Cronus Magnum II

Did you ever do this? Curious about your thoughts.

 

From when I had, the Budgie is very nice sounding. On par or maybe a touch better than the phono pre on the CMII. IMO its sounds more SS than tube for the Budgie. But nice and clean sounding. In my experience, getting an older EAR834P which uses 12AX7 tubes really takes it to another level, really tube "bloom" with that one, but the price is much higher for that unit, so apples to oranges....still overall you cant go wrong with the Budgie...

 

I'm considering adding a CMII to the stable. I currently have a Leben CS300XS (15w EL-84 design) that is a bit underpowered for my Harbeth C7ES3 speakers. It sounds excellent with a refined presentation, but it is underpowered in bass slam and loses its grip on more complex passages of music, like louder volumes of R&R and also brickwalled cd's. Granted, brickwalled cd's sound like crap anyway, but solid state and higher-powered tube designs seem to hold it together better. I want to see if the CMII will address these issues and also offer refinement akin to the Leben.

What? Hi-Fi states that the CMII "is a viable rival" for a NAIM Supernait 2. Interestingly, I had a demo of a NAIM XS-2 a couple weeks ago (dealer demo/closeout). It was an illuminating contrast with the Leben. The NAIM had excellent low-level details and layering of stage depth, but at the expense of that magic Leben tube midrange. I spent considerable time going back and forth between the two and liked each for its strengths. I realize this may be too much to ask, but if the CMII can deliver some of that NAIM slam and reveal but retain the tube magic, then I'm in!

Being a longtime guitarist, I have a stash box of NOS tubes. I was perusing it the other day and found I have all the magic tubes for a CMII, including an Amperex 'Bugle Boy' 12au7, a Mullard (1963 Blackburn, from the 'B' date code) 12au7, branded Amperex and "Made in Gt. Britian" in gold lettering, and a whole sleeve of 5 NOS RCA clear top 12au7 in the original boxes and sleeve. Add to that a sleeve of 5 GE 5751's in the mobile radio sleeve and boxes. These were the same as the JAN GE 5751, just branded for mobile radio. So, the tubes might offer a tipping point.

 

Definitely has the power and the grace.
-Bill

 

The cmII / c7ES combo is spectacular. If you're in the market it is a no-brainer. Soundstage, smoothness, detail, dynamics and slam are all there.
responds extremely well to tube upgrades- i'm currently running a bugle boy treble clef logo in the 12AU7 spot and Sylvania 5751 12AX7s. i hear systems 3X the cost at audio shows that do not sound nearly as good.

 

CmII/c7es3

 

Thanks! This sounds very promising. Has anyone compared the CMII to a British SS amp like a NAIM. I found it surprising (and encouraging) that What? Hi-Fi put the CMII in the same arena with a Supernait 2.

 

If you think those NOS 12AU7's would do wonders in the CMII, just stretch a bit a stuff them in an RP5 and add a nice power amp to it.

 

wow, never saw that review. quite a thumbs up!

 

In June I received my new Cronus Magnum II from Rogue Audio in Pennsylvania. Well, more precisely, I sent my Rogue Audio Cronus Magnum back to Rogue and received my unit upgraded to the Magnum II. Why upgrade the Magnum to a Magnum II you may ask. Well if you compare the two you will understand the major improvements the guys at Rogue made to this outstanding award winning design.

First, the original Cronus Magnum (I’ll call it the Magnum I for clarity sake) originally boasted a robust 90 watts per channel using Tung Sol KT-88 power tubes. These were eventually upgraded in the same Magnum I package to Tung Sol KT-120 power tubes making it a 100 watt per channel amplifier. (I purchased my Magnum I with the KT-120 upgrades and I rolled the 12AU7 with a NOS mallard 12Au7.) The Magnum I also had the following major attributes: 3 12AU7 JJ tubes and 2 12AX7 JJ tubes; headphone amp, phono stage with 39db of gain for MM cartridges; Phono, CD, Aux 1 and Aux 2 inputs; 1 fixed and 1 variable output for subwoofers; 5-way binding posts for various speaker connection options; 4 or 8 Ohm speaker impedance (adjustable by owner); an on/off button, aluminum knobs for source selection, balance and volume mounted in a beautiful anodized aluminum faceplate available in either silver or black and an aluminum two button remote control unit.

