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Headphone out to line in

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Tony Connoly
Headphone out to line in
on Jan 14, 2011 at 9:29:35 am

When connecting a headphone out (which of course has volume control) from a portable cassette player to the line of something like the Marantz PMD661, how do you suggesting keeping the distortion at a minimum?

Many thanks in advance.


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Peter Groom
Re: Headphone out to line in
on Jan 14, 2011 at 10:28:41 am

Well if you really MUST do this, and a proper cassette machine with correct line out connections cant be found anywhere, then Id strongly suggest having headphones / speakers on the recorder. Find the loudest part of the recording and set the level for that transient using your ears and the meters on the recorder.

Im surprised you have a cassette. Ive not seen or touched one in over 10 years and I spend every day in the sound industry.

NB be aware that your azimuth may well be miles out on the player and so mono compatibility could be goosed.

Peter

Peter


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Tony Connoly
Re: Headphone out to line in
on Jan 14, 2011 at 10:41:55 am

Thanks for the tip on the azimuth. I might look for a cassette player that has an adjustible azimuth. You mentioned mono compatibility in connection with azimuth. Why is that.

As far as the levels go, for a given aggregate level, is it better to have have the cassette low and the recorder high, or the other way around?

And yes, I have lots of cassettes. Some of them have pretty irreplaceable stuff. Dialogue, recorded on so so equipment to begin with.


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Peter Groom
Re: Headphone out to line in
on Jan 14, 2011 at 11:11:45 am

Azimuth.
If the azimuth is out, then the relationship between left and right is non coherent. In stereo this shouldnt have too great an effect (remembering theory form a dark and distant part of my mind) but if a listener listens in mono then losses may occur / phasing may occur.
If youre adjusting azimuth, then you must listen in mono to get it right.

Levels wise. Having either one too high or low would be a problem. If the cassette is too high, the output amp on the cassette may not be able to cope and cause distortion. Or the input on the recorder could do the same. But having any 1 too low will increase hiss as the noise floor on cassettes was never great. id go for an inbetween value where everything is sensible and adjust from there.

Youll also have to get the dolby sorted. Things have probably got dolby B on them. If recorded dolby b then you need to enable dolby on playback as dolby encoding on a recorder increased the hf on recordings. non dolby pb would make things over bright and hissy. BUT if there is no dolby on the recording then switch off the dolby on pb as this will turn down the hf value on pb significantly.

Youngsters dont know theyre born these days with everything so simple.
Peter

Peter


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Ty Ford
Re: Headphone out to line in
on Jan 14, 2011 at 8:30:10 pm

Hello Tony,

Why are you trying to connect the two? They are of very different electrical characteristics.

Regards,

Ty Ford

Want better production audio?: Ty Ford's Audio Bootcamp Field Guide





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Tony Connoly
Re: Headphone out to line in
on Jan 15, 2011 at 12:39:01 am

The only cassette player I have access to is a portable player, similar to a Sony Walkman (if you remember those), but made by Panasonic. It has a 1/8" stereo headphone jack. The Marantz recorder has XLR inputs and a digital input, but I was looking to use the 1/8" line in.


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Ty Ford
Re: Headphone out to line in
on Jan 15, 2011 at 3:22:32 am

Tony, Again, please. What are you trying to do?

Ty Ford

Want better production audio?: Ty Ford's Audio Bootcamp Field Guide





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Tony Connoly
Re: Headphone out to line in
on Jan 15, 2011 at 11:04:58 am

Ty,

I am trying to transfer cassette tapes to digital format.


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Ty Ford
Re: Headphone out to line in
on Jan 15, 2011 at 12:34:30 pm

Tony,

The headphone jack on your cassette player isn't really designed to drive the input of the recorder you have. You will probably be able to get audio from one to the other but frequency response may suffer and you may have more noise.

Here's a better solution. One that's actually designed to do the job. I own one.

http://www.ionaudio.com/tape2pc

Regards,

Ty Ford

Want better production audio?: Ty Ford's Audio Bootcamp Field Guide





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Jordan Wolf
Re: Headphone out to line in
on Jan 15, 2011 at 4:02:09 am

Alrighty - now we're getting somewhere! :-)

First, you'll really want to use the XLR inputs (yes, both of them).

Second: Interfacing...

The best option is to balance the signal coming out of the tape player. This can be achieved by using a direct box of sorts (both Whirlwind and ProCo make good units). Using this method will allow for longer cables runs with less interference from external sources. You can then use the XLR inputs without fear of overload. You could also use the box's "sum to mono" function, buy/make a XLR to 1/8" TRS cable, and run that into the Line Input of the recorder.

The next best way would be to buy/make a 1/8" TRS to dual-XLR cable (about 3ft. long would probably be fine). That will keep the signals separate, although unbalanced, so a conservative estimate for cables run lengths would be no more than 15ft.

Hope that helps. Please report back on your decision.

Wolf
<><


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Tony Connoly
Re: Headphone out to line in
on Jan 15, 2011 at 11:06:24 am

Jordan,

Does that solve the issue of the outputs being headphone and not line level?


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Jordan Wolf
Re: Headphone out to line in
on Jan 18, 2011 at 2:50:57 pm

Tom,

The Whirlwind unit will balance the signal and make it "mic level". The ProCo unit should do the same thing, although from what I remember, it does not have inputs pads like the Whirlwind one does (very handy to taming hot signals).

As long as there is sufficient headroom in the circuitry, it doesn't really matter what "level" anything is. The only thing you may notice AFTER the signal is balanced is that there is a teeny bit more noise from added preamp gain. But, that depends...so try it and see if you go that route.

Wolf
<><


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Jordan Wolf
Re: Headphone out to line in
on Jan 14, 2011 at 10:58:13 pm

Could you give us the make/model of the gear you are using? A "headphone out" is usually stereo (2 channels) and uses unbalanced circuitry, whereas a [true] "line input" is mono and uses balanced circuitry.

Interfacing them can be a bit tricky depending on what you are using and the parameters you have control over.

Wolf
<><


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Richard Crowley
Re: Headphone out to line in
on Jan 15, 2011 at 7:46:50 pm

1) LEVELS - The "headphone level" out of a piece of consumer gear is close enough to "line level" (or at least "consumer line-level") that it is reasonably compatible. It is the least of your problems. I would start with the output level of the player set for somewhere between 1/3 and 1/2 full scale just to optimize the signal-to-noise ratio (SNR). It is most critical to optimize the player output level (for max signal before distortion) to maximize the SNR. Then adjust the record level to accommodate the output level of the player.

2) QUALITY - The quality of headphone outputs is typically not as good as the proper line-level output. Specifically, they tend to be more noisy as a "line output" because they are optimized for low-impedance loads. It is always preferable to use designated line-level outputs vs. any kind of headphone output. This is pretty much universal for all equipment on the planet.

3) PINOUT - The 3.5mm or 1/4 inch output from a headphone jack has left on tip, right on ring, and ground on sleeve. Whereas a 1/4 inch line-level input on a pro recorder may very well be balanced (differential signal on tip/ring and ground on sleeve. Plugging a stereo headphone output into a balanced line-level input will deliver the difference between the left and right channels. This is almost certainly NOT what you are after. So you must use proper cables/adapters to at minimum break out the left and right signals from the 3.5mm mini-phone plug. Adapters and cables to do this are available at minimal prices, and even at Radio Shack (at inflated Radio Shack prices).

4) STEREO/MONO - You didn't say whether the cassettes are mono or stereo. If they are mono, then summing the left + right outputs from the cassette playback is probably NOT desirable. Listen separately to the "left" output and the "right" output and select the better one. Note that this preference may change from tape to tape, and even from side A to side B of the same tape cassette.

OTOH, listening to L+R summed (or even better L-R differenced) is a good aid to azimuth adjustment for a mono tape....

5) AZIMUTH - Cassettes are most notable for really really terrible azimuth control, even with premium $10 cassettes and "professional" $2500 equipment. The pinnacle of cassette equipment (Nakamichi Dragon) features a servo motor that CONTINUOUSLY adjusts the azimuth while the tape is playing to maintain optimal azimuth. If you are going for only "transcription grade" transfers from your cassettes, then you can probably get away without bothering with azimuth, using a "walkman" style player. But if you are aiming for any kind of quality, you MUST use something that you can adjust the azimuth for each tape before starting the dubbing. This applies to both mono and stereo tapes, and is even more critical for stereo.

If you MUST use the walkman player, consider the copies to be "working copies" and not archival quality. And by no means discard the original tapes.


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Tony Connoly
Re: Headphone out to line in
on Jan 18, 2011 at 2:04:58 am

Thank you all very much. This has been very informative.


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