Bias question on a Rogue Cronus Magnum 2

I checked the bias the other day, following the instructions from the manual.

Three tubes went perfectly.

On one, however, when I flipped the bias switch the meter jumped up like it was supposed to. I went to adjust it like the other three, but when I used the tool to turn the tiny screw...the meter didn't move at all. The meter is supposed to move when I adjust the screw. When I flipped the switch back the other way the meter went to zero.

I tried it a couple times and same thing on that one tube. I could turn the screw all I wanted back and forth, but the meter didn't move. Audio sounds fine, so I'm not sure whats going on. Is it the fuse? Is that screw stripped?

Thanks in advance for any advice!

Paul
__________________________________________________
2 Channel
Turntable - VPI Scout 1.1/Ortofon 2M Blue
Integrated Amplifier - Rogue Audio Cronus Magnum II
Speakers - GoldenEar Triton 2
__________________________________________________
7.1 Home Theater
Denon AVR-X3300W; Rotel RMB-1066; Polk CS350ls, LS90's, FXi3's, RC60i; SVS PC Ultra; BenQ W1070; Elite Screens 120"
__________________________________________________
Man Cave
Turntable - 1) Pro-Ject 2.9 Wood/Grado Gold; 2) Sony PS LX410/Grado Green
Phono Stage - PS Audio GCPH, Parks Audio Budgie; CD - Marantz DV4001
Preamp - Dared SL2000a, Luminous Audio Axiom II; Amplifier - Parasound HCA-1500A
Speakers - SDA 2A (x-overs etc...); Epos Epic 2; Polk Audio Monitor 70 (my first)
__________________________________________________

Comments

  • mikeyb128mikeyb128 Posts: 2,784
    I would Contact rogue. I emailed them a question regarding my stereo 100 and I had a reply in about 2 hours.
    2 channel:
    Bryston 4B3, Bryston BDA3, Cary SLP05, Shanling CDT1000SE with parts conneXion level 2 mods, Nottingham analogue ace space 294, soundsmith Carmen MKii, Zu DL103 MKii, Ortofon MC 20 MKii, Dynavector XX2 MKii, Rogue Audio Ares, Core power technologies balanced power conditioner, Akiko Corelli power conditioner with Akiko Audio HQ power cable, Nordost heimdall 2, Frey 2, interconnects, speaker and power cables, Focal Electra 1028 BE 2, Auralic Aries Femto, Black diamond racing cones, ingress audio level 1 roller blocks, JL Audio E110 with Auralic subdude, Primacoustics room treatments.
    Theater:
    Focal Aria 926,905,CC900, SVS PB ultra x2. Pioneer Elite SC85, Oppo BDP93, Panamax M5400PM, Minix neox6, Nordost Blue heaven LS power cables.

  • FaustinFaustin Posts: 808
    ^^^This^^^
  • hochpt21hochpt21 Posts: 5,079
    Good thought. I will do that.
    __________________________________________________
    2 Channel
    Turntable - VPI Scout 1.1/Ortofon 2M Blue
    Integrated Amplifier - Rogue Audio Cronus Magnum II
    Speakers - GoldenEar Triton 2
    __________________________________________________
    7.1 Home Theater
    Denon AVR-X3300W; Rotel RMB-1066; Polk CS350ls, LS90's, FXi3's, RC60i; SVS PC Ultra; BenQ W1070; Elite Screens 120"
    __________________________________________________
    Man Cave
    Turntable - 1) Pro-Ject 2.9 Wood/Grado Gold; 2) Sony PS LX410/Grado Green
    Phono Stage - PS Audio GCPH, Parks Audio Budgie; CD - Marantz DV4001
    Preamp - Dared SL2000a, Luminous Audio Axiom II; Amplifier - Parasound HCA-1500A
    Speakers - SDA 2A (x-overs etc...); Epos Epic 2; Polk Audio Monitor 70 (my first)
    __________________________________________________
  • hochpt21hochpt21 Posts: 5,079
    Just a quick update, Rogue was great with e-mail communication and I ended up sending the unit it. Haven't heard anything back yet, and Monday will be two weeks, so I'll probably check in then. I'm sure it is very busy around the holidays.