Now this original Magnum I unit was highly rated and in my system I hooked up a Sony CD player, Harmon Kardon tape deck, BlueSound Vault and a Project Debut Carbon Esprit running an Ortofon 2M Blue MM Cartridge all outputting to KEF LS50 speakers. This is a fine setup that the Magnum I handled with ease, and with power to spare. So, why bother with the upgrade?

Well, better sound is always the reason for doing what we do and my system is predominantly running analog as my turntable and my records are the major use of the system. Online reviews consistently rated the Magnum I a 4.5 out of 5. It was reviewed highly for sound, design, and value. All the reviews touted the Rogue as an affordable tube amplifier that could give more expensive brands a run for their money.

The only issues ever raised were regarding the 39 db gain in the phono stage as a little less than optimal and the lacking power in the headphone amplifier. This was fine for me, at the time, as I was using a ProJect turntable running an Ortofon 2M Blue cartridge. I really got into the analog sound and it just felt right getting deeper into records and thus improving my equipment. I decided to upgrade my turntable to a 2017 VPI Prime Scout and run the best MM cartridge, the Ortofon 2M Black, I could afford. Based on this new gear, the 39db of gain on the phono stage was not the optimal amount of gain needed to run the 2M Black to its utmost potential.

Next, the headphone amp was insufficient to run my Beyer Dynamics Custom Studio headphones (ultimately upgraded to Grado RS1e’s) and when I did use them I had sound bleeding through the speakers, which is normal according to the manual, but was immensely annoying. I bought a Schiit Audio Vali 2 to run the headphones which worked perfectly, but I still had to ramp down the volume knob to zero to avoids the bleed through because you could not mute the Magnum I.

So what to do? Buy a new phono stage add-on for $700-$1000 in order to get a little more juice out of the 2M Black cartridge and maybe expand my soundstage a bit and allow myself to ultimately use MC cartridges or spend the same $700 and upgrade the Magnum to a Magnum II. After I spoke to Nick at Rogue, the answer was simple…invest in my current amplifier with a new upgrade that will make it better than just adding a phono stage. Here is what the new Magnum II has improved (BOLD) over the Magnum (MI v. MII):

General Features and Specifications:

MI & MII - 100 WPC
MI & MII - 20Hz-30KHz bandwidth
MII - Lowered Noise Floor
MI & MII - 4 and 8 ohm transformer taps
MII - Slow start turn on sequencing
MII - Improved massive high storage linear power supply
MI & MII - (2) 12AX7, (3) 12AU7, (4) KT120 tubes
MII - Gold plated RCA inputs
MII - Gold plated binding posts
MI & MII - Machined aluminum faceplate
MI & MII - 4 inputs (phono, line 1,2,3)
MII - 44 dB gain phono input +/- 0.1 dB 20Hz - 20KHz
MII - 1W Headphone amplifier
MII - Remote with volume and mute (Add $100 for an aluminum remote)
MII - Buffered variable outputs (great for subwoofers)
MII - Active outputs for subwoofer or biamping
MI & MII - 4 RCA inputs (phono, line1, line 2, line3)
MI & MII - All precision components
MII - Heavy (2 ounce) copper circuit board
MI & MII - Full tube cage/cover (optional)
MI & MII - Fully tested, burned-in, and auditioned
MI & MII - Detachable IEC power cord
MI & MII - 18" W x 17"D X 5.5" H (actual)
MI & MII - power requirements: 120V/240V - 50/60Hz
MI & MII - Entirely designed and hand built in the USA

I sent the Magnum I to Rogue on June 15 and it was back in my house on June 22. That is excellent customer service and turnaround!

