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Rogue cronus as a power Amp adventures

Lavane said:
I haven't tried those yet. I do like the Tung Sol octal driver tubes and 5881 power tubes.
The only thing keeping me from trying different KT-88's in my mono blocks is I need two quads of them. It gets expensive.
Have you tried the amp by itself without the McIntosh preamp?
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IMHO-save the money and get them on sale. Amplified Parts/Viva/Tube Depot will have 10-15% sales soon. IMHO the KT120 gives you the best world of the bass of the KT120. And the mid sweetness of the EL34. I disagree the are soft on top. Very detailed top to bottom. Even and full response. In my 2 Atlas Magnum III's I run KT120's and NP Gold Lions in both positions. Far from sounding solid state-it give you more of the tube euphoria then most setups I have heard. It's just a more linear even response. That's why I put the NP Gold Lions in there. The bass control and dynamics can't be matched by any EL34/KT88 etc.
If you want old time tube/old CJ syrupy sound-look else where.
If you enjoy hearing all the details in your audio reproduction in a musical way solid state can't come close to-check them out for sure. Rogue amps don't sound tubey anyway. Especially the newer stuff-IMHO they sound the best with the best sounding NP tubes.
I mean honestly-the NP Gold Lions 12AX7, 12AU7, KT120's. Very few vintage tubes -IMHO of course that can compete with their overall blend/balance of dynamics fullness, and euphoria without being overly colored. The whole balance of the tubes sound. Not to mention a lot of value in sound for the money spent-IMHO.
People -esp these day-not so much in the real tubes days-like to color their sound more. Back in the 50's 60's, people were striving for a less colored, clearer sound.
 
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And honestly-guys would have killed to have the big dynamic, wide and deep sound stage (when the amp is designed for it) with the KT120, back in the golden era of tubes. No vintage tubes has the same combo of qualities the KT120 can have when the amp is designed to use it. IMHO it's far from sounding solid state. Being dynamic isn't a solid state exclusive quality.
 
Well.... I just had a purple fireworks show inside a KT120 tube and rogue recommended a full quad of KT88 tubes. They're being replaced by the reseller I bought my Amp from. We'll see how it goes!
 
tube failures happen. I had an EL34 go spectacularly bad, lighting bolts and it even cracked the glass. Scared the hell out of me since it was about 2 feet away and made some pretty awful noises both through the speaker and just directly from the amp itself. Did a nice job roasting a couple of parts inside too. Took me like an hour to fix, not exactly a big deal, but it most certainly got my attention.
 
I had a KT-77 put on a light show and make some awful noises. I think that was the only power tube I've ever had fail like that.
 
Yeah, this was quite a show. This all took around 30seconds, but it was surprisingly dramatic for a virgin. I was sitting in my chair, and sound started flickering in/out, I looked up, saw purple fireworks, then it went bright red and smelled smoke as I jumped up to hit the power button. Glad I was in the room when it happened to turn it off. It makes me wary about leaving my Amp on when I'm not listening , but turning it on/off throughout the day doesn't feel right either. . .
 
I just don't leave them on when I'm not home. I have forgoten to turn off an amp or preamp a few times, leaving them on overnight and into the next day.
Nothing bad happened though. I did this with my Dynakit ST-35, VTA ST-70, Magnavox 9303, my main preamp, and a single gain stage preamp I built used in another system. So it happens.
 
Lavane said:
I just don't leave them on when I'm not home. I have forgoten to turn off an amp or preamp a few times, leaving them on overnight and into the next day.
Nothing bad happened though. I did this with my Dynakit ST-35, VTA ST-70, Magnavox 9303, my main preamp, and a single gain stage preamp I built used in another system. So it happens.
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Which is why I'm surprised some folks here are so bold as to leave their amps on 24/7. I don't, and I remember one situation when testing an amp which was working just fine, I left the room for about an hour. When I returned, the amp had smoke billowing out from it! One of the multicaps gave up the ghost in dramatic fashion.
 
