Dual voltage transformer

Orange Amps Technical Q&A's

Moderator: bclaire

Post Reply
New Member
Posts: 1
Joined: Sat May 12, 2018 12:51 am

Dual voltage transformer

Post by Oby » Sat May 12, 2018 1:09 am

I have an Orange Crush Bass 50 which has no power.
After opening the box I discovered the wiring to/from the power transformer is not all connected and when I trace the circuit it is clearly incomplete.

The transformer is dual voltage (110/240) and the switch on the amp is pre-set at the factory to 240v but the wiring on the back of this switch is connected for the 110v side. It also has a 2A fuse inside which is supposed to be for 110v (240v uses a 1A fuse).

Power transformer has 4 input wires (2 on each side) and 4 output wires (these go to the main circuit board).
On one side the input wires are black and brown. The other side is red and blue.
The brown wire is connected. The red wire is connected. Blue wire is connected to the power socket (the wall power) then goes to the wrong side of the switch where it also continues on to the transformer. Black wire is not connected at all.

So it appears the red wire is useless because it is connected to the switch which is set to 240v and therefore doesn't complete any circuit.

My limited understanding of power transformers and voltage is when you put voltage in series you add the voltage. In parallel the voltage stays the same.
So I "think" the black and red wire should be connected in series and the brown and blue wires should take the input from the wall power.

So... do I connect the black wire To the 240v side of the switch and remove the blue wire then connect the black and red together? This should put the two halves of the transformer into series right?

Mr Mustard
New Member
Posts: 41
Joined: Sun May 09, 2004 11:52 pm

Re: Dual voltage transformer

Post by Mr Mustard » Sat May 12, 2018 4:27 am

Most interesting post I've seen in a while. So you bought the amp new or used? :lol:
Mr. Mustard

Forum Moderator
Posts: 17489
Joined: Thu May 02, 2002 9:19 pm
Location: Outside Boston MA, USA

Re: Dual voltage transformer

Post by bclaire » Sat May 12, 2018 10:16 am

No idea. I would err on the side of bringing it to an amp tech. Should be quick and relatively inexpensive.

Les Paul Lover
Duke of Orange
Posts: 6390
Joined: Tue Aug 18, 2009 9:08 am
Location: Derby, England

Re: Dual voltage transformer

Post by Les Paul Lover » Mon May 14, 2018 9:34 pm

It's difficult to provide advice without seeing the schematics and pictures of what you are describing.

Tramsformers wires not being connected isn't always a bad sign. It's usually cheaper to get 200 transformers with the same specs and extra wires than 100 of each type.... and having the extra wires makes the stocking of parts easier- you've got them for which ever market you get an order.

Orange Gear: RV50 MKI, R30, AD15, AD5, PPC212
Past Orange: Orange AD30TC Combo, Tiny Terror

Guitars: Gibson Les Paul Standard Faded, Vigier Expert Retro 54, Gibson SG 70s Tribute, Aria Pro II RS X80, G&L ASAT Special Tribute

Post Reply

Who is online

Users browsing this forum: No registered users and 11 guests