Sony APR speed experiments

Richard L. Hess — Tue, 07 Mar 2006 02:18:00 +0000

We have been wondering just how far we can push the Sony APR-5000 capstan servo system, so we ran a few tests using an external oscillator feeding the reference port. Unlike Ampex, Otari, and Studer machines which use an external reference of 9,600 Hz; the Sony machines use an external reference of 19,200 Hz.

We found that the APR-5000s did not run reliably below 1.88 in/s — and that is achievable with a -50% varispeed already. It didn’t matter what the base speed was.

The APR-16 (cousin of the APR-24) did not run reliably below 3.75 in/s. But the good news was that we could bring 15 in/s down to 3.75 in/s using the external reference source. We were also able to run the APR-16 at 60 in/s, but takeup tension was a bit low.

Sony APR-16 Memory Locations (APR-24)

Richard L. Hess — Tue, 07 Mar 2006 00:23:59 +0000

The 108 memory locations for storing setups is a real feature of the APR-5000 series tape machines. The APR-24 manual alluded to this but did not provide any instructions.

I have the only APR-16 that Sony ever made, but it is essentially the same as an APR-24. My APR-16 is running firmware version 5.01.06.0.

It appears that there are a total of 18 total preset locations in the APR-16 (and presumably the APR-24).

There is a small DIP switch board like the ones on the APR-5000 head assemblies located underneath the control panel at the left side, near the Network switch. Removing the two screws in the top front of the side of the machine releases the control panel to swing forward on its hinges.

Switch positions 7 and 8 appear to be the only active positions on this switch.

Switch 7Â Â Â Â Â Â Â 8
Â Â Â Â Â Â Â Â Â 0Â Â Â Â Â Â 0Â Â Invalid
Â Â Â Â Â Â Â Â Â 0Â Â Â Â Â Â Â 1Â Â 8-tracks
Â Â Â Â Â Â Â Â Â 1Â Â Â Â Â Â Â 0Â Â 16-tracks
Â Â Â Â Â Â Â Â Â 1Â Â Â Â Â Â Â 1Â Â 24-tracks

While this is more limited than the APR-5000, the good news is that each of the three valid settings provides a different memory storage location. This means there are a total of 18 storage locations on the APR-16, 6 each for the 8-, 16-, and 24-track settings. The Preset 1, Preset 2, and Preset 3 positions could conceivable be used for different head assemblies, with both speeds active.

My current thinking for this is:

8-track — Preset 1 — 8-track 1″
8-track — Preset 2 — 8-track 1/2″
8-track — Preset 3 — 8-track 1/4″ (using an APR-5000 to pull tape)

16-track — preset 1 — 16-track 1″
16-track — preset 2 — 16-track 1/2″
16-track — preset 3 — 4-track 1/2″ (two possible presets: tracks 1-8 and 9-16)

24-track — preset 1 — 7-track 1/2″ IRIG (two possible presets: tracks 1-8 and 9-16)
24-track — preset 2 — possible future 14-track 1″ IRIG
24-track — preset 3 — future, unassigned

I tried the other switch combinations and they did not seem to do anything. It’s too bad that this is only a 15/30 in/s machine as there is a need to go to 7.5 in/s for audio tape (at least at 4-track 1/2″ and even more speeds for the IRIG instrumentation tapes). However, we can transfer 7.5 in/s and 3.75 in/s 4-track 1/2″ on our Sony APR-5000 pair.

Restoration Tips & Notes » Sony APR-16/24

Sony APR speed experiments

Sony APR-16 Memory Locations (APR-24)