    I'll update when I hear from Rogue on what the actual issue is and the solution.
    __________________________________________________
    2 Channel
    Turntable - VPI Scout 1.1/Ortofon 2M Blue
    Integrated Amplifier - Rogue Audio Cronus Magnum II
    Speakers - GoldenEar Triton 2
    __________________________________________________
    7.1 Home Theater
    Denon AVR-X3300W; Rotel RMB-1066; Polk CS350ls, LS90's, FXi3's, RC60i; SVS PC Ultra; BenQ W1070; Elite Screens 120"
    __________________________________________________
    Man Cave
    Turntable - 1) Pro-Ject 2.9 Wood/Grado Gold; 2) Sony PS LX410/Grado Green
    Phono Stage - PS Audio GCPH, Parks Audio Budgie; CD - Marantz DV4001
    Preamp - Dared SL2000a, Luminous Audio Axiom II; Amplifier - Parasound HCA-1500A
    Speakers - SDA 2A (x-overs etc...); Epos Epic 2; Polk Audio Monitor 70 (my first)
    __________________________________________________
  • erniejadeerniejade Posts: 4,446
    edited December 2018
    Sounds like solid customer service.
    Lumin D1,Wireworld Silver Eclipse, KEF LS50 Wireless, Velodyne SPL1200, Technics 1200, Denon DL160, Jolida D9,
    USB helpers: w4s Recovery
    Living Room Elite SC27, LSI25, SDA 3.1TL
    Have but haven't used in a while: LH Labs VI Dac, Cayin SCD50T

  • hochpt21hochpt21 Posts: 5,079
    This was the diagnosis.

    The output tubes in your amplifier are the correct brand and tube type, but it appears that some of the specs of this tube set are not ideal for use in the Cronus Magnum. They do operate fine, but having a high plate current rating may result in the tubes blowing fuses occasionally and it is also the reason why the bias will not adjust below 30-35mA on any of the 4 tubes

    I have the Tung Sol 120's. Two I believe are stock and two I purchased after to replace a broken one.

    Can someone help me out? They said my tubes are not bad, but will not bias correctly because of a high plate current rating in them. They said my tubes will work, but may blow fuses occasionally.

    They offered the option of purchasing a quad of the same tubes.

    Does that mean my tubes actually are bad? Or are there different specs in the same exact tube of new production tubes.

    I don't want to spend the $ on a new quad if I don't need it. But will if I do.

    Help!
    __________________________________________________
    2 Channel
    Turntable - VPI Scout 1.1/Ortofon 2M Blue
    Integrated Amplifier - Rogue Audio Cronus Magnum II
    Speakers - GoldenEar Triton 2
    __________________________________________________
    7.1 Home Theater
    Denon AVR-X3300W; Rotel RMB-1066; Polk CS350ls, LS90's, FXi3's, RC60i; SVS PC Ultra; BenQ W1070; Elite Screens 120"
    __________________________________________________
    Man Cave
    Turntable - 1) Pro-Ject 2.9 Wood/Grado Gold; 2) Sony PS LX410/Grado Green
    Phono Stage - PS Audio GCPH, Parks Audio Budgie; CD - Marantz DV4001
    Preamp - Dared SL2000a, Luminous Audio Axiom II; Amplifier - Parasound HCA-1500A
    Speakers - SDA 2A (x-overs etc...); Epos Epic 2; Polk Audio Monitor 70 (my first)
    __________________________________________________
  • mikeyb128mikeyb128 Posts: 2,784
    edited December 2018
    I would buy their tubes, which are fully tested and burned in with your amp. Maybe shoot over to YouTube and watch some videos on kt120 by kevin deal. He explains the importance of a thorough screening process with these new production tubes.

    “They do operate fine, but having a high plate current rating”

    ^^^ this doesn’t sound like tubes that are still ok. They may play “fine” but blow fuses....
    2 channel:
    Bryston 4B3, Bryston BDA3, Cary SLP05, Shanling CDT1000SE with parts conneXion level 2 mods, Nottingham analogue ace space 294, soundsmith Carmen MKii, Zu DL103 MKii, Ortofon MC 20 MKii, Dynavector XX2 MKii, Rogue Audio Ares, Core power technologies balanced power conditioner, Akiko Corelli power conditioner with Akiko Audio HQ power cable, Nordost heimdall 2, Frey 2, interconnects, speaker and power cables, Focal Electra 1028 BE 2, Auralic Aries Femto, Black diamond racing cones, ingress audio level 1 roller blocks, JL Audio E110 with Auralic subdude, Primacoustics room treatments.
    Theater:
    Focal Aria 926,905,CC900, SVS PB ultra x2. Pioneer Elite SC85, Oppo BDP93, Panamax M5400PM, Minix neox6, Nordost Blue heaven LS power cables.

  • hochpt21hochpt21 Posts: 5,079
    mikeyb128 wrote: »
    I would buy their tubes, which are fully tested and burned in with your amp. Maybe shoot over to YouTube and watch some videos on kt120 by kevin deal. He explains the importance of a thorough screening process with these new production tubes.

    “They do operate fine, but having a high plate current rating”

    ^^^ this doesn’t sound like tubes that are still ok. They may play “fine” but blow fuses....

    Thanks for the input.

    I replied with a message asking about the plate current rating on any tubes I purchased through them and if there was a warranty of any kind. They said the tubes they use have a low iP rating so there would be no bias issues. 90 day warranty.
    __________________________________________________
    2 Channel
    Turntable - VPI Scout 1.1/Ortofon 2M Blue
    Integrated Amplifier - Rogue Audio Cronus Magnum II
    Speakers - GoldenEar Triton 2
    __________________________________________________
    7.1 Home Theater
    Denon AVR-X3300W; Rotel RMB-1066; Polk CS350ls, LS90's, FXi3's, RC60i; SVS PC Ultra; BenQ W1070; Elite Screens 120"
    __________________________________________________
    Man Cave
    Turntable - 1) Pro-Ject 2.9 Wood/Grado Gold; 2) Sony PS LX410/Grado Green
    Phono Stage - PS Audio GCPH, Parks Audio Budgie; CD - Marantz DV4001
    Preamp - Dared SL2000a, Luminous Audio Axiom II; Amplifier - Parasound HCA-1500A
    Speakers - SDA 2A (x-overs etc...); Epos Epic 2; Polk Audio Monitor 70 (my first)
    __________________________________________________
  • delkaldelkal Posts: 391
    edited December 2018
    I don't like the sound of this. Everyone knows tubes do not have the consistency of solid state components and their microohm output does vary (even between 2 new tubes, same brand, and made the same day............

    But all tubes have specs that should be designed for. Sounds like Rogue based their design on some lower output KT-120's (probably Chinese made) they had lying around. But all KT-120's should work. Sounds like a design flaw.

    Now they want you to buy their one brand of tubes so their amp works? BS! You don't buy tube amps if you can't tube roll.
  • hochpt21hochpt21 Posts: 5,079
    Yes, I was a little unsure of the whole situation, but went with the recommendation of new tubes.
    __________________________________________________
    2 Channel
    Turntable - VPI Scout 1.1/Ortofon 2M Blue
    Integrated Amplifier - Rogue Audio Cronus Magnum II
    Speakers - GoldenEar Triton 2
    __________________________________________________
    7.1 Home Theater
    Denon AVR-X3300W; Rotel RMB-1066; Polk CS350ls, LS90's, FXi3's, RC60i; SVS PC Ultra; BenQ W1070; Elite Screens 120"
    __________________________________________________
    Man Cave
    Turntable - 1) Pro-Ject 2.9 Wood/Grado Gold; 2) Sony PS LX410/Grado Green
    Phono Stage - PS Audio GCPH, Parks Audio Budgie; CD - Marantz DV4001
    Preamp - Dared SL2000a, Luminous Audio Axiom II; Amplifier - Parasound HCA-1500A
    Speakers - SDA 2A (x-overs etc...); Epos Epic 2; Polk Audio Monitor 70 (my first)
    __________________________________________________
  • mikeyb128mikeyb128 Posts: 2,784
    edited December 2018
    delkal wrote: »
    I don't like the sound of this. Everyone knows tubes do not have the consistency of solid state components and their microohm output does vary (even between 2 new tubes, same brand, and made the same day............

    But all tubes have specs that should be designed for. Sounds like Rogue based their design on some lower output KT-120's (probably Chinese made) they had lying around. But all KT-120's should work. Sounds like a design flaw.

    Now they want you to buy their one brand of tubes so their amp works? BS! You don't buy tube amps if you can't tube roll.

