There is nothing wrong, and quite a bit right with a gapped C core tranny for a SE amp...
Amorphous core transformers are made from the relatively new metal alloy known as Amorphous Steel, alternately known as "Metglass" because of the way it is made and the lack of crystaline structure. It happens that it has extremely excellent magnetic qualities. They are very expensive cores and the primary effect in an audio transformer is fantastic HF response.
You need to get a transformer that is gapped properly for the current you are going to send through it. Ungapped transformers are unsuitable for most SE use. (the so-called parafeed design is an exception - I think that's what they call it)
The other thing, is that if you make the chassis layout somewhat flexible, you can put any transformer(s) in that you want. So, it may make sense to start with an inexpensive transformer.
The other option is to take the laminations apart on an otherwise non-gapped transformer, and turn it into a gapped transformer for SE use. That will take a little research, but it is a worthwhile project.
The Lundahl people make some nice iron... there are others too.
Amorphous core transformers are made from the relatively new metal alloy known as Amorphous Steel, alternately known as "Metglass" because of the way it is made and the lack of crystaline structure. It happens that it has extremely excellent magnetic qualities. They are very expensive cores and the primary effect in an audio transformer is fantastic HF response.
You need to get a transformer that is gapped properly for the current you are going to send through it. Ungapped transformers are unsuitable for most SE use. (the so-called parafeed design is an exception - I think that's what they call it)
The other thing, is that if you make the chassis layout somewhat flexible, you can put any transformer(s) in that you want. So, it may make sense to start with an inexpensive transformer.
The other option is to take the laminations apart on an otherwise non-gapped transformer, and turn it into a gapped transformer for SE use. That will take a little research, but it is a worthwhile project.
The Lundahl people make some nice iron... there are others too.