SimpleSE Checkout/CL-90 Fail

[wushuliu]

Ok, just went through Ty's(?) photo Checkout and everything was fine until I actually powered the amp to check voltages (No tubes, no speaker load). Then CL-90 inrush limiter smoked and broke in half!

I am using Antec 350-0-350, SS rectification. What should I check?

[VictoriaGuy]

Sounds like a short somewhere.....

I'd suggest (as I always do, sorry...) taking an hour or so and putting together a light bulb current limiter to help prevent smoking your power transformer. Luckily, the inrush limiter blew this time, but it can get tedious replacing limiters.
What size fuse did you have installed?


I don't have much experience with CL90 and similar, but I think they are supposed to be quite reliable??

BTW, you should have speakers or load resistors on the outputs - you don't want to forget them once you put the power tubes in.

[wushuliu]

Originally Posted by VictoriaGuy

Sounds like a short somewhere.....

I'd suggest (as I always do, sorry...) taking an hour or so and putting together alight bulb current limiter to help prevent smoking your power transformer. Luckily, the inrush limiter blew this time, but it can get tedious replacing limiters.
What size fuse did you have installed?


I don't have much experience with CL90 and similar, but I think they are supposed to be quite reliable??

Yes, checked the board again and saw that i had not jumpered sw1 for ss rectification. I used a 1.5A fuse... so off to get more fuses, this time 2A (since thats what everyone seems to be using).

[rknize]

The CL-90 can pass 2A continuous. A short should have blown the fuse nearly instantly...long before the CL-90 could have heated that far. I suspect a wiring error. Can you take a picture of this area? The CL90 should be in series with the load (like the fuse), not in parallel with it.

[wushuliu]

Yes the fuse was in series. I also forgot to wire sw 1. I mean jumper. Could this have caused it?
I forgot to mention That's the fuse did blow as well...

[wushuliu]

Turns out I miswired the 6.3v. Rest of the checkout went fine, no problems. BUT I see that I have 563v on B+!!! Is this because I have no load or tubes on the amp?

[spopepro]

You are using an Antek traffo? They are rated for 115v on the primaries. If you're in an area with highish mains, like I am, you are probably actually getting 380-390 on the secondaries.

...not that I've ever made this mistake with Antek iron.

[wushuliu]

Originally Posted by spopepro

You are using an Antek traffo? They are rated for 115v on the primaries. If you're in an area with highish mains, like I am, you are probably actually getting 380-390 on the secondaries.

...not that I've ever made this mistake with Antek iron.

Actually 138v on Mains. 420v on secondaries. WTF! : (

And 36v on main filaments

Also do I jumper or do anything with the 5v tube rectifier connections. Since I am using SS I have them untouched...

[wushuliu]

Ok, I've plugged the amp into a voltage regulator, B+ is now 510. 32v at T1 GRN. And the tubes are not lighting up.

[rknize]

Is that an Antek toroid? Can you post the specs on it? It looks to me that you have wired the filament windings in series. This is not what you want. It sounds like your meter is a bit out of whack. 36V on the filaments is not good at all! It's best to check these before putting the tubes in.