Well the Big-W LED strings are out on the shelf and yes they are different to last year.
The LEDS have 10 connected in series with 20 LEDS making one section due to the two channel wiring, for the strings with an average 100mm spacing each section is 2M long.
All colours are the same this year (thanks Geoff) with resistors being used on all series groups.
All wiring is clear insulation and it will remain to be seen if this survives in the aussie summer.
Reports are already occurring of variable build quality and i have had the same experience, the white string i have has an intermittent series group that would normally see someone take them back as not working.
Whilst the initial build quality looks ok with all LED's having heat-shrink over the solder connections, this is not sealed.

The 8 function controller actually take the incoming AC and rectifies this with four diodes wired as a bridge but NO filtering resulting in a pulsed DC wave form.
The two channels are controlled with a CT-55M IC (no info found) and the channel outputs use PCR406 SCR's wiring for each half cycle, at least it looks that way.
For comparison between supplied AC adapter and DC use, actual Light Output readings were taken, these are only relative for the measurements. 10 Leds were measured and the average value used.
Measurements:
The supplied adapter is a big heavy AC-AC transformer rated at 22V and 10W.
Output Voltage with 200 LEDs was: 25V RMS AC
This will be common for all colours.
Cool White:
LUX with supplied Power: 55
DC power.
Just turned on - 25.1V DC
55 LUX - 28.2V and 3mA - this reading is the DC voltage needed to achieve the same brightness as the supplied Adapter
My variable supply max is 32.3V
At this voltage the current had increased to 15mA (still short of 20mA) and the LUX reading was now 200 LUX
The supplied resistor used is a 200 Ohm value.

So at 15mA the resistor will drop 3V exactly with the remaining 29.3 dropped across the 10 LEDs giving each LED a average Vf of 2.93V.
This value is for Cool White only.
20mA of current draw would occur at 33.3V
At 36V you would be drawing 34mA
Red
LUX with supplied Power: 15.5
DC Power
Just turned on - 17.2V DC
15.5 LUX - 23.8V and 4mA - this reading is the DC voltage needed to achieve the same brightness as the supplied Adapter
My variable supply max is 32.3V
At this voltage the current had increased to 12mA (still short of 20mA) and the LUX reading was now 37.7 LUX
The supplied resistor used is a 1000 Ohm value.

So at 12mA the resistor will drop 12V exactly with the remaining 20.3 dropped across the 10 LEDs giving each LED a average Vf of 2.03V.
This value is for Red only.
20mA of current draw would occur at 40.3V
At 36V you would be drawing 15.7mA
--------------------------------
Conclusion:
With regards to the likely best voltage to use with these leds, it would seem to me that from 32-34 volts would be a good range. This is can be achieved by using a 36V SMPS and adjusting the voltage down.
If you want to combine with 2009 versions then 33V may be a good compromise between all the colours with some being a little overdriven and some being under driven.
In light of this i'm going to order a couple a couple of 36V SMPS for my own use.
Cheers
Phil
- Starter Kit - AC to AC Transformer plus 200 LEDs
- Extension Kit - 100 count string


The LEDS have 10 connected in series with 20 LEDS making one section due to the two channel wiring, for the strings with an average 100mm spacing each section is 2M long.
All colours are the same this year (thanks Geoff) with resistors being used on all series groups.
All wiring is clear insulation and it will remain to be seen if this survives in the aussie summer.
Reports are already occurring of variable build quality and i have had the same experience, the white string i have has an intermittent series group that would normally see someone take them back as not working.
Whilst the initial build quality looks ok with all LED's having heat-shrink over the solder connections, this is not sealed.

The 8 function controller actually take the incoming AC and rectifies this with four diodes wired as a bridge but NO filtering resulting in a pulsed DC wave form.
The two channels are controlled with a CT-55M IC (no info found) and the channel outputs use PCR406 SCR's wiring for each half cycle, at least it looks that way.
For comparison between supplied AC adapter and DC use, actual Light Output readings were taken, these are only relative for the measurements. 10 Leds were measured and the average value used.
Measurements:
The supplied adapter is a big heavy AC-AC transformer rated at 22V and 10W.
Output Voltage with 200 LEDs was: 25V RMS AC
This will be common for all colours.
Cool White:
LUX with supplied Power: 55
DC power.
Just turned on - 25.1V DC
55 LUX - 28.2V and 3mA - this reading is the DC voltage needed to achieve the same brightness as the supplied Adapter
My variable supply max is 32.3V
At this voltage the current had increased to 15mA (still short of 20mA) and the LUX reading was now 200 LUX
The supplied resistor used is a 200 Ohm value.

So at 15mA the resistor will drop 3V exactly with the remaining 29.3 dropped across the 10 LEDs giving each LED a average Vf of 2.93V.
This value is for Cool White only.
20mA of current draw would occur at 33.3V
At 36V you would be drawing 34mA
Red
LUX with supplied Power: 15.5
DC Power
Just turned on - 17.2V DC
15.5 LUX - 23.8V and 4mA - this reading is the DC voltage needed to achieve the same brightness as the supplied Adapter
My variable supply max is 32.3V
At this voltage the current had increased to 12mA (still short of 20mA) and the LUX reading was now 37.7 LUX
The supplied resistor used is a 1000 Ohm value.

So at 12mA the resistor will drop 12V exactly with the remaining 20.3 dropped across the 10 LEDs giving each LED a average Vf of 2.03V.
This value is for Red only.
20mA of current draw would occur at 40.3V
At 36V you would be drawing 15.7mA
--------------------------------
Conclusion:
With regards to the likely best voltage to use with these leds, it would seem to me that from 32-34 volts would be a good range. This is can be achieved by using a 36V SMPS and adjusting the voltage down.
If you want to combine with 2009 versions then 33V may be a good compromise between all the colours with some being a little overdriven and some being under driven.
In light of this i'm going to order a couple a couple of 36V SMPS for my own use.
Cheers
Phil