Jimswms said:
Yeah, this was quite a show. This all took around 30seconds, but it was surprisingly dramatic for a virgin. I was sitting in my chair, and sound started flickering in/out, I looked up, saw purple fireworks, then it went bright red and smelled smoke as I jumped up to hit the power button. Glad I was in the room when it happened to turn it off. It makes me wary about leaving my Amp on when I'm not listening , but turning it on/off throughout the day doesn't feel right either. . .
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Just me I would never leave my tube amps on with no idea of a problem to hit the power off quickly..I cant afford to find any other new 1961 tube Mono Blocks amps with brand new Tung-Sol 6550 3225904 tubes was purchased in original boxes never energized so the wait for a great analog tech wasn't hard to do that here in AudioKarma. Nor was the time to wait until they were finished. they are on youtube under "Phil analog basement" amps are Stromberg Carlson AP-437 p/p 6550, Mullard Blackburn plant GZ-34, RCA- 12bh7a, Stromberg Carlson Tung-Sol 7025 3225936 great dreamy creamy sound out of them. 40 watts continuous -100 watts instantaneous. only have a gain control and on/off. full out put on amps #3 on pre amp Stromberg Carlson, Altec Lansing 15" woofers, horn mids, horn high end. all are Alnico Magnet very easy to get a lot of dbl out of them. they sound effortless driving them. Ive driven them with 12 -15 watts a side stereo 6v6GTA sylvania. Push ya out the door with 12-15 watts. Still have all 4 of those amps will be selling soon.
 
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I've had very few issues with an amp while being used. Over the yesrs I've lost two rectifier tubes, both the same brand, a power tube, and a driver tube while an amp was on. Nothing else happened to those two amps though. No burnt resistors, failed caps, or damaged transformers. I really don't worry about it.
I do like having exposed tubes though so I can glance over and see if a tube is red plating. But it's not like I'm glancing over at an amp or preamp every few minutes. I had a power tube loose vacume once while the amp was off, and having the tubes exposed I was able to notice it right away before turning the amp on the next day. To be fair the tube was old, used, and weak to begin with.
 
Jimswms said:
Yeah, this was quite a show. This all took around 30seconds, but it was surprisingly dramatic for a virgin. I was sitting in my chair, and sound started flickering in/out, I looked up, saw purple fireworks, then it went bright red and smelled smoke as I jumped up to hit the power button. Glad I was in the room when it happened to turn it off. It makes me wary about leaving my Amp on when I'm not listening , but turning it on/off throughout the day doesn't feel right either. . .
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So, long story short, 4 new kt88 tubes, led to some cooked caps. The Amp is currently at the Rogue Audio health club and spa in PA getting treated to a Dark upgrade, and hoping for a switch to allow me to run it as a atlas dark in the future for shits & giggles if I choose. I asked, we'll see if they can deliver. Stay tuned
 
My outlook is an amp is more likely to fail on power up then at idle. Prior to the transistor many of the old amps served duty providing background music all day and halve the evening in some department store, all day long and even at some movie theater, or many were used as PA speakers powered up just on standby for someone to announce a message in some train station, airport, or bus station. I try to reduce the number of power ups more than I worry about how long my amp is on. But living here in Florida where lightning can happen anytime with quick little thunderstorms I can't really in good mind leave my amps on unattended as those storms will kick the power on and off with surges which can be deadly to an amp. I turn mine off even when I am in the middle of listening to it when I start to see a storm moving in, which is just about every day this time of the year.
 
Ken Boyd said:
My outlook is an amp is more likely to fail on power up then at idle. Prior to the transistor many of the old amps served duty providing background music all day and halve the evening in some department store, all day long and even at some movie theater, or many were used as PA speakers powered up just on standby for someone to announce a message in some train station, airport, or bus station. I try to reduce the number of power ups more than I worry about how long my amp is on. But living here in Florida where lightning can happen anytime with quick little thunderstorms I can't really in good mind leave my amps on unattended as those storms will kick the power on and off with surges which can be deadly to an amp. I turn mine off even when I am in the middle of listening to it when I start to see a storm moving in, which is just about every day this time of the year.
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Your theory makes 100% sense to me. Guessing it's a liability thing for a manufacturer to recommend leaving it powered on forever. Rogue strongly suggested not leaving their tube amps on while not listening . He said they do a slow start up on the tubes so turning on/off doesn't affect tube life.
 
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