Burns Orbit Three

[J M Fahey]

GOSH !!!
GAWK !!!!
A nightmare come true !!!
Although .... it should have "the best sound in the World" , it has all Wima capacitors, plus "Mustard" caps and ...... suspense ..... carbon composition resistors, all 1963 vintage !!!!!!!!!
And transistors are "sweet sounding Germaniums"
Eat crow, "parts-are-the-sound" crowd !!!

[Ted]

I have to tell you that it may just be the vilest sounding amplifier I've ever heard. Slightly improved by modern speakers (the original Burns-branded Elacs last about 25 seconds at full power). Anyone who doesn't get a headache from one of these is probably under 21.

[welsh_chris]

One thing that I would advise anyone using or repairing one of these to look out for. On the one that I serviced last year, the taps on the mains transformer were brought out to a tag strip on the outside of the chassis. If anyone reached inside the cabinet and stuck their fingers into the gap between the chassis and the front of the cabinet, it is possible to touch these live (mains voltage!) terminals. Presumably the idea was to make changing from 240 volt to 120 volt operation relatively easy without the expense of a voltage selector switch. I permanently spliced the wires together with heat shrink sleeving over the joints, thus eliminating the potentially lethal exposed terminals.

[Littlecarl]

Hi I'm new to this forum.. I have a Burns Orbit 3 double 12 and a Double 12 too that I need to look at.. These are the later Printed Circuit Board type compared to the earlier turret and point to point.. I did a successful rewind of a voice coil on a 10" Elac.. The glue had let go of the coil and found the top layer winding found it's way under the dust cover lol..
I have tried to view the pic files in this thread but they don't seem to work?? Any help appreciated..

[g1]

I have tried to view the pic files in this thread but they don't seem to work?? Any help appreciated..

Many of the old files were lost due to a server crash several years ago.

[willy barden]

I've got a schematic/circuit diagram for the pc board version of the Orbit 3. The diagram was folded up and ended up in a waste bin - luckily was recovered but in poor condition - this print shows the damage. The circuit has several errors according to the amp examples I have seen and the symbols used for components are very old - other then that it's OK .....see attachment

[dmeek]

Here's the Orbit 3 schematic, just barely readable. Burns Orbit Three 3 schematic.pdf

[welsh_chris]

Hi I'm new to this forum.. I have a Burns Orbit 3 double 12 and a Double 12 too that I need to look at.. These are the later Printed Circuit Board type compared to the earlier turret and point to point.. I did a successful rewind of a voice coil on a 10" Elac.. The glue had let go of the coil and found the top layer winding found it's way under the dust cover lol..
I have tried to view the pic files in this thread but they don't seem to work?? Any help appreciated..

I've still got the schematic files I downloaded from this forum 10 years ago. I've just uploaded to drop box, https://www.dropbox.com/sh/bkiee08i7...C1rt2r-Pa?dl=0

[vintagekiki]

https://www.diyaudio.com/forums/instruments-and-amps/255726-burns-orbit.html
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http://schems.com/bmampscom/burns/Burns_20_Orbit_Three.pdf

http://blackguitars.com/burns-amplifiers.html

https://elektrotanya.com/?q=showresult&what=burns

[Littlecarl]

I've still got the schematic files I downloaded from this forum 10 years ago. I've just uploaded to drop box, https://www.dropbox.com/sh/bkiee08i7...C1rt2r-Pa?dl=0

Thanks Chris. I have those but was hoping for a layout or anything else that might help without me having to unpick everything. I also have copies of the schematic that was inside the earleir point to point cabs. I tried transposing that clearer info to the full page and found there was a lot of different values and altered circuits.

[Littlecarl]

I've got a schematic/circuit diagram for the pc board version of the Orbit 3. The diagram was folded up and ended up in a waste bin - luckily was recovered but in poor condition - this print shows the damage. The circuit has several errors according to the amp examples I have seen and the symbols used for components are very old - other then that it's OK .....see attachment

It seems to be the only surviving copy doesn't it?

[Littlecarl]

https://www.diyaudio.com/forums/instruments-and-amps/255726-burns-orbit.html
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http://schems.com/bmampscom/burns/Burns_20_Orbit_Three.pdf

http://blackguitars.com/burns-amplifiers.html

https://elektrotanya.com/?q=showresult&what=burns

Thank you.. That brochure on Black guitars is fantastic..

[Littlecarl]

I'm slowly getting somewhere with one of the Burns amps I have.. A lot of the wires of the NKT 213 transistors had bad joints to the PCB where the wires had oxidised down the solder joints.. I have renewed the wires and those transistors are much better.. One of the input transistors had been replaced with something modern but signal was very low to the other channel so in the process of swapping the CH2 input transistor the a leg had fallen off. The one fitted is an OC706 device and I'm having a hard time trying to find on or out any information about it to find an equivalent device.. Any pointers?

[Jazz P Bass]

[Jazz P Bass]

OP76 data