A safe power supply for valves. This power-supply design ensures extended tube life and user safety.
AUDIOXPRESS Apr 2002 (v.33#4) pg. 26
Direct heaters. A guide to help decide which scheme to use in applying power to vacuum-tube heaters.
AUDIOXPRESS Jan 2003 (v.34#1) pg. 28
Added Info AUDIOXPRESS Aug 2003 (v.34#8) pg. 67
How to salvage the DC to DC inverter circuit found in disposable flash cameras and use it in the power supply for tube amplifier projects.
AUDIOXPRESS May 2003 (v.34#5) pg. 46
Free filament and bias voltage. Circuit which uses the filaments of the preamp tubes in place of a high-wattage cathode resistor to feed the output tubes.
AUDIOXPRESS Oct 2003 (v.34#10) pg. 68
Long life for your amplifier tubes. Simple circuits used to control vacuum tube voltage levels will help prolong their life.
CQ. THE RADIO AMATEUR'S JOURNAL Jan 1991 (v.47#1) pg. 68
Screen overcurrent protection. Considerations in designing a power amplifier (which uses tetrodes or pentodes) to prevent damage to expensive vacuum tubes.
DX MAGAZINE Jan 1992 (v.4#1) pg. 12
Extending tube life. Hints look at filament voltage, filaments in series-parallel, application of B+ voltage, and power tube heaters.
GLASS AUDIO 2/1989 (v.1#2) pg. 16
Added Info GLASS AUDIO 1/1990 (v.2#1) pg. 33, 35
Simple circuit uses an LM317 voltage regulator to "soft start" the filament supply on a vacuum tube.
GLASS AUDIO 2/1990 (v.2#2) pg. 40
Build a novel vacuum-tube AC heater continuity monitor circuit which has three useful applicatons. (1) It controls the B+ voltage, (2) signals an open heater or faulty tube, and (3) disconnects equipment if line voltage fails.
GLASS AUDIO 2/1991 (v.3#2) pg. 32
Filament/heater supply and regulator circuit that eliminates the noise and hum directly introduced from other heater supplies.
GLASS AUDIO 1/1992 (v.4#1) pg. 38
Correction GLASS AUDIO 2/1992 (v.4#2) pg. 54
A low-dropout voltage regulator circuit for vacuum tube circuits delivers a 6.3V DC output from a 6.3V AC winding.
GLASS AUDIO 4/1992 (v.4#4) pg. 14
Added Info GLASS AUDIO 2/1994 (v.6#2) pg. 48
Added Info GLASS AUDIO 4/1994 (v.6#4) pg. 28
Circuit for lighting vacuum tube filaments is especially useful for the 45 and 2A3 tubes.
GLASS AUDIO 1/1997 (v.9#1) pg. 64
Added Info GLASS AUDIO 4/1997 (v.9#4) pg. 57
Advice on lengthening the life of 7591 vacuum tubes in older audio equipment by (1) decreasing the negative grid bias, (2) lowering plate voltage, and/or (3) improved cooling.
GLASS AUDIO 5/1997 (v.9#5) pg. 52
Foolproof circuit for turning on the filaments prior to applying plate voltage.
GLASS AUDIO 2/1998 (v.10#2) pg. 58
Heater care and feedings. An analysis of issues surrounding heater circuits and regulation. Techniques for getting the "hum" out of vacuum tube audio circuits.
GLASS AUDIO 6/1998 (v.10#6) pg. 52
Correct way to wire the vacuum tubes in amplifiers to guarantee that all tubes will receive the same heater supply voltage.
GLASS AUDIO 1/1999 (v.11#1) pg. 67
Filter enhanced regulated heater supply. Modification for a typical voltage-regulator circuit results in a super-stable, ultra-pure, regulated DC voltage to power a vacuum tube heater without ripple, hum or noise.
GLASS AUDIO 2/2000 (v.12#2) pg. 68
Added Info GLASS AUDIO 6/2000 (v.12#6) pg. 62
Simple "crowbar" protection circuit for vacuum tube supply voltage.
POPULAR ELECTRONICS [2] Jul 1993 (v.10#7) pg. 71
Correction POPULAR ELECTRONICS [2] Nov 1993 (v.10#11) pg. 3
Voltage requirements for early vacuum tubes of both the filament and heater style are explained. Part 1.
POPULAR ELECTRONICS [2] May 1998 (v.15#5) pg. 62
Voltage requirements for early vacuum tubes of both the filament and heater style are explained. Part 2.
POPULAR ELECTRONICS [2] Jun 1998 (v.15#6) pg. 50