Tips on tubes – Getting the best performance from tube amplifiers

guru Technical Information

Vacuum Tube Life Expectancy:Vintage tube amplifier restorations. Specializing in Fisher, Scott and Sherwood tube amplifiers
Tubes do wear out, and eventually need replacement. However, new tubes should last between 6 and 10 thousand hours. That’s 3 to 6 years at 4 or 5 hours playing time every day!

If you only average 2 or 3 hours a day, they should last up to 10 years.  This goes for all types of tubes, even power output tubes— as long as they are in well-designed amps and properly biased.

Placement of Vacuum Tube Amplifiers:
Tube amplifiers need space to breathe. They can’t be ‘tucked-away’ inside fully enclosed audio furniture without some type of forced air ventilation. But because they look nice, most people leave them on a shelf or counter top. Many people display tube amps with the cover off so everyone can enjoy those beautiful glowing bulbs.  Just be a bit careful though… the output tubes do get hot and can burn unsuspecting fingers.

What Speakers are Best for Tube Amplifiers:
Tube amps don’t sound their best with just any random loudspeaker solution. Careful matching and pairing is required for best sound quality.

Most (but not all) tube amps exhibit low damping factors that affect low bass reproduction when mated with the wrong speaker system. They also generally have lower output power than typical solid state amps, making more efficient speaker types the best choice.

In our experience, speakers utilizing horn drivers are often a great match.  The vintage or heritage line of Klipsch speakers seem the easiest to match with high quality tube amps. Infact, between our three listening rooms, we have nearly every model of the early Klipsch line .  From Heresy II’s to Forte, Chorus, Cornwall and La Scala’s — we often use them for critical listening evaluations. We also have and recommend Altec’s line of horn speakers. The ones that we often use are the Model 19 and Model 15. All highly recommended…

See our post “The Killer Klipsch Lineup”  for more details about which to choose and why.