@hiend2 , Thanks for you’re input. I started to pull the cover on the one that’s having issues just to have a look. Unfortunately the screw didn’t want to budge and started to loose the head, so I stopped. I didn’t want to start whacking them with a mallet and you certainly can’t heat them like we do on motorcycles, so I just left it alone. Last month I received my Yiggy back from Schiit due to a failed USB card. And it was in a new chassis as the tech broke off the screws holding the board to the chassis. Considering I want the boards updated and brought up to spec they’re best just shipped. I would like your input on power tubes and speakers. I have a relatively fresh set of GL KT-77’s and in my mind they’re glorified EL-34’s. Down the road I’ll be considering KT-120’s and GL KT-88’s. So any input especially speakers is appreciated. Regards , Mike B.
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.
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@mulveling Hi all, here are todays updates. I received my boxes from Rogue and will pack and ship to Rogue for the repair and the Dark upgrades. Also I’d like to mention that I obtained the Hera II from the owner of the amps. Back when the amp had a problem the owner shipped the Hera to Rogue for a checkup and it received a clean bill of health. A fresh set of Sovtek tubes were installed that are graded by Upscale Audio. I’m not sure if Rogue or the owner replaced them. Also included with the Hera are the original set of tubes and the metal remote along with factory packaging. The Hera looks like new and hasn’t been used since the trip to the factory. I paid $2K for it, which seemed pretty fair. Another interesting fact is the Dark upgrade no longer includes NOS small tubes. They are using better grade new production which I’ll still replace. I’m planning on all 6 small tubes being NOS Telefunkens. Regards , Mike B. |
Hey, cool your doing the dark upgrades! I listen to the Apollos regularly have them in a Bi-amp setup them on top and am amazed on the added resolution I get over the krell monos That I can swap in. So Factory no longer send NOS input tubes thats okay, think they had Clear top rca and teles. I have over here Nice sweet 5751's sound quite good in there have them all as well kt88 Gold Lion kt90 Electro and kt120 Electro all have a certain signature the Gold lion are smoothest. Please keep us informed on your factory upgrades! |
Cool! Man that Hera was a great deal, I would’ve bough it for sure. They’re hard to sell, but the sound quality you get for $2K is amazing. A hidden gem. IMO it showcases the 6H30 sound at its best - caveats aside (high gain, microphonics), in some ways I like it better than the much more expensive Audio Research Reference 6 (which also is a great manifestation of 6H30 sound). I just didn’t get that kind of "6H30" sound from the RP-9; must be the MOSFETs. I was certainly expecting it, and it wasn’t there - kind of a bummer. Interesting about the report on Rogue’s Dark tubes - they couldn’t keep a large NOS stash around forever, so it’s to be expected. I think it’s more fun to roll your own, anways. 5751 can be a fun sub for the 12AX7 slots - they generally have a more precise, tigther image and better "clarity" and smoothness than 12AX7. 12AX7 tend have a bigger image and dynamic sound. At least that was what I found when rolling my original Apollos. Mazda Silver plate 12AX7 gave the best of both worlds, at the expense of a little extra treble energy (strangely enough, they have "T" plates like more 5751). Don’t get the silver-plate 5751 though - they’re brightness monsters. As aforementioned, you can always sub 6189 and 5814 for 12AU7 slot. 5963 is usually too microphonic as a 12AU7 sub for preamp / phono amps, but it’s OK to use them here! The RCA 5963 are a nice tube for cheap. 12BH7 are more dynamic sounding and draw more heater current, but OK to use here too. Enjoy! Hope your really like the Hera w/ 180 Draks. I know I would! I’m playing with Stereo 100 (non-Dark) and Hera in my 2nd rig right now. The ST100 is just a hero for its price point; such a fun amp and lots of tube rolling options - got Tung-Sol 7581A power tubes in there currently. |
@buellrider97 message received, I replied with a separate message as Agon has the Cc policy I wont use nor care to for security reasons. Anyhow, reading the thread, IF you did decide to send the Rouge in, and you mentioned your others system with Zu's. Not sure if you plan to use those speakers or not. If yes, if you can, I'd stick with the Rogue recommendations to send, test, and dial in those amps with KT77s, [I'm a KT120 tube user btw], but like KT77s for this. If I could reconfigure my larger QS Mono 120s, dialed down plate voltage, and bias more, i'd likely be running KT77s instead as I'm like EL34s with a jolt, like KT77s. If you do send/sent them in - they can bias the input, outputs, and check for noise across the board. Getting the noise way down is key over which vintage tubes to use any more. Properly set up, tested, you could do fine with new/re-issue tubes imo. This granted you don't need extra power, no need for KT120s, go KT77s, |
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