Valve lifespan.

[Mikeandvan]

My Audio Innovation S500 started playing up a few days back, so I changed the KT77s for some spare EL34s I have and that sorted it. So ordered a single new KT77 from Rox - Golden lion same as the others, and narrowed it down to one bad/spent valve. With new valve in it sounds a bit odd, is this normal, as Rox supply them 'burned in'. I got the Golden lions from someone on here about a year ago, and I use the amp alot and sometimes even forget to turn it off when I go out! Should I just replace all the KT77s? Is a years heavy use considered getting one's money's worth? Is there a way of testing valves independent of one's hearing ? Actually another one of Golden Lions went about 6 months ago, so now only 2 are from that batch.
Ta.

[Barry]

There is no clear-cut answer. It all depends on the quality of the valve: how much cost saving (time) has been applied to the pumping out, the sealing, as well as depending upon the design of the valve and materials used, and to the final quality control.

It also depends on the operating conditions, that is the circuit design in which the valve operates.

Having said that, small signal valves can last as long as 100,000 hours, whereas power (output) valves can last up to 5,000 hours.

[Macca]

I would not leave a valve amplifier powered on while you are out of the house. That's asking for trouble as well as costing you money in leccy and replacement valves.

[Mikeandvan]

Is there some independent way of testing them?

[Macca]

Yes but you need a valve testing machine. Or access to one.

[Mikeandvan]

Yes but you need a valve testing machine. Or access to one.

Cheers, they seem expensive though.

[Lawrence001]

Some places offer a service but it's not cost effective unless they're expensive.

[Lawrence001]

Valves that is, not the service!

[Bourney]

Hows the old valve/ ANs journey going Mike?

[Mikeandvan]

Hows the old valve/ ANs journey going Mike?

Pretty much the same, I still find it strident with a large part of my listening - 60s rock. But I'm thinking here I could do with finessing the front end, whether cd or vinyl. But it continues to be a revelation with better produced rock music like Bowie, and of course Jazz, soul, etc. It's the most hifi system I've had, hands down. I see you've sold yours yet again!

[Bourney]

Ks are still here ��

[Firebottle]

Pretty much the same, I still find it strident with a large part of my listening - 60s rock.

I rather think it is the recordings and the equalisation/sound that was prevalent at the time.
I find 60's recording rather over bright compared to more recent, so I don't think it is your system.

[mik_rik]

It may be possible to "tailor" the sound by the choice of small signal valves,sometimes more so than the o/p valves.Usually cheaper too.

[Mikeandvan]

It may be possible to "tailor" the sound by the choice of small signal valves,sometimes more so than the o/p valves.Usually cheaper too.

Well, I'm pretty new to valves, but I can tell a difference going from standard EL34 to Golden Lion KT77s, a nicer sound, easier on the ear, and just more harmonious, currently using Genelex on the smaller valves too, I think.

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https://live.staticflickr.com/65535/51677388819_a5f72ebf71.jpg (https://www.flickr.com/photos/145505522@N02/)20211113_170023 (https://flic.kr/p/2mJy8hp) by [url=https://www.flickr.com/photos/145505522@N02/

[Barry]

KT77s and EL34s have a different design, so will sound different.