RM Italy KL-300P Modification
from Class C to class AB amp
(from Rabbit Ears)



Well, here it is the mods for the KL-300P
amp for work great in all modes.
Yesterday, both 300P amps were tested and
sounded really great!! Sure was neat-o!
Okay Guys and Dolls here it goes!!
(assuming your unit is new in the box) This
is going to be very lengthy.
(You will need heatsink grease, a 1N5004 diode,
and a 100 Ohm 10W power resistor for this job)
1. Remove the KL-300P amp from the box and
remove all of the packaging. Turn the thing
upside down to remove the bottom cover..(it
slides off) to expose the circuit board
inside. Take a moment to read what version you
300P amp is.
(The one that we will be covering will be
a 300P version 4.1.)

2. Okay, now you'll look for the service
pins (numbered one through four) they should
be between the input jack and T1. See if pins
#1&2 have a shorting block betwwen them...if
not, push a shorting block over them.





3. Remove all screws from black plastic front,
the three from the pc board, the four from the
RF transistors, and the four from the co-ax
jacks. Now, very carefully wiggle the unit
out of the red aluminum casing. Take note of
where the heatsink grease was applied to it.
Set it aside for later.

4. Take a look at the now and see where T1
is located at, it is the smaller transformer
by between the switches and the RF SD1446
transistors

5. Unsoldier both ends of T1's blue wire
from the PC board.





6. Now use a Dremel or an exacto knife to
cut the pc board foil around where the T1
"tubes" are soldiered. take a look at the
gaps between the PC board and the transformer.
Start your cut at the gap, cutting around
the soldiered end to the gap on the other
side. Careful of your blue wire. Resistance
should measure about 5 Ohms across your cut.
Resoldier both ends of T1's blue wire to
the PC board where you had disconnected
them from.





7. On the other side of the transformer
where the transistors are soldiered to
the "tubes" is a good place to soldier the
diode and the resistor to. The cathode of
the diode is soldiered to ground the other
end to T1 where you cut around, the 100 Ohm
resistor is soldiered to where you just
soldiered the diode to the trasformer's
"tubes". The other end to where the power
switch is soldered to the PC board. Be sure
that the bare leads of the resistor and diode
do not short to any other component on the
board. Yep, a lot of work...but worth it.





8. Reassemble your amp, and do not forget
to apply a generous amount of heatsink grease
on the red aluminum case where your
transistors screws screw into it.

9. Test your amp...
NOTE: This mod is at your own risk,
however...it worked great for me!

Rabbit Ears

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