News:

Forum may be experiencing issues.

Main Menu

Wall wart (PSU) for tube amp use

Started by angrykoko, February 21, 2014, 02:37:02 PM

Previous topic - Next topic

angrykoko

I"m wondering if the wall wart I bought has short detection?

I've been working on a sub mini tube amp, just got it done but wont power up... heaters are not glowing even.
Noticed that the wall wart has a little led on it that goes out when I turn the amp power on....

Long story short, the heaters are directly connected to the power and run to ground.  I'm wondering if this PSU has a short detection safety switch and cant use it  to power a tube amp.   Is a built in safety feature like this a thing?  could it possibly be what's plaguing me?

It's a qsee QS12500MA (it's for cameras, cheep only 9.00)

Anyone?
The early bird may get the worm, but the second mouse gets the cheese in the trap.

angrykoko

Yep, it was the power supply.
Found another around, and it worked for a min but now I have some.real debugging to do.
The early bird may get the worm, but the second mouse gets the cheese in the trap.

jubal81

Sounds like an interesting project. Which design did you use?
"If you put all the knobs on your amplifier on 10 you can get a much higher reaction-to-effort ratio with an electric guitar than you can with an acoustic."
- David Fair

angrykoko

Superfly  http://www.diystompboxes.com/smfforum/index.php?topic=78302.0

Need to debug it, tone pot not working and the mosfet in the power section got crazy hot (hopefully not dead).
I'll post pics when I get it going the next couple of days.
The early bird may get the worm, but the second mouse gets the cheese in the trap.

angrykoko

Grr.. boiled my inductors innards.
Time to play the waiting game for a mouser shipment.
The early bird may get the worm, but the second mouse gets the cheese in the trap.

jubal81

Ugh. Bummer. I've been reading up on that 555 SMPS and it seems at least a 2A inductor is recommended.
"If you put all the knobs on your amplifier on 10 you can get a much higher reaction-to-effort ratio with an electric guitar than you can with an acoustic."
- David Fair

angrykoko

really?  damn, talk about "should have posted before I ordered".
The one I"m using is max 670ma (the same as what Frequency Central used on his).

I have other issues in my build though;  I swear I was not drinking when I put this one together but.. wow.. I have no excuse for some of it (looking at it again).
The early bird may get the worm, but the second mouse gets the cheese in the trap.

angrykoko

IT'S ALIVE!!
I'll do a build report once I finish.  Very cool little amp, not very loud but loads of fun so far noodling around with it.
Have it pushing a single Vin 12.

The early bird may get the worm, but the second mouse gets the cheese in the trap.

jubal81

Wow. Very, very cool. Are you going to be able to give us some sounds?
"If you put all the knobs on your amplifier on 10 you can get a much higher reaction-to-effort ratio with an electric guitar than you can with an acoustic."
- David Fair

angrykoko

Quote from: jubal81 on March 05, 2014, 07:42:19 PM
Wow. Very, very cool. Are you going to be able to give us some sounds?

Sure...  except in my head I"m jimmy page.. but to the rest of the world I sound like henry kaiser and his wang bar.
But at least I have my electrons in a crystal lattice - all Dumble style  :P

It'll be sometime late next week till I get back to this.. Boyscouts "Space Camp" weekend (boo ya!!) this weekend.

Cheers!
The early bird may get the worm, but the second mouse gets the cheese in the trap.