Recording on magnetic tape media

[Terry Bites]

Do you have a copy of Walt Jungs book? https://www.amazon.co.uk/Audio-op-amp-applications-Walter-Jung/dp/0672215586
An oldie but a goody!
see https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjQrITO3s7xAhXBilwKHftmCDgQFnoECAcQAA&url=http%3A%2F%2Fwww.jrfmagnetics.com%2FNortronics_pro%2Fnortronics_silver%2Fpdfs%2FNortronics_Silvr_pp1-9.pdf&usg=AOvVaw1RVQa5BCamXSnNN1P-Levl
You'll find it interesting I'm sure.
Lots of older desings used a Royer Inverter for the bias generator. A CCFL backlight controller may be a good starting point for that.

[Dcline]

Congratulations on your endeavors to build a record/playback tape system. I have been playing around with Revox A77 dolby and a Ferrograph model 7 for some time. The suggestion to look at Jung's books on op amps is great and I have attached more info on this book plus some other material including some of the service manual for the A77. Seems that yo need to choose the type of tape that you plan to use if you want to get the best results. If you want to get interchangeable recordings then you will need to choose an equalization NAB, IEC DIN etc and then buy a calibration tape to get a flat playback response. Normally the calibration tape is at a specified speed ie 7.5ips and you can do some adjustment for other speeds. If you want to add Dolby B to the process there are additional circuitry requirements and calibration steps. If you get the playback side done first, you can go on to the record side. This is where your choice of tape becomes important. The tape chosen will have a "best" bias amount in the recording mode. This will balance high frequency response, distortion and noise floor. You cannot get one without affecting the others. The tape chosen will also affect the "overhead" that you have in maximum recording level. Pick a tape that you can get. My preference is Scotch 207. Good luck!