New headphones

[Herb]

Hey all and Woody
                              I recently bought some new headphones and speaker off you Woody and had a chance to try them out the other day. The headphones are great and a pleasure to use . It sounds like your using a booster when using these in noise cancelling mode . Great but not perfect as with a lot of things  . I get a slight high pitch noise when using in noise cancelling mode . I ve experienced this before when using a booster and it's slightly annoying when using in this mode all the time . Can this be easily rectified ? Also the cord could be another 6" longer as mine pulled out during the day's detecting . I'm am 6'3" though so they'd be no worries for anyone shorter. Crystal clear on the targets even when not in cancelling mode . Speaker ok but sounds a bit tinny and quiet but as I only use it for back up it'll do the job! Any one else used these headphones or speaker ? Any thoughts ?
                 Cheers Herb

[woody]

Hi Herb,

The high pitched noise is caused by the current through the coil getting into the headphone electronics, if you are using a booster and it does not have decoupling built in then it will cause this noise, a bad internal grounding in the detector will cause this noise as will a bad coil connector.    Try a smaller coil and if the noise gets less then it is coil switching current, try connecting the headphones directly to the detector with a non amplified battery and see if it has gone.

[Herb]

Cheers Woody
                     I'm still swinging an unmodded 45 and standard battery that came with it and no booster I'll try another coil next time I go out but the evolution 17x13 I've got on there is relatively new ! The headphones dont make the noise when not in noise cancelling .I don't have another battery to try but may be able to borrow a mates. I'll hopefully be looking at sending you my detector in the new year to work your magic upgrade on. Will this help ? And  what's the turn around time roughly ? Cheers Herb

[woody]

Hi Herb, 

Turn around time is a week or so,   The ML battery has an amplifier inside the battery, it may be a case of double amplification and boosting the switching noise from the coil.

I use my own small batteries and that noise does not show any noise.