Crack will not power up =(

[skylark91]

Hi, I'm new this build, and this is my first time with the crack. So I've connected and soldered everything in place, and done the resistance checks, and everything works fine. Problem is, when trying to power the crack up to check the voltages, the fuse always blows. I've burned through 5 fuses now.. and I've checked and re-checked my connections every time.

My initial suspicion was on the PT-3 transformer, which I believe is meant to work with 120V AC mains, but here in my country, we use 240V AC.
I emailed Bottlehead and Paul informed me that this will not blow the fuse, and suggested a wrong connection with the capacitor, or diode. I checked those, and they seem alright.

Any help/ advice? 

 

[mcandmar]

A 120v transformer will not work on 240v, that is almost certainly your problem.

 

[Doc B]

There are two versions of the PT-3, a 120V version and a 240V version. It looks in the photo like you ordered a 120V version of the amp. So plugging it into 240VAC mains would definitely be a bad idea.

The easiest solution at this point would be to buy an inexpensive 240V to 120V step down transformer to plug the amp into. It only needs to be rated about 100VA so it shouldn't cost too much and won't degrade the sonic perforomance. With the step down in place you can try again and determine if there was any damage done to the internal components when they were exposed to the higher than specified voltage.

The more expensive and time consuming solution would be to replace the 120V PT-3 with a 240V PT-3

 

[Wisor]

Sorry for old bump,

Is "PT-5 power transformer" suitable replacement for PT-3 (as power transformer on Bottlehead Crack) ?

 

[Doc B]

Nope.

 

[Wisor]

One more thing, is it possible to buy pt3 ?

 

[fullheadofnothing]

Nope.