Okay, so I want to digitize my collection of 4-track audio cassettes, partially for convenience, partially for preserving content that was never made available in any other format. Thing is, none of the tapes are the standard format onced used for commercial album releases. The two types of tape I'm mainly working with are: National Library Service for the Blind and Physically Handicap(NLS) Books-on-Tape, which compared to normal tapes run at half-speed(15/16 inches per second compared to the usual 1-7/8 inches per second) and instead of using two tracks per side to produce 2 stereo sides, uses one track per side to produce 4 mono sides. Tiger 2-XL program tapes, which record tracks 2 and 4(side 2 of a normal cassette) in reverse, allowing all 4 tracks to be used on the same side, which combined with playing a single track and switching on the fly allows for interaction. I own the hardware to playback these tapes properly, a portable media player with line-in recording to wav, and the appropriate cable to connect the player's headphone jack to the recorder's line-in jack, but using the original players, capturing only a single track per pass, and in the case of the 2XL tapes, rewinding after each pass seems needlessly time-consuming. I recieved a suggestion to use a regular tape deck and then use sox or another command line utility to slowdown the rip of the NLS tapes, separate the false stereo capture of the NLS tapes into proper mono rips, and reverse the tracks normally used for side 2 on the 2-XL tapes, but I don't own a normal cassette deck, and I'm having trouble finding something suitable on Amazon. Decks specifically marketed for digitizing tapes are common even at low price points, but many seem to be hardwired for producing mp3, and its hard to tell which ones can be used for making wav that can be losslessly compressed. I've also read at least one guide online that recommends using a line-out jack over a headphone jack on the source side, though didn't offer an explanation as to why. If anyone could direct me to a suitable tape deck for this task or suggest other means of speeding up the process without scarificing quality, it would be greatly appreciated.