Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Oddvar on October 18, 2016, 04:33:37 am

Title: Champ blows fuse?
Post by: Oddvar on October 18, 2016, 04:33:37 am

Hi.  I have just buildt a 5e1 amp.  But it blows the fuse as soon as I turn it on, even without the tubes in.  I have the Hammond 291AEX transformer.  It says 240 v is the two black leads.  Trouble is that one of the black leads has a white stripe, so I wonder if there might be some other leads, it has also has two white leads with red stripes and two brown onews, with a yellow stripe on one.  I have askes Hammond, but they don't answer.  Any suggestions?

Title: Re: Champ blows fuse?
Post by: TIMBO on October 18, 2016, 05:04:22 am

Does the box have a sticker on it that id's each wire???
Do each of the same (main colour)colour wires have continuity????

Title: Re: Champ blows fuse?
Post by: Oddvar on October 18, 2016, 05:14:12 am

No, they haven't.  I don't know what you mean by continuity?

Title: Re: Champ blows fuse?
Post by: VMS on October 18, 2016, 05:47:07 am

This page has different datasheet for the transformer:

https://www.hammfg.com/electronics/transformers/classic/290 (https://www.hammfg.com/electronics/transformers/classic/290)

https://www.hammfg.com/files/parts/pdf/291AEX.pdf (https://www.hammfg.com/files/parts/pdf/291AEX.pdf)

Title: Re: Champ blows fuse?
Post by: Oddvar on October 18, 2016, 05:52:15 am

Thanks, that must be it.  Why operate with two different schematics?

Title: Re: Champ blows fuse?
Post by: Oddvar on October 18, 2016, 06:00:13 am

Black-Black/White is 120 v
Brown- Brown/white is 120 v.  To get 240 v should I connect Black/White and Brown/White then?

Title: Re: Champ blows fuse?
Post by: VMS on October 18, 2016, 06:13:17 am

If you scroll down this page you see how to connect for 240V:

http://www.hammondmfg.com/300series.htm (http://www.hammondmfg.com/300series.htm)

In your case I believe you connect BLK/WHT and BRN together and BRN/YEL and BLK are your previous black wires.

Title: Re: Champ blows fuse?
Post by: Oddvar on October 18, 2016, 06:40:13 am

Thanks again.  It worked...