Rogue Cronus Magnum II Tube Rolling

Discussion in 'Tube Audio' started by CLB3, Apr 21, 2017.

  1. CLB3

    CLB3 AK Subscriber Subscriber

    Messages:
    2,336
    Location:
    Concord, NC
    I am a relative newbie to tubes. I bought my first tube amp, a Rogue Audio Cronus Magnum II, about three months ago. I absolutely love this integrated amp and plan to keep,it for a long, long time. I had read some about tube rolling, but decided to live with the stock tubes for a while to become acquainted with it. Well, the rolling bug bit last week and I decided it was time to "go exploring."

    As can be seen in the picture below, the amp has 4 KT120 tubes, 3 12au7 tubes, and 2 12ax7's. FYI, I am only interested in rolling the 12au7's & 12ax7's. I contacted Rogue for suggestions and received a very quick response from Bill (GREAT customer service BTW). He said to begin with the center 12au7 because that is the preamp tube and will have the most impact on the sound. He told me that his advic is simple. If you want more warmth, got with Mullards. If you want more detail, go with Telefunken. If you want something in between, go with RCA Clear Top. BTW, the stock tubes are basic JJ.

    [​IMG]

    Since I always lean toward more detail, I decided to start with Telefunken. So, I orders a Telefunken Black Diamond 12au7. Being naive about tubes (and admittedly not having researched things thoroughly) I did not realize that this was a reissue and made by JJ. Lesson learned. I figured I would give it a try and see what happens. It arrived today so I popped it in, warmed up the amp, checked the bias on the output tubes (it was time), and gave it a whirl. I used my favorite test album, a vinyl version of Dire Straits' Love Over Gold. Dropped the needle and...WOW! This tube sounded great! Crisp highs, improved mids, and tight base. Overall, more dynamic. Pleasantly surprised and pleased.

    I am going to live with this one for a while, but want to try out a few more before replacing more than just the preamp tube. So, my question is what reasonably priced ($100ish or less) tubes would you suggest that I try? Thanks for your input.
     
    Lavane likes this.

     

    Please register to disable this ad.

  2. bacobits

    bacobits Active Member

    Messages:
    130
    Location:
    USA, NC
    I just got in a mint Cronus Magnum and it is quite nice!!
    All Tele tubes in pre, nos diamond on bottom.
    Went over by Brooks Berden.
    Also just added a Vista Audio Phono II and it fits extremely well with the Magnum.
    I am outside Charlotte btw.
     
    CLB3 likes this.
  3. CLB3

    CLB3 AK Subscriber Subscriber

    Messages:
    2,336
    Location:
    Concord, NC
    Well, hello neighbor!
     
  4. GordonW

    GordonW Speakerfixer Subscriber

    Messages:
    17,735
    Location:
    Marietta/Moultrie GA USA
    It's hard to go wrong with a clear-top 12AU7.

    As inexpensive as they are- they're one of the biggest bang-for-the-buck tubes of that type.

    Regards,
    Gordon.
     
    CLB3 likes this.
  5. CLB3

    CLB3 AK Subscriber Subscriber

    Messages:
    2,336
    Location:
    Concord, NC
    I will definitely try the clear top. Thanks!
     
  6. bacobits

    bacobits Active Member

    Messages:
    130
    Location:
    USA, NC
    I will look into those.

    Hello clb3 we should get together sometime.
    Everyone's so spread out.
     
    CLB3 likes this.

     

    Please register to disable this ad.

  7. biscuithead

    biscuithead Me likes the eargasm retroplasm... Subscriber

    Messages:
    4,162
    Location:
    Northern Colorado
    I have the first version of the Cronus Mag... and I have piles of tubes all over... but I haven't rolled any into the Rogue... Must do this.
     
    CLB3 likes this.
  8. CLB3

    CLB3 AK Subscriber Subscriber

    Messages:
    2,336
    Location:
    Concord, NC
    Sounds good. I am in Concord
     
  9. AvFan

    AvFan AK Subscriber Subscriber

    Messages:
    1,580
    Location:
    El Cajon, California
    At the recommendation of Upscale Audio I bought a Mullard CV4003 for the preamp 12AU7 position in my Cronus Magnum. I agree it is warmer than the JJ it replaced. All other tubes are stock.
     
    CLB3 likes this.
  10. CLB3

    CLB3 AK Subscriber Subscriber

    Messages:
    2,336
    Location:
    Concord, NC
    How do you like the sound? I plan to try one. I have also been reading some good things about the Psvane tubes. Will,probably try them as well.
     
