Hoping someone can identify the turbo noise which I am getting under light acceleration and just beginning to build boost on a 1JZ GTE?
Noise is not present under WOT driving and can be heard in the link below:

http://www.youtube.com/watch?v=GTk9TWZjkic

Am running a set of highflowed CT12a turbos with T28 core's, can't recall the size of the compressor/turbine wheels...but do recall that they were slightly larger than the stock CT12a ones...Have removed the boost controller in case it might have been a faulty solenoid...same problem exists, checked all lines to the turbo setup, looks fine...have still yet to test intercooler piping.

Is it a boost leak or are the turbos surging?

BOV has been changed to an aftermarket turbosmart one mounted in the same location as the factory stock one...same issue was occurring when the stock factory BOV was in place as well, thus why the turbosmart one was bought...to eliminate a faulty or weak BOV.

Hoping to get some other people's advice, as I have been trying to work out this problem now for over a month and not having any luck

Cheers,