How often should you replace tubes?

[Ankkor]

I just replaced Gold Lions in my preamp and they had been in there 5 years+. The system is on an average of 5 hours a day.
The new tubes have tightened up the sound and expanded the soundstage.

[Cohibaman]

Here’s a pretty good read on the topic from our dear friend Dan...


https://www.audioaficionado.org/show...4&postcount=10

[PHC1]

Well I certainly can’t keep an accurate enough captain’s logbook to track 7000 hrs....

[George Prentice]

I think it varies by tube and component. For my AR preamp the large 6H30P is 2,000 hours the rest of the 5 smaller tubes it is 3,000 hours according to Audio Research. But after about 2,000 hours one channel developed an intermittent whistle. So I changed all the small tubes and it went away. There recommendation may be based on optimal performance, not how long they will work. I have “heard” there is a performance drop off, but I cannot confirm from experience.

[2fastdriving]

Originally Posted by George Prentice

I think it varies by tube and component. For my AR preamp the large 6H30P is 2,000 hours the rest of the 5 smaller tubes it is 3,000 hours according to Audio Research. But after about 2,000 hours one channel developed an intermittent whistle. So I changed all the small tubes and it went away. There recommendation may be based on optimal performance, not how long they will work. I have “heard” there is a performance drop off, but I cannot confirm from experience.

George, small correction: the larger tube is a 6550. The smaller tubes are the 6h30.

[Puma Cat]

Originally Posted by 2fastdriving

George, small correction: the larger tube is a 6550. The smaller tubes are the 6h30.

The 6H30 (aka known as 6N30, as the actual Cyrillic letter resembles both an "N" and an "H") are a Soviet military avionics tube and are extremely durable. They should be good for at least 10,000 hours or so.

[2fastdriving]

Originally Posted by Puma Cat

The 6H30 (aka known as 6N30, as the actual Cyrillic letter resembles both an "N" and an "H") are a Soviet military avionics tube and are extremely durable. They should be good for at least 10,000 hours or so.

Another fun fact about the 6h30 is that if you want to do "tube rolling", then avoid a preamp that uses this tube. There are only 2 tubes you can get for this, and my understanding is that they are essentially the same. There's the sovtek version and the electroharmonix. The EH version is the same as the sovtek, except it has gold pins.

Same with the bigger 6550 tube. However there are NOS versions of this tube that are in high demand.

This is why you don't hear many people talking about tube rolling with Audio Research. There's not much you can do.

[PHC1]

It was Victor Khomenko of Balanced Audio Technology who first introduced the 6H30 to the audiophile world being that he is from the mother land of the tube and knew it well.

Yes, that tube was designed for maximum longevity and reliability for space and military applications.

In terms of sonics of that tube? It does its job, the BAT gear with that tube sounded richly textured in harmonics with a slight tilt to the darker side of neutral which bodes well with many speakers, rooms and music genres.

It just works, no need to look for all the "cliché" replacements.

[Puma Cat]

Originally Posted by 2fastdriving

Another fun fact about the 6h30 is that if you want to do "tube rolling", then avoid a preamp that uses this tube. There are only 2 tubes you can get for this, and my understanding is that they are essentially the same. There's the sovtek version and the electroharmonix. The EH version is the same as the sovtek, except it has gold pins.

That's correct, Marc. I used Sovtek 6N30P-DRs in my CJ CT-5, which I just sold, BTW. I would classify them as a very neutral tube. but they are not Amperex Bugle Boy 6922s, either.

Originally Posted by 2fastdriving

Same with the bigger 6550 tube. However there are NOS versions of this tube that are in high demand.

This is why you don't hear many people talking about tube rolling with Audio Research. There's not much you can do.

With respect to the 6550s, I would agree. It's not...um, my favorite power tube. Luckily, with C-J's blessing, I was able to substitute the specified 6550's in my LP-70S with Tung-Sol KT120s, which are not only a much better-sounding tube, but more durable as well.

[Formerly YB-2]

Originally Posted by Puma Cat

The 6H30 (aka known as 6N30, as the actual Cyrillic letter resembles both an "N" and an "H") are a Soviet military avionics tube and are extremely durable. They should be good for at least 10,000 hours or so.

This is generally true for most all small signal tubes (12AX7, 6SN7, etc.).
The 'rule of thumb' for power tubes (EL34, 6550, KT88, etc.) is 2000hr.
Power tube life varies depending on the amp, as some are harder on the power tubes than others, being run at higher plate voltage, etc. I owned a pair of Cary monoblock SET amps that used a Russian military tube that would literally break (either the internals or the glass envelope would crack) after ~1000hr. At $150/per, they were expensive to keep running.
And, we all hear what we hear. For me, in McIntosh MC275 & MC75s the 'Winged C' 6550 was a terrific sounding tube. Sad they shut down the plant that made all 'Winged C' tubes.