At your own risk.
This is the Pleiades class A (electrons flowing at all time) power amplifier connected next to each full range speaker.
Possibly the simplest signal path ever. Just one transistor, one resistor, battery, from CD player to each speaker.
Careful use of li ion batteries would reduce the size.
The transistor is the AD149 Germanium which sounds very nice. Germanium transistors have a higher electron mobility. Electrons feel lighter!
2N3055 can be used too with reverse power supply polarity to the germanium transistor.
The speaker is the collector load itself.
DC passes through the speaker and it's fun. Electrons flow all the time there too so it may be called a class A speaker.
The equilibrium point of the cone changes. This is nice, the non symmetric end excursion points would give even order harmonic distortion like on triode single needed 300B power amplifiers.
On this particular example power supply is just 6 Volts.
The current through the battery or speaker is only 250mA.
The sound is loud, dynamic, smooth. Amazing treble, creamy midrange. And believe it or not the bass was deep. (For more bass, nearby speakers may be used in series parallel combination or each with its amplifier. This gives a resultant large vibrating area for each channel).
Open back speakers attenuate bass much lees at only 6dB per octave. Much like a Pleiades microphone filter.
Everything was hanged from the ceiling, including the CD player.
Setup (signal path):
Large room with Pleiades broadband absorbers - The Real Ray Conniff 3 CD collection - Portable Sony CD player headphones out - Pleiades one transistor power amplifier on each channel- RFT full range speaker for each channel
As you would expect the trumpets of the Ray Conniff orchestra sounded as if the 30th street, Columbia converted church studio, in York, was transferred to the smaller living room.
References:
The Pleiades power amplifier on euroelectron posts
Audio Amplifiers - J. R. Davies - Data Publications LTD - London - copyright 1968 - first printing 1969 - 2-Transistor miniature A.F. Amplifier - pages 41-42
This is the Pleiades class A (electrons flowing at all time) power amplifier connected next to each full range speaker.
Possibly the simplest signal path ever. Just one transistor, one resistor, battery, from CD player to each speaker.
Careful use of li ion batteries would reduce the size.
The transistor is the AD149 Germanium which sounds very nice. Germanium transistors have a higher electron mobility. Electrons feel lighter!
2N3055 can be used too with reverse power supply polarity to the germanium transistor.
The speaker is the collector load itself.
DC passes through the speaker and it's fun. Electrons flow all the time there too so it may be called a class A speaker.
The equilibrium point of the cone changes. This is nice, the non symmetric end excursion points would give even order harmonic distortion like on triode single needed 300B power amplifiers.
On this particular example power supply is just 6 Volts.
The current through the battery or speaker is only 250mA.
The sound is loud, dynamic, smooth. Amazing treble, creamy midrange. And believe it or not the bass was deep. (For more bass, nearby speakers may be used in series parallel combination or each with its amplifier. This gives a resultant large vibrating area for each channel).
Open back speakers attenuate bass much lees at only 6dB per octave. Much like a Pleiades microphone filter.
Everything was hanged from the ceiling, including the CD player.
Setup (signal path):
Large room with Pleiades broadband absorbers - The Real Ray Conniff 3 CD collection - Portable Sony CD player headphones out - Pleiades one transistor power amplifier on each channel- RFT full range speaker for each channel
As you would expect the trumpets of the Ray Conniff orchestra sounded as if the 30th street, Columbia converted church studio, in York, was transferred to the smaller living room.
References:
The Pleiades power amplifier on euroelectron posts
Audio Amplifiers - J. R. Davies - Data Publications LTD - London - copyright 1968 - first printing 1969 - 2-Transistor miniature A.F. Amplifier - pages 41-42
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