tubehunter
27-06-2016, 08:20
Here is my take on a John Linsley Hood 1969 Class A power amplifier.
I built this to evaluate, quality parts used through out.
Runs warm @ 40c on the heat sinks but well within manufacturer's SOA specs, just needs a free standing position with good ventilation.
I've fitted a Zobel network on the speaker outputs since the pictures were taken.
Running on 28v rail, bias @ 1A with Nelson Pass inspired power supply.
Sounds very good indeed but will need speakers of >90dB sensitivity if you want party levels:)
Duncan
£85 plus postage
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/IMG_8547_zpssxvzlfaz.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/IMG_8547_zpssxvzlfaz.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/IMG_8546_zpstqjyyqjp.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/IMG_8546_zpstqjyyqjp.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/IMG_8548_zpsk87gd7q2.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/IMG_8548_zpsk87gd7q2.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/6_zpsqjvs0t4q.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/6_zpsqjvs0t4q.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/4_zpseqmfc6pb.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/4_zpseqmfc6pb.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/2_zpsg3zh1zp0.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/2_zpsg3zh1zp0.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/5_zpsrdzhwidk.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/5_zpsrdzhwidk.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/1_zpshm9rxjo1.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/1_zpshm9rxjo1.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/IMG_8550_zpscit9olds.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/IMG_8550_zpscit9olds.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/IMG_8549_zpshje8l55h.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/IMG_8549_zpshje8l55h.jpg.html)
I built this to evaluate, quality parts used through out.
Runs warm @ 40c on the heat sinks but well within manufacturer's SOA specs, just needs a free standing position with good ventilation.
I've fitted a Zobel network on the speaker outputs since the pictures were taken.
Running on 28v rail, bias @ 1A with Nelson Pass inspired power supply.
Sounds very good indeed but will need speakers of >90dB sensitivity if you want party levels:)
Duncan
£85 plus postage
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/IMG_8547_zpssxvzlfaz.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/IMG_8547_zpssxvzlfaz.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/IMG_8546_zpstqjyyqjp.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/IMG_8546_zpstqjyyqjp.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/IMG_8548_zpsk87gd7q2.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/IMG_8548_zpsk87gd7q2.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/6_zpsqjvs0t4q.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/6_zpsqjvs0t4q.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/4_zpseqmfc6pb.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/4_zpseqmfc6pb.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/2_zpsg3zh1zp0.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/2_zpsg3zh1zp0.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/5_zpsrdzhwidk.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/5_zpsrdzhwidk.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/1_zpshm9rxjo1.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/1_zpshm9rxjo1.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/IMG_8550_zpscit9olds.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/IMG_8550_zpscit9olds.jpg.html)
http://i514.photobucket.com/albums/t350/halx00/John%20Linsley%20Hood%201969%20Class%20A/IMG_8549_zpshje8l55h.jpg (http://s514.photobucket.com/user/halx00/media/John%20Linsley%20Hood%201969%20Class%20A/IMG_8549_zpshje8l55h.jpg.html)