I had intended to post this thread under my CD4-10s project, but I figured that since it could apply to anyone who buys Japanese gear that runs on 100Vac and does not have a voltage select option. This mod allows me not to have to use an external voltage converter. All you need do is select a 120V to 20V transformer of the correct VA. The transformer can be placed inside, like the CD4-10 that has room, placed on outside the back of the case or put in a separate box. The PDF file shows the schematic and a brief description on how it works.
CD4-10s Mod, 120Vac to 100Vac Bucking Transformer
- Thread starter jwb474
- Start date
Help Support QuadraphonicQuad:
Yes, you certainly can, but It is hard to find a 120/34VAC transformer at the right VA. The 120/20VAC is very common and from several manufacturers and in immediate shipment status.. They are readily available in several VA sizes. Since I get quite a bit of stuff from Japan that the voltage is not selectable, I have made it a point to keep several different VA sizes in stock. The CD4-10 is a best case unit: Plenty of room and only one secondary winding. Most gear there is no room inside and the transformers are very special in both physical size and most have multiple secondaries. This was an exercise in what can be done easily and explain the theory behind the bucking transformer. I was also able to dead ringer the 100Vac to the CD40-10's primary.
