Film-Tech Forum ARCHIVE: Found, new 6 track magnetic heads

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Posted by Steve Roberts (Member # 9544) on 07-17-2018, 02:40 AM:

I have 2 DP70's, Philips/Kinoton stopped making the original heads in the 1970's I am told so I was very concerned that I would not be able to run any more 70mm as my heads are worn. For the last few month I have been looking for new replacement magnetic heads which has proved to be almost impossible to find until I contacted Terry Summers of Summertone here in the UK. Terry was good enough to send me a sample 6 track head for a DP70 which I have tested using the SMPTE test film and a 6 track recording of the overture to West Side Story and the results were fantastic.

Posted by Steve Guttag (Member # 268) on 07-17-2018, 05:57 AM:

Philips continued making the heads, in their various forms, into the 1980s (the ones where the heads were in blue molded plastic). They were available in 6, 10 and 4 track versions.

However, once Teccon and other manufacturers of sendust and other hardened metal heads came out, the original Philips heads, quickly, fell by the wayside.

There was no point in trying for azimuth alignment on an original head, they weren't aligned well enough in the plastic to achieve that accuracy over 70mm (from left to surround though it is advisable not to use track 6 in an alignment in case its inherent delay for surrounds was left on when the test film was recorded).

The wear on the original heads was like butter. In normal usage, I think we got something like 3-months on a head (a summer). Compare that to a Teccon where life space was measured in 10s of millions of feet (or many years of usage). The Teccons didn't cost much more either. Cost per footage of film run on them was a small fraction of the Philips heads.

Kinoton sourced another manufacturer of the heads (also a harden metal) and made available 6 and 10 track (perhaps 4 track, but I never saw any of those for the DP70/75/FP75). They also could supply 4-track heads for FP20/30 projectors. They had the heads available with different inductances too to match with different preamp styles. The name of the company that supplied them to Kinoton escapes me at the moment. It would not surprise me if Kinoton has some heads left though they may have sold them all in their most recent purging of excess parts.

For precision, I liked Teccon heads best. They even made, for us, a version of the DP70 head that allowed for precise azimuth alignment without danger of messing up the zenith alignment. When Teccon went out of business, they had a "last buy" sale. Honestly, there was so little magnetic film after that I'm sure all of those heads will last indefinitely.

Posted by Jim Cassedy (Member # 4115) on 07-17-2018, 10:42 AM:

In the late 1980's & 90's I was an engineer at a big video editing facility here in
San Francisco. All of our switchers, TBC's, DVE's & 1" VTR's (VPR-80's - one
of the most amazing 1" VTR's ever made) were all manufactured by AMPEX,
which was located about 25mi South of here.

We had a service contract with AMPEX, who would send a tech out every couple
of months to do the required periodic maintenance. During one visit, he
happened to mention that he had started off his career at AMPEX working in their
cinema sound division, which at this point had been shut down for some years.

So I mentioned that I had a 35mm set-up at home, which was equipped with
AMPEX 4-track mag penthouses, which were working fine, except that the
heads were definitely wearing down.

So he told me that although they were no longer 'in the cinema sound business'
and no longer manufactured the mag heads, when he got back to his office he
would send me the name of a company AMPEX would recommend to former
cinema clients looking to have their old mag-heads re-lapped or even re-built.

I never heard back from him with that info.

- - but, several months later, when the guy came back to our facility for a
scheduled maintenance visit, he gave me two, brand new, still-in-the-box sets
of AMPEX 4track mag heads for my projectors.

The story he told me was that when AMPEX made the corporate decision to no
longer support mag sound systems, somebody forgot to tell the facility that
made their mag heads for several months and as a result, there was "a whole
warehouse" (his words) of the heads "just sitting there", and he managed to
score a couple of 'em for me.

(And just to make this story more 'cute'- the day he showed up and gave
them to me, just happened to be my birthday. awwwwwww...)

Posted by Steve Roberts (Member # 9544) on 07-17-2018, 01:44 PM:

Can I still get a Teccon or Ampex 6 or 10 track head for a DP70 or any other 70mm projector?

As to the Philips heads when the Gaumont Manchester UK (Todd-AO installation No2) closed, in a room by the Solo organ chamber we fond 6 boxes containing 42 worn Philips heads which proves how soft they were. In the 32 month run of the Sound of Music they used 6 heads.

Terry Summers assurers me that the heads he supplies are all hard wearing so they should last longer than I will be able to lift a reel of 70mm on to the DP70!

Posted by Sascha F. Roll (Member # 9043) on 07-17-2018, 04:42 PM:

Steve, any chance the company that manufactured the heads for Kinoton was WINKLER in Germany? They closed a few years ago and I know someone who managed to buy the „leftovers“ and also let them make heads for shrunken (vintage) prints.

