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
Post removed 
Post removed 
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?
facten
2,764 posts
 
Will ask the obvious, have you contacted Rogue and discussed what you are hearing with them? Might get to the heart of the matter quicker
avanti1960
1,411 posts
 
sounds like a gain miss match between your preamp and the medusa.
i just read online about people with your preamp having difficulties with edgy sound because of the very high gain of the mfa magus.
if you cant adjust the gain there are inline gain attenuators available, i have never used them.

https://www.diyaudio.com/forums/tubes-valves/77149-schematic-mfa-magus-5.html?s=b8b8a461bc471ad57fd0...
as others have mentioned you can email rogue and they will get back very quickly. go to their site for the contact link.
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