These penny-stock Maxells are still being made for office and portable use, and you usually even find them at drug stores if you’re in a pinch(they’re much cheaper at Amazon). These cheap dictation tapes have no mu-metal shields over the head area.
The TC-KA3ES easily calibrates to these dictation-grade tapes for flat frequency response even with Dolby C.
While their modulation noise and surface finish isn’t as good as the above tapes leading to slightly less clean sound if you’re using only Dolby B and monitoring carefully over electrostatic headphones, with most music and conventional speakers like B&W Diamonds or Wilsons, the TC-KA3ES can make great-sounding tapes with only Dolby B if you get stuck. Pop on Dolby S, and even these dictation cassettes, once calibrated in a moment with one dial-dot less bias and one dial-dot more record level, sound great.