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Author Topic: Full track playback with two track heads  (Read 16405 times)

Offline cvandyke

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Full track playback with two track heads
« on: March 20, 2018, 08:45:23 AM »
Would there be any negative sonic effects of playing back a 1/4" full track tape with a two track head? Obviously, you don't get the benefits of the whole recorded width of tape. Are there any other downsides?
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Chris Van Dyke

Offline High and Outside

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Re: Full track playback with two track heads
« Reply #1 on: April 13, 2018, 10:26:53 AM »
Chris,

One other thing happens, which is generally considered a downside but someone might prefer it in some circumstances.

Whenever you play back a wide track recording on a narrower band playback head it is subject to a phenomenon called "fringing." The effect is to raise the low frequency content several dB above the balance that was recorded.

What happens is that the recorded portion that lies outside the track width of the playback head adds its low frequency content to the part that is picked up normally. It's like pushing the Loudness button, except that you can't turn it off if you don't like the effect.
Paul Stubblebine
Managing Director, The TapeProject

Offline cvandyke

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Re: Full track playback with two track heads
« Reply #2 on: April 18, 2018, 09:19:05 AM »
Thanks! I didn't particularly like the bass on the mono tapes I played and I hope this is the cause. The tapes are production masters which contain transfers from 78 sides so it's just as likely be the recording.

Another question about this general subject: is there a reasonable way to determine if a tape labeled "mono" was recorded as full track or two track mono? The tapes I have so far are labeled so it's clear but it seems likely I'll face this issue in the future.

I do have a mono repro head for my deck (Otari MTR10). I need to mount it and to figure out how I want to handle routing the signal from the head. I really don't want to make any non-reversible changes, have an awkward cable dangling, or put a switch in the signal path. I've already spent some time pondering how to proceed and, so far, I've come up empty.
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Chris Van Dyke

Offline High and Outside

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Re: Full track playback with two track heads
« Reply #3 on: April 23, 2018, 11:36:58 PM »
Another question about this general subject: is there a reasonable way to determine if a tape labeled "mono" was recorded as full track or two track mono? The tapes I have so far are labeled so it's clear but it seems likely I'll face this issue in the future.

The only way I can think of is to use one of those magnetic viewers--that's a thing you place over the tape and gradually an image appears of the magnetic information.

I don't know of any currently being made, and I rarely see them for sale though. I was lucky to pick one up several years ago when Fred Thal had a few for sale. Anybody else have a lead on one?
Paul Stubblebine
Managing Director, The TapeProject

Offline cvandyke

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Re: Full track playback with two track heads
« Reply #4 on: April 24, 2018, 12:18:52 PM »
This might work: www.ebay.com/itm/122438609117

I ordered one and will report back once I have a chance to try it out. It ships from the UK so it may be a few weeks. The total cost was about $6.
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Chris Van Dyke

Offline Waltzingbear

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Re: Full track playback with two track heads
« Reply #5 on: May 20, 2018, 01:06:29 PM »
have you received it yet and had a chance to try it?

I am concerned that it won't be sensitive enough to see the detail of the channels at 350nW/m

Cheers
Alan

Offline cvandyke

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Re: Full track playback with two track heads
« Reply #6 on: May 21, 2018, 08:30:11 AM »
I did receive it but haven't had a chance to try it. I'm in the process of moving and somehow misplaced it. Grrr. I'll report back when it turns up.
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Chris Van Dyke

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Re: Full track playback with two track heads
« Reply #7 on: May 26, 2018, 12:32:28 PM »
Another question about this general subject: is there a reasonable way to determine if a tape labeled "mono" was recorded as full track or two track mono? The tapes I have so far are labeled so it's clear but it seems likely I'll face this issue in the future.

The only way I can think of is to use one of those magnetic viewers--

I should have mentioned the more obvious way: play the tape on a 2-track head and see what comes out of the right channel. If the original recording is full track mono you'll hear the same program on the right channel as the left.  If it's half track mono with nothing recorded on the other half, that's what you'll hear on the right channel: nothing. Or practically nothing. If it's half track mono with another program recorded after flipping the tape over then you'll hear that program backwards on the right channel.
Paul Stubblebine
Managing Director, The TapeProject