What's likely to happen when an 845 tube fails?


I've been running tube gear as far back as I can remember and other than a CJ mono amp blowing a 6550 and requiring factory service many years ago, I've never had any serious issues. Sure, tubes age and you eventually replace them or on a rare occasion, a tube blows, maybe you replace a fuse, then you're back up and running, but that's been it.

Atma-Sphere MA-1 monos and MP-1 pre currently hold pride of place and I'm also very fond of a Cary SLI-80 F1 all triode that I run in another system. But... I've been itching to try a pair of deHavilland Aries 845-G SET monos and am wondering how much grief those big, high voltage 845's might cause me?

In the case of "catastrophic failure", is it likely to do serious damage to the amp? Worse yet, how 'bout my speakers? Any comments from those having personal experience with 845's or 211's would be appreciated.

Regards!
128x128rfogel8

Showing 6 responses by rfogel8

Thanks for your responses. I agree that the amp's circuit is very important and that's why I'm considering the deHavilland.

I never leave tube gear on and unattended for very long and always keep plenty of spares around "just in case." I also have a Hickok tester and keep pretty good tabs on my tubes.

I was hoping for a few more responses from those who've lived with the 845 for a while, wondering how reliable they are and what I can expect if one fails.

Again, thanks to the two who responded!
Phil, now that's the kind of useful info I was looking for!!! Thanks for taking the time and being so thorough.

Joe/Trelja, thanks too for your comments. You and I discussed the merits of the 845 a while back and I'm still dragging my feet. I know it's not your favorite choice for SET but the only other amps that peak my interest are the Wavelength Cardinal's. I'm fearful the 300B will fall a bit short on power and probably be a little "soft" compared to the 845. Yah, I know, many feel the 300B has a more interesting sound.

Decisions, decisions.
Phil, Thanks again for your excellent input. Many of the points you make, I've either heard or read before so I was already thinking along the same lines. All things being fairly equal, the extra power of an 845 seems preferable to the alternatives and certainly provides more flexibility.

Chayro, thanks too for your comments. I'll make sure to wear a protection suit when I'm listening!
Joe, correct, the 845's will only power my sats, running full range. It's amazing how much cleaner and extended bass is since Joel and I switched to the ScanSpeak's. Bass duties still relegated to powered subs(blended in around 50Hz).

I picked up a couple pairs of the rediculously priced Dueland Cast caps not long ago and am anxious to hear their effects. With only one cap and two inductors in the x-over, everything matters.
Joe, I forgot to mention, "Charlesdad" brought over his 8 wpc 300B Coincident Frankenstein's a while back. He wanted to hear them in my system with my MP-1 and I was glad to oblige.

Running only my sats(they're not really Fried's anymore so Joel and I refer to them as FrankenFried's), in my 28'x 22' great room with 11' ceiling, 8 watts was more than enough to fill the room at SPL's that were more than adequate and then some. Really nice amps!

Personally though, I'd still prefer a bit more power and control, thus my interest in the 845.
Joe, what you say about varying ZETA is certainly true; Joel's been saying the same thing for a long time. That said, there's no substitute for good amplification, especially with speakers as revealing as the C's.

In my mind, 1st order series is THE way to go. Very few parts in the signal path and no big surprise, when we eliminated the resistor on the tweeter, dynamics and clarity improved tremendously.

Charles, yes, your Franks sounded wonderful and as mentioned previously, mated beautifully with my speakers. Big, open, spacious, organic and just plain easy on the ears. Your Franks are the reason I was considering the 300B in the first place but in the end, I'd still prefer a few more watts; call it extra headroom for those musical peaks.

Both of you, I wouldn't say I've been "lusting" after the deHavilland's but yes, I have been thinking about them for a long time. Problem is, I'm "married with children" and don't want to part with my Atma-Sphere MA-1's; or anything else for that matter.

Finally Charles, it would be fun doing a "friendly" comparison between the Franks and the deHavillands. My guess, they'd both win!