Right off the bat I noticed the lowered noise floor when turning the volume up with no source. There was no sound until the volume was turned up to the 4 O’clock position on the dial then there was a slight hiss. However, that is a position that in no way ever gets that high in my listening room.

Next was the test I was really eager to hear, the difference in the phono stage. In the Cronus Magnum I the phono stage gain was 39db. Adequate, but lower than what the Ortofon 2M Black needed to coax out its best sound. After I spoke to Ortofon, I knew what I was supposed to listen for. At the higher db gain, I was going to hear more detail, more clarity and a better soundstage separation at a lower required volume. Playing my albums on my VPI Prime Scout with the 2M Black, Phoenix Engineering Eagle PSU and Roadrunner tachometer and TTWeights Carbon fiber mat, the Magnum II definitely passed the test.

I used my personal reference recordings to tell the difference. I listened to Pink Floyd, the Dark Side of the Moon, Bernstein’s classic 1959 conduction of, and performance with, the Columbia Orchestra of Gershwin’s “Rhapsody in Blue” and Bruce Springsteen’s 1975 “Born to Run”. These are not esoteric audiophile specific recordings, but I am not so pretentious to play little known albums to sound, well… pretentious. I listen to music I know and love and I comment on what I now hear that I may not have heard well before. That is my test.

On the “Dark Side” album I listened to the music of course, but I specifically focused on the non-musical portions, like the money tinkling, the clocks ticking and chiming and the footsteps in the airport. I listened for the clarity of the chimes, the clear sound of a coin, that realistic not muddy clink and the “surround sound” illusion in the footsteps in the airport moving from left channel to right. My expectations were met and exceeded. The coins jingling in “Money” were clear and concise. There was no “blurring” of the sound. It was if you could hear each individual group of coins hitting the change drawer. Roger Waters’ bass was right there and each note resonated. As for other non-musical sounds, the clocks ticking in “Time” were also clear and the chimes did not roll off. The announcement in the airport had the muffled “in the subway” lack of clarity and running footsteps in the airport were also well heard in space and moved across the room from speaker to speaker almost convincing me that someone was walking on linoleum in front of me. Overall, the 2M Black put out what I thought was its clearest, most detailed and best sound since I have owned it and the additional 6 db in the Magnum II from 39db to 45db of gain really made a significant difference in my ears.

Next was the Gershwin classic I have been listening to since high school. Again, the additional 6 db of phono gain provided for the 2M Black to really pull out the separation in space of the opening Clarinet. I could “see” where the Clarinetist was standing and having seen a video performance of “Rhapsody in Blue” he was right where he was supposed to be compared to Bernstein’s piano. Oh, and the piano notes? Perfectly place in the middle of the room with distinct separation of the keystroke, hammer strike and tone resonating through my LS50’s. It sounded as though the piano was in the room and the sustained notes rang true with no distortion. Even higher frequency sounds of woodwinds and strings sounded fresh and alive in my listening room. The detail and clarity were fantastic.

As for my Rock albums, I listened to Bruce Springsteen’s seminal “Born to Run”. Now if you are a Bruce fan, you will know that Bruce took great pains in recording this album to get the “Phil Specter Wall of Sound” through to the audience. I have five different releases of Born to Run, including an original US pressing and a pristine Japanese pressing from 1975. The Japanese pressing is my favorite since it is so quiet and well done album. The 2M Black tracked perfectly and the sound was phenomenal. The bass was clear, the guitars detailed and even the glockenspiels in the song “Born to Run” were clear concise and un-muddled. The “wall of Sound” experiment was absolutely successful. Even quieter songs such as “Thunder Road” and “Meeting across the River” were well played with the additional gain in the phono stage at listenable and reasonable volumes. With the Magnum I, I had the volume at 10:00 to 10:30. Now I did not need to go over 9:30 for the same effects and improved clarity and detail. Nice job Mark and Brian!

