AD140 Tech Question???

tripface · Post by **tripface** » Wed Jun 11, 2003 1:04 am

Hey all, just a quick question about my AD 140 HEAD.

I bought my new head about a month ago. I brought it home and hooked it up to a 4OHM Mesa Boogie cabinet. I realize now that this is a no-no. Anyway, I started playing and the amp sounded great. However, right at about the hour mark the amp cut out. The re was no flash or anything, I trouble shot the equipment and it seems that one of the fuses was severely blown. It was the one on the bottom. So I took the two fuses and had them replaced @ a Radio Shack around the corner and tried the amp again. It turns on and the tubes glown and everything, exept that, alas, no sound! I had even used an 8 OHM Fender Cabinet and a monster speaker cable. DOES ANYONE HAVE ANY IDEA WHAT HAPPENED. The guy at the store said it might have been the transformer, but it seems that if that was the case, there would have been some pop, or flash of light. what gives??

birdiehop · Post by **birdiehop** » Tue Jun 17, 2003 8:27 pm

First did you make sure that the new fuses are slo-blow?

It sounds like you may have blown a power tube. These will normally take out an HT fuse when they go. My suggestion would be to get it to your local guitar store and try a new set of EL34's. They should help you out just to try to get the tube sale!

fiveightandten · Post by **fiveightandten** » Fri Jun 20, 2003 1:25 am

<BLOCKQUOTE id=quote>quote:<hr height=1 noshade id=quote>
Hey all, just a quick question about my AD 140 HEAD.

I bought my new head about a month ago. I brought it home and hooked it up to a 4OHM Mesa Boogie cabinet. I realize now that this is a no-no. Anyway, I started playing and the amp sounded great. However, right at about the hour mark the amp cut out. The re was no flash or anything, I trouble shot the equipment and it seems that one of the fuses was severely blown. It was the one on the bottom. So I took the two fuses and had them replaced @ a Radio Shack around the corner and tried the amp again. It turns on and the tubes glown and everything, exept that, alas, no sound! I had even used an 8 OHM Fender Cabinet and a monster speaker cable. DOES ANYONE HAVE ANY IDEA WHAT HAPPENED. The guy at the store said it might have been the transformer, but it seems that if that was the case, there would have been some pop, or flash of light. what gives??

<hr height=1 noshade id=quote></BLOCKQUOTE id=quote>

Sounds like you toasted the output transformer. Unless they have a fast acting fuse in there somewhere that's not accessible unless you open up the chassis.

When you turn the amp on are the plates of the tubes glowing red (the metal you can see, closest to the glass)?

If they're glowing red and you don't get any sound, or you get very low volume even when it's cranked...yup, you fried your output transformer.

-Nick

Meole · Post by **Meole** » Wed Jun 25, 2003 2:09 am

<BLOCKQUOTE id=quote>quote:<hr height=1 noshade id=quote>The guy at the store said it might have been the transformer, but it seems that if that was the case, there would have been some pop, or flash of light. what gives??<hr height=1 noshade id=quote></BLOCKQUOTE id=quote>

Transformers can go lots of ways. They don't always explode in flames, shooting sparks and smoke.
They usually overheat, the windings melt together and they short out.

AD140 Tech Question???

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