Yes, 6C45 could do.
You don't need the full mu; so no need for current source loading, even with resistive anode load you'd have a bit too much gain.
With a 3:1 interstage transformer you'd be perfectly there with enough gain and ample drive current for the mosfet.
One of multiple options...
Not just nice looking
)) but also "audio" grade as the core is 0.23 mm thin laminate HiB silicon steel.
Hi Anand,
I mistakingly thought I have the same (LL2733) set of Lundahl’s as you, which would not be sufficient for the LuFO bias current. But yours (LL2773) do look like a good option. Nice!
Sorry, MOT = Microwave Oven Transformer.
In the U.S.A., these surplus transformers can be used to as a high current choke load on Class A amps. I have used them on MoFo, Glass Harmony, and now LuFo. They were not made for audio, obvioulsy, but seem to handle a pretty high DC current (as high as 6A) and make good music for cheaps. On eBay, search for "Microwave Oven transfromer MD-803AMR" that is the model I use. There are others that may work too. The 230VAC ones in EU and Asia have a high DCR and will not work.
For example: Midea Microwave HV Transformer MD-803AMR-1 used | eBay
You can also find dead microwave ovens on the curb on trash day and pull your own.
It is the big 8lb block of iron and copper on the lower left:
Interesting video - first time I have seen someone cut the weld off a MOT to rewind it:
How To Make Custom Power Transformers - YouTube
In the U.S.A., these surplus transformers can be used to as a high current choke load on Class A amps. I have used them on MoFo, Glass Harmony, and now LuFo. They were not made for audio, obvioulsy, but seem to handle a pretty high DC current (as high as 6A) and make good music for cheaps. On eBay, search for "Microwave Oven transfromer MD-803AMR" that is the model I use. There are others that may work too. The 230VAC ones in EU and Asia have a high DCR and will not work.
For example: Midea Microwave HV Transformer MD-803AMR-1 used | eBay
You can also find dead microwave ovens on the curb on trash day and pull your own.
It is the big 8lb block of iron and copper on the lower left:
Interesting video - first time I have seen someone cut the weld off a MOT to rewind it:
How To Make Custom Power Transformers - YouTube
Last edited:
I checked out a couple of the how-to videos on the MOTs, thanks for the links. If you were to remove the secdondary windings, would you add what amounts to an additional primary that would channge/augment its specs, or simply to avoid safety issues with the high voltage in the secondary?
Thanks,
Skip
Thanks,
Skip
You can leave the secondary alone if you don’t need to add another leg to the primary. Just tape it off and don’t use it. I have wondered if it’s output could be used for driving electrostatic speakers.
A secondary could be wound for a split primary for a balanced output amp - I’ll have more details on that soon.
A secondary could be wound for a split primary for a balanced output amp - I’ll have more details on that soon.
Hi Skip,
If you added a second primary winding to the MOT, you can make a balanced output amplifier and reduce distortion and boost power to a 100w amp.
SuSyLu Where Are You?
If you added a second primary winding to the MOT, you can make a balanced output amplifier and reduce distortion and boost power to a 100w amp.
SuSyLu Where Are You?
