Burns Orbit Amplifiers
A few of these turning up these days but not a lot of service information. They're some of the earliest mainstream transistor guitar amps and Orbit Twos and Threes can still be had for a few hundred pounds.
EDIT: If anyone's got an orbit of any sort with original parts (doesn't have to be working) I'd be interested in buying or borrowing it to document.
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Burns Orbit Two
Available initially as a 2 x 10" and later as a 1 x 12"
16"h x 121/2"w x 91/2"d
Advertised output 40watts (British)
880. Orbit Two
Burns Orbit Three
881 and 882: 'Orbit Three' 3 x 10"
885 and 886: 'Orbit Three Double 12' 2 x 12".
21"h x 25"w x 10"d Weight approx 37Ib
Advertised output power 60watts (British)
Worth noting that the 'Orbit Three Double 12' is not the same as an 'Orbit Double 12' (see below).
881 / 885. Orbit Three Standard
882 / 886. Orbit Three Reverb "with extra dimensional control" if you're into that sort of thing.
Burns Orbit Three Schematic
The next drawing is a bit of a mystery at the moment. Thank you to Jon Free at Black Guitars in Australia for posting photos of some back panels with factory schematic stickers. They're described as a 6303 Amplifier but we don't know which model they came from.
Some of the values are unclear, but the circuit for Channel One in particular is a lot different to the BE 009 03 version. Jon's site's got some very interesting Burns archives. Well worth a look.
BLACK GUITARS
347 BELGRAVE-GEMBROOK ROAD, EMERALD, VICTORIA 3782, AUSTRALIA
Burns Orbit Double 12
Note the rotary Bass control instead of a tone selector switch.
Orbit Double 12 Reverb
Burns Orbit Six
Available as a 6 x 10" or 3 x 12"
23"h x 331/4"w x 12"d Weight (insert large number)
Advertised output power 100watts (British)
883. Orbit Six Standard
884. Orbit Six Reverb
Baldwin - Burns Orbit 75
Advertised output power 75watts
2x12" speakers now on the same face as the control panel.
Semiconductor Details
1B40K20
If: 4A
Vbr: 200V
Silicon Bridge rectifier
NKT213
Vcb max: 32V
Vce max: 18V
Veb max: 10V
Ic: 250mA
Ptot: 200mW
Hfe: 50
PNP Germanium
NKT217
Vcb max: 60V
Vce max: 40V
Veb max: 10V
Ic: 500mA
Ptot: 200mW
Hfe: 50
PNP Germanium
NKT304
Vcb max: 30V
Vce max: 20V
Veb max: 15V
Ic: 2500mA
Ptot: 750mW
Hfe: 50
PNP Germanium
PNP Germanium
NKT403
Vcb max: 80V
Vce max: 32V
Veb max: 40V
Ic: 10A
Ptot: 50W
Hfe: 50/150
PNP Germanium
NKT404
Vcb max: 60V
Vce max: 32V
Veb max: 20V
Ic: 10A
Ptot: 50W
Hfe: 50/150
PNP Germanium
NKT452
Vcb max: 36V
Vce max: 32V
Veb max: 10V
PNP Germanium
Ic: 3A
Ptot: 43W
Hfe: 30/90
PNP Germanium
OC25
Vcb max: 40V
Vce max: 40V
Veb max: 10V
Ic: 4A
Ptot: 23W
Hfe: 15
OC35
PNP Germanium
Vcb max: 60V
Vce max: 32V
Veb max: 20V
Ic: 8A
Ptot: 30W
Hfe: 25
OC706
PNP Silicon (The only silicon transistors in the circuits, used as channel input devices)
No other data available
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