How can I turn 120VAC to 100VAC for Tango MS-UVD in an 845 SE amp?

[HP8903B]

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[zigzagflux]

http://www.diyaudio.com/forums/tubes-valves/133843-how-wire-buck-transformer.html

The principles are all there. If you need more specifics, let me know.

 

[Rodeodave]

Also here: Bucking Xfmrs
If I understand correctly you'll need a xformer with a 20V secondary. Primary and secondary winding are then wired in series (Fig4) and used as a voltage divider.

 

[HP8903B]

Thank you guys for the information.

It seems like the best way to reduce the voltage is by using a buck transformer.

Do I need to buy a separate transformer or do I use the secondary voltage of the Tango power transformer that is in my amplifier?

 

[HP8903B]

Here is a picture of the Tango power transformer.

 

[HP8903B]

Picture

 

[HP8903B]

I see that I would need a separate transformer.

My main voltage is 124V. Seems like I would need a transformer with 24V secondary. What about the primary voltage?

Could you guys tell me where I can get a good transformer?

 

[kevinkr]

I see that I would need a separate transformer.

My main voltage is 124V. Seems like I would need a transformer with 24V secondary. What about the primary voltage?

Could you guys tell me where I can get a good transformer?

Current transformers intended for the U.S. market generally have 120V primaries, no real choice here. Anything in the 20V - 24V range is going to work fine.. You haven't mentioned what the current consumption of this amplifier is on 100V - that is a part of the puzzle that is missing, and I usually like to chose a transformer that is rated at twice the maximum current I will use it at for this sort of application.

Antek makes toroids that are pretty good for this application for very reasonable money.. Digikey, Mouser and Allied Electronics also sell a variety of transformers that would be well suited for this application.

 

[HP8903B]

I haven't measure the current of this amp. I need to replace the fuse on my meter. The amp is an 845 SE so I suspect that it draws about 300w or 3 amps.
I will measure the current when I get the fuse. Assume that it draws 3 amps, what is the current of the transformer I should get?

 

[woody]

Apex Jr. has a 160va toriod with dual 24v secondaries. If you wire the
secondarys in parrallel that should be good for 24v at 6.6A. By the way
just for YOU in keeping with the holliday sperit. I have a small isolation transformer case that would probably be neet to wire the bucking transformer up in. Free for the shipping.

miscellaneous.html

 

[HP8903B]

Thank you woody for the offer. I plan to just put the transformer inside my amplifier so I won't need the case.