Your ASL might have just simply blown a fuse. My BAT BK-75SE does that from time to time. Most tube amps have protective fuse inside in case the tube arcs. Check the manual to see if it has tube fuse and how to replace it.
No idea where you buy your tubes, but perhaps they prematurely began to fail causing the blown electronics. I personally buy all output tubes from Kevin @ Upscale Audio. He runs every single one for 72 hours and closely matches according to your needs. His prices aren't the best, but the product is -- I have never had a tube from him fail. I cannot say that of any other new or NOS tube source!
most tube equipment failures aren't subtle: loud noises, arcing, multiple fuses blowing, no sound at all, etc.
that may not sound reassuring, but, as you see when you look inside tube amps, there really aren't that many things (other than the tubes) to fail - caps are a common one. they're usually simple fixes. if you're going to own tube gear, it's useful to know of a local tech who knows tubes.
the bottom line here is that you passed the test: you knew something was wrong. subtlety comes in when it comes to the gradual aging of tubes; if you have a non-auto bias amp, you probably want to check the bias every 6 months or so.
Could think of it this way, in solid state gear, if a cap went it would probably have taken out the entire output stage of that channel. Sure, you would have "known", but the result would have been more costly...
you could also pick up a tube tester for your own personal needs like a Card matic... and/or another int with separation of the pre & amp to test with in order to see which area the problem is in to begin with... or separates... and it/they shouldn't be inordinately expensive... and lastly, if none of the above ideas suits you, simply have another set of tubes on hand for the pre & amp sides so if one or the other is suspected to be errant, plugging in known new - good, tubes will also narrow things down.
As to self bias or auto bias, even with the difficulty involved in the now and then biasing, I prefer the self type over the auto biasing type... having had both types. 'Course, I'm sort of anal about knowing what's going on with my stuff too. additionally, self biasing gives one some lattitude and insight as well. Only fresh tubes in an auto bias item affords any change in the hands off biasing types. Lastly, if there is indeed some minor desparity between electronic parts in the auto types, you're pretty much stuck with what's going on, or sending the unit into the maker for testing & repairs, especially if there is no gain or balance controls available.
Tubes are high maintanence. I had a hybred pre and it was beautiful sounding and broke down regularly.
It's the price you pay. And for tube fanboys, yeah, YOUR tube stuff runs for YEARS without a looky-see I KNOW that..
It's everyone ELSE's tube stuff that is a P.I.T.A.
Tubes are kinda like a high maintenance, beautiful woman. They're lush, incredibly revealing, hot, and sweet on the highs.
But, they need more work than your average, dependable solid state, who's always there for you, cooks you meals, and gets along with mom, but are one trick ponies, good bass and reliability.
Pick your poison ;)
I have been running my older model tube amps for years without any issues at all.
Especially with newer tube amps, it is wrong to suggest they are high maintenance.
Any piece of high-end equipment can have failures, tube or solid state.
I have had tube amps and tube preamp now for 5 years, i bought the pieces used on the 'Gon, i have replaced 2 sets of power tubes in the amps and one set of small signals in the pre, all in all they have been extremely low maintenance except for the occasional biasing on the amps, this coming from a guy who had only Solid State experience in the past.
Tube amps especially, and pre amps to a lesser degree, CAN be, a PITA, but need not be if you are careful in selecting them to match your personality and skills.
In amps for example you can get an idiot proof auto bias with a fuse protecting the bias curcuit if a power tube shorts out (Primaluna for example) or you can get a big powerful ARC amp which can be a nightmare to bias in the first place and when a tube shorts out it will not only take out a fuse it will take out a resistor and you will either repair it yourself if you know how or take it to the shop for repairs.
Those are the extremes - there are all kinds of permutations in between. My ideal choice would be a manual bias which could be done without going into the amp and a fuse which would protect the bias curcuit in case of a short. That way I get the best of both worlds. Lots of flexibility in tube selection and ease of adjustments when fine tuning is required as well as the ability to monitor power tube life.
Tube pre-amps are a no brainer. But you do need to check driver tubes for long term wear occasionally. Age can, and does, creep up on you. I'd keep a minimum one of set of extra tubes available for insertion from time to time to check and see if the ones in use need replacement. No big deal.
But, the upside is just great for folks who like to fiddle with their stuff and fine tone the electronics to get the sound you want. Its amazing what you can do with an open mind and some extra tubes. You'll lose all interest in buying expensive cables, etc, which many people seem to resort to as tone controls for SS stuff..........:-)
Thank you for all of your responses. Very helpful.