  11. CohibaJoe

    CohibaJoe AK Subscriber Subscriber

    Messages:
    2,471
    Location:
    Central Jersey
    Very Nice and Sound!!!!!! I was looking at Cronus Magnum II at my local Dealer "Audio Nexus". Wound up getting the PrimaLuna.

    Power Tubes are Tung-Sol KT150...This takes 6 12AU7's....and 2 12AU7's Center are Gain Tubes....I have used Telefunken Smooth/Plated NOS, Mullard NOS, GE 5814 5 Star NOS..
    I am now using 2 Brimar CV4003 (These are Really Fine sounding). I am using 4 Amperex 12AU7 Orange Globe (Driver Tubes).

    PrimaLuna.jpg
     
    CLB3 likes this.

     

    Please register to disable this ad.

  12. AvFan

    AvFan AK Subscriber Subscriber

    Messages:
    1,580
    Location:
    El Cajon, California
    My tube rolling experience is pretty limited but I like the Mullard better than the JJ; less edge, smoother, if I recall correctly. NOS ones are on the expensive side but it sounds like Rogue and Upscale Audio agree that changing the preamp tube will impact Cronus Magnum's sound the most and Mullards are very nice tubes.
     
    CLB3 likes this.
  13. GordonW

    GordonW Speakerfixer Subscriber

    Messages:
    17,735
    Location:
    Marietta/Moultrie GA USA
    Yes- the center preamp tube is not inside the output feedback loop, so it would be more apt to show differences between tubes. AFAIK, all the other small tubes are within the output feedback loop- so that would somewhat mitigate any sound variations from tube differences.

    Regards,
    Gordon.
     
    trainbuftony, Old Guy8 and CLB3 like this.
  14. Hyfi

    Hyfi Addicted Member

    Messages:
    5,170
    Location:
    Bucks County, PA
    JJs just don't seem to have it anymore, yet lots of MFGs use them as stock tubes. I recently re-tubbed a pre with Genalax Golden Lion Gold Pins with great results in improved detail and bass.

    I have been wanting to hear one of these Cronus units for a while now as I hear nothing but good things for the cost vs performance.
     
    CLB3 likes this.
  15. airtime

    airtime Super Member

    Messages:
    2,085
    Location:
    Central Arizona
    I was VERY surprised at how good the TungSol 12AU7W sounded in my Latino amp. For a new production tube and reasonably priced again, you can't go wrong.
     
    CLB3 likes this.
  16. CLB3

    CLB3 AK Subscriber Subscriber

    Messages:
    2,336
    Location:
    Concord, NC
    Thanks for the input. Had not considered the Tung Sol, but will add it to the list. I ordered an NOS RCA clear top and Psvane tube. Will definitely try NOS Mullard and Telefunken. Maybe a couple others. I really hope to find a new issue tube that I am really happy with. I know some of the tube purists scoff at that, but realistically NOS tubes are only going to become more scarce and expensive and I plan to have this amp for a long time.
     

     

    Please register to disable this ad.

  17. airtime

    airtime Super Member

    Messages:
    2,085
    Location:
    Central Arizona
    Don't be too fooled by NOS vs new tubes. My Gold Lion B759 out performs and out shines my famed RCA long black plate 12AX7. And the TS 12AU7w I mentioned is just as good as my Sylvania and other vintage tubes. There are some EXCELLENT new production tubes out there.
     
    Hyfi and CLB3 like this.
  18. CLB3

    CLB3 AK Subscriber Subscriber

    Messages:
    2,336
    Location:
    Concord, NC
    Thanks! That's what I like to hear.
     
  19. Lavane

    Lavane AK Subscriber Subscriber

    Messages:
    6,804
    Location:
    northern cal.
    Im using RCA 12au7 clear tops in my line stage. Nice sounding tubes.
     
    CLB3 likes this.
  20. CLB3

    CLB3 AK Subscriber Subscriber

    Messages:
    2,336
    Location:
    Concord, NC
    Ok, the NOS RCA clear tube that I ordered for the preamp position arrived today. So I swapped it out for the Telefunken Black Diamond (JJ reissue) that I had been using. Initial impression...underwhelming. Better than the stock JJ, but not as good as the black diamond. Not as detailed. Got better the more I let it play. I will let it burn in before making any decisions. I will keep you posted.
     
    Lavane likes this.

Share This Page