Alamo CHallenger 2562 Serial #92840 What year? ALso only humming sounds cumming out?

[cossackboy]

Tubes light up checked all three inputs. Only has low volume humming sound. Please help! Cheers, Chris.

[52 Bill]

[ATTACH=CONFIG]28904[/ATTACH] Tubes light up checked all three inputs. Only has low volume humming sound. Please help! Cheers, Chris.

Welcome to the place. The first thing to check in any tube amp are the tubes.

The Challenger is a basic three tube amp with a single ended output stage. 5Y3 rectifier, 6V6 output tube and a 12AX7 preamp/driver tube.

Do you have access to a tube tester? Or another amp with a set of tubes that you know are good?

Do you have a multimeter that can read high voltages? Do you have the skills to work on an amp that is plugged in and running?

[cossackboy]

I think I do Bill

Welcome to the place. The first thing to check in any tube amp are the tubes.

The Challenger is a basic three tube amp with a single ended output stage. 5Y3 rectifier, 6V6 output tube and a 12AX7 preamp/driver tube.

Do you have access to a tube tester? Or another amp with a set of tubes that you know are good?

Do you have a multimeter that can read high voltages? Do you have the skills to work on an amp that is plugged in and running?

I have a Kalamazoo 1 and a Kalamazoo 2 that look to have Similar tubes. Both those amps sound great. I will try switching out the tubes and let you know how it go's. Thanks for the welcome. I do have some basic knowledge. I took industrial electricity and have built a distortion peddle. Its been a while I would be so pumped if I can fix the old Alamo on my own. You guys will be hearing from me alot in the future. It's great to be on board with you gentleman and Ladies(IF THERE ARE ANY WHO PLAY AROUND WITH THESE OLD VINTAGE TUBE AMPS). I have another project getting ready to do too. A 1960's Gibson Thor bass amp. I am remembering the Alamo first. Cheers, Chris..

[gui_tarzan]

Can you take more pics of the chassis, both inside and out? I have an Alamo Paragon I want to rebuild but there is no schematic for it so I want to try to draw one if possible.

[tedmich]

blow up this picture! Its a real paragon (real ugly

on the OP I know nothing, 1990 is my amp cut off year....good luck!

[cossackboy]

Some pics of my Alamo Challenger. I hope this helps.

Can you take more pics of the chassis, both inside and out? I have an Alamo Paragon I want to rebuild but there is no schematic for it so I want to try to draw one if possible.

Here are pics of my challenger from alamo

[cossackboy]

I had the tubes tested today. It was working half ass last night after I cleaned the pots and tube sockets. One of the 6v6gt tubes then started losing power got a bluish color inside then no more sound. I had that tube checked today and it was fine. Is it a voltage problem? Not enough power to the socket? It going over my head quickly. Its a really clean old amp and was hoping not to have to put much money in it. Any more suggestions from anyone out there?

[The Dude]

Post edited (Initial reading the OP's last post, I thought we were talking about a push pull amp. Therefore, my first writing did not pertain):

I just realized.....is this not a single ended amp? You say, "One of the 6V6gt tubes". Are there two of them? According to the schematic, there should only be one and the other large tube would be a rectifier. Can you confirm that this is your amp?

[cossackboy]

I can read the numbers on them and you are probably right. This is my first time playing around with tubes. I know own 7 Vintage tube amps. The guy that fixes these locally in des moines is way pricey. I am just feeling really stupid right know. I will get better but will need some help from you guys. Here is a p\couple of pics and tell me what you see if you would be so kind.

[cossackboy]

My amp only has one preamp tube looks like that one has 2?

[g1]

My amp only has one preamp tube looks like that one has 2?

Do you mean the schematic? A 12AX7 preamp tube has 2 halves, both the same. It is called a dual triode. On the schematic is says "1/2" for each side of the preamp tube.
It is the small one in your amp, the middle one is probably the 6V6, and the rectifier (5Y3) is usually located closest to the power transformer.
Which one was doing the blue thing, the middle one? If so, try another 6V6. Tubes can develop faults that only occur at high voltage, and usually tube testers do not test them at high enough voltage. So just because a tube tester says it is good, it can still have a fault that only shows up in your amp.

[cossackboy]

The middle one was doing the blue thing. That one tested fine. I bought a new old stock from him just in case. I tried the new one today and still nothing. The amp does not even hum anymore. thanks for explaining how a 12AX7 works I would not have had a clue. Anymore suggestions?

[g1]

You said the amp doesn't even hum anymore. Can you see if the tubes heaters light up when it is on? Are you sure the speaker is ok?

[52 Bill]

When the amp was humming, you could guess that the rectifier tube was working to some degree, and the output tube was working to some degree, otherwise there would be no hum.

You said that you cleaned the tube sockets and pots, what did you do to them? If there is a dirty tube socket that's bad enough to not make good contact, you could lose power.

Either try swapping the 5Y3 rectifier with another one or read the dc voltage to ground at the filter cap nodes to see if there is any dc voltage. Remember that if you start doing this, be careful. If you don't know how to do this safely, then it's time to refer servicing to someone qualified.

[g1]

Also, make sure the 2 larger tubes didn't get switched around, 6V6 should be in the middle.