Max length of input cable from tape heads

Tubejack · 9271

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Offline Tubejack

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on: November 07, 2016, 07:40:22 AM
I have an Otari MTR-10 which I have wired the playback head directly to RCA's on the back panel.  My setup (just moved, new house) currently is cumbersome wrt equipment placement, etc.  My RCA interconnects will be about 2M.  Seems long.  Using low cap good quality IC's (well, no, not the $1000/M kind, but not el cheapo either).  What's your best guess on max length for connection to a Repro?

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Offline Doc B.

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Reply #1 on: November 07, 2016, 08:05:27 AM
One meter, as low capacitance as possible and well shielded is a good rule of thumb. I'd suggest 50pF per meter or so as the maximum capacitance. It's difficult to suggest anything more specific without knowing the inductance of the repro head. That's not to say you won't be happy with your 2 meter cables, you pretty much just have to try it and see if it sounds OK. Belden 89259 has the advantage of very good magnetic interference rejection due to its coaxial construction and is around 52pF per meter. That is my preference. Mogami 2549 is a good choice if you want shielded twisted pair.

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Offline Tubejack

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Reply #2 on: November 07, 2016, 09:17:18 AM
Thanks, Doc.  IC's are actually 6', and spec'd at 12.2pf/ft, or approx 73pf, double braid shield.   I also have a 3 ft pair, I will try to see what I can do do get the Repro closer to the deck.   The head Z may be spec'd in the service manual, but since the move it's probably with the left Lucchese boot I can't find ..... :'(

There are 10 types of people in this world,
Those that understand Binary and those that Don't!