Q: Should I leave my amplifier powered on all time?
A: It is not recommended to leave a vacuum tube amplifier powered on all day. If you do not need to hear music program for an hour, it is recommended to turn off the power. This will prolong the life of the vacuum tubes and save electricity.
 
Q: Should I use a power line conditioner with my amplifier?
A: You may try a power line conditioner for line amplifier to see if it benefits improving the sound quality. If the sound is what you like, you may leave it with the line amplifier. However, it is generally not necessary for use with power amplifier. If you must want to try, make sure the power rating of the power line conditioner is higher than the power amplifier’s power consumption. This also applies to line conditioner for line amplifier. For example, if a 100W power amplifier has a power consumption of 200W at rated output, you should use a power line conditioner with no less than 200W.

Q: Why are filaments of some tubes visible after power on and some are not?
A: Not all filaments are visible even for the same type of tubes produced by different manufacturers. It depends upon the construction methods used. Because of the physical size, filaments of power tubes are easily visible after power on. However, the filament of the small signal tubes 12AX7 used in this amplifier is not easily visible after power on.

Q: Why do different brands of tubes of the same type sound different?
A: There are no standard industrial materials for constructing a tube. Each manufacturer uses slightly different materials in construction and thus this may lead to the difference in sound between brands. But all brands guarantee the same type of tubes meeting same electrical characteristics as specified in data sheet so that they can be substituted.

Q: Why is one of the tubes in my amplifier turned white?
A: The tube is damaged and should be replaced. There are many possible causes of damage to a tube. A common cause is leaking. Tube is vacuumed and filled with an inert gas to enhance the life span. When the inert gas leaks, the tube internal materials get oxidized and the tube should be replaced immediately.

Q: Should I clean the tube pins and tube sockets?
A: Before you clean a tube, you should power off the amplifier and disconnected the AC line for at least 30 minutes so that the internal voltages have been fully discharged and the temperature of tubes reduced to near room temperature. The pins of the vacuum tubes can be cleaned by removing and replacing a tube from the socket once or twice. If the tubes are replaced every two to three years, this should be sufficiently cleaned the tube sockets.

Q: How can I replace a tube?
A: Before you replace a tube, you should turn off the power of the amplifier and disconnected the AC line for at least 30 minutes so that the internal voltages have been fully discharged and the temperature of tubes reduced to near room temperature. Only replace tube with the same type. For power tubes such as KT88, there is a guiding post in the base that allows the tube to be inserted into the tube socket in only one correct position. For small signal tubes, there is an uneven gap between pins so that the tube can only be inserted into the tube socket in one correct position.

Q: How long will I need to replace the tubes?
A: This depends the type of tubes (i.e., power tube or small signal tubes) and the number of hours of use. On average, it takes about 1,500 hours for power tubes before the degradation of performance becomes noticeable. This is about two to three years if the amplifier is turned off when not in use. Normally tubes will continue to function for a long while after this, but the sound quality will be reduced and noise level will increase. Small signal tubes will have 2,000 to 3,000 hours of operation before degradation of performance becomes noticeable. This is about three to four years.

Q: Can I purchase tubes from JE AUDIO?
A: JE AUDIO stocks all tubes using in our products. All tubes sold by JE AUDIO have gone through at least 50 hours of burn-in before they are tested for several critical electrical characteristics. For any tubes that do not meet our requirements, they will be destroyed. This ensures our tubes will perform optimally for use in any vacuum tube amplifiers.