Posted by Steve Guttag (Member # 268) on 07-17-2018, 05:22 PM:

That name sounds familiar. I would think that the business model for such heads is pretty much like everything else film, if not worse.

Posted by Steve Roberts (Member # 9544) on 07-18-2018, 01:33 AM:

The worst mag penthouse I ever found for warped film is the Cinemaccaneca Vic 8 and 10. To run the 35mm mag film on his Vic 10 my good friend had to fit an extra roller to hole the film flat on the head.
One of the best for 35mm mag has to be the Westrex, its down side was taking the head to bits to fit individual replacement heads, then lining the thing back up again.

Posted by Martin Brooks (Member # 1269) on 07-18-2018, 10:58 PM:

quote: Steve Roberts
Can I still get a Teccon or Ampex 6 or 10 track head for a DP70 or any other 70mm projector?

10 track head? What's that about? I never heard of that for 70mm.

Posted by Stephen Furley (Member # 1277) on 07-19-2018, 02:47 AM:

Presumably a combined 35/70 mm head block. Some machines used these, while others had separate heads for each format.

Posted by Sam D. Chavez (Member # 1841) on 07-19-2018, 10:18 AM:

On projectors where the 70 and 35 film paths thru the penthouse were the same, the 10 tracks were very convenient as the mag head did not need to be swapped out. The problem with 10 track heads is while very convenient were kind of impractical as inevitably either the 70 or 35 set would wear out way earlier and then you were back where you started, with only one set usable. This was not such a problem once Tecconn came around (and lasted seemingly forever) but they were very late to the scene and there was lots of 70 mag film and almost no 35.

Posted by Sam D. Chavez (Member # 1841) on 07-19-2018, 10:21 AM:

On projectors where the 70 and 35 film paths thru the penthouse were the same, the 10 tracks were very convenient as the mag head did not need to be swapped out. The problem with 10 track heads is while very convenient were kind of impractical as inevitably either the 70 or 35 set would wear out way earlier and then you were back where you started, with only one set usable. This was not such a problem once Tecconn came around but they were very late to the scene and there was lots of 70 mag film and almost no 35.

Posted by Leo Enticknap (Member # 534) on 07-19-2018, 10:46 AM:

quote: Stephen Furley
Presumably a combined 35/70 mm head block. Some machines used these, while others had separate heads for each format.

We had a pair of original Philips ones for the DP-70s at the Egyptian, plus a couple of pairs of Teccon 6-head (70mm only). The six 70mm heads on the OEM ones were worn-out garbage: it was impossible to tune a decent response or get enough gain out of most of them. The 35mm inner heads, however, were near perfect. We were able to tune the MPU using an old THX analyzer to OEM spec response on all but one of the channels (surround, thankfully), which had just a little bit of an HF dropoff. At the final Cinecon at which I worked, we played UCLA's 35mm IB mag print of King of Kings, which sounded great. The picture was scratched and beaten up throughout, but the audio was quite something.

The condition of these heads suggests to me that 70mm mag was in prolonged, mainstream and widespread use, but that 35mm mag never really took off.

Posted by Steve Guttag (Member # 268) on 07-20-2018, 05:46 AM:

35mm mag was in widespread use (more so than 70mm) for a long time. When Dolby Stereo took off, that was, much like 70mm after digital audio) that it dropped like a rock.

Can you imagine the cost difference (both to the studio and the exhibitor) of optical stereo versus 4-track magnetic?

Think about most any "stereo" title before say 1977...odds are, it had a 4-track version, including 70mm titles, there were likely 4-track 35mm versions. Whereas Fox insisted on CinemaScope and 4-track at the onset of CinemaScope, those first few years had 100s of titles.

After Dolby Stereo took hold...I think I handled maybe 5 "new" titles (Blues Brothers, Yentel, Scarface, I think the remix of Fantasia had 4-track.

For retro festivals, we had a set of Norelco 10-track heads where, like you, the 6-tracks were worn out but the 4-tracks were "like-new." I'd put them in for the 4-track movies (mostly musicals) that would show up.

It wouldn't surprise me if some of the extra 10-track heads came from when people order something they keep ordering the same thing. So if they started off ordering 10-track heads to cover everything...when the 4-track prints slowed down...they kept ordering the 10-track heads.

For our "new" 70mm installations in the 1980s, I'd always start them out with the capability of 4-track knowing that we'd never burn through those heads but we were covered for the "festivals" were a 4-track would show up unexpected.

Posted by Louis Bornwasser (Member # 3063) on 07-21-2018, 11:33 AM:

If it can help anyone, I have Teccon in new and used condition. All are 6 track and mostly Century/Westrex mounts. Be aware that if you already have the mount that most Teccon heads are identical.