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New to AK ,bought an old tube amp ,need help

Yes the amp powers up ,heaters light but that mallory gets real hot ,and amp puts out very low distorted volume ,no tripping breaker or fuse tho,so i wont power on again,till those caps are replaced ,again thanks
 
One or some of those caps in the can might go to the external preamp/tuner through the octal socket. you might not need to replace that one if that's the case.

As you are moving forward, try to figure out that octal socket, if you can clean that up, and clean up the can cap area, you will have a better understanding of the circuit.
 
Usually there is a tab on the bottom of the can itself that pokes through the chassis and is soldered to it. Possibly two. That's where the negative leads from all the internal caps go to.

On the outside of the can next to each of the cap values, there will be a little shape, a square, circle, triangle. Those are also stamped on the bottom of the can next to the appropriate leads. Those are the hot leads to the various sections. Make sure you keep track of what's what as you disconnect them. If you use discretes caps underneath, you can tie their negative leads to the negative terminal on the can (=chassis), or use a tag strip with one tag connected to the strip's mounting screw and screw that to the chassis.
 
Ahhh thanks,i see,that helps alot guy,ill be posting back soon about it i posted wrong values its a 40/40/20/25 multicap 350v except last 25 is 25v so is it ok to fudge the capacitance a bit? I know upping the voltage to a point is ok ,ill try to get the capacitance spot on ,the voltage i can go up some
 
Best to keep capacitance within about 10% if you can, 20% at the outside. The 20, you're probably going to find 22 available. 25, no idea, 22 is fairly close, but 25V caps are not nearly as expensive so you can also parallel multiple caps (say 22+3 or 12+12 etc.). Higher voltage is fine, although it gets pricey at 350V. But if you end up with a 35 or 50V cap for the 25V one it won't hurt a bit. Just don't go under, there are surge voltages at turn-on that can be higher than operating voltages.
 
The entire contents of the can are polarity sensitive. Yes, you definitely need a polarized capacitor(s) to replace the can.
 
If you remove the 6CA4 rectifier tube, you can power it up with or without the