Step-Up Transformers for Moving
Coil Cartridges
So, you have the Step-Up Device and you want to properly install it into
your system:
Step 1 - Connect
the leads from your turntable to the input connectors on the Device.
Step 2 - Connect
the ground lead from the turntable to the ground lug on the Device.
Step 3 - Use a
short pair of interconnect cables to connect the output of the Device to the
input of your Phono Preamplifier or Phono Inputs. For best results,
this set of cables should be like the ones in this DIAGRAM
.
Step 4 - Turn
everything on and listen to the background noise. Move the ground /
lift switch to whichever position is quietest. Then move the
transformer around to find the quietest location.
If you are
continuing to have problems, try connecting an ordinary piece of wire
between the ground lug on the phono preamplifier and the device (in addition
to the one from the turntable). Then try the ground / lift switch in
both positions to see what sounds best. Then, if it still is not
quiet enough, take a look at the following information:
Start
from your cartridge and follow the wires, looking carefully for any places
where the negative terminals of the cartridge (lets call them system
ground) are connected to equipment grounds (let's call them chassis ground,
sometimes referred to as drain wires) We only want one chassis ground
connection between pieces of equipment. When there is more than one chassis
ground connection, there is the possibility of a ground loop (it doesn't
know which way to go, so it keeps on moving and generates noise.)
The
other type of noise is interference (you get that from any parts of your
system wires running too close to power transformers, power cords, or any
kind of AC power.)
Now,
since we all use RCA cables from the turntable to the phono preamp, the
negative (system ground) wires have to be shielded with a chassis ground.
(Read that sentence twice). Some turntables connect the shield of the RCA
cables to the chassis ground wire at the turntable, and some do not.
The next 2 paragraphs
repeat the initial steps above, but written in narrative format, and in more
detail:
If
your turntable has a pigtail along with the RCA connectors, then that is
the chassis ground from the turntable. Connect that pigtail to the
ground lug on the step up transformer. Then connect everything else,
without connecting the ground to the phono preamp. Try the ground /
lift switch in both positions and see which is quietest. Then,
additionally, connect a separate wire between the ground lug on the step
up transformer and the ground screw on the phono preamp and see if that
is quieter or noisier in either of the ground / lift switch positions. Then you can
determine whether you need to ground the phono preamp to the step-up
transformer or not. Regardless, you need the proper interconnect as
shown in my
DIAGRAM
to go between the step up transformer and the phono preamp.
You
only want them connected that way at one end, hence the ground / lift
switch. So, here is the short answer. Remove the ground wire connecting
the turntable from the phono preamp. Connect ONLY the ground from the
turntable to the Box you got from me. Don't connect the wire from the box
to the Phono Preamp just yet. Now, make sure that you use interconnect
cable between the transformer and the Phono Preamp that have 2 wires inside
(positive and negative) and the shield is connected to the outside (chassis
ground of the cable) at only one end. (The cable will have the negative
lead and the ground attached to the outside of the RCA connector at one
end. The cable will only have the negative lead (Not the ground) attached
at the other end.) Now, with everything hooked up, turn it on and listen to
the hum. Then move the switch to whichever position offers less hum.
Then touch the preamp ground wire to the ground lug and see if it is less or
more noisy. Then remove the wire from the phono and see if it is quieter or
not. Then touch the phono wire to the preamp wire and see if that is
quieter.
Sounds
like trial and error. It basically is, but the idea is to make sure that
everything is grounded, and only grounded once, and the all the audio
cables' shields are grounded, and only grounded once.
You will find that the transformers are very
susceptible to Electro-Magnetic Radiation, and you may need to move them around a bit to
find the quietest location. For me, it is just below my turntable and on
top of my preamp.
If you want more
information, check out
Included on their site
are some diagrams on wiring that may be helpful. You
are welcome to send me any questions or suggestions.
Regards,
Bob Sattin
bob@ec.rr.com
www.bobsdevices.com
