I have a 1710W and can confirm it is a two-channel machine with quarter-track spacing as described in the prior post. In other words, you can record up to two separate tracks at a time, not four. Like many consumer units of that era, it only has two heads -- an erase head and a combined record/playback head -- so you also cannot listen to a track and record on the same track at the same time. I have not tried the proposal above about playing back one track while recording on the other, but I think that can be done. I can try it later if you like and I get time.
With the right tape it is not a bad sounding unit. By "right tape" I mean stuff that is low bias, as there is no bias or EQ adjustments on this machine to adjust for different tape. The 1710W is a hybrid of a transistor preamp and tube output, and if you use the "line out" you still get one tube stage in the signal path. If you use the "headphone out" you get the full tube path on playback and record-monitoring. I tracked down the elusive Akai 15 i.p.s. kit for mine and have found that at 15 i.p.s. with older low-bias tapes you can get a pretty flat frequency response with pink noise measurements. The signal-to-noise ratio, wow and flutter, and other specs are certainly dated though, and with limitations like two heads, a belt drive, single capstan/reels motor, no bias/EQ adjustments, etc. you are not going to compete with the specs produced by Studers, Otaris, etc.
