One of the keys to successful analog tape transfer is matching the reproduce head to the recorded track layout. The closer the match, the more optimized the information recovery.
While other pages here relate a good deal of information concerning these formats, here are some links to other resources that provide additional detail.
The major resource for this is the IASA-TC04 publication.
Other resources include:
- The Ampex List reference document (from Ampex) pdf gif (The PDF is probably more readable)
- The Studer reference document
- A drawing here showing how 2-inch 16-track and 24-track line up (and why you will not get the best results playing a 16-track tape on a 24-track head
- A copy of the Nortronics drawing showing track configurations
- The denser multitrack formats are not represented in the above. 8T 1/2″ & 16T 1″ have track widths of about 30 mils
- The super dense Tascam and Fostex formats that put 8T on 1/4″ tape and 16T on 1/2″ tape have a track width of about 17 mils.
John Chester recently asked the track dimensions for half-inch, two-track and between the IASA document and a set of Woelke heads for the Sony APR-5000 that I have here that there might be a discrepancy among various two-track, half-inch configurations. John Chester contacted John French at JRF Magnetic Sciences and he provided the following data.
Two-Track, Half-Inch Track Dimensions
Dimensions in mils (0.001")
Manufacturer track guard band out-to-out width
Flux Magnetics 200 60 460
Studer 197 62 456
Otari 202 95 499
Woelke 192 80 464
TC04 "IEC" standard 197 98 492
In 2024, I had the opportunity to measure an early 1/2 inch 2T
repro head for an Ampex ATR-100 (metal face) and it measured
approximately using a digital caliper:
210 60 480
Note that there is a minor discrepancy between the measured
Studer figures and the above-referenced drawing, on the order
of about 2 mils, which is pretty inconsequential.
The IASA document quotes IEC, but no standard number and I have included that in the table as well. I added the out-to-out dimensions as well. The lower value of the Flux, Studer, and Woelke heads comes close to the out-to-out width of half-inch, four-track at 460 mils.