Looking for advise regarding Rogue M180’s
Last week a friend gifted me a pair of Rogue M180’s. They were sold as 180’s and I received them from the original owner. Im guessing them to be 10-12 years old. They were used when first purchased for about 5 years sparingly. Since then they have resided on a flat dolly in a spare bedroom. The amps still have the original Phillips ECG 5751 and 5814A’s installed. The original EH KT 90’s are loose in a box with an octet of low hour Gold Lion KT-77’s . Years back when in use the owner contacted Rogue and stated they were too powerful for his room size and speaker selection. Rogue responded by recommending the GL KT77’s and suggesting that he could also lower the bias from 40ma to 30ma. I was provided the supporting emails dated September 2019. Here is my situation followed by my questions. I currently have a low power single ended system with Zu speakers. Second, the owner stated one might have a hum, but was not sure. He’s on his second complete system since and has a room full of gear he’s lost interest in and his memory is vague. Also back then he had power issues with his provider and stated they installed a new transformer on the street. So my questions are first, checking for any hum. My intent is to take a single amp and connect one JBL 4312 to it. Install the KT77’s, plug it in and listen for a hum and bias the tubes. Do I need the input open or shorted ? Or something else ? Second, the 12AX7’s being replaced by the 5751. I see there’s a mu of 70 Vs 100 with the 12AX7. Does that effect the overall output power of the amp or just change tone and distortion? FWIT I have 6-7 pairs of NOS Telefunken 12AU7’s but zero 12AX7’s. My intent is to check for hum without causing any damage. If a hum exists, I’ll ship to Rogue. In the short term if I’m successful, I’ll test drive with my existing Rogue RP-1, the JBL 4312A’s that are mint and the 26” Sound Anchor stands I have with them. And I’d like to get some Telefunkens to put in the 12AX7 positions. After that, there’s a pristine Rogue Hera that’s been inspected and re tubed by Rogue that I’ll ask to purchase before I start looking for speakers worthy of the pairing. Also I emailed Rogue for support a week ago and have not received a response. Thanks in advance for any feedback and my apologies for grammatical spaghetti, but I’m limited to an IPhone. Cheers , Mike B.
@buellrider97 Happy to hear of your communications with Rogue. They got back to me quickly for the three times I had questions on the Apollos. As for paying for the Dark upgrade, compare the cost of updating your amps to Dark vs. selling your amps once they are running well, and seek a good deal on a used pair of Dark. Here is one example, from a dealer no less. Notice the Make Offer option. |
Todays update. First off thanks for your guidance, second they’re going to Rogue for either repair or possibly a Dark Upgrade. Bill at Rogue spent 30 minutes on the phone with me while the tech listened. The amp in question went into a nasty screeching oscillating that scared everyone. They also recommended using Pirate Ship for shipping fees. Thanks to all, Mike B. |
@mulveling @audphile1 @jafox , we’ll here’s the latest. Got involved with helping my elderly mother and missed my window to call Rogue. However I added a streamer and a dac/pre combo that’s single ended from a headphone system. The amps had some hum, but it’s budget single ended stuff. Anyway played some music and when I cranked it up the right side had a garbled background sound that sounded like static and a dying transistor ( just my description). Switched sides on input, then switched sides on speakers , it’s definitely the amp. Also with it all hooked together, I noticed a slight ground loop issue. When I muted the source and turned off the good amp , there was a mild pop from the bad amp. I’m wondering if there might be something failing in the power supply filter that causes noise but the amp still functions. Also I went to Rogue’s website for the owners Manuel and there’s only the M-150. The 180, does not have the ground loop switch like the 150. Also I tried the 4 ohm tap and when I powered one on it sounded dead. I immediately shut it off as not to cook a tranny. Another reason to need a Manuel , are both sets of terminals connected? Anyway I’ll try Rogue tomorrow, but again, any input is appreciated. Cheers, Mike B. |
