My first build, What should I do before thuning it on?

[Mont]

Double and triple checked everything and it looks good. any comments as to what I should do before I fire up this bad boy?

[M Fowler]

Are you going to use bulb limiter or variac? Just take it slow and easy.

[Mont]

i don't have either.any sugestions?

[marcoloco961]

http://ampgarage.com/forum/files/expres ... te_187.pdf



Above is the address to the Build guide in the Trainwreck files section of this forum. Start at page 44 and read on. It will explain how to build a bulb limiter and how to use it properly. I wouldn't suggest throwing the switch without using this method unless you are a gambler and don't mind losing some tranformers and / or caps.

[Mont]

Thanks.

[rawnster]

I do a lot of this

[img:408:380]http://www.fillthevoid.org/Images/pray6.gif[/img]

[rbryerton]

LOL, tell me about it.

Be ready to pull the plug if some of the magic smoke starts escaping

[Structo]

Build one of these and start with a 25w light bulb.

[IMG:800:618]http://i23.photobucket.com/albums/b392/ ... imiter.jpg[/img]

If it passes the first step, install a 75 w bulb and try it again.

If it passes that, plug it into the wall and make some noise.

Be sure to always have a speaker connected to an amp if it has power tubes installed.

[marcoloco961]

P.S. After you install the tubes and hook up the speaker cabinet, when you go to check your voltages again with the standby on, touching your tester to some pins of the pre-amp tubes induces a fairly loud "buzzing" noise through the speaker. I always place the amp in standby, then put the tester on the pin and then flip the standby back on. This helps with the "flinch" factor when working around high voltages.

This is one thing I wish someone would have mentioned when testing my first build. My hands were shaking to begin with knowing what large voltages I was near and since it was my first build.

I damn near had to change my shorts afterwards............... .

[geetarpicker]

[img:400:368]http://www.all-security-system.com/uplo ... her(1).gif[/img]

Please take this as a joke (!), but the first time I fired one up (even using the inline bulb setup) I had an extinguisher handy! I've seen caps explode just because they were bad with no problems in the amp itself. I guess the bulb trick would in theory keep such bad days from happening, but better safe than sorry.

[paulster]

I've seen caps explode just because they were bad with no problems in the amp itself. I guess the bulb trick would in theory keep such bad days from happening, but better safe than sorry.

Glen makes a very valid point here. If you don't have safety glasses or eyeglasses (not ideal but better then nothing) then don't sit there with your head right over the amp looking for problems as you power it up.

Not that anything should go wrong if you've double-checked everything and especially if you use a current limiter, but you don't want that fluke failure causing you to lose your eyesight.

[Mont]

You guys got me crapping my pant's. lol. so I checked everything one more time. Better safe than soiled. I used the ceriatone layout and it shows one end of the bias pot not being used, is this correct?

[Structo]

Is this an Express?

It looks like just the top lug and middle are connected.
Sometimes the bottom lug and middle are jumpered.

[fishy]

The first step for me after going over the build several times is to understand what I expect to see where.
Identify the ground and power points. Review a voltage chart and identify what you need to measure. It is better to do this without power on the amp first so that you are sure of your actions once it does have power.

You need to understand what has power when. For example, C15 & C16 in the capstack get power form the start and are hot as soon as you switch the power on. The standby distributes power throughout the amp.

You also need to understand how to make the amp safe when you turn it off. The caps need to be drained and verified that they are safe before you poke around.

Don't forget to check the integrity of your grounds.

[Mont]

Yeah, it is an Express. so is it right that the one lug not be connected?