Hi guys,
understandably companies working on improving audio transformers have businesses to run and, I guess, therefore don't like so much to sell naked cores which is much less money to make with. I think that might be the reason for that cores are offered so rarely. The ones I found, I could never find any reviews or any indication to their quality at all....
Could you please do me a favor and tell me the vendors you would recommend who sell hifi OPT-cores of quality for fair prices? I hope for affordable (double) c-cores because self-wired coil bobbins could be swapped easily. If they would turn out to be really much more expensive than EI-cores e.g., the effort taking them apart to change coils would be worth though of course.
For this help thank you guys so much in advance, this one I will appreciate a lot!
understandably companies working on improving audio transformers have businesses to run and, I guess, therefore don't like so much to sell naked cores which is much less money to make with. I think that might be the reason for that cores are offered so rarely. The ones I found, I could never find any reviews or any indication to their quality at all....
Could you please do me a favor and tell me the vendors you would recommend who sell hifi OPT-cores of quality for fair prices? I hope for affordable (double) c-cores because self-wired coil bobbins could be swapped easily. If they would turn out to be really much more expensive than EI-cores e.g., the effort taking them apart to change coils would be worth though of course.
For this help thank you guys so much in advance, this one I will appreciate a lot!
Last edited:
Do you mean cores or lamination stacks?
Transformer manufacturers would order custom laminations for their designs, so there isn't much trade in laminations only.
Double C isn't normally used for laminations as you need the intimate interleaving of alternating EI/IE format to complete the magnetic circuit properly. Laminations are aiming for very high permeabilities With ferrite C-cores the surfaces are highly polished to reduce any airgap to a few microns, laminations are stamped, they don't have polished edges.
For extending down to 20Hz lower cutoff ferrite or iron dust cores aren't efficient as they don't have the high permeability of silicon steel or nickel-iron, nor the high magnetic field handling (iron based materials saturate around 2T, ferrites around 0.5T)
For small runs of custom laminations you can get laser-cut laminations, but this isn't cheap - and for stamped laminations you have a setup tooling cost to pay. I suspect a lot of specialist audio transformer firms have to pass these costs on to the customer as they aren't doing large production runs.
Transformer manufacturers would order custom laminations for their designs, so there isn't much trade in laminations only.
Double C isn't normally used for laminations as you need the intimate interleaving of alternating EI/IE format to complete the magnetic circuit properly. Laminations are aiming for very high permeabilities With ferrite C-cores the surfaces are highly polished to reduce any airgap to a few microns, laminations are stamped, they don't have polished edges.
For extending down to 20Hz lower cutoff ferrite or iron dust cores aren't efficient as they don't have the high permeability of silicon steel or nickel-iron, nor the high magnetic field handling (iron based materials saturate around 2T, ferrites around 0.5T)
For small runs of custom laminations you can get laser-cut laminations, but this isn't cheap - and for stamped laminations you have a setup tooling cost to pay. I suspect a lot of specialist audio transformer firms have to pass these costs on to the customer as they aren't doing large production runs.
Last edited:
