reubensm
Well-Known Member
Received a question earlier today from our forum member WLG. He acquired a Technics SLBD20 belt drive TT which works on a 110 volt mains supply and wanted to know if this TT's power transformer may have a tap for 220volts. Thought I'll share my response for the benefit of all.
The Technics SLBD20 was generally manufactured in 4 versions:
1) for USA and Canada only: AC 120 volts, 60 Hz
2) for UK and Australia only: AC 240 volts, 50 Hz
3) for Continental Europe only: AC 220 volts, 50 Hz
4) for other all other countries: AC 110-127 volts, 60 Hz or AC 220-240 volts, 50 Hz (switchable)
From a power supply perspective, the difference was predominantly with the transformer type. Version 4 (listed above) came with a tapped transformer with a voltage selector.
Here are the schematics of the 2 broad versions:
1) The single voltage option PSU:
2) The multi-voltage option PSU:
From the multi-voltage PSU circuit, it is evident that the transformer is predominantly a 220 volt one with a 110 volt tap (which is switched).
Here are the actual PCB layouts for both types:
1) The single voltage option PSU layout:
2) The multi-voltage option PSU layout:
Hence if the TT does not have a voltage selector, it is most likely that it is a single voltage option TT and hence is not likely to have a power transformer with the 110volts tap. However there's no harm taking a look inside if you are a bit adventurous.
As the rated power consumption of this TT is not more than 3-5 watts, it is safe to use a low cost 220-110 volt adapter, one could pick up from any shop selling Chinese toys or general electricals. These little adapters usually have a rating of about 10-15 watts.
Hope this helps.
The Technics SLBD20 was generally manufactured in 4 versions:
1) for USA and Canada only: AC 120 volts, 60 Hz
2) for UK and Australia only: AC 240 volts, 50 Hz
3) for Continental Europe only: AC 220 volts, 50 Hz
4) for other all other countries: AC 110-127 volts, 60 Hz or AC 220-240 volts, 50 Hz (switchable)
From a power supply perspective, the difference was predominantly with the transformer type. Version 4 (listed above) came with a tapped transformer with a voltage selector.
Here are the schematics of the 2 broad versions:
1) The single voltage option PSU:
2) The multi-voltage option PSU:
From the multi-voltage PSU circuit, it is evident that the transformer is predominantly a 220 volt one with a 110 volt tap (which is switched).
Here are the actual PCB layouts for both types:
1) The single voltage option PSU layout:
2) The multi-voltage option PSU layout:
Hence if the TT does not have a voltage selector, it is most likely that it is a single voltage option TT and hence is not likely to have a power transformer with the 110volts tap. However there's no harm taking a look inside if you are a bit adventurous.
As the rated power consumption of this TT is not more than 3-5 watts, it is safe to use a low cost 220-110 volt adapter, one could pick up from any shop selling Chinese toys or general electricals. These little adapters usually have a rating of about 10-15 watts.
Hope this helps.
