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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
roscoeiii's avatar
roscoeiii
1,155 posts
 
On the issue of the recommended bias for KT120s, in the Stereo 90, the bias meters are off by 5mA (as stated in the manual), so to bias to Rogue's recommended 40mA, the meter should read 35mA.
actusreus OP
733 posts
 
Roscoe,
I'm not sure what's going on with your amp, but Mark was perfectly clear that you should bias the KT-120s at 40 mA in the M-180 monoblocks, and that's what the meter should read. The M-180 manual says nothing about the meter being off, which frankly does not make sense.
roscoeiii's avatar
roscoeiii
1,155 posts
 
As I mentioned, the bias meter on the Stereo 90 reads 5mA low. As is stated in the Stereo 90 manual. I don't know about the other Rogue models. But for the Stereo 90, when the meter reads 35mA, the actual value is 40mA. And an actual value of 40mA is also what I was recommended by Rogue.

Other people with KT120 tubes have recommended a higher bias than this.
dhcod
710 posts
 
I have biased my Rogue Atlas as high as 55. It's heaven but hot and I don't suspect the tubes will last more than a year or so but for me it's totally worth it.
roscoeiii's avatar
roscoeiii
1,155 posts
 
Dhcod,

Are these tubes KT120s?
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