    There is only one brand of KT120. Only made in Russia by Tung Sol. There is no Chinese KT 120, there is no other brands of KT 120 to roll. If you do your research you will find that some of these tubes have excessive plate voltages that some amps are sensitive to. Maybe his amp is one of those? Not quite a design flaw. Some tubes work great in some equipment and some don’t. I have had micrphonic tubes in some equipment but quiet as a mouse in others. That’s just the way it goes.

    The quality control in new production tubes can’t touch what it used to be. And if you do more research the Russian and Chinese manufacturers pump out tubes
    Like crazy. noises ones, ones that don’t meet specs etc... that’s why companies like rouge, upscale, the tube store test these tubes prior to selling them, that way you don’t have issues.
    2 channel:
    Bryston 4B3, Bryston BDA3, Cary SLP05, Shanling CDT1000SE with parts conneXion level 2 mods, Nottingham analogue ace space 294, soundsmith Carmen MKii, Zu DL103 MKii, Ortofon MC 20 MKii, Dynavector XX2 MKii, Rogue Audio Ares, Core power technologies balanced power conditioner, Akiko Corelli power conditioner with Akiko Audio HQ power cable, Nordost heimdall 2, Frey 2, interconnects, speaker and power cables, Focal Electra 1028 BE 2, Auralic Aries Femto, Black diamond racing cones, ingress audio level 1 roller blocks, JL Audio E110 with Auralic subdude, Primacoustics room treatments.
    Theater:
    Focal Aria 926,905,CC900, SVS PB ultra x2. Pioneer Elite SC85, Oppo BDP93, Panamax M5400PM, Minix neox6, Nordost Blue heaven LS power cables.

  • pitdogg2pitdogg2 Posts: 12,081
    Yep true i seen a video on upscale about KT120 and 150's and they said theirs are more expensive because a lot of them do not pass muster and I believe he said there is no way for them to return them to the manufacturer as "defective" so they have to make up the money they're losing on tubes they refuse to sell you and be able to guarantee the good ones they do sell.
    I believe it was Kevin Deal in the video and showing how stringent they were with testing these power tubes not just once but many times before they went to be sold just so they can guarantee them.
    It's well known that Russia is all about putting out tubes not putting out quality tubes it's all on the number of tubes they put out. Do they put out some quality tubes of course they do they also put out tubes that they know are junk or near junk that's just the nature of the beast these days in making tubes just like Mikeyb is stating.
  • Had High IP tubes cause problems in my Rogue 88. Talked to Nick at Rogue and he told me to use tubes below IP of 59. The factory tubes were in the 30s. I had my tube vendor pick a quad in the 30s and it was solid as a rock after that.
  • heiney9heiney9 Posts: 23,921
    Check with Jim McShane. He's honest and knowledgeable about a lot of gear that uses New Stock tubes. Power tubes do vary a bit, but, IMO, the amp should be designed with enough tolerance to accept that variance unless it's way out.

    New Stock tubes do have their issues as consistency isn't like old stock tubes.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • hochpt21hochpt21 Posts: 5,079
    Yea, I was just trusting Rogue on this one. They said that my tubes have a high plate current rating, but when I asked them if there was an option (even for a charge) to test the tubes and put the results on the box (in case any of them didn't have issues, I could use them for back up), they said their tester only tests for shorts and emissions. Not plate current rating.

    Doesn't make sense to me, but I openly admit to not being well versed in the operations of tube amps, so I am going with their opinion on this one.
    __________________________________________________
    2 Channel
    Turntable - VPI Scout 1.1/Ortofon 2M Blue
    Integrated Amplifier - Rogue Audio Cronus Magnum II
    Speakers - GoldenEar Triton 2
    __________________________________________________
    7.1 Home Theater
    Denon AVR-X3300W; Rotel RMB-1066; Polk CS350ls, LS90's, FXi3's, RC60i; SVS PC Ultra; BenQ W1070; Elite Screens 120"
    __________________________________________________
    Man Cave
    Turntable - 1) Pro-Ject 2.9 Wood/Grado Gold; 2) Sony PS LX410/Grado Green
    Phono Stage - PS Audio GCPH, Parks Audio Budgie; CD - Marantz DV4001
    Preamp - Dared SL2000a, Luminous Audio Axiom II; Amplifier - Parasound HCA-1500A
    Speakers - SDA 2A (x-overs etc...); Epos Epic 2; Polk Audio Monitor 70 (my first)
    __________________________________________________
  • heiney9heiney9 Posts: 23,921
    Makes no sense for them to claim their tubes have lower plate current and then have no way to test for it. I wouldn't pay a lot of $$ for tubes that weren't thoroughly tested, especially since your amp (made by them) is a bit finicky with power tubes.

