2. amps-preamps
  3. 157532-21620

Problem with Rogue Medusa Amp (I need advice)

Hello fellow Audiogoners,
I recently upgraded from a Rogue Pharaoh integrated amp to a Rogue Medusa amplifier. My older MFA Magus tube preamp ended up sounding better than the preamp that is in the Pharaoh, so I ended running the Magus through the Unity Gain input on the Pharaoh and only using the amp section. I was happy with the sound of this setup, but decided that I could improve the sound by getting a Medusa amp to replace the Pharaoh integrated amp.

I am now running the MFA Magus preamp through the Rogue Medusa, but am having a problem with how the Medusa sounds. In every recording, LP or CD, that I play there is an unpleasant emphasis in the mid and high treble range during the intial attack of a musical phrase. It is an emphasis that is glaring a bit harsh and it makes my listening experience fatiguing and unenjoyable. Overall the Medusa has more depth, low end, and is more revealing than the Pharoah, but it is really unlistenable the way it is. 

I have tried three different sets of tubes with this amp, the original JJ tubes, vintage RCA tubes and Tungstrum tubes; all producing the same problem. So, I am wondering if I need to find better matching tubes for the amp to get rid of this problem, or if something in the amp has gone bad and I need to send it to Rogue for inspection. Has anyone had this problem with their Medusa amp? Please advise. Thanks!
jbcello

Showing 2 responses by jbcello

jbcello OP
25 posts
 
Thanks for your reply. I have the Egglestonworks original Rosa speakers. They sound great with the Pharaoh integrated, but not with the Medusa. Right now the Medusa has the JJ tubes that came with the amp, but I get the problem with any tubes I use.

If it has a negative feedback problem, does that point to a specific electronic part that might have gone bad in the amp? Is there any way I can test for a negative feedback problem or do I have to send it back to Rogue to have it checked out?
jbcello OP
25 posts
 
Thanks for all this technical information, which may be the reason that the Pharaoh is a better match for my Magus than the Medusa. But, I did try running the Pharaoh preamp through the Medusa amp and heard the same problem. I do a little more troubleshooting before I decide what to do. It is possible that there is a malfunction with the amp, so in the end I might send it to Rogue for evaluation just to make sure. I also, know someone selling a Rogue RP-5, which I can't afford to get, but it would be interested to hear that paired with the Medusa to see if I hear the same problem.

I assumed that the Medusa would be a substantial upgrade over the Pharaoh, because even though they are at the same price point, the Pharaoh includes a phono section and preamp section, so I assumed that the Medusa, being an amplifier only would be of a much higher quality, since all of the manufacturing and design costs are going into creating as good an amplifier as possible, as opposed to having to create an integreated amp with three different functions.

Mulveling, what changes in sound did you get when you replaced the 12AU7 with the 12BH7's? Did you end up having any problems, since they draw twice the current.  Why do you dislike the 12AU7's so much?


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