Using Aging Tubes: A Dangerous Guitar Tone Tweak?

Though very, very rarely mentioned in interviews by superstar guitarists, is the use of aging tubes to create your very own unique guitar tone very dangerous to your very expensive gear?


By: Ringo Bones


I’ve probably lost count since 1997 on how many guitarists around my neck of the woods explored in finding ways to make their renditions of Veruca Salt’s Earthcrosser intro sound more “soulful”, especially by resorting to tone tweaks that could irreparably damage to their extremely expensive (3,000 US dollars MSRP) electric guitar amplifier. From connecting four 8-ohm speakers in series to a push-pull based tube electric guitar amp – which could result in a very high voltage build up of the output power tubes – to using aging tubes. Though by far, the use of aging tubes is the most common. Given that tubes are becoming very scarce compared to latest generation mobile phones – especially in the US – the “poor” unsigned amateur guitarist is more than likely be using output power tubes in his or her electric guitar amplifier that are past its prime.

I’ve read an article about the summer NAMM 1992 in Guitar Player magazine about a company introducing a digital electric guitar effects processor - with an effects setting - that emulates the sound of an aging tube, such tone never became popular. Even during the guitar-heavy musical genre of Seattle Grunge that went mainstream a few months after reading that feature.

Given that I’ve only began building and owning tube-based amplifiers in the mid 1990s, I’ve asked some veteran audiophiles on how an aging power tube sounds in a “hi-fi audio setting.” Most of them pointed out the “quirky acoustics” of the Tori Amos song China from the Little Earthquakes album as what music would sound like when played through a tube amp with output power tubes past its prime and will be arcing anytime soon.

Back in April 2009, I was asked to help an amateur unsigned guitarist who wants his performance to be video recorded for You Tube posting. He was using a family heirloom 1965 Fender Twin Reverb with aging 6L6 tubes. He did manage to conjure up a very unique tone until 30 minutes into the session when one of the 6L6 tubes started to arc and fused into its tube sockets, though it did manage to emit a very cool apocalyptic-sounding high-pitched squeal when the final chord was struck.

Given that equipment of this vintage still uses plastic / phenolic resin output power tube sockets for the 6L6 output tubes / valves instead of being upgraded to military-spec porcelain tube sockets with silver plated contacts when it became widely available during the mid-1990s. Fortunately, only the output section of his Fender Twin was damaged. But it resulted in a very expensive repair bill, especially when you live in a place where most people live on slightly less than a dollar a day.

It is still a mystery why guitar digital effects processors still don’t add an aging tube emulator proviso on its menu of effects, especially ones that do advanced 24-bit 96-kHz digital signal processing are now relatively cheap and widely available. An aging tube sound / tone obtained through digital domain physical modeling is a much safer way of doing things compared to using actual aging tubes on your very expensive tube-based electric guitar amp since complete catastrophic failure resulting from such practice is not that far from impossible. Maybe guitar effects manufacturers are ignoring this sector of the market at their own peril since the sound of an aging tube is very interesting and very soulful.