I have had a number of power amps, both tubed and solid-state, and like the previous poster said, any electronic piece can fail. I have had failures of both types: in SS amps it was usually voltage regulators; in tube amps it was usually output tubes. I am like you and don't really like to mess with biasing output tubes and have had tube fuses blow intermittently. Someone told me it was usually due to impurities in tubes causing arcing and an overcurrent blowing the fuses. So now I use a tube preamp and solid-state power amp, the best of both worlds. Tubes work better for voltage amplification and transistors for current amplification. In all the years I have used small-signal tubes in voltage amplification, only one has failed.
Help me out here, do solid state amps have meters to tell you when they fail? If not, how would you tell if your solid state amp is failing? Or your CD player? Or is it that solid state gear doesn't need meters, as it tends to fail catastrophically?
having read all of the responses to this question, it seems clear that while the tubes require you to pay some attention to them, it's not really too big a deal. bottom line seems to be that any high end piece of equipment, regardless of its function, can be a bit cantankerous, or high maintenance.
the pay-off seems to be the lush, full quality sound that comes with the tube gear...seems the auto bias may be all smoke and mirrors, the way to go is probably the manual-bias option? with the tubes themselves, maybe it's a good idea to buy what was originally in the piece, as recommended by the manufacturer? or at least know where your tubes are coming from/ who the supplier is?
i have had several older types of SS amps, preamps, etc. tho none were too high end... nad, luxman, sae, mcintosh MC50 monos, mcintosh MA6100- it was all just ok...i just got a pair of quicksilver M-80s that simply smoke all other amps i have had, and also got an older ps audio III phono preamp with linear control unit, which has the straight wire with gain set-up... suddenly, life is GRAND! i can't imagine that spending more money on brand new gear would have yielded better results!
in any event, good luck, don't sweat it too much, and enjoy the music...like someone said, maybe tubes are a P.I.T.A. but at least yours is an an easy fix. and you were paying attention enough to notice the problem when it did occur!
there are those among us who are so totally into it that they will fiddle and tweak and keep their stuff dialed in to the hilt. that's fine. we can learn much from their experience. but then there are those of us who, while we want the best sound we can afford, also simply want to sit back and not have to constantly do anything other than turn on and take off.
keep it as simple as you can. there's only so much that is required, and all else above that will eventually cause a headache. that's the rule i have learned to live by.
Perhaps I've something wrong with my ears or my rig... but given the above posters account of tubes possessing a "lush" sound... I'd say my own system is not lush.. In fact many Ive heard arent lush.
Maybe I'm nit picking here but unless the aim of that comment was pointed at SET amps, I'd say tubes act very similar in reproduction to SS, but with more decay and body. How much more depends on several things too, not just the fact theyre tube appliances.
Lately I'm liking big band jazz, the recent stuff, 70s & 80s to present, I can't detect any sluggishness or bloom, just very natural sound and the aforementioned qualities. ON the whole, it just seems more correct a presentation. If it is lacking anywhere, I might fault it in its attack, or leading edge, but I'm splitting hairs to do so, 'cause it ain't by much. Brick wall or Oak tree? Both hurt if ya hit em at 30 mph.
As to sound differences between tube & SS by comparison, In fact I like the sound of the BAT SS gear more so than their hollow state gear... so go figure. Current Tube tech is sure aimed at being way more like SS than not, I'd say... what with the big push on HT currently, it's encumbent on tube component makers be more SS-like now.
That's too bad. IMO.
There is surely a quality with Hollow state that is attractive to me anyways. Once you get it dialed in, and tubes do afford one greater flexibility there. It just seems righter. More trouble? Again, it depends on how esoteric you get with the tube gear
Like how many tubes it takes
Wanna use NOS tubes or current run tubes.. the topology.. bias choices... etc. A good tube vendor will ease the way a lot. How easy you are to satisfy will relate directly to the expense of it all as well.
I'm standing by "lush" dammit! Every tube amp I have had, although I have never had a set, has a "lushness". It's a known, measurable fact that tubes, no matter how well built, have higher harmonics, but different, and generally more benign at that, then the very best solidstate amps. This doesn't make them bad, it makes them different. What I am calling "lushness" I suspect are one in the same with the above poster, there is a sense of "rightness" in female vocals, that my 9011's with Tara cabling come very very close to, but don't quite hit.
Don't mean to hijack the post, Lenkevy, but I happen to like "lush". Lush is Maui, the best solid state is Laguna Beach, really bad tubes are jungle, and really bad ss is Arizona, at leat to me. Every single piece of stereo equipment I have ever owned, there has been a trade-off, and oftentimes "lush" is good.