Rabbit
Administrator
Posts: 7,087
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Post by Rabbit on May 6, 2015 10:03:34 GMT
Amazing how they go slowly and you just don't realise.
Using the Ember this morning, I felt that the sound was a bit 'off' so I took a look and noticed that as soon as I touched the casing, I was hearing noises through the headphone. The tube seemed to be very microphonic. Tapping the caps sent it bonkers.....
So off to the garage to pick out a 6n23eb. Excellent sounding tube.
Into the Ember. No microphonics whatsoever, but the sound .......
Black silence and more of an edge at the top. Cleaner sounding and more spacious.
Just goes to show, these things go slowly and we aren't always aware because of that. So .... Check yer tubes!!!
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Post by jhelms on Aug 10, 2015 17:15:54 GMT
Agreed on that! As tubes get old - towards the end of their life, lots of things happen to the sound that is measurable. Normally, more happens on the bottom end. Bass response starts to get rather lumpy but in the mids and higher... things are just not right either.
I normally do not trash a tube if it is microphonic as they can still sound excellent in a headphone amp. But when they get to the point that you bump the amp, or move the cable and you hear them ring... off to a jar of duds they go. Now for home audio, use with monitors and such... microphonic tubes can be obnoxious! Every bass note causes them to ring.
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Deleted
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Post by Deleted on Aug 11, 2015 13:20:34 GMT
It's funny you should say this. Just last night I was beginning to think I was going a bit deaf in one ear. The central image with my favourite valve isn't so central any more. Switching back to the stock valve & it seems better. Could be placebo though because the difference isn't massive. Is it possible for one side to fail quicker than the other?
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Post by jhelms on Aug 11, 2015 14:22:55 GMT
Hey Gordon, Very common for one side to go before another. Know anyone with a good tube tester? Will give a general idea if things are going south with one side. Or if you have a test setup, it is easy to loop things back through a sound card, use free RMAA and check the balance of the tube between left and right.
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oldson
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Post by oldson on Aug 11, 2015 17:13:38 GMT
how long would you guys expect a tube to last?
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Post by jhelms on Aug 11, 2015 17:35:33 GMT
Generally - they should last a LONG time. I have tubes that I use often which I have used for 5 years or more and they are still excellent. It just depends on how much use the tube had prior to purchase / its overall condition, how often you use it or if you leave the amplifier on and sitting for periods of time.. Also, the type of tube has a lot to do with it.
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Deleted
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Post by Deleted on Aug 11, 2015 18:10:21 GMT
Thanks Frans & Jeremy. Like I said, it might be placebo as I know I'm prone to that. It's certainly subtle anyway. I'll try tonight with a mono test tone and see how that works out.
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Deleted
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Post by Deleted on Aug 11, 2015 21:36:03 GMT
OK, I've been testing all evening using every valve I have & the experience is consistent throughout. This happened to me once before many years ago & I went to the Doctor & got my ears syringed. Hey presto! Balance was restored. I guess I need to make an appointment ASAP.
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