Tube warm up complicating my listening

I buy power tubes every year or eighteen months, rectifier tubes every three or four, input tubes about the same.

 

Then I'm doing something wrong. I guess if I ever learned how to bias the tubes that would help. I've got a meter, just can't figure out how to use it.

 

All my tube equipment is self-biasing. . . I won't say I'd be good at biasing things myself.

 

Well, I cook in my house, so

Right. After you have food to cook in the house and people are home, turn on the amp, listen to the classical station on terrestrial, Get prep done. Then after a whle spin records and cook. Repeat.

 

Not at all difficult, but it can be a little dangerous and inconvenient if you have an amp that must be opened up for the procedure.

 

No, I don't have to open the Bob Latino 120.

 

Easier for beginners if using a digital meter. If you know the ideal operating range of your power tubes, it's a matter of setting the meter to either mV (DC) or mA and putting the probes to the test points. Then you adjust the tube's potentiometer screw or knob until the meter reads the desired figure. Make sure the amp is connected to speakers and the volume is at its lowest setting. Also allow the amp to warm up for at least 30 min before checking.

 

Thanks! But my meter doesn’t have mv or ma as a setting.

 

I've found it helps a bit to have it on (I'll play shuffle on iTunes) before a listen... but it still "comes alive" after I've listened at listening volume for a period of time.
Hearing myself say this, I'm more convinced that it's me who warms up.

 

Average life for power tubes is 1500 to 2000 hours.

Signal tubes, current production, around 4000 to 5000 hour. It depends on how hard the designer of the audio equipment pushes the tube.
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Totally agree. Most tube gear sounds good after just 30 minutes, and perhaps 5% better than that following a full hour warmup. But some sand amps, sound like crap until they have had the better part of a day to warm-up. And the funny thing is that the higher the quality of the SS amp, the longer that the warmup period typically is.

 

If I'm planning on listening, I just turn the gear on and walk away. I usually have something I'm doing anyway. I've always followed Peter Q and my owner's manual recommendations. 30-40 minutes --No big deal.

Speaking of which. Time to fire it up ...

 

My tube amp has no warm up period. It sounds great at start up and does not change. Perhaps my older ears are missing something.

 

The longer I wait for my SS gear to warm up the more beer I drink and the better my system sounds. Science!

 

If you are lucky enough to live in a city with Classical radio, it's great to have a tuner. That's my default source, and how I warm 'em up every day.

 

I don't think thats true with every SS amp/pre amp. Most i've owned ( more than I can count ) only seemed to improve slightly with warm-up. Some tube amps i've owned on the over hand could sound horrible for the first hour or two.

 

Also depends on power tubes, methinks. With stock EL34s my PrimaLuna would be up to snuff in 10-15 min. After I rolled in NOS RFTs, it does take about 45 min to start sounding good, and close to two hours to sound as good as to remind my why I bother with a tube amp to begin with.

I would not say the amp sounds raspy at srartup. To me it sounds rather anemic - no dynamics. So, for the first 45 min I will also either play the Jazz FM station, or play some music where dynamics are not as important as detail - solo piano for example.

As a matter of fact, Im exactly in that situation right now - just turned on the amp about 25 min ago, spinning Horowitz Plays Chopin.

 

Sometimes I don't turn my pre-amp off for days on end. I do turn the power amp off. Both components are tube driven. If tubes are anything like lightbulbs, it's the turning on and off that wears them out. The system sounds way better with the pre-amp being left on though.

 

Interesting comments about solid state and warm-up.

Now, I realize that I am at the entry level of anything close to a high-end system, but it has been my observation that leaving my Rega Brio-R (which is inherently a warm-sounding amp) powered on full-time makes it sound too thick and congested after a couple of days.

 

Since I have (well, had - job hunting now) the pleasure of working from home, my daily routine was to get up at 6AM, feed the dogs, come into my home office/music room and flip my gear on and then go about the morning breakfast/showering/kids to school, etc. By 8AM everything was good and my system on until the evening. Some days I'd listen for hours, other days, when lots of conference calls, less. But they were always on, except on the rare day when the work schedule was just too booked with zoom and I wouldn't bother at all.

The big downside for me (and I'm experiencing it now) is when the KT88 power tubes start to go bad. My right mono amp started blowing fuses. There are 6 KT88's on each side, so not cheap to do a wholesale replacement. And I don't have a tube tester, so isolating the culprit(s) isn't easy. Carver has a way to test each tube individually in the amp, but waiting for a new package of fuses to start the process.

 

Once those cathodes start emitting electrons I'm good to go. Takes about 2 minutes for all 4 bias lights to extinguish and they don't come back on for the duration of the listening session so I know it's stabilized. Nobis Cantabile. Fet front end, tube outputs.
Most SS service manuals say to allow 20 to 30 minutes for the amp to stabilize before any adjustments or alignments are performed.
So what has changed after 2 hours that would improve the sound ?

A tube tester would most likely be cheaper than 12 new KT88's. I bought my B&K 606 used for $40.

 

I've switched from seperates to higher end integrated amps and leave them on 24/7.

 

I did exactly this nearly continuously for over 15 years with one of my preamps. But I discovered that doing this was wearing-out some of my expensive NOS tubes quite quickly. Also, this the continuous heat from the tubes and regulators was scorching my circuit boards, and this was concerning to me.

So now I just turn it on as my first act every day when I return from the office, and wait between 30 to 60 minutes before listening. This has greatly extended the lives of the tubes inside of my preamp. Tube's emissions suffer from being on all the time, and so this really takes a tole on a tube's lifespan. The thermal cycles of daily on/offs is actually less destructive over the long term.