How to properly conduct voltage check?

[howie75]

Hello,

As a first time DIY'er of any sort of electronics,  I would appreciate some hints
on how to properly conduct the voltage check.
I was able to conduct the resistance check fine, and all the numbers looked ok.
After reading the warning statements on the manual, I am a little hesitant because
I am not sure how to safely conduct the voltage check.

In the manual, it states that I should plug in the power chord and conduct the voltage checks.
In order to conduct it, the aluminum chassis should be upside down, resting on the wooden
case, with the tubes plugged in. When I briefly try to flip it, I felt that the tube was going to hit
the table when I was trying to rest it on the wooden case.

After finishing the build past midnight, I really wanted to see if it will work, and
actually plugged it in to headphones and a dac, and was able to listen for 10 minutes
without anything blowing up.  Although I now know that it works, I still would
like to conduct a safe voltage check for assurances.

BTW, I would like to thank the Bottlehead team for such a great  kit and instructions,
I enjoyed the whole process so much.

[adamct]

It's a great feeling, isn't it?

Here is what I did:

1. Stack 3-4 books underneath either end of the wooden case, so that it is raised up, with an empty space underneath.

2. Make sure the power switch is OFF and the power plug is NOT plugged into a wall outlet.

3. Insert the power plug into the IEC socket on the chassis.

4. Flip the metal chassis over, and feed the power cable through the wooden case and out the side (since the case is raised on the books, the tubes should have sufficient clearance, and there will be room on the sides for the power cable to exit).

5. Plug the power cable into a wall outlet.

6. Reach underneath the case to flip the power switch.

7. Let the tubes warm up and conduct your voltage checks.

8. Since the tubes will be quite warm by now, I didn't want to fumble around from underneath trying to find the small power switch, so I just pulled the power plug out of the wall, waited for the tubes to cool, then flipped everything back over again and enjoyed the sweet, sweet music!

Best,
Adam

[howie75]

Aha, Why didn't I think of that.
Thank you for the detailed instructions!
Although I did feel a little dumb asking such a basic question.

[adamct]

Don't. I did the same thing. The Bottlehead manual is great, but it gets you in this mode of following the instructions to a "T". Then, you get to the most dangerous part of the instructions, and you have to improvise a bit. Ordinarily, you would come up with this by yourself, but when you've been following orders for so long, you suddenly fail to think independently! BTW, we're not along. There are at least a couple other threads where people have asked the exact same question.

[Grainger49]

Adam,

I prefer to turn the amp on and use the plug at the wall, where everything is insulated, to turn it on and off.

The books are a good idea if you don't have to stack 10 Kindles to get there.  (As Egon said, "Print is dead.")

[Paul Birkeland]

I generally let the tube(s) rest on the work surface (gently).

-PB

[howie75]

Ok, I couldn't resist and ended up listening to the amp for about an hour
as soon as I got home from work before conducting the voltage check.
I figured since nothing was smoking or burning for the 10 minutes I ran it
after finishing the build, there was no real danger.
At least, that's how I justified myself, hehe.

After turning off the unit and letting the tubes cool a bit, I ended up
using a couple of shoe boxes, and ran the voltage check.
All the values came out as listed on the manual, plus or minus 5%.Whew.

On  a side note, I recall reading a comment by Doc that some builders experienced
some builder's withdrawal symptoms after finishing the build.
When I first read that comment, my first thought was a suspcisious "yeah, right".
But now I know exactly what he meant.
Although this was my first DIY amp,  first time I soldered anything in my life,
I really enjoyed it and have gained some confidence and eagerness to try
additional builds.
I'm already considering the S.E. X amp, but first thing's first, I need to install the speedball upgrade.
I am going to TRY to wait a couple of weeks and enjoy the crack as is.
While previewing the speedball manual and the parts, it looks like the soldering
tip needs to be fine tip, and soldering should be accurate.
I saw a couple of sections where there were three separate solder joints that were really close together.
I currently have the standard ST3 tip that came with the Weller WLC100 40-Watt Soldering Station,
and the tip looks a bit wide for the speedball work.
Would a conical soldering tip be recommended to work on the speedball?

 

[Doc B.]

Everyone seems to have to find the tip that works for them. I like a fine tip for PC board pads, but the guys here like chisels because they work with the iron so often that have a good feel for the speed of the heat delivery and a fat tip gets the heat into the joint more quickly. Along with a conical tip you can find - at least for some irons - a tip that reduces to a straight rod about 1/16" dia. with a bologna sliced end. I like that one a lot. Unfortunately I can't get one for my ERSA station, but I think maybe you can get them for Hakkos.

[adamct]

I like this one for fine PCB work with my Weller station.

[howie75]

Thank you very much for your advice and suggestions.
I ended up purchasing the conical tip, similar to the one Adam suggested, and was able to install the Speedball upgrade.
Honestly, I do not know if I would've been able to install it without the thinner tip.
Fortunately, I was able to install it without any major issues, and the voltage check results were good.
I have never been a critical listener that conduct A, B comparisons, but I definitely thought there was a significant improvement in sound quality.  Sound definitely sounded fuller, clearer, and better.
I am also grateful to the tools suggestions by Doc and other members, as I purchased most of the recommended tools
and put them to good use.  The magnifying glass/ third hand tool was definitely worth every cent.