From James.eaton@accenture.com Tue Sep 04 04:17:09 2001
Subject:Re: Pro 3T volume

--- In CloneWheel@y..., jarrell7@y... wrote:
> Also, when I plug the Pro 3T low output into my amp and turn it up
> to a decent volume, I definitely hear the 60 cycle hum. I don't
> remember hearing this until recently, though.

Jarrell,

I have hum problems with my Pro-3T but I only notice them at home so
I have stopped worrying.

I tried to eliminate the hum with an earth loop isolator transformer
at the input to the Pro-3T which got rid of some of the hum but the
impedance characteristic affect the the Pro-3 so that it got a kind
of distortion that occurred below a certain threshold. Also the
transformed started to roll off below 40Hz which was too high and
affected the bass sound.

I tried another isolator on the output but I think the problem is
that the Pro-3T is prone to hum. I think maybe some components are
susceptible to pick up from transformers in other equipment, and that
the earth design leads to hum loops. I use the low-pro connector
and send it to a custom lower rotor using the analogue ground
connection, but it still hums.

I have run out of ideas for the moment.

By the way, I just painted the inside of the revolving drum on my
lower rotor (it had some old matt black paint on it) with black satin
finish paint and the improvement to the bass is dramatic. In fact it
found all sorts of new resonances in my cabinet that I never knew I
had - oh dear. Back to the drawing board...

Cheers

James