Otari mx-55 tape machine sounds like static.

[pucho812]

Machine Otari mx-55  1/4 2 track with center time code. center tc track not being recorded.

got an MX-55 that a friend is using as a mix down deck. It was aligned and was working quite well until yesterday. Yesterday, when recording to it and monitoring off the repro head I get the sound of static in one channel only(the left side) of the 2 audio channels. Static is random and will be present at all times. If just have the machine in record and monitor off repro head and am not sending audio to it, I still have the random static. I have so far swapped cables and no change. I swapped audio cards around and the sound didn't change, it's still on the left side.  Tried different tapes both fresh new reels and still the random sound of static. Could it be the heads? it's the only thing left I can think of as there really isn't much else in the audio path

Oh yeah and before anyone asks  this is happened before and after  we used a hand demag on the heads.


O.k. so searching lead me to this.

http://soundcloud.com/blungo2/march-tape-noise

that is it that is the noise. In the recordings it's louder then the mx-55 I am working on but that's it. Further searching has lead me to an answer that it could the  relays on the audio cards. But that would suggest that it would follow the card when swapped.

might be time to do a head relap.

 

[ruffrecords]

That sounds like a leaky resistor or cap  or a dry joint to mem possibly in a circuit outside the audio path - maybe the control circuits. If it really is static you can test by playing back with no tape running.

Cheers

Ian

 

[pucho812]

only does it when tape is running, and only does it on new recordings as of yesterday anything prior does not have it at all. Oh yeah and it goes away if the audio card is not plugged into that slot. But that last one makes sense as how would you know it was there otherwise.

 

[ruffrecords]

only does it when tape is running, and only does it on new recordings as of yesterday anything prior does not have it at all. Oh yeah and it goes away if the audio card is not plugged into that slot. But that last one makes sense as how would you know it was there otherwise.

OK'it is not a fault on the replay side, it must happen during record. It does not go with the audio card so it must be something else interfering with on record amp. Is that card near the transport controls? Another thought, is there PSU decoupling external to each audio card?

Cheers

Ian