Popping/scratchy sounds on engaging the bias switches, and triode/ultra mode (I generally prefer ultralinear and leave it there), are normal. They’re loud & clear on 96dB Tannoys, but not anwhere near danger or concern for tweeters. It’s also typical on shutoff, though it shouldn’t be too intensely loud. The hum on one side that dissipates over time is odd, I haven’t encountered that one before! Worth asking Rogue about. Definitely call ’em up to chat! Though there’s absolutely nothing here that’s too concerning to me - I’d have taken those amps to town and back by now lol. The years in storage doesn’t concern me too much either - there’s nothing in these amps that has proven unstable or problematic, excepting any 2000s era EH KT88 - which were before the M180’s time anyways (M150's got hit by this). I’ve had one Tung-Sol KT120 lose vaccum in storage - its getter flash turns chalky white so it’s easy to spot those. |
Hi Mike - I understand wanting to return the amps to Rogue if they have issues. There are 3 systems in tge virtual section, i’m guessing you looked at my vintage gear.. The fish is a Lake Erie Steelhead my Dad caught on very light Walleye gear - quite memorable… It sounds like we chase the same fish. i mostly fish the wild west coast of Vancouver Island. Thank the son in law for his service. in a prior life i helped build T-45 and iron out a few other aerospace widgets. it sounds like you stay busy - chase the music also !,,, I’m in Carlsbad Winters if you get this way… Jim |
@mulveling @jafox Well I have them both powered up. The inputs are open and they’re biased at 40ma and holding steady. They are absolutely dead quiet. However I have encountered an issue. The first amp was great, no hum, and no popping. The bias was at zero for all four tubes so I set it at 30, let it sit for another 30 minutes and set at 40. When I flipped any of the four meter switches or the Triode/ Ultra linear switch, it was quiet. After an hour I hit the off button and it quietly shut down. However on the second amp it started with a very slight hum that went away. The 4 bias switches caused the amp to make a popping sound as did the Triode/ Ultra Linear switch. After about an hour the hum went away and only 2 of the bias switches cause a popping sound. When I pushed the off button it made a moderately loud pop and shut down. I came back after letting them cool and started both of them again. Both dead quiet, bias good. But I still get a static sounding pop from two bias switches on one side, the same sound when I flip the Triode/ Ultra Linear switch either way. And the pop upon shutdown. I’m leaving them powered on overnight. After all, they’ve been unused for 6-7 years. Tomorrow I’ll call Rogue as they never responded to my email. I want to get their thoughts before I add a source. I’ll post my findings. Regards, Mike B. |
@tomic601 Hi, thanks for the input. I have the factory packaging and if a repair is needed I’ll ship to them. That being said , I really enjoyed your system pictures. You have some cool collectibles. I love your Mac amps and the other retro gear. Nice mount, it doesn’t look like a Rainbow, may I ask what it is ? I float tube fly fish at Lake Almanor in the fall. I’ve fished Monterey Bay my whole life, and currently pursue Tuna from San Diego. One last question, do you fly ? My son in law flew a Rhino at LAS Lemoore. Now he’s a T-45 instructor in Florida. Between fishing, hunting, target shooting and motorcycles I’m lagging on audio gear. Father Time is catching up with me and I have a lot more time for listening to music. Regards, Mike B. |
@buellrider97 - I goofed. No idea why I entered KT90 tubes above. The Apollos came with 12 KT120 TungSol tubes . I saw a tube site a couple weeks ago with a great sale on KT88's. But I thought I'd enjoy the Apollos for awhile before I look to compare other power tubes. Find a preamp with the sound you like rather than worry if it is balanced or not. And the IC that you use between the preamp and the M180s will greatly determine whether you hear the amps' capabilities or not. |
