Tube reliability in amps


I am contemplating the purchase of a tube power amp. I already have an Audible Illusions pre-amp, which has given me virtually no problems tube wise. I would like to hear from a bunch of Audiogoners on how long power amp tubes last in the real world, do I have to keep matched pairs or sets around or can I just replace one? Also I have B&W matrix 804's and I have been told tube amps are not a match for them or that I need a lot of power (read expensive tube amp). Wavering between tube and SS, HELP.

PS. I listen to orchestral music and piano. Sometimes loud like about 90 db.

Thanks
drjjpdc
I have a pair of Hales Designer Reference three way sealed speakers and push them with VAC PA160 MKII Mono amps. I run them with KT88 tubes in triode settings, 75w. Plenty of sound and the riches of tube designs. I have tried SS and find that the sound stage becomes flat and somewhat boring. SS may give you the impact but the tubes will give you the color of the orchestra and or solo instrument. Call the guys at VAC they are super in their knowledge of their equipment plus their competition.

Good Luck
How long tubes last in a circuit will depend both on the maker of the tube as well as the circuit design. I've known McIntosh tube amp owners who have left their amps on for years continuously with hardly any wear on the output tubes. My ARC Classic 150's lasted me 5 years on a set of Philips 6550 tubes, where the same vintage tubes barely went for more than 15 months in my Jadis JA80s. But NOS Gold Lion KT88s in the Jadis have gone over 3-1/2 years with very little wear. So no hard and fast rules here.

Of the brands out there now of which I have knowledge, the VTL and ARC designs, as well as Macs, seem to be easy on their tubes; I'm not that familiar with how long tubes last in VAC or CJ products, I'm sure others can comment here.

