I seek some advice in converting my DSP3100HC from 110V to 220V.
The unit was from US and has been verified to work on 110V AC using an external step down transformer by myself. However, I would like to get rid of the step down transformer, if possible and easy.
The toriod is made by Toriod Audio Ltd in the UK. I failed to get any information of the toriod on internet. I uploaded the photos of the toriod
here.
The existing 110V connections of the inputbrown wire - Live
white wire - Neutral
blue wire - un-connected
green/yellow - Ground
There are seemingly six output wires on the outputorange x 2
yellow x 1
red x 2
black x 1
The above looks a bit unusual for me because it does not look like a typical dual 110V primary windings, which has four (or six for 100/110/200/220V) input connections. It does not look like a dual secondary output, which has four output connections.
I guess that I can change the unit from 110V to 220V by:
(i) disconnecting the white wire from the neutral connection on the circuit board (T11, photo #7); and
(ii) connecting the blue wire to the neutral connection on the circuit board (T11, photo #7).
The above assumes that the white wire is a 50% tap off from the Brown-Blue (220V) primary winding. But it seems uncommon because this design is a waste of wiring when being used in 110V mode. That is also the reason for dual 110V primary winding as far as I understand.
For your information, the following is the official reply from Meridian's Customer Service.
As you suspect, the M33 and DSP33 loudspeakers both have toroidal transformers dedicated to operation in specific territories. If you move to a country with a different mains supply, you must have the product rewired for that supply. You could use a step-up/step-down transformer, but this would reduce performance and impact listening pleasure.
It tends to indicate that it is possible to rewire DSP33 and M33 for different voltage.
My request:
(i) Grateful if anyone savvy could advise the verification procedure or provide your comment.
(ii) If anyone has the wiring photos of M33, DSP3100 or DSP33 on 220V verison, please consider sharing it with me.
Thank you in advance.
Best Regards,
KC