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Author Topic: Nagra iii speed issue?  (Read 3138 times)

Offline messyone

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Nagra iii speed issue?
« on: June 08, 2014, 07:09:31 AM »
Hello, I’m new to reel to reels but have a feeling ill be interested in them for many years to come!.... cant believe I didn’t get into them sooner.
Anyway I’ve just acquired a Nagra iii and after cleaning the heads and parts where the tape passes along the hiss has gone and it sounds pretty cool,
However it seems to record/play back the recording slightly faster than the source material, its actually pitched up about 1.5 semitones. Any ideas what is causing this?

I should note the tension pulley on the right is moving a bit whilst the left is not, could that be anything to do with it?
Also I’m using Ampex 406 tape, should I be using anything else?
Also powering with batteries and recording at 15ips.

Any ideas would be greatly appreciated!...
Thanks,
Lee

Offline ironbut

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Re: Nagra iii speed issue?
« Reply #1 on: June 08, 2014, 02:54:36 PM »
Hey Lee,
Welcome to the forum.
If I got it right, after you recorded and then played back that recording, the pitch is up?
If this is so, either;
A. The machine was running slow when the recording was made or
B. The machine was running fast when playing back the recording.
In other words, the speed was inconsistent.
Since the machine is new to you and could have been out of service for a while, it's very possible that it needed a bit of "running in" for the speed to stabilize.
This could be a purely mechanical issue having to do with thickened or even hardened lubricants in bearings etc or electrical with old capacitors needing a bit of time to reform.
I would try and run the machine for a while, then start/stop/rewind etc to exercise it for a bit.
Also, use a bit of contact cleaner on friction connections you can see.

I would suggest taking the machine to a qualified service tech at some point even if the problem seems to solve itself.
If you don't have a service manual, it would be a good idea to search around for one.
You might be able to find one online for free (check with film sound folks since these were often used by them).
steve koto
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