Just adding the lines to /boot/config.txt didn't get the tlv modules to load and I could not see the sound card. If I put those lines before the drtparam=audio=-on then aplay -l said there is no sound card found.
In the Stretch version there is a module udrc loaded. What does that do and do we still need it?
I am presenting my 3d printed case for the draws hat on a Pi4 at the Tech Connect 285 club the first Saturday in September and would like to tell everyone how great the product is. We have a lot of SOTA folks (Colorado is SOTA heaven) and the draws hat is one of the smallest interfaces available. The following Saturday we will be having our annual picnic on a SOTA peak and showing off equipment.
The long and short of it is you have a show stopping problem and it would appear you can not duplicate it. I am not the only one who is having the problem. I know what I would do if it were my product. It would not be to blow it off until after some hamfest more than a month down the way.
Frank - K0FEI