@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.
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.
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. |
I've got vintage and NOS tubes from all of these same people sitting in boxes my cabinets. Priors from AZ, some of Brent's very best curve-tracer triode matched triodes too. Each has its own character, and depends on the rest of the system. While they sit in boxes hoarded away, JJs stored too, I'm still running later version PSVANES the past year solid with zero issues. A tad softer and fuller sound if you like that. @buellrider97 I say let all those stock large and small tubes burn in so you get the caps, diodes, resistors all burned in [first] on cheap tubes you'll pull and replace anyhow in a few weeks. |
Well I’m on day 2 and the harshness is starting to subside. Unfortunately I could not stand the JJ 12AU7’s any longer. Although they’re the gold pin version I just couldn’t take it anymore. I had turned the mid and treble settings on the JBL’s to 1 and it still sounded harsh. So I put in 2 pairs of Siemens nickel plates in the 12AU7 slots and ordered a trace curve matched pair of smooth plate 12AX7’s from Brent Jesse. With just the Seimens in it’s already more listenable and the Telefunkens will arrive next week. I will take your advice and contact Arizona Tube regarding some additional tubes. About 5-6 years ago I was at the Barrett- Jackson car show in Scottsdale and there was a big booth selling restored vintage radios and vintage tubes. My memory is foggy, but I can’t help thinking it was the vendor you mentioned. BTW I noticed the amps are biased at 35ma. , what do you guys run ? Cheers , Mike. |
@hiend2 Hi , I agree the RCA’s would be an improvement, probably quite significant. My Tekefunkens should arrive in a few days and I’ll replace the new production Tung Sol 12AX7’s. I have the system burning in on the dining room table. I used all the cables in my leftovers box, it’s quite an ugly scene. It’s all running through an old Monster power filter and discarded unbalanced interconnects. The speakers are on the table too, it’s quite comical. I’m getting moments of nice sound depending on what’s streaming. I’ve emptied the living room and got out my big Sound Anchor stands. They were damaged by dissolving Blue Dots and I have to clean and repaint. I’ll have to get some balanced IC’s real soon. Thanks for your input. Cheers, Mike B. |