Panelhead said "Do not know, yet. Working on the boards for this. Using the two channels with the lowest dc offset.
Hope that the use of a SI board per channel with give even more slam and dynamics. Terminating the unused channel with a 8 ohm resistor and 0.15 cap on the board. Grounding the unused input.
Finally, did like some others and soldered a pair of 120 ufd Nichicon UHE caps right to the pins, bypassing the 0.10 ufd SMD cap. Also installed a 680 ufd cap as the onboard filter cap.
If I get feeling brave, may try soldering the input power lead to the chip also. This is one trick the Clari T has on most of the diy 5066 jobs. But not quite that brave tonight."
I would NOT terminate the output of the unused channel at 8 ohms. If going that route, you want to use a VERY high value non-inductive resistor. This reduces the thermal and current demands of the unused channel of amplifier circuitry. Since the amplifier can't deliver much power into such a high impedance, the use of a physically smaller, lower wattage resistor is also possible. This is cheaper, more effective and easier to work with i.e. a win / win situation in every aspect.
If i were messing with one of these and wanted to go the "mono-block" route, i would take the above approach a step further and disable the input of the unused channel at the chip and shunt it to ground using a reasonably low value resistor i.e. 50 - 100 ohms. You now have no potential for crosstalk between the channels, no potential for the channel being used to modulate the unused channel ( or vice-versa ) with signal or RFI / EMI. Even if there was signal leakage / cross-contamination, the amount of signal being conveyed between the two channels would be so low due to the impedances chosen as both input and output shunts that it would be negligible.
As far as the power supply wire routing goes, bare in mind that these are "dirty" amplifiers. Altering the feedpath will not only alter impedances, but also change how the power supply related noise is distributed ( sprayed around ) inside the amp. While this can be beneficial in terms of increased current demands with less potential voltage sag, try to use some type of a heavy gauge shielded cable. As far as shielding goes, a high percentage heavy copper braided shield is more effective than less braiding and a foil shield. In this regards, a 98% copper braid is more effective than a 60% braid with a 100% foil shield, so don't fall for "double shielding is better than single shielding". The shield should be connected to ground as that will keep unwanted radiation to a minimum. Otherwise, your power supply lead will act as an antenna and could actually degrade the sonics of the system. This is a common problem with mods as people try to improve the performance in one area and end up creating yet another problem. The end result is that the mod is beneficial, but possibly not to the extent that it could be if all the various design attributes were taken into consideration.
You might also want to install a larger value cap and a bypass cap at the point where the shielded power cable feeds into the chip also. This will not only act as a reserve for the chip right where it draws power in, it will also act as a RFI filter for any type of noise that the chip tries to feed back into the supply lines. This may further reduce the potential for RFI from being sprayed around inside of the amp, which would find it's way into the signal related circuitry.
I've not studied this amp at all, but those are just basic precautions that should be taken with the overall perforamance of the product taken into consideration. Not all circuits are the same though, so not all "mods" or "tweaks" will work in the same manner or with the same effectiveness. Sean
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