The headphone amplifier was improved and now a new remote with a mute button was added so the annoying speaker bleed issue is resolved. I upgraded the Beyerdynamics to Grado Rs1e’s (but that’s a review for another day). I still use the Schiit Audio Vali 2 (with a NOS Telefunken E88 tube) to run the headphone exclusively except if I use my cassette deck to record. Without going into extensive details, the Magnum II does not have a tape monitor or tape loop circuit. Therefore, I have the Schiit Vali 2 and the tape deck on an audio A/B switch. When, and if, I want to record a cassette and switch the components, I can still use the headphones to monitor the recording by using the Magnum II headphone amplifier and mute button.

Overall, the Magnum II upgrade was excellent. Customer service from Rogue is outstanding. Mark and Brian will actually take the time to speak to you and they will tell you if what you want out of the Magnum II is possible with your set-up. Oh, and the turnaround with shipping was less than 10 days! (Your turnaround time may be different) The phono stage with additional gain is a major factor for anyone to seriously consider the Magnum II or upgrade the Magnum I. I can now even use high output Moving Coil cartridges in the .9mv and up. I already purchased a second VPI arm wand so I can try the Dynavector 10x5 2.5mv MC. I highly recommend the upgrade or purchase the Magnum II outright.

Steve

 

@Spsesq - Thanks for taking the time to write such a detailed comparison between the two versions.

Has anyone run a LOMC by using a SUT with the CMII? I have a Rega RP8 with DV 20x2L into a Rega Aria phono stage. I'm wondering if there is any advantage to using the CMII phono stage instead of the Aria. Does the CMII phono pass through the 12au7 preamp tube, or is it a Mosfet or IC?

 

FWIW, I don't think the issue with the CMI phono stage (and headphone amp) was the 39DB - and that actually is enough for the 2MBlack as the 2M carts are very hot output wise. The problem is that they just weren't very good. A situation that I understand is greatly rectified in the CMII, though I wish they had taken it a step further and offered the much better stage that is in their preamps and Pharaoh.

I notice on their site that they have done away with all the older preamps in favor of the new RP series. As much as I love my RP5, having not heard the RP1, I hate to see the demise of the Perseus Magnum as it was a great box and one of the best values out there. I hope the RP1 is up to the task!

 

That's something I'd like to see comparisons on -RP1 versus Perseus Magnum.

 

Actually, the 39 db of gain was problematic because I contacted both Rogue and Ortofon USA before I bought the 2M Black. One factor in my decision to upgrade my amplifier to a Magnum II was that BOTH companies told me that 39 db was "adaquate" to run the cartridge. However, optimal gain for the detail and clarity that set the 2M Black above its competitors would in the area of 42db. Furthermore, the ability to run a High output magnetic coil, like the Dynavector 10x5 would be in the 43-44db area. So the extra 6 db in gain does in fact, allow the 2M Black to operate as intended by the manufacturer. The 39 db gain of the Magnum I precluded ANY use of an MC cartridge as there wasn't enough gain to run even a HOMC that was 2.5mv.

 

You really need about 46db for the 2.5ish HOMCs. The 2m Black is rated to 5mv output which is very high in the scheme of things. My point was that the original phono stage just wasn't very good regardless of the gain. I owned a CMI, and own a 2M Black as well as a Sumiko BPS III which is very similar in output to the DV. I have run them both on the onboard and on various discreet stages and the 40db is fine for the 2m. I alson have a Blackbird LO and a DL103 that need 60db to work well. I've run them all on the RP-5 and on either the high or low gain settings they are very nice.

I am sure you will love the upgrade it certainly improves what the CMI did very well, and fivpxed wha it didn't. Win Win!!!

 

Thanks for the specs on what the upgrade buys. Their website is so out of date I was half wondering if they had gone out of business. They price the upgrade, but don't really tell you what they do for the $$$.