@buellrider97 My last set of Apollo monos (I had the og verison first, before Darks) had a minor hum on one side, into 96dB Tannoys. It was minor enough at seating position to ignore. As someone else mentioned, once the music starts it's gone and that's often good enough for me. I'd say there's a higher incidence of Rogue gear having little stray hums here and there, but frankly the hum and/or hiss is going to rear its head at some point when exploring tube gear, no matter the brand(s). Rogue tube gear generally gets you lots of gain and killer dynamics, bass, and slam - at some expense to noise floor and a "drier" midrange than most tube gear. I said to test w/ inputs open, and that's always worked for me. I don't find shorting necessary; it should be quiet enough even open, at the amp level (nothing downstream to further amplify stray RF/EMI pickups). But it would be fine to test inputs shorted too, if you choose. Yes, the modern KT90 has the EH label, not Tung-Sol. Rogue never shipped the older Ei KT90 tubes - they used EH KT88 back in the 2000's before they started getting some REALLY bad batches from Russia and switched to KT90 which were fine (the EH KT88 issues have long since been resolved - nice tube). I'm generally a big fan of Tung-Sol KT120, but Rogue's big tube monos seem to benefit more from the GL KT88's sweet midrange (and KT88 in general). I often prefer KT120 in VAC amps, but usually KT88 in Rogue. You just have to try for yourself - these Rogue amps facilitate quite a range of power tubes with their per-tube bias trimpots - I LOVE this feature! Again, great "score", and what a great friend - enjoy! Try to give the Hera a listen. It's not for everyone, but will always be one of my top favorite preamps, and I think it's a killer combined with M180 or Apollos. |
@jafox , Hi thanks for the detailed advice, I’m going to hook them up tomorrow. I returned home this afternoon from a trip to see Collective Soul in Las Vegas. I have a strong suspicion that the previous owners hum issue was circuit related. He had a dedicated equipment room adjacent to his listening room that housed some of his theater gear, a server, and his reference system amps. He utilized long runs of Acoustic Zen cables to go from his Hera to the M180’s, then another long run to his speakers and subs. As you noted room heat became an issue so he put the amps in a separate climate controlled room. That room was a new build and had a wiring issue and the power company’s transformer had to be changed. As mentioned above I have a modest single ended low power system. One plus is I’ve had the opportunity to tube roll before prices exploded. I have about 6 pairs of Tekefunkens including Tektronix and the black G 73-R’s, Seimens CCa , Silver plated Seimens, RCA tripple mica. In 6922 numerous NOS American and my favorite Tekefunken E88CC. I’m wondering if the KT 90’s you have are EH not Tung Sol. I like the new KT 120 and 150 tubes. I very much like the GL KT 88’s. One of my all time favorites is the Svetlana Winged C, but they’re hard to come by and mostly factory seconds. They have the sweetness of the Gold Lion KT88 and the low end of the Tung Sol KT -120’s. I needed to know about an open loop on input , which has been answered. But you guys have given me tremendous advise regarding input tubes. I do not own any 12AX7’s or 12AY7’s or any of the lower gain tubes. The advise I’ve received will help me with my choices. After this, I will shop for an affordable balanced pre. Unfortunately my quest for the appropriate speakers will be on hold as my wife is purchasing 2-3 slabs of Quartz tomorrow for our pending kitchen remodel. She’s looking at Taj Mahal quartz, Thermidor appliances and oak flooring. My dreams of Big Boy speakers will have to be put on hold . Also I’m very humbled and honored that the three of you have taken the time to guide me. Regards , Mike B. |
Congratulations on such an exciting gift. I have read a lot of positive comments on the Rogue amplifiers on these forums. Finally, the curiosity got the best of me to try one of these out when a good deal was found on the Apollo Dark monos. I was a long time user of the CAT JL-3 mono amps. These throw out a lot of heat. And with the huge number of tubes, they are costly to maintain every few years. I have heard nothing in my system, tube or SS, that comes even close. But finally, I found a SS amp, the Symphonic Line (SL) Kraft 300 amp that is truly impressive. The SL product line is quite special. It does so many things beautifully, but the CAT amps are in a different ballpark, in dynamics, clarity and openness. The CATs are not tubey-sounding amps. I’m sure these 20 year old amps still hold their own against all the latest ARC, CJ, etc., of