As far as power goes for your 804s, the only way to really know is to try them out, but if you're not after the deepest bass (and you won't get it out of the 804s, anyway), and you don't have a large room or listen too much at 90+db levels, you'll be surprised how well tubes will drive your speakers. Some of the best sound I ever heard from a pair of Dunlavy SC-Vs came from a VAC Renaissance 30/30 (it wasn't organ music or earthshaking volume levels, admittedly, but certainly a normal listening level), and I remember years ago hearing a pair of B&W 801 Matrix speakers being driven beautifully by Kebschull 35 watt tube monoblocs. It would pay to give some of the manufacturers, like VAC as noted above, CJ or VTL a call and see what they think they have which will drive your speakers (I'm sure ARC's 100+ watt designs would work well on them, but I consider them expensive amps). Good luck--I think given your musical tastes you'd like tubed amplifiers with your speakers.
Check out the Wollcott amps. They have an auto biasing circuit and do not neet to be left on or have extensive warmup, thus a very long tube life. they also are one of the few tube amps with descent bass.
the life of a tube is like a tank of gas. there is a finite amount which is determined most greatly by how much you use it and how far the amp pushed its operating envelope in making the amp (read how much bias required - the more bias required, the shorter the life. i would expect on average that you should get at least 1500 hours on power tubes - up to about 3000 is possible. you should get at least twice as much on the driver tubes. its helpful to have an amp that lets you easily bias the tubes yourself, and if you can do this having matched pairs/quads, is not as important (look for amps with individual biasing for each tube. keeping spares around is like keeping gas in the tank - you won't have to walk.
hey newbie, instead of me calling up a whole lot of manufactuers, can you give me an idea of what is a lot or little bias on a tube, so I can hone in on the guys with longer life tube designs?
drjjpdc, you inquired about tube life - thats easy stuff. there are just too many varibles involved in answering your question re biasing of any particular tube absent a specific application and i am not a resource on the tube amp market.in my opinion you are much better served not being concerned with the life expectancy of tubes but by finding an amp which will sound good with your speakers. after going thru some arc and sonic frontiers amps i settled on a mesa baron - its a fairly powerful and neutral amp using 6L6's biased at 38ma. i have speakers by paragon which are full range and very neutral which are rated 86dba @1watt. using a power stage w/120wpc and a little neg feedback i get the kind of sound i want, however someone with speakers tilted up in the midrange, or high end, would hate it. this is not a testimonial to mesa - the point is you sould consider auditioning push/pull pentode based tube amps with your speakers to find the sould you like. once found you won't care how long the tubes last. cj, arc, vac, cary, sonic frontiers, are all good high end amps to try. if you want to start out on the cheap just to experience the tube sound there is much available and talked about in this and the audio asylum forums.
I B&W Matrix 802S3's.....they sound GREAT with my ARC VT100 MKII which you can pick up used for about $2500. Don't fall for the "you have to use SS" BS, at least not with your speakers .....& unless you find a SS amp you really like.
I have N804s and am about to go tube as well. From this and the Audio Asylum forum, I have found that at least my N804s will be alright with 100wpc tube amps for loud hard rock, and around 50wpc for jazz and vocals at good volume levels. Two reasonably priced tube amps float my boat at this time. The Cary V12 which can do 100wpc ultra linear and 50wpc triod at the flip of some switches ($4000 retail new) The other is the VAC PA 100/100 which does 100wpc. I have seen the VAC used here for $1800-2500 and the Cary used at $2500. There are other choices. My Cary SLP 2002 pre will arive this week . Present amp is a BelCanto EVo 200.2.
I am currently running the BC21/BC22 combo from Blue Circle and am very happy with it. Since I got this setup two months ago it's been turned on constantly. The sound is much better when I leave them on all the time. I really haven't worried much about tube life since only the BC21 preamp has two tubes and the BC22 amp is solid state. However, I just received an e-mail from Blue Circle warning me against this practice. Aside from the lightning strike consequences, they feel many of the citcuits will suffer for it and it robs tube life. They suggest a 15 minute warm up period before each listening session.
Hi, I agree w/the posters who mentioned ARC power amps for having long tube life. Both of my ARC amps use 6550's; ARC gives a very conservative estimate of 1500 hrs on these power tubes but I and other owners have found much longer life. My VT100 Mk 3 uses 6H30 supertubes for drivers, rather than 6922's as the older VT100's do, and the 6H30's are rated for 10,000+ hours. BAT gear also uses the new 6H30's w/this very long tube life. But again, these are driver tubes and they tend to last longer anyway. My ARC gear need matched quads of 6550's, so keep a spare single around just in case one tube goes bad and you have a good one to test with. About B&W 804's w/tubes: there is a guy selling his Matrix 804's and his Anthem tube amp on this site right now, I would email him about his experience running the 804's with tubes. I think 100 tube watts would be fine w/these speakers, but I haven't heard them for myself.
I've had very good luck with Conrad-Johson, first MV-75A1s and now Premier l2s. The output tubes are biased individually (and easily). And, IMO, the sound is outstandingly musical. have to confess, though, that the fact CJ is about l2 miles away is very comforting.
Gads, it ain't just the amp;It's the type of tubes within the amp.My CJ Preimerer 5a's have 16 el 34's.--Rewired for all triode. The Svets last much longer,but are dull, compared to nos Siemens which get eaten at an expensive rate.
Find the amp whose sound you like, then contact the manufacturer to see which brand of tubes he recommends and which setting to bias at. Different brands in different amps perform differently. Also, the guys at the tube store (.com) have a lot of experience with this subject.
to blues man and the few last posters, I am not an audio novice. It's just that I am a tube novice. I know listening is top priority. It's just that I am not a tweaker. I don't want a lot of down time due to finicky tubes, long warm-ups etc. My listening time is limited as it is. To use an analogy from the the world of cars and bikes, I never understood all the tweaking that the early Harleys or British bikes and cars required. Seemed their owners spent more time fiddling with them than actually driving them. Have the same fear with tube power amps.
I have had great success with the Music Reference RM 9 MK II
amplifier. I have had EL34's in there for years already, and I still have no problems with noise or sonics. This amp
creates a good argument for tube reliablity.
I've been very happy with CJ tube amps for reliabilty, sound, and ease of tube replacement and rebiasing. I'm running the CJ Premier 11a as it does a fine job with my Thiel CS 1.5's. I'm not familiar with your B&W's and if they are in fact "difficult to drive" then you might want more power and that usually equates to higher cost. (not talking about low power SET amps here as they do not apply in this situation).
Ive been using a pair of VTL monos that have easily adjustable bias (about 30 min 2x per year and it could be done a lot quicker but i'm kind of a-r about it). Warm-up time is usually about 30-45 minutes before they start sounding real good, they keep getting better for the next hour or so...they sound somewhat dry and one dimensional at first...kind of like solid state. I bought them 6 mo old about 2.5 yrs ago and am still on the original tubes excepting 2 a near hit lightning strike claimed. They will probably need to be changed out by summer end (getting a tad soft but still sound good). I also use tube guitar amps exclusively and they live a MUCH harder life than any audio rig...no problems there so far either. try the tubes you won't be sorry
Drjjpdc, I like Jena would recomend the Music Reference RM9 as a very user friendly, musical, and indestructible power amp. This amp can use (8) EL34's (very inexpensive) which are very musical, or 6550c's (a little more expensive not necassarily better) with a little more authority or KT88's (much more expensive than the EL34's) that some people love. It is rated at 100 watts per channel with the EL34's and probably more with either the 6550 or KT88 tubes. Is very easy on tubes, probably well over the 2000 hours that seems to be the norm. Very easy to bias (won't need any meters, uses LED's), right from the top of the amp, and is a very pretty amp INHO. Usually you can find these amps for around $1200.00, they came in two versions RM9 and RM9 MKII. I personally favored the origianal. I have owned 2 and will surly own one again. Good luck with you search.....Bob
Might add the Music Reference RM-200 to this list.Lots of bass for a tube amp and absolutly beauitiful to look at.All Music Reference products designed for long tube like.