Help troubleshoot first build. More info was added (updated again)

[hesamadman]

Here's what happened.
Finished the build. Plugged it in. Heard slight pop.

Going back and re-reading your first post... do you have a light bulb limiter?

http://i23.photobucket.com/albums/b392/Structo/Lightbulb_Limiter.jpg

You should use one any time you fire up an amp during a build or after repair/maintenance to the power supply. It's easy to build if you don't have one. All you really need is an extension cord and a light bulb socket. The socket is wired in series on one side of the cord. The filament of the bulb (you must use an old school incandescent bulb - not the new fangled fluorescent type) acts as a current limiter. You can make fancier ones (mine has an outlet box and is mounted on a piece of 1x4 wood) but that is not necessary.

Under normal conditions when you switch the amp on plugged into the limiter the bulb will light up a bit and then dim down as the filter caps charge. If the light gets very bright and stays there you have a short circuit somewhere. The limiter can save you lots of trouble and costly repairs. After you test and things are okay you can unplug the amp from the limiter and plug it straight into the wall.

This is not just a handy tool to have. It is a "must have" item for your bench and you should always use it every time.

WOW thank you. Im a full time electrician. I can build that easy. Ha. Hope to get as good at amps as I am at wiring a house.

[hesamadman]

I've been where you're at a few times. You have the best advice here that you can get.

Do all the things mentioned, especially the insulated clips on your meter like Willabe  mentioned.

I did all my first few builds using a lay out, they were easier builds, like a 5E3. I got lucky the first time and the amp played great. I though, boy this is easy till the next build I had problems like you're having now. So this is normal.

If you don't understand the schematic and can't relate to the wiring by looking at the schematic, use the layout. And by all means double check every connection (and resistor value with your meter) just before before soldering, it will be slow but worth it. Once soldered make the mark on your layout and on the bd. a dot with a sharpie (non-permanent). This will help make sure your not making mistakes.

Another thing is the tendency to wire things backwards, like pots. So position your layout next to the build exactly the same and follow.

Now when your done and if the amp doesn't have the correct voltages don't start over. Go slow and recheck everything. It's hard to check the values of resistors wired in a circuit, so do what Sluckey recommended, measure the resistor before you solder it in place.

You could be having "cold solder joints or burning up components, don't leave the tip on a connection more than five seconds (hope you have the right tip). Heat both the lead and turret at the same time for about three/four seconds and then apply the solder to the lead not the tip, it should flow and be shinny when first done.

I still have some problems reading some schematics but I find I can now better repair or build an amp by the schematic than a layout.

Believe me you'll get it going, and remember you're dealing with high voltage that can hurt you so be careful.

Just the other day, I put a 7591 power tube NOS, in the 5Y3 rectifier socket and turned on the amp. I mixed the two tubes. After a few minutes trying to find out why I had no sound I saw the problem. But I fired a perfectly match NOS Westinghouse 7591.  We all still make mistakes, I'm still leaning.

Go slow, and keep posting.

al

 

What kind of tip should I be using. I just bought the Weller Temp controlled WTCPT. It was expensive but only came with one tip.

[sluckey]

What kind of tip should I be using. I just bought the Weller Temp controlled WTCPT. It was expensive but only came with one tip.

I use a #8 chisel tip for this kind of stuff. #8 is 800º. That may be the tip that came with the station. #6 and #7 tips are more for pcb work.

Unscrew the barrel of the soldering iron. Remove the tip and look for a number stamped on the butt end. What's the number?

BTW, these stations regulate the temperature of the tip with some magnetic magic. Always wipe the tip on a wet sponge (one is provided) every time you pick up the iron to make a solder connection. The tip will last a long long time if you do. And never ever use sandpaper or a file on that tip. There is a special coating on the tip that will be destroyed if you do. Wet sponge is your friend.

Read the info that came with that station. That's the station that is/was used by the USAF depot and FAA. Great tool.