today. I have been running the SL Kraft for about a year with great success and only two issues: 1) the SL amp sounds horrible until a long warmup, many hours to a day, and keeping it on all the time gets pricey! ; 2) I miss the "magic" that comes with a tube amp. Enter the Rogue amps. After living with the Apollos for two weeks, I can share some setup details. Mine came with TungSol KT-90s. They came with Amperex 12ax7, and unknown 12au7’s. A number of years ago I spend a lot of tube rolling to find the coveted triplet (12ax7, 12au7, 6922) for the CAT amps. Replacing the Amperex with the 5751 (I can’t see the brand on the glass) I had used on the CAT was significant; there was a bite in the upper mids/lower trebles that was gone thanks to the 5751. The sound was good but I had one more test - replace the 12au7 pairs with my all-time favorite here - the RCA 12BH7. Every time I have used this tube in 12au7 sockets for DAC, Line Stage, amps, it always reigns supreme and it did not let me down here either. The mids were much more smooth with greater decays. After an hour or so, I was so impressed for the value of these amps. They locked onto the SoundLab A1s incredibly well. I use the 8-ohm terminals as I always have when I had a choice. With all the success, I had/have some issues that I did not have with the SL Kraft or the CATs. With the Apollos, I suddenly had a ground-loop hum. I have three circuits in the room, one each (different phases) for when I use the cat amps, and the third for the rest of the system. I never had hum issues with this. Using the SL amp’s both power cords into a circuit on the opposite phase of the system never caused a problem. But this same setup caused hum out of the right speaker with the Apollos. I changed to my backup power cords and the problem was gone. Back to the first cords and the hum was back. I fussed with cable routing, cable lifters, etc. Finally I threw in a cheater plug and the problem was resolved. But I don’t like to have to do this. So you might need to be extra careful with cable layout, cables crossing/touching, circuits, phases, etc. With the Apollos, I have more tube noise vs. with the SL amp, but once the music starts, you can’t hear it. And I tried the Triode mode. This was quite disappointing as I expected an even more lush sound, but it was too mellow and the strong bass foundation much diminished. So you can play with that switch as well to see what mode works for you. I am back to a fully tubed system. And I have to say that I love it. Enjoy the 180s. John |
I has some of Quicksilver's Horn monoblocks for a while and they were really good with my Klipsch Chorus speakers. I was most impressed by how quiet they were. I moved away from tube amps, as much as I like the sound, I got tired of the issues with tubes, the heat, and cost of replacement tubes. I like the combination of solid state amps and a tube pre. My current setup is PS Audio M1200 monoblocks, Herron Audio VTSP-360 preamp, and Gershman Studio Xdb speakers. The Gershmans are pretty hard to drive and the M1200s handle them well. If you are going to go down the nearfield monitor route, it's hard to go wrong with either a LS3/5 variant or Harbeth P3ESR. |
@big_greg , thanks for your input. I have Zu, Klipsch, and JBL 4312A’s that are in excellent condition. My front end is Innuos, Schiit Yiggy, Thorens TT with Grado Prestige. I’m currently running the Rogue RP-1 with Telefunken G73-R’s , vibration isolation under footers and upgraded power cord. I’ve reached the limits of what it can do without adding a separate phono stage. I have a Dennis Had Inspire Sep amp with 1/2 doz NOS rectifier tubes, 8 NOS input tubes, and about 10 pairs of power tubes from NOS GEC to KT-150’s. I rotate that with a modded Akitika SS 50wpc amp. My long plan is an entire new back end with a better pre and some speakers that like that much power. I will not connect them with the ZU’s at all. I was considering new tube monos when I was gifted the M180’s. I live about 2 hours south of Quicksilver and was considering the KT’s as Mike recommended at least 100 wpc for my JBL’s. However as a near field studio monitor, they are not that musical. If this works out I’ll be looking at some speakers in the $10K region which is a lot for my modest income. And again your comments are appreciated. Regards, Mike B. |
