1st time power up questions with a TAG limiter

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Curranproducer
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1st time power up questions with a TAG limiter

Post by Curranproducer »

Hey there-

I got an 18 watter I am getting ready to juice up for the 1st time. I usually use the Paul Ruby 1st time power up steps BUT he says to un-solder both my PT and OT to test them for open or shorted leads. With a tag limiter light bulby thing can i eliminate this step and just go to the next phase of testing? with the limiter plugged in it should protect my amp from shorts in the power tranny and anything that is wrong with the OT correct? I did do a search and it yielded no results for me so this is why I am posting about this question. I just want to stream line the start up and power up stage of the amp adventure
Curran

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xtian
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Re: 1st time power up questions with a TAG limiter

Post by xtian »

Yes, if you have a critical fault like that, the light bulb will glow very brightly and consistently when you turn on, and you will be able to power down before you burn anything up. That's the theory, anyway. :)
I build and repair tube amps. http://amps.monkeymatic.com
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xtian
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Re: 1st time power up questions with a TAG limiter

Post by xtian »

Let me add, what SHOULD happen on first power up (you SHOULD NOT have any tubes installed) the light bulb should flash briefly as the reservoir caps fill, and then go very dim, as the amp pulls very little current.
I build and repair tube amps. http://amps.monkeymatic.com
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Curranproducer
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Re: 1st time power up questions with a TAG limiter

Post by Curranproducer »

yep, No tubes for the 1st power up, want to make sure the lamp kicks on, and then the light bulb dims. form there I do my voltage checks, and move through the paul ruby check list. thanks for the answer!! woo hoo!!!
Curran

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Structo
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Re: 1st time power up questions with a TAG limiter

Post by Structo »

Also the lower the wattage of the light bulb, the less current is supplied to the amp.

For example, if you use a 25w bulb, the amp is fed with about 250ma.

I use that for a first time power up without tubes.

Then if it passes that test, I install the rectifier if so equipped.

And so on, add tubes and go with a 75w bulb.

Some amps differ in the way the bulb looks depending on rectifier tyoe, filter capacitors, number of power tubes and preamp tubes.

But generally, the bulb should flash bright the go to a lower glow.
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cbass
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Re: 1st time power up questions with a TAG limiter

Post by cbass »

Once you get the tubes in the bulb should flash as the caps charge then dim and then light up a little more as the tubes draw current
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Phil_S
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Re: 1st time power up questions with a TAG limiter

Post by Phil_S »

Remember that brand new caps may take a bit of exercising to charge and discharge... and maybe not. First time under power, it seem erratic for a very brief interval. Sometimes it's not something you notice and other times it is.

I think this is particularly so for cheap caps. I remember one build that didn't pass any sound. Checked it out and everything seemed OK. Tried again. All of a sudden there was sound.

If already had the PT soldered, I'd leave it and use the 25W like Tom suggested.

The bulb limiter is cheap insurance and it is wise to use one. Good luck.
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