Today I received a new Heyboer Dynaco 470, NTS-8093 (their part number for it) that is intended as a replacement for a Dynaco A470 output transformer. Unfortunately it is not. The Dynaco A470 is an ultra-linear transformer with a primary winding equipped with a center tap, two screen grid taps and two plate leads. Instead the Heyboer transformer I received has a primary winding with only a center tap and two plate leads - a Williamson type transformer. Yes, I could rewire the amplifier to use a Williamson type transformer, but I refuse to compromise on the original design. I consider a Williamson design a step backward. I immediately wrote an e-mail to Heyboer asking about returning it for credit against my account.
This is bad in multiple ways. I will have to get return authorization, pay for shipping to return, wait for the credit back to my account, order from another company and wait again to receive one. Plus Heyboer gets attention for not supplying the correct design part in the market. I have already waited about two weeks since my original order was placed. My next order will be from Triode Electronics.
Joe