With 2-way shipping of a 55lb amp, this has got to be getting close to a $900 upgrade. Did they test and replace the tubes too or just ship it back with the originals?

Thanks again.

 

First, Rogue is still in business and doing quite well. Second, The upgrade was worth every cent to upgrade the Magnum 1 get the 2! The shipping was about $40 each way for me. I am in NJ and they are in PA. Finally, they gave me new matched power tubes (KT-120's) and returned my Mullards which I rolled on my own. The phone gain upgrade saved on a preamp alone. I can now run HOMC cartridges and I got a Dynavector for my second JMW-9 armwand on my Prime Scout. My totals upgrade was about $750 because I wanted the aluminum three button remote. That was $100 additional.

I can't say one negative about how Rogue answered all my questions and did the upgrade within 10 days. Great service great guys there!

 

I am getting my CM II tomorrow. I have the Ortofon 2m black on my Clearaudio Performance DC Turntable. This thread had got me excited. First tube amp.......going from a Proton D1200 power amp and a Yamaha cx-2 Preamp. Cant wait!!!!

 

Proton D1200? This is really a blast from the past - the near-golden age of stereo ...

 

Looking forward to your impressions. Enjoy!

 

And it still performs perfectly...power switch is losing spring power but everything else is great....I use a Yamaha cx-2 pre with it......it will be my 2nd system now and I will pair it with klipsh quartets or large advents.....it will serve its purpose still

 

Thank you......I'm a 95% vinyl person so I figured why not get an amp using a power source that almost went the way of vinyl.....before the "comeback"

 

Many folks actually think a tube amp can do magic to CD sound as well ...

 

It can. I take every digital audio source and input it into the Peachtree iNova, which I only use as a DAC/input selector and preamp.

The iNova, was designed to "tame" harshness that often accompanies digital music.

I have a stereo/HT set up which is all solid state, which is driven from the preamp outputs of the iNova, into external SS amplifier's.

But I have a third tube based system in the same room that powers large Altec Lansing A7, VOTT's (Voice of the Theater), speaker system.

I use "Y" RCA connectors to split the preamp output of the iNova into a 6SN7 tube preamp into one of several tube power amps, which includes a vintage Fischer 500C receiver and a vintage Scott 222C integrated amplifier.

The main tube power amplification are a pair of Rogue Audio, KT88 based M-150 monoblocks that sit behind the TV on a reinforced table.

I bought a used original CM to have as a back-up integrated amplifier, should one of the monoblocks go south. It has a home on top of a half size audio rack, also behind the TV.

Later, I bought a Rogue, Stereo 90 off of eBay because, it burns through half the amount of power tubes that the monoblocks have. The monoblocks have four KT88's in each monoblock, for a total of eight KT88's. The Stereo 90 has two KT88 output tubes per-channel for a total of four, exactly half the number of tubes that the monoblocks have.

I have a vintage restored and modded TT, with a tube phono-pre, that I play through the tube chain, ending up at the A7's.

But, most of the time, during the day (and evening) I am listening to streaming digital music (I live and work at the same place).

When I want to light up the A7's, I like to play them all day and sometimes all night, so I am trying to cut the tube replacement overhead as much as I can for normal listening.

But, when listening to music and the music is digitally sourced, the signal goes from the iNova's preamp output, into the analog input of the tube pre-amplifier, which drives the A7 chain.

Post DAC (and including tube based DAC's), everything is analog and is delivered through a pure tube chain.

Believe me! Tube electronics are beautiful devices for sources that are digital. They are even more important if you are delivering the results through high efficiency speakers, which are famous for showing up any little defect, that may be present. Tubes can provide a pure analog experience

Yes, tubes and digital music!

 

Congrats!!! You will love it. Just pay close attention to initial set up and biasing...its very easy. Good Luck and post you impressions.
Steve