How do you burn in new tubes

[Strabo]

I recently picked up a used amp that needed some tubes which I replaced right away. I only get an hour or so per day to listen and I'm not real big on leaving it running all the time, so I thought I'd start an informal poll on how people are able to get it done.

My amp is almost to 60 hours on the new tubes. That equates to listening to about 80 albums. I've found myself digging deeper into my music library than usual in order to accomplish this. Even running the amp to watch TV.

This has also got me wondering about tube rolling. At this point I don't want to try something different if it means starting all over again. So NIB is not high on my priorities at this point.

How do you do it?

[edwinr]

I've run tubed amps for over 10 years sourced from Anthem, Copland and currently Jolida. Usually I burn my tubes in for 80 to 100 hours continuously playing low level music - radio etc with some serious listening during this time to see how they're going. Depending on the amplifier I check bias at the end of the burn in and then every 500 hours after that. I don't think your method of burning in is any better or worse than mine - just that I reach optimum tube performance sooner. I run matched pairs of Sovtek EL34's - a minor upgrade from the standard Jolida tubes (I think) and I anticipate about 3000 hours from them. So 100 hours burn in doesn't significantly effect the lifespan. Tube rolling (swapping stock tubes for different or better tubes) sounds like fun. If the new tubes sound better to you then they are the ones to go for. But to be frank I haven't really got into it.

[Audible Nectar]

As a "tube newb", I will approach it the same way I always approach system changes - slow and deliberate, and with an intended purpose. Before making a change, I do my "homework" on that change if at all possible, to see if that change aligns with my intended purpose.

When one makes a system change, it takes some time to fully understand the ramifications of any change to the setup. A prime example was a forced change in 6U8's (MX-110 linestage) due to a faulty tube. I installed the Telefunken 6U8's in the unit, and initially did not like them. As I began to play more material through them (as I had no choice if I wanted to hear tube tunes), I began to appreciate the Teles more....at least to the extent that I understand better what is good about the Teles.

Also, if one purchases good used tubes for trials (instead of brand new), I would assume this addresses any "break in" issues associated with such tubes, and saves cash in the process when trying out tubes. From my admittedly limited experience in tube gear, I usually find that warming up the system (running for 1 hour before serious listening) gives me enough "information" (by allowing the system to "open up") to tell me audibly if I am on the right track.

[edwinr]

...and I agree about warmimg up the tubes for an hour before serious listening. The difference between switch on and an hour is like chalk and cheese sonically.

[NOSValves]

I would say "don't worry be happy" I would use the amp like you normally do and forget it. Its not like all the sudden a light switch will be turned on and the tubes will open up and say "I'm Broke in"

Craig

[Deang]

"...and I agree about warming up the tubes for an hour before serious listening. The difference between switch on and an hour is like chalk and cheese sonically."

I don't agree at all. Every tube amp I've ever owned sounds the same after an hour as it did when I first turned it on. So, what electrical parameters are shifting that would cause chalk to change into cheese?

[Parrot]

An hour? That's nothing. Try never turning your tube amps off at all! 24 hours, 7 days a week, never mind the extra pollutants being tossed into the atmosphere hourly. Anything to feed the romantic delusion that the chalk has not only turned into cheese, but into brie.

[Deang]

Oh yeah, Parrot the environmentalist. You toss more trash into the air (sonically and environmentally) after 15 minutes with your push-pull amps than what most SET users do in a year!!

I am confused though -- I thought we were supposed to freeze our tubes first.

[jt1stcav]

...So I need to freeze my tubes first, then plug 'em in and burn them? Won't that break 'em into a bajillion pieces?

Now I'm confused...(nuthin' new there)!

[Deang]

I was kidding, please don't do that to your tubes.

[edwinr]

Okay, you guy's have convinced me, I'm going solid state.

[Deang]

It's worse for solid state -- you have to bake them in the oven for almost a week just to warm up the sound.

[Colin]

I used to notice a warm-up of both solid-state and tube amplifiers after about ½ hour before, in my town house with my walnut-oiled Cornwall 1s, with their B2 crossovers. In this house, the power sags were enough for me to invest in three APC UPS for reef tank, home movie and music reproduction system and PC. Result? No more power fluctuations and no audibly discernable difference in amplifiers after warm-up.

