@mulveling @decooney @hiend2 @big_greg Well my amps came home today. UPS had them on their side using a 2 wheeler in typical UPS style. Anyway they received the Dark upgrade and have all new tubes. I took the Hera out of the box and set it all up on the dining room table much to my wife’s dismay. The system is dead quiet and sounds nice considering they’re basically new. The Hera has not been used since 2019. I’m streaming some music now and I’m going to let it run all night at low volume. It’s been on about an hour so I’ll check the bias and call it a day. Next week I’ll roll some input tubes and see how it sounds. We’re getting ready to gut our kitchen and den for a remodel. Even though the system will be in the living room I’ll probably box it up during construction. I do have a few questions, 1) How many hours for break in ? 2) How much of a difference will balanced interconnects make ? 3) What do you like your bias at ? Regards , Mike.
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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@buellrider97 Hi Mike, you might ask if they ran them in for 2-3 days already before shipping out as some do. You might let them play for at least the first week [or two or three] before changing any tubes, let the caps [if new] settle in, and keep checking for noise and get a solid baseline. Take notes if you can on sound of low, mid, high frequency and what you hear for your own refer-back reference later on. I'm a dork and pretty conservative about this first phase, maybe even letting the amps play 2-3 weeks as-is before messing with anything at all. Check bias now and every few days if you can as tubes and bits inside settle in. This way you'll know they are still solid and still dead quiet as you stated. I think of it letting everything to simply stabilize to a baseline with added confidence about the "upgrade" itself. Then, maybe a few weeks down the road, when you start changing any tubes, or start hearing any new noises, you can isolate it a bit easier if by chance a new tube with problems/noise gets introduced. If so, swap the original tubes back in to confirm. Why do i suggest this - here is why. I recall a few times for different amp owners where "recently upgraded" amps and preamps were shipped right back to the factory for them to test and find out the recently changed-in tubes were the culprit, not the upgrade itself. If it were me, I'd just let 'em play 3 weeks on/off. See how it goes for ya. At that point, you'll know what's going on, and how solid the upgrade is. And then can introduce changes, and will easily notice problems if any changes, tubes, bias, causes new issues. This approach can also give you an etched-in-the-brain baseline about how it sounds after the upgrade, and then how it sounds again once you change in the new tubes you want to try. People have different approaches, this is mine fwiw. |
@decooney Hi , thanks for the advise. I have no idea how much time they ran after the repair. They installed new resistors, Hexfred diodes, new caps in addition to MORE caps. You can see massive pairs strapped to the chassis on the inside edge. Plus all new tubes. It’s been on low for about 14 hours. Wife just left so I turned it up, still harsh but I can tell an improvement. The upgrade tubes include 2 JJ gold pin 12AU7’s and a new production Tung Sol 12AX7 in each amp. Pardon my language but JJ’s sound like shit. I have a quad of Nickel Seimens and a quad of Tekefunken G73-R’s to try. I’m going to call Brent Jesse and get a pair of quality Tekefunken 12AX7’s this week. I have zero 12AX7’s to try. I wish there was a tube library so I could try some stuff. But at $3-500 a pair for good 12AX7’s I’m kinda screwed. The other issue is my wife took all my play money for her kitchen remodel project. I still need big boy speakers. But this is a First World problem and I’m a lucky guy. So after the amps get a week or so, I’ll change all the small tubes. If these Psvanes don’t improve in the bottom end I’ll try my Schiit Loki, but I’ll probably get an octet of KT 120’s. Having been warned by Rogue every time I mentioned new tubes, I’ll probably buy an octet from Upscale. |
I co-admin a Rogue group on Facebook and I frequently comment: "JJ’s go right in the trash". Any of the Russian 12AX7 options are better (EH 12AX7 and 12AU7 are a bit too bright, though). Don’t pay a big-guy tube dealer $300 to $500 per pair. These days, it will be either very "questionable" NOS, or late production overstocked dregs from the 70s / 80s. Buy a couple sets of vintage "used, tests good" tubes from a smaller seller with a good track record. Example - I always liked Arizona Tube Supply. At least you’ll be getting what you paid for (used). Good vintage tubes should still last a very long time - not worth paying so much more for NOS, in my opinion. There should still be plenty of Telefunkens, Mullards and RCA black plates out there. 5751 work well in Rogue amps too. You want tighter imaging at the slight expense of some "size" and dynamics gusto? Use 5751. Upscale is an excellent choice for buying new power tubes. It’s worth their premium here - BUT you definitely don’t need the Cryo treatment or "ARC Select" / "Kevin’s Stash" premiums. I’ve tried those and they are no better than Platinum grade. Their burn-in process should filter out most of the problem tubes. I’ve bought dozens of Russian KT120 / KT88 from them over the years and NEVER had a single problem. The one EH KT90 I’ve had blow up on me (15 years ago) was supplied by Rogue! |
@mulveling Thanks for sharing your experience. I was thinking Brent Jesse, but I will definitely check out Arizona Tube Supply. In the Rogue RP-1 I rolled everything from Mullards to high grade Telefunkens. Same with the single input tube in my Had Inspire. But these were 12AU7’s in the Rogue and a 6JD/ecc88 in the Had. But my assumption is the sound characteristics will carry over in the 12AX7’s. Please correct me if I’m wrong. Of the American tubes RCA and Phillips were pretty good. It came down to Telefunken, Seimens and Amperex in that order with Telefunken my favorite. The Seimens CCa was second with the nickle plates and the Amperex next. What I found with the Seimens and the Amperex is the treble was too forward , where as the Telefunkens were smooth across the frequency range. I’m changing walls for my stereo and will be getting a new TV. Unfortunately the TV will be on the wall behind the stereo. But my room is 19’ wide by 28’ deep so I’ll be able to put the speakers 3-4’ off the front wall. I just removed a huge 3 sided cloth covered sectional from the room and came to realize how much it dampened the room. The guy that I got the gear from offed my a free pair of unused GIK wooden diffusers. My intent is to mount the tv, change to that wall and set up the system. Then I’ll play with the diffusers and experiment with bass traps and absorbing panels. My friend also has a commercial sound analyzer that’s in a travel case with mics and stands. I don’t remember the brand and I’ve not played with it. It’s older but probably still useful. Again , thanks for your wisdom. Cheers , Mike B. |
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