    I'd be leary, but just like any other manufacturer, they are out to make money. Possible they bent the truth a little bit. If that's what you feel comfortable with and you can sleep at night, then no one here can fault you.

    Next time check with Jim McShane, if for no other reason than to just get some knowledge. He's a straight shooter.
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • delkaldelkal Posts: 391
    hochpt21 wrote: »
    they said their tester only tests for shorts and emissions. Not plate current rating.

    An outfit like Rougue only has a simple Emission tube tester? That is hard to comprehend. I won't buy a tube off ebay if its not tested on a Mutual conductance tester that has a real readout in micoohms.

    I wouldn't buy tubes from them either. There is no way to match tubes with an emission tester. All they can tell is the heater works and they have no clue if the plate current of the tubes they sell you don't have the same problem!

    This will take a while to sink in. No wonder they couldn't get the design right.

  • hochpt21hochpt21 Posts: 5,079
    One final follow up.

    They replied a final time and said the tube manufacturer puts the iP rating on the box and they only buy ones with a low rating.

    I have the unit back and it is singing sweetly. Was it a wanted expense? No. BUT, they checked the whole unit over while in the shop, and ideally I should be good for a long time with the new quad.

    It sounds good...
    __________________________________________________
    2 Channel
    Turntable - VPI Scout 1.1/Ortofon 2M Blue
    Integrated Amplifier - Rogue Audio Cronus Magnum II
    Speakers - GoldenEar Triton 2
    __________________________________________________
    7.1 Home Theater
    Denon AVR-X3300W; Rotel RMB-1066; Polk CS350ls, LS90's, FXi3's, RC60i; SVS PC Ultra; BenQ W1070; Elite Screens 120"
    __________________________________________________
    Man Cave
    Turntable - 1) Pro-Ject 2.9 Wood/Grado Gold; 2) Sony PS LX410/Grado Green
    Phono Stage - PS Audio GCPH, Parks Audio Budgie; CD - Marantz DV4001
    Preamp - Dared SL2000a, Luminous Audio Axiom II; Amplifier - Parasound HCA-1500A
    Speakers - SDA 2A (x-overs etc...); Epos Epic 2; Polk Audio Monitor 70 (my first)
    __________________________________________________
  • erniejadeerniejade Posts: 4,446
    Awesome!
    Lumin D1,Wireworld Silver Eclipse, KEF LS50 Wireless, Velodyne SPL1200, Technics 1200, Denon DL160, Jolida D9,
    USB helpers: w4s Recovery
    Living Room Elite SC27, LSI25, SDA 3.1TL
    Have but haven't used in a while: LH Labs VI Dac, Cayin SCD50T

  • vcwatkinsvcwatkins Posts: 1,834
    I had very similar circumstances. I had problems with KT-120's - were blowing fuses and impossible to bias. Took into local shop that is a new Rogue dealer/service. Replaced the tubes and made a few other minor repairs. I've been fine since then - about a year.

    I had bought 4 tubes on eBay at a discount and used 2 of them. Dealer thinks - and I have no evidence to think otherwise - that the tubes were defective. Looked up the seller - "Hilliard I LLC", but I'm unable to see the listing or any current listings by Hilliard.
    Den: Rega RP6 * AT33PTGII * Jolida jd9 * Roon (Sonic Transporter) * PS Audio DirectStream Jr. * Joule-Electra LA-100 iii * Sunfire Signature II * PSAudio p3 * MIT S3 * Polk SRS 1.2
    Office: Roon * Sonore UltraRendu (LPS-1, ISo Regen) * ProJect Pre Box S2 * Pass Amp Camp Amp * PSAudio Dectet * DH Labs Q10 * Brines Folded ML-TQWT RS 40-1354
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  • delkaldelkal Posts: 391
    edited December 2018
    All Rogue needed to do is change a couple resistors and the amp wouldn't have the plate current problem with higher output tubes. I am surprised they didn't offer you that option.

    But they would not be able to make their 100 watt wattage ratings with standard /mediocre tubes. This is all about marketing. No one will never hear any difference if an amp puts out 90-95-100 watt output at max.

    But it HAS to be 100.
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