Re: [Harp-L] amp tube life

[MARK BURNESS <markwjburness@xxxxxxxxxxxxxx>]

It's worth making a distinction between used, but properly functioning tubes and tubes that are unable to perform to spec.
 
If every tube in that bassman was changed for different tubes, some of those changes may have been unnecessary but also the operating voltages & currrents will also have changed. I have retubed many amps with "new" tubes (whether NOS or current production) and the amp always sounded better for it. It sometimes takes a couple of goes to find what sounds best, but you retube an amp primarily to make it sound better, as well as to make it reliable. Few people are happy with a poor sounding amp, even if it is unlikely to blow up in their lifetime  - it is actually easy enough to build amps whose tube life expectancy will be about the same as a human's...it's just not so easy to make music with it, or to get anyone to buy one! ;-). The bassman owner should have got his money back from the tech, rather than take away an amp that sounded worse than before.
 
Using power tubes tubes of unkown age/usage to faciltate an "aged" sound is a risky thing to do. If they can't sound clean & let the amp make it's rated power, it's because they are malfunctioning & are likely to malfunction to a greater degree with time...a "plate to heater" short is typically accompanied by flames! :-o  It's akin to retuning your harp by waiting for a reed to flatten...then hoping you get a tune out of it before it fails completely...not a good idea.
 
Preamp tubes (of the original type as fitted to the amp) draw so little current that it is unlikely to to serious damage by using old/tempered/malfunctioning tubes. I had a Reverberocket that sounded best with some of the 40 yr old preamp tubes, simply because replacement tubes (even NOS) were a different spec & killed the tone. Different tubes, even of the same brand & type, sound different.


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From: Timothy Kane <hawkeyekane@xxxxxxxxx>
To: Harp-L <harp-l@xxxxxxxxxx> 
Sent: Friday, 6 January 2012, 21:02
Subject: Re: [Harp-L] amp tube life

 
    I have a '65 Kalamazoo Model Two with it's original complement of Raytheons. Now, I haven't had the amp all that long, and I have no idea how much use it got with its previous owners. But I'd have to imagine they've gottens some wear and tear over a life of 47 years. To me though, harp sounds better with the natural distortion brought on by old tubes. I've heard a Bassman 59, before and after getting a full complement of brand new tubes, and to my ears, it sounded better with the old ones still in it. I have acquired a spare set of tubes for my K-Zoo, but I'm only gonna change them out if a tube happens to break.