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Messages - papa_bear75

#1
I really appreciate all the suggestions from everyone. I popped over to a local vintage guitar shop in town on the off chance that they would have a similar headphone jack as a spare part. They had something very similar to I bought it for $7. As it turns out, the switching inside the jack is identical to the original. Even though I rang out all the connections on the old one, and everything seemed to be working, I went ahead and wired up the new jack and installed it. It ended up working perfectly. I'm guessing that perhaps the contacts internally were corroded, which may have loaded the circuit more than expected but that is a wild guess. Either way, I'm happy to say that the new jack worked.  :)
#2
I didn't realize anyone had replied to my post, since I didn't get email notifications. I appreciate everyone replying! I have to use headphones where I live, since I live in a condo complex and this thing is loud!

I've used the same headphones with another amp before so there is nothing wrong with them. And I'm using a 1/4" to 1/8" stereo headphone adapter for with my sony headphones.

Here are photos of the S/N plate and the back of the headphone jack. After examining the schematic, it looks like plugging in the headphones disconnects the speaker from the output. The output is then routed through two 330 Ohm resistors, one for the right channel and the other on the left. I checked the jack and there doesn't appear to be any foreign objects inside of it. And with headphones plugged in, there are no pins shorted to ground or to any other pins. I had ordered a jack from Syntaur but it turned out to be the other type of jack used on the amp. The one for the headphones is unique. I'm stupmed at this point. Preliminary poking around in the circuit leads hasn't caused me to find any obvious issues.

The amp works perfectly apart from this issue, which led me to believe the jack itself was faulty or had a piece broken off inside of it. I'm pretty sure my dad never used it with headphones.

Thoughts?
#3
I inherited the amp from my father who passed earlier this year and was excited to use it. However, I soon discovered a problem. The amp worked perfectly well until I plugged in a set of headphones. As soon as I did that, the audio in the headphones was distorted. After a couple seconds, the audio started fading. The LED on the power switch faded in sync with the audio until they were both completely off. I checked the main fuse and it was fine. I opened up the unit and found that both 4A fuses were burned. I picked up some replacements and installed them thinking the amp had a deeper issue. I powered it up and the amp worked perfectly. I proceded to plug the headphones back in and the fuses burned again. I replaced them again and tested the amp without headphones. It worked perfectly. I do live in a condo so having the ability to use headphones is key.

Is this something that anyone has encountered before?

Thanks!