After making a couple of DIY audio cables (both interconnects and speaker cables) from cat 5e cable, HQ coaxial cable and Tasker C850 cable, I had inner DIY-man evoked in me. I have also modded my computer in the past with low-noise fans, noise absorbing wall material and replaced stock coolers with low-noise overclocking coolers etc, so what I did was not hard for me at all nor would be hard to even less experienced DIYer.The "whole new" and "improved" Mod-5004:
I got "little" paranoid about these issues concerning both 5004 and 6004. Whether or not they rise from exessive heat, I bought today a 8,5x8,5cm(covers transformer wholly), 2cm tall heat sink and 1,5mm thick heat conductive silicon pad to be placed under the heatsink. I thought it can do no harm to take some "safe measures", although I highly think that if the receiver were going to pop, it would have done so already. Safety first, said the modder and opened the receiver with power cord still plugged (just kidding, heh).
Now heat sink sits happily on the transformer of the Mara, lol.
The package is held in place with two 15cm long stripped 1,5mm2 copper wires that go through the transformer (there are holes in it) and through the screwholes of the heatsink and then are twisted very tight with pliers. This keeps the heat sink in place (it does not move at all) and tightly pressed against the heat conductive silicon pad between the transformer and heat sink.
Top of the heat sink is touching tightly the chassis of the Maranz, so now the chassis is also part of the cooling system.
One can speculate (= dream) whether the lowered temperature of the transformer could benefit it by being able to produce couple of RMS watts more or same watts more easily and with prolonged life expectancy.
The latter part concerning life time is not dream though. As a thumb rule you can prolong any electronic component's life time by keeping it cooler.2.
In addition, I quess you all have read some measurements from test like this
. It shows that S/N ratio differs from channel to channel. Usually they place the front speakers' amp farthest from the transformer/power section to gain maximum S/N ratio because transformer and some other power components generate (powerful) electro magnetic waves. Sometimes you see receivers where the transformer is behind a heatsink or metal wall that separates the transformer from amps and other componenets, like in this one: http://www.pacificvalve.us/images/BA...2AU7_Front.JPG
. Btw, that amp has metal cover over the transformer and metal wall separating the power section, double insulated
Marantz uses a insulated transformer, although it is not fully covered in metal and therefore insulation could be better.
So I made a metallic insulator pad to separate power section from the amp section. Waves radiating from transformer are stopped by the metal in the pad. The pad is approx 0,3-0,5cm thick and is made from multilayered (like 80 layers) tinfoil covered with kitchen "natural membrane" and tape on top of that to hold it together nicely. The pad would not win a beaty contest or place even in the top-100, but I married her because of her inner beaty!
There is a gap between the power section's and amp sections's boards, where the pad fitted just right. I attached the pad with tape to the amps' heatsink right next to it on the right so it won't touch the transformer and hinder the warmth from evaporating.
Now, in theory, nearly all of the possible interference that was coming from the power section of the receiver and were interfering the amplifiers, are gone.
There is always room for improvement and these mods would benefit (how much, dunno) nearly all av-receivers that have powerful, heat producing transformers ("400 watt and below" transformer owners might skip the heat sink.) that are not behind metal wall or heatsink(= not insulated). Don't worry about the looks, it does not show outside the receiver
If ever needed, both mods are easily removed without leaving any marks to the receiver, so they are not questionable in warranty's point of view. Can the same time be used more creatively or are the mods otherwise smart or stupid, no comments
Despite the picture, the pad is taller than the transformer alone, the heat sink skews the dimensions.