I'm not sure I have much to add, mulveling covered a lot of ground. As he said, some hiss is normal with high efficiency speakers. I think I had Klipsch speakers when I had my M180s and if you got close to the tweeters, you could hear some hiss, but while listening it wasn't noticeable. Also consider the KT120 power tubes and give the triode / ultralinear modes a try, and try both the 8 and 4 ohm taps. I preferred ultralinear, but triode might be better with the Zu speakers. It's worth experimenting. And yes, nice gift! Having said that, if it was me, once you are confident they are working properly, I would consider flipping them and getting lower powered tube amps that are better suited to your speakers. |
@audphile1 , Thank you for your input, your experience with a vast amount of gear and your straightforward recommendations are always appreciated. @mulveling , I was hopeful you’d respond and save me sending a PM. I’ve long read your advice and admired your equipment. Your knowledge of tube gear including Rogue is greatly appreciated. Your comments on small tube sound characteristics has been invaluable to me. I was concerned about the input being open Vs closed by means of a shorted input connector. Having read online I noted in guitar amp forums it was stated to short the input when checking for hum. As I’m planning on using the JBL’s, I’m not too concerned with the noise I get with high dB speakers like my Zu and Klipsch. I also didn’t realize the the Hera had such a high amount of gain and that would explain the original owners complaints of too much power. FWIT the original owner was formerly a dealer that changed careers and went into estate law. I know he carried Rogue, Modwright, Acoustic Zen, and Dali. He once loaned me a Modwright KWI 200. After the Rogue gear he had a full quiver of Bryston with Dali stand mounts and JL Fathom subs. His current system is Macintosh and B&W’s. His room is treated with GIK items. I couldn’t live with those B&W’s, the tweeters are deadly. |
First off - WOW, nice gift!! The og owner’s claim that the M180 was "too powerful" is a bit odd, and Rogue’s response to them was equally odd. These amps have a very high gain, and that is the main issue when paired to high efficiency speakers. Compounding this - Rogue doesn’t make the quietest tube gear. Yeah - hums and tub hisses are quite common with high sensitivity speakers. If it’s not noticeable from your seating position then don’t worry about it. I’ve long said Rogue should use a 2nd reference system with high efficiency sepakers, so they can hear some of these issues. That said, Rogue can still make some great sounding and high-value tube gear. It’s perfectly fine to turn on the amp with input open / unconnected. Just make sure it’s hooked up to a speaker - DON’T turn a tube amp on without a load connected to its binding posts. Also don’t connect or disconnect its inputs while it’s on. The 5751 sub is a good choice for a couple reasons: 1. they have a different sound quality than 12AX7, with more precise imaging at the expense of image size. 2. they have a lower gain by about 1-2dB, which will help in your case. You can also sub 12AY7 and lose another dB or 2 of gain. The KT77 sub (and bias adjustment) is fine, but not strictly necessary. The EH KT90 tubes sound a little bright and lean / dry through mids, so you might well prefer GL KT77. An RP-1 is not anywhere near the performance level of those M180. The Hera is one of my favorite preamps ever - but it’s got a very high gain, so you’ll probaly be cutting its gain knob all the way down. And you’ll still probably be hearing some tube-rush "hisss" through your high sensitivity speakers - even from your sitting position. You’ll also hear that trademark "pting-tashhhhhh" sound of its 6H30 tubes when they’re disturbed (mute / unmute). But past that, I think it should be an amazing sounding combo! I preferred Hera to their current flagship RP-9. The RP-9’s sound reminded me a lot of those EH KT90 - not bad, but not my thing. |
Make sure all the tubes are seated. Plug the amps in and connect them to your jbl speakers. Power them on with no signal flowing thru. Let them warm up for 30-45min and adjust bias. Leave them on and see how the bias holds. If no noise try them out. As to Rogue support…just call them. My experience with these guys is very positive. I dealt with Nick and Mark there when I had RP1 and ST100. Good sounding electronics. Best of luck. |
