30Watt classA Phoenician amplifier
A Phoenician is a negative resistance load. If it is mounted in parallel with the speaker,it delivers power to the amp/speaker.By this ,it can double the power of the host amplifier.
A simplified circuit is shown in figure below. The power op amp multiplies the current of R4 by -1000 . As the voltage across R4 is that of the terminal's than the terminals behave as a resistance of -16ohms for R4 of 16kohms.The C1/R2 provides stability for inductive componant of linking wire and the opamps phase shift.With C1/R2=0 ,the circuit is known as NRC, negative resistance converter,without known application.
Example: If a Williamson type amplifier having 15watt output power with a damping factor of 30 is loaded by 8 ohms and -16ohms phoenician in parallel on 16 ohms output tap, the williamson provides 15w and the phoenician the other 15w .But the DF is reduced to 14.This means ,amplifiers having DF of over 22 are candidates to be associated with a phoenician to remain a DF of min. 10.
A miracle occurs if a Phoenician is used not to amplify but to unload the host amplifier.In this case the host amp sees the load twice higher ,to be 16 instead of 8 ohms. When the host amp shows a voltage at its output ,the phoenician already starts pouring half of the current that the speaker will be asking for .This current lead, metamorphoses the solid state sound,tearing off the angry vowels and the strangled consonants ,leaving a white celestial voice.
This example uses a pair of lm3886 running at class A . The output stage of the host amplifier is reduced to a simple darlinton follower .The Phoenician draws 1.4amps by its 1.4ma ccs ,using a pair of led light(switching) power supplies of 24 V3A each, allows the amplifer to provide 30W to 8 ohms load .Each lm3886 dissipates constant 35W , the heatsinks (see the picture) 8inches long 1½wide are tailored to function at 75°C at 30°C ambient . The case temperature Tc is cooled down to 90°C (maximum safe operating Tc is 108°C for 35W) and average junction temperature Tj is 125°C. It requires about 6 minutes after powered on, to get the sound perfected.
Notice: The Phoenician must receive its ground only from the host ,at the same point serving the output.
The switching power supplies must have (earth, N , L) of mains respected.
Mount the heatsink using termally isolated from the chassis by washers or 5mm plywood under the screws.
The vocation of the Phoenicians was to serve others.
KOKORIANTZ
A Phoenician is a negative resistance load. If it is mounted in parallel with the speaker,it delivers power to the amp/speaker.By this ,it can double the power of the host amplifier.
A simplified circuit is shown in figure below. The power op amp multiplies the current of R4 by -1000 . As the voltage across R4 is that of the terminal's than the terminals behave as a resistance of -16ohms for R4 of 16kohms.The C1/R2 provides stability for inductive componant of linking wire and the opamps phase shift.With C1/R2=0 ,the circuit is known as NRC, negative resistance converter,without known application.
Example: If a Williamson type amplifier having 15watt output power with a damping factor of 30 is loaded by 8 ohms and -16ohms phoenician in parallel on 16 ohms output tap, the williamson provides 15w and the phoenician the other 15w .But the DF is reduced to 14.This means ,amplifiers having DF of over 22 are candidates to be associated with a phoenician to remain a DF of min. 10.
A miracle occurs if a Phoenician is used not to amplify but to unload the host amplifier.In this case the host amp sees the load twice higher ,to be 16 instead of 8 ohms. When the host amp shows a voltage at its output ,the phoenician already starts pouring half of the current that the speaker will be asking for .This current lead, metamorphoses the solid state sound,tearing off the angry vowels and the strangled consonants ,leaving a white celestial voice.
This example uses a pair of lm3886 running at class A . The output stage of the host amplifier is reduced to a simple darlinton follower .The Phoenician draws 1.4amps by its 1.4ma ccs ,using a pair of led light(switching) power supplies of 24 V3A each, allows the amplifer to provide 30W to 8 ohms load .Each lm3886 dissipates constant 35W , the heatsinks (see the picture) 8inches long 1½wide are tailored to function at 75°C at 30°C ambient . The case temperature Tc is cooled down to 90°C (maximum safe operating Tc is 108°C for 35W) and average junction temperature Tj is 125°C. It requires about 6 minutes after powered on, to get the sound perfected.
Notice: The Phoenician must receive its ground only from the host ,at the same point serving the output.
The switching power supplies must have (earth, N , L) of mains respected.
Mount the heatsink using termally isolated from the chassis by washers or 5mm plywood under the screws.
The vocation of the Phoenicians was to serve others.
KOKORIANTZ
