KT88s and thought they were an improvement over the 120s the units came with. In reference to your current query though, I think your best bet is to just call Rogue and speak with Nick or Mark. They answer the phone and are super knowledgeable and helpful. 

Another think I did that brought some extra magic was run the tubes a little harder. I think they recommend you bias to 40 but I ran mine at 45. 

@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

Mullard, GE 5751 Black plate.

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

@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?

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.

I live relatively close to Rogue Audio (less than an hour). I will probably give them a call and pick up some new tubes soon.

FYI: Tung-Sol is the only manufacturer that makes KT-120 and KT-150 tubes!

@500homeruns  I ended up buying JJ kt88s. I ended up liking them better than the kt120s. If you can afford some nicer 88s or 6550s I think you’d be happy. I would not bother spending a ton on NOS power tubes. Spend your money on the smaller signal tubes. You can also always talk to Nick or Mark at Rogue.

I own the same monoblocks and preamp. I wish that you would have received some replies because I have the same question.