Musicians inevitablyhave some misconceptions about tube equipment. Let's face itmost players have no need to become engineers or tube experts; they want to play. However to keep you safe, your amp working, and your tone awesome knowing a few things about tube amps is very useful. In this article I'll cover three common misconceptions about tube amps: two prong power cords, Tone control settings, and keeping tubes hot. More is to come!
Myth: there's more tone in a Two Prong Power Cord
Truth:There is no difference in tone between a safe three prong and a dangerous Two Prong
Un-grounded powers cords (two prong) in amps are simply unsafe. All a power cord does is deliver wall voltage to an amp's power transformer. There is no tone in a power cord. If someone tries to sell you an amp and promotes the two prong power cord as a tonal feature you know the amp have never been properly serviced and requires an overhaul if you buy it. NEVER operate an amp without a grounded three prong cord; no amp is worth your life.
Myth: Set all the controls half way for flat EQ
You see this all the time: demos where the person says they have set the EQ flat or all halfway up. Guitar amps do not have a flat frequency response and setting the controls half-way does not demonstrate an amp's basic sound. In fact some amps sound pretty bland set up that way. The tone controls on most amps are interactive and every amp is different in how they sound depending on where they are set. Even amps of the same model with differ slightly in how the EQ responds so matching your favorite guitarist settings is just a tonal quagmire. Trust your ears and set the EQ!!
Myth: tubes need long warm up periods and need to be very hot to sound good.
I've known many players who believe that leaving a tube amp on Standby for an hour between a set or before a set improves tone. This is not true. All you are doing are wearing the tube's filaments and building up heat that will damage caps and resistors. There is a phenomenon know as called cathode poisoning that occurs in tubes when a amp is left on standby for long periods of time. It reduces the life of the tubes. So leaving an amp on standby for long period is bad idea.
Tubes do need to be certain temperature to operate but excessive heat damages the tube which is why proper ventilation is a must and spec sheets advise engineers about the maximum allowed temperature. Past the optimum operating temperature you are actually reducing tube life.
Don't leave you amp for long periods of time when not in use.