This is the interesting article of the Son of Jen amplifier.
http://www.firstwatt.com/pdf/art_soz.pdf
Could the MOSFET used be made to a single ended Pleiades power amplifier of low power with the DC current passing through the speaker making it too metaphorically operate in class A (electrons flowing all the time)? The speaker becomes the load resistor itself. The circuit is derived by further simplifying the Jones circuit.
So far on Pleiades experiments great sound on driving a loudspeaker with just one transistor is made with the following. Using a single 2N3053 operating in class A driving a 800Ω Philips AD5046n speaker. An alternative is a 2N3050 driving an 8Ω speaker but it is less efficient due to impedance mismatching. The AD140 sounds nice too but it may be more difficult to current drive. An OC81 type transistor looks promising as it is shown to be close to 8Ω on the article by A. Kinloch. The 2N3053 being RF too just sings through all the frequency spectrum. The 2N3053 if all ear protection procedures are observed should be great for supplying studio quality hi impedance headphones (attention to levels a low supply voltage should be used, typically 1.2V?). Just a small DC (a typical value may be around 3mA) current can pass through each headphone driver, see for example the Pleiades Electra II one electron tube only per channel power amplifier driving the Sennheiser HD580.
This is another interesting article on high Z out amplifiers which refers to the First Watt Nelson Pass amplifier:
http://www.audioxpress.com/article/Current-Source-Amps-and-Sensitive-Full-Range-Drivers
Or
http://www.firstwatt.com/pdf/art_cs_amps.pdf
References:
http://euroelectron.blogspot.gr/2018/03/madonnas-voice-coming-from-point-source.html
2 Transistor Miniature A.F. Amplifier by K. Jones - page 41 - Audio Amplifiers - Edited by J. R. Davies - Data Publications Ltd - London
2 Watt 9 Volt Audio Transistor Amplifier - A. Kinloch (from the same book as reference 2)
No comments:
Post a Comment