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Fender Hot Rod DeVille Output Transformer Teardown
- Thread starter CJ
- Start date
Help Support GroupDIY Audio Forum:
it is hard to drill a hole dead center, so if you slot the mandrel, you can use threaded rod to adjust things
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they have been doing leas all on one side for years, but lately i have noticed that sometimes things are getting sketch, the pressboard with the staples is the way to go, like they did back when.
vinylglass sleaving works pretty good, high voltage, good for about 5 KV. and more puncture resistant, they call it by different names depending on who makes it, kind of a rubberized fiberglass mesh,
if you are careful you really do not need any extra insulation, just make sure your anchors are good , and a good varnish bake session does not hurt either.
vinylglass sleaving works pretty good, high voltage, good for about 5 KV. and more puncture resistant, they call it by different names depending on who makes it, kind of a rubberized fiberglass mesh,
if you are careful you really do not need any extra insulation, just make sure your anchors are good , and a good varnish bake session does not hurt either.
soapfoot
Well-known member
Very interesting to follow this--
Is your goal to make it sound exactly like the original, or do you expect it to be improved?
Is your goal to make it sound exactly like the original, or do you expect it to be improved?
done rewinding this guy, used a bifilar wind for the 4 ohm secondary 68 turn wind instead of doing two winds and connecting in parallel,
had a mistake on the print, sec turns s/b 28 on the top wind, not 34, so P-P Z goes to 4K which is more typical for Fender for a pair of 6L6GC's.
and we attached a build chart which has outside dimensions of the coil as you wind. you really have to smash the arc out of the heavy #21 secondary layers to get everything to fit, that wire really ants to bow out and cause problems. i bet they had a wooden clamp for squeezing those layers at the factory. but you have to be careful not to damage the small primary wiry layers.
winding those speaker layers really puts a lot of torque on the coil, so the primary insulation has to be taped down tight. some folks use super glue to minimize leakage inductance by lessening tape volume. I will nuke the other print.
had a mistake on the print, sec turns s/b 28 on the top wind, not 34, so P-P Z goes to 4K which is more typical for Fender for a pair of 6L6GC's.
and we attached a build chart which has outside dimensions of the coil as you wind. you really have to smash the arc out of the heavy #21 secondary layers to get everything to fit, that wire really ants to bow out and cause problems. i bet they had a wooden clamp for squeezing those layers at the factory. but you have to be careful not to damage the small primary wiry layers.
winding those speaker layers really puts a lot of torque on the coil, so the primary insulation has to be taped down tight. some folks use super glue to minimize leakage inductance by lessening tape volume. I will nuke the other print.
and the build chart which is used to keep an eye on the overall dimensions of the coil as you wind.
numbers are loose in tolerance as measuring is never exact due to varnish buildup and operator error.
numbers are loose in tolerance as measuring is never exact due to varnish buildup and operator error.
SwedishWings
Member
yes, layer insl 0.003" Kraft Paper (brown paper they wrap your steaks in) transformer grade probably dried out, maybe treated, or not,
SwedishWings
Member
No they did not.
I have a blown C3070 on the rewind station right now.
I have a blown C3070 on the rewind station right now.
SwedishWings
Member
radardoug
Well-known member
CJ, somehow we have to save your brain. What an awesome repository of knowledge. And your writing style is classic!
Too much varnish has fried my brain. Two cells left and one is flickering.
https://groupdiy.com/threads/marshall-jcm-900-opt-100-watt-dagnall-c3070.57431/
https://groupdiy.com/threads/marshall-jcm-900-opt-100-watt-dagnall-c3070.57431/
SwedishWings
Member
Maybe, I want to play Efren Reyes!
Great and educational rewind, thanks for showing!
How long do they have used those Dagnall OPT? Is the newer amp series the same OPT (JCM900 combo shown here), it looks different? Do they use chinese parts instead nowadays? I read that about Ampeg, all chinese parts today.
How long do they have used those Dagnall OPT? Is the newer amp series the same OPT (JCM900 combo shown here), it looks different? Do they use chinese parts instead nowadays? I read that about Ampeg, all chinese parts today.
early drake, radio spares, partridge,
