Dramatic Visible? Power Issues -- What Next?


My system has developed a new problem. It strikes me as whole lot more complicated than it likely is, but any input from those more knowledgeable than I (not too hard) would be greatly appreciated. This one’s got me worried.

Start simple: after being on for anywhere between 1/2 hour to two hours, the system develops a loud hissing, much like a very strong tube rush.

Complicate slightly: the volume of this "rush" is inversely proportional to the volume setting at the preamp. Which is to say that above a certain (variable, but too loud for listening levels) volume setting, the "rush" disappears. At a zero volume setting, the "rush" is the loudest, which can be very loud.

Complicate further: the volume, consistency and pattern (yes, pattern) of this "rush" changes. Sometimes it's constant. Sometimes it pulses. Sometimes it builds to peaks and then snaps to silence, only to build again -- sometimes rhythmically, sometimes erratically. It's in both channels. Preamp is tubed, amp is solid state.

Complicate yet more: it's tied to the power system and draws quite a bit of power. Yesterday, at zero volume and no input, the rhythmic "rush" pattern caused the lights in my apartment to pulse along with the soundtrack. (There is a Richard Gray Power Block between the system and said lights). This is when it started to scare me a bit. If that’s not enough, the amp clips while powering down and has blown internal fuses twice in as many weeks.

Prognosis? Clearly, a problem. Something is storing and then leaking a whole lot more power than it ought to be someplace it definitely ought not to be. This problem has been happening (rarely and subtly at first, but recently far more dramatically and without fail) ever since I got the preamp, so that is my first suspect. I have another preamp that I intend to swap in before I try anything else. In the meantime, any thoughts or pointers would be greatly appreciated. Looks and sounds like there is a lot of errant power in there someplace -- and I’d hate to stick my finger in the wrong spot...
mezmo
Please be careful, if you decide to power up the old pre again. If this unit has sat unused for the 7 years since the original post, I'd take it to a shop and have them put it on a Variac to bring it up slow....I'm betting on a dried up cap.
Yea, at the time it was strictly RCA. Haven't tried the thing out for near on seven years, but it would be nice to dial in whether there is actually anything wrong with it (so that, someday, it can come back out of its box, if not in my home, someone else's.)

Since things have changed, the set-up that put on the show was: Meridian 508 - Rogue 99 Magnum -- Bryston 4b-st -- Thiel 2.3. Interconnects all RCA, then I think Homegrown Super Silver. All run through a Richard Grey power block.

End of the day, this sort of shenanigains is what ultimately drove me to cut the cord on tubes entirely. Just too many unanswered questions. Whether that was the culprit or no, went all SS (all balanced), never had another problem, and haven't looked back. In a game where second-guessing things all-too-insideously leads to the upgrade virus, tubes just seemed constantly to require entirely too much second guessing.
Since it tests properly, I'm wondering if it has anything with the fact that it inverts the signal. although I can't see why. Might not be the preamp at all if it's dc coupled, in which case it could just be incompatible with the amp. Strictly RCA?
Our goes the pre, in sails the wife:) Congratulations, Mezmo!

(Just goes to prove that stereo is good for you, in more ways than one.)
Get it fixed by a pro.
Probable causes are very limited and mostly component related....bad caps or tubes.
Does unit emit any smell? You know, that here-we-go, the electrons are out, kind of smell?
And FWIW, that's one reason for ME to avoid tubes.....I simply don't want to mess with it and end up owning a tube tester, scope, signal generator and a couple DVMs.
Dunno. According to its maker, nothing. Spent a good deal of time speaking and corresponding with the good folks at Rogue (it's a 99 Magnum). Actually dealt with the owner / engineer, whose name sadly escapes me at the moment, but genuinely interested, engaged and an all-around great fellow (gotta concede, the devil-possessed preamp does make for an intriguing story). Ultimately, sent it in for a full battery of tests and they had it hooked up on a bench for a bunch of days trying to make it act funny or do wacky tricks -- and it never did. (Don't you love that...fickle, primadonna little bitch -- only throws a tantrum when it's not the center of attention). Great preamp and fantastic company, but ultimately decided it just didn't play well with the rest of my gear and moved on. Actually still have it, but it lives in a box in the basement these days.
Can't resist. Seven years later now (and uncounted stereo changes), the previous post officially describes my last first date. Upgraded same "gal" to No. 1 Special Lady Friend of the Legal Variety (a.k.a. The Wife). I chuckle.
It's definitely the preamp. Swapped in the old one and everyone is getting along just fine now. Time to talk to the good folks at Rogue.

What I really love about this "high-end" stuff is remembering the cheap old Yamaha and Infinity system I had that never once stopped making music (and nothing else) for ten years. Over the past three years of "high-end," I've replaced a driver in a speaker myself (with parts from the manufacturer), sent an amp back to the factory to have a bad muting switch replaced, and now the preamp is on the blink (not to mention the countless hours on DIY wires, tube rolling, and just general tomfoolery). Sure, it all sounds a lot better, but it seems to spend an inordinate amount of time not sounding at all, what with all the "maintenance." What more, the stuff seems so damn fragile, half the time I'm almost wary to use it -- say I want to listen to something for 10 minutes before running out: is it worth firing up the tubes for 10 minutes? I hate to turn it on and then just turn it off again? can't leave the thing on because lord only knows what it will do while I'm gone? (Used to be I'd leave the amp on for weeks at a time, now I come back after two hours and it's blown fuses in my absence). Call it a crisis of faith, but I'm questioning my trust in the fickle gods of "high-end." Maybe I do need a priest....

As for dimming the lights from the preamp -- yep, not good. Not good at all. However, at the risk of talking out of school, I have to say that at the time it decided to put on the show I was approximataly 12 hours into what ended up being a 25-hour first date. So, without more fanfare than a simple "humm, that can't be good," I just shut it all down and didn't mess with it again before switching out the preamp alltogether last night. All things considered, I'm sure it's for the best. If I didn't have something else to distract me at the time, I might have attempted to take the fool thing apart and likley would have killed myself in the process. Shoot, this gal might just have saved my life . . . imagine.
Don't you just love high end audio? I would unplug it and have the amp and pre-amp checked out. You could do some real damagew to the remainder or your system if you keep playing with it. Take it from a guy who fried a cd player, pre-amp, amp and speakers!
Talk to the factory.Maybee bad tube,bad fuse bad cap bad reistor all of the above.
Wish I could offer better advice than this, but call a priest.

Keep us posted of your fix, I'd like to hear what could cause that. It seems to me the amp is the most likely culprit with a bad capacitor or resistor???? But then again I don't know jack about that stuff;)
...and worried you should be. I would unplug the sucker immediately and place a phone call to the preamp's mfr tech support. Dimming the lights??!!