Humming sound when I use phono inputs on Mbox 2 Pro

[James Tongham]

I'm getting a continuous hum when trying to transfer a piece of music (Mancini's version of Jesu Joy of Man's Desiring, FTR) onto my computer via my new Mbox 2 Pro.

I am hoping someone might be able to advise me here, as I'm not so hot on technical matters. I think I've set it up corrrectly, but possibly someone who know about these things can spot where I might be going wrong??

Back of cassette player/CD player (early 90's ghetto-blaster type thang) has a mini-jack putput, and I need to go from this into the L/R phono inputs on back of Mbox. For this purpose I bought a stereo mini-jack to Left and Right phono cable from Studiospares.

In the Pro-tools mix window, I make the inputs Analog 3-4, as suggested in manual, then record enable, and I flick on the Phono switch on Mbox front. Music comes through strongly, but with an underlying hum, which I can't seem to get rid of no matter how I twiddle the levels.

Studiospares sent through another cable today, as they said it sounded like a faulty one had been sent. Alas, no luck, hum's still there!

I talked to someone about the possibility it's because I'm neglecting to use my grounding post on the back of my Mbox, but the someone I talked to said such hums normally happen when connecting DJ turntables. Is this right, or is the grounding post the key? If so, how, considering the cassette/CD player doesn't have a grounding post of its own, do I go about utilising it?

Any other ideas/suggestions would be very welcome!

[bennychico11]

your problem is you're connecting it to the phono input....a CD/cassette player does not plug into the phono inputs. Phono inputs are reserved for record players/turntables.

You need to plug into the line inputs on the Mbox2.

[Lt. Bob]

Originally Posted by bennychico11

your problem is you're connecting it to the phono input....a CD/cassette player does not plug into the phono inputs. Phono inputs are reserved for record players/turntables.

You need to plug into the line inputs on the Mbox2.

Ditto ........ in addition to the hum you're getting, the phono inputs are goona apply RIAA equalization to the signal which will muck up the sound of a CD/cassette source.

[James Tongham]

Aha, and suddenly it all makes sense! Thanks very much for that.

So, next thing to do is try the same set-up with my non-preamped turntable, which is currently stored at my parents house.

You don't think I would have done any damage to the Mbox by trying to put the CD/cassette player into the phonos instead of the line?

[Lt. Bob]

Probably not ....... but that line input is WAY hotter than a typical phono signal so it could be possible I suppose.

Check it out thouroughly and if it seems to work ok I wouldn't worry about it further.