[Deang]

Mark,

Al K. has a very technical way of describing the phenomena as it relates to audio:

"There's no such thing as break-in, it's just your ears getting used to the new sound."

[Strabo]

I was hoping that this would stay as more of a poll than a debate of whether break in occurs.

Since we are there:

I observed over time that this amp has gotten brighter. It started out very dull. So dull that I even e-mail my concerns to someone where I stated that the amp was so slow that it was rolling over fine the details that I used to hear. After about 50 hours things improved somewhat. The detail is back but so is some brightness.

Almost 70 hours now and the detail is good, but the amp seems brighter than I wanted.

Maybe 30 more hours will fix it.

(Experiment)

A=previous amp

B=Current amp

If upon first listening A seems brighter than B. Over time the tonality of B seems to have become closer to A. Assuming this is all psycho-acoustics and the only thing that really changed was my hearing then if I substitue A back in it should "sound" bright enough to drive the bats out of my belfry. If not, then the change happened in the amp.

No?

[dodger]

Hello:

A simple summary: you have glass, wire and current supplied to the aforementioned.

Unless you have impurities, there should be no "burn in" period.

A simple test: take two (2) amplifiers, same brand, same model. Have someone blindfold you and then have them play the same tracks at the same volume. See if you hear any difference.

Now changing brands of tubes may exhibit a different "sound," as quality is better, tolerances are lower.

But glass is glass in most cases, wire is wire. Try the blindfold test and see if there is any audible difference using the same amplifier and the same brand of tube, also have the person experimenting with you leave the same tubes in but state that they have changed tubes.

See what your mind tells your ears.

dodger

[edwinr]

Yes this has turned into a debate, albeit an interesting one.

...and I am reminded of the time I worked for a radio station in New Zealand back in the late 1970's. I was told that most of our studio and transmitter amplifiers were tube based. On a number of occasions we had power failures for various reasons and being a 'Radio Cadet' I assisted the technician in replacing various tubes that had failed. I was told me that the tubes had a lifespan of several years and they were left on all the time. It was only when these devices were switched on and off frequently or were subject to power anomalies, did they fail. I wonder if we kept our amplifiers on all the time would it significantly increase the suggested 2-3000 hours of quality sound manufacturers usually suggest as the maximum lifespan?

I can see some merit to the argument that our ears are just getting used to a sound that we hear - it becomes familiar therefore it becomes correct. It's like when I sing in the shower. My ears have adjusted to the sound and I think it's good - when I hear someone else sing I think they can't hold a note as good as me. Perhaps that hour warmup I regularly use is merely my ears adjusting to the sound. I'd like to think not.

[edwinr]

Yes it makes more sense to switch on and off as you please, as I have always done. I have friends who leave their gear switched on all the time (or so they tell me - although none run 300B's). I had a thought about the debate about tube rolling. I think ultimate tube sound is more influenced by transformer limitations rather than the actual choice of tube or whether PP or SET (not that I have much SET experince). If transformer design and quality is top notch only then would the selected tubes be able to show their full potential. My amplifier is definitely low to middling in quality (Jolida 202b) and any tube rolling I may do would be more for fun than a serious attempt to improve sound quality.

[D-MAN]

As long as you're having fun, then it's a good thing.

The whole music thing should be fun, shouldn't it?

We get a little too serious around here at times.

I'm not sure that there is such a thing as breaking-in period in the formal sense. But I'm also not close-minded about it, either...

Warmup times, of course.

DM

[dodger]

Hello:

As long as we're actually discussing equipment, besides my IsoBars, I had an electrician make a gang box with four (4) outlets controlled by four (4) switches.

I use the flip switches in order to turn my equipment on/off. Also seems like an additional layer of protection against surges, etc.. The IsoBars have the EML/RFI filtering.

Not a perfect thing, but it seems like it should help.

RE: Tube Burn In: years of working for bands (with hearing protection), inevitably a tube would die while the musician was playing. Shut amplifier off after seeing which was dead, grab hot tube, put in a new tube. Didn't notice any audible difference.

dodger