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Author Topic: OTARI recording level +4 dB vs. pre-amp outs of ?10 dB  (Read 5489 times)

Offline analogfan

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OTARI recording level +4 dB vs. pre-amp outs of ?10 dB
« on: December 26, 2009, 08:16:06 AM »
OTARI recording level +4 dB vs. pre-amp outs of ?10 dB

I am new to pro-level decks, having recently acquired an OTARI 5050 B3. I have owned other R2R decks and cassette decks but have not run into this problem as they were consumer/prosumer level decks and the pre-amp tape-out levels matched the tape recorder, record-in levels.

The tape-out levels from my BAT VK30 pre-amp are ?10 dB or around .3V rms (I verified using a Nakamichi deck?s VU meters and can easily get 0 dB with the recording level pot at the 4 o?clock position).

My OTARI B3 is looking for a +4 dB input level or around 1.2 V rms for recording. I have to crank-up the record pot to about the 3 o?clock position to get 0 dB on the OTARI VU meter. I am assuming that I will have to re-align the recording electronics using a calibration tape (e.g. MTR) recorded at ?10 dB reference levels to re-calibrate the OTARI operating levels for ?10 dB? Is this correct?

Am I missing an easy solution or do I have to go the alignment route? Any other suggestions/comments are appreciated.

I have the OTARI operating manual which provides the alignment procedures and the required test equipment but will have to obtain an alignment tape. I have found vague references to ?operating levels? in the manual and on the Internet but nothing as to this specific problem and how to deal with it.

I will not be using this set-up for studio work ? only home recording and Tape Project playback.

Thank you ? any ideas would be appreciated.

Bob Edwards

Offline ironbut

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Re: OTARI recording level +4 dB vs. pre-amp outs of ?10 dB
« Reply #1 on: December 26, 2009, 11:28:08 AM »
Hi Bob,

If you think of the mic/line input pot as a mixer or preamp of your machine which could be outboard just as easily. This mixer just adjusts the input level to the record section of the machine. So, the record section doesn't really care how the levels were adjusted properly, they just care that it is.
Calibration of the record section is all about the head/tape interface and optimizing that.

So, you don't need to do any adjustments to your machine as long as the levels can be made.
steve koto
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Offline analogfan

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Re: OTARI recording level +4 dB vs. pre-amp outs of ?10 dB
« Reply #2 on: December 27, 2009, 02:26:41 PM »
Thank you for the reply Ironbut!

So if I am cranking-up the record "line input" to whatever, the OTARI doesn't care where the pot is adjusted to, is what I think you are saying.

So I don't need to worry about re-calibration or say a Jensen PC-2XR transformer for matching consumer level to pro level, which was suggested as a possible approach by a buddy?

I am think of having a cable made-up (Canare/Neutrik) with an RCA at the pre-amp end and an XLR at the line-in OTARI end.  Do I need to worry about Z match?

Thanks again - appreciate it!

Bob Edwards/analogfan

Offline ironbut

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Re: OTARI recording level +4 dB vs. pre-amp outs of ?10 dB
« Reply #3 on: December 27, 2009, 03:24:39 PM »
Hey Bob,

The input impedance is 10k ohms so unless you have an unusually high output impedance on your preamp, that should be fine.

If you're having a pair of custom cables made and you don't expect to be using them for anything else, you might as well have them made with the correct XLR connections for the Otari.
The conventional is;
Pin 1>ground
Pin 2> hot
Pin 3> cold
The Otari is;
Pin 1 >ground
Pin 2>cold
Pin 3>hot
There's a diagram of how to connect to RCA cables in the manual.

I doubt if having those switched will make an audible difference since it's an absolute phase issue but like I said, if these cables are dedicated for your Otari, why not?
steve koto
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Offline analogfan

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Re: OTARI recording level +4 dB vs. pre-amp outs of ?10 dB
« Reply #4 on: December 27, 2009, 07:00:26 PM »
Thanks again Ironbut,

Appreciate the feedback!  Understand the pin 3 vs. pin 2 (consumer) wiring.

I have been amassing information on the OTARI 5050 B3 - if anyone needs any thing that I have am happy to share.

Happy New Year!

Bob Edwards