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Post by iamasound on Sept 6, 2016 7:30:11 GMT -6
I am hearing a sizzle sound when playing through my new used amp and thinking that it is that microphonic telltale sign that one or more of the tubes are entering the home stretch and need be put out to pasture. Should I just switch out all of them or is the sound that I am hearing indicative of a preamp tube fading away or perhaps a power tube begging for retirement. The last tube amp I had was a Mesa Mark IV that was good to go until I needed to sell it, so I am not well versed on the life of a tube and never had any extended conversations on the philosophy of bulbs. I beg ignorance on the subject. Thanks to those in the know.
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Post by EmRR on Sept 6, 2016 7:47:59 GMT -6
Sub one preamp tube at a time. Tubes can last forever. Or not.
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Post by iamasound on Sept 6, 2016 11:51:31 GMT -6
Thanks EmRR,that I will do. I mostly wanted to swing it by to see if the raspy ssssss that I hear only when I play something was actually symptomatic of microphonic nonsense and not something else that I actually should worry about. Cool bones. I will rest a little easier.
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Post by EmRR on Sept 6, 2016 20:24:09 GMT -6
Microphonic is also situation specific, if a tube proves microphonic in one thing it may be fine in another. Really unrelated to tube life.
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Post by iamasound on Sept 7, 2016 5:50:58 GMT -6
I guess I will buy one each of preamp and power amp and see if it rids the amp of the ssssss's. It is both channels so I am thinking it might be V1 or one of the two power stage bulbs, but really, I'm kinda talking out my butt as I am only book knowledgable and not a veteran tube guy, except for the sometime light that turns on above my head if I have a great idea about something. Thanks for the response.
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Post by EmRR on Sept 7, 2016 6:06:45 GMT -6
Power tubes must be done in pairs. You don't change one of a power set, at least not without test gear capabilities.
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Post by svart on Sept 7, 2016 7:04:36 GMT -6
Microphonic is also situation specific, if a tube proves microphonic in one thing it may be fine in another. Really unrelated to tube life. Except when a tube that was not previously microphonic, becomes microphonic. Sometimes that does indicate imminent failure. Tubes are fickle things. |
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Post by EmRR on Sept 7, 2016 7:33:38 GMT -6
Sometimes it means a new tube in an amp got its innards loosened when the amp fell out the back of the van. It may be perfectly quiet in studio equipment for 20 years but furthermore unsuitable in a combo amp. Point being no one should toss a vintage $200 Telefunken etc that's suddenly microphonic in an amp on the assumed basis it's 'worn out'. Let's not push vintage tube prices higher unnecessarily. Adding to the combo amp picture, there's no such thing as a non-microphonic EL84 combo amp. They all have singing filaments from the speaker vibration. It's not a tube type that should even be built into a combo, they should be a separate head/cab scenario. Oh yeah......we're talking about a Vox aren't we?
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Post by Ward on Sept 7, 2016 23:34:47 GMT -6
If yeti have a multimeter and some experience, check all capacitors too whilst you're at it. Or get someone to do that.
Many times bad caps are the culprit for a lot of what we blame on those little bottles.
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Post by iamasound on Sept 13, 2016 9:09:28 GMT -6
Thank you all for the good info. I guess since I have no experience in or any education in the rhealm of ampifonics that I will hand it off to some self proclaimed expert in my immediate area. I will come back to this thread when all is said and done and the amp is omce again quiet-ish and well behaved.
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Post by iamasound on Sept 13, 2016 9:09:49 GMT -6
Thank you all for the good info. I guess since I have no experience in or any education in the rhealm of ampifonics that I will hand it off to some self proclaimed expert in my immediate area. I will come back to this thread when all is said and done and the amp is omce again quiet-ish and well behaved.
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