Hi All,
is there a general "rule of thumb" when it comes to tube placement on a chassis?? in other words how close can you place the tubes to the transformers before the trannys effect tube performance??
Bill
Rule of thumb ???
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jckid66
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Alexo
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I did a build where the output tubes are about a half inch from the OT: http://18watt.com/files/q5watt.jpg. I don't think you have to worry about the transformer affecting the tube's performance but rather about the tubes heating up the transformer too much. I didn't have any problems with mine but the tubes were running at a reduced voltage, though they still get really hot.
A lot of power tube datasheets will tell you the minimum distance between two tubes.
Whether or not OT signal can radiate into nearby preamp tubes and cause oscillations is something I would be curious about.
A lot of power tube datasheets will tell you the minimum distance between two tubes.
Whether or not OT signal can radiate into nearby preamp tubes and cause oscillations is something I would be curious about.
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drgonzo2
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Some rules of Thumb I've read are:-
1) Power valve spacing should be at least 1.5 times the diameter of the valve, e.g. 2x 6v6 @ 30mm, should have a minimum of 45mm between them at their closest point.
2) Ideally there should be a minimum of 30mm between power valves and the opt.
3) Preamp valves should be placed as far away from the p/t as possible, ideally shielded by the opt and any capcans.
4) Ideally there should be a minimum of 50mm between power valves and the p/t.
Rules 1+2 are mainly to do with heat issues, 3+4 to reduce electromagnetic interference from the power transfo.
As I've said, these are rules of thumb, derived from comments in various texts that I have read (mainly Jones' books and rdh3+4), so others may disagree, YMMV, etc.
Hope they prove helpful...G
1) Power valve spacing should be at least 1.5 times the diameter of the valve, e.g. 2x 6v6 @ 30mm, should have a minimum of 45mm between them at their closest point.
2) Ideally there should be a minimum of 30mm between power valves and the opt.
3) Preamp valves should be placed as far away from the p/t as possible, ideally shielded by the opt and any capcans.
4) Ideally there should be a minimum of 50mm between power valves and the p/t.
Rules 1+2 are mainly to do with heat issues, 3+4 to reduce electromagnetic interference from the power transfo.
As I've said, these are rules of thumb, derived from comments in various texts that I have read (mainly Jones' books and rdh3+4), so others may disagree, YMMV, etc.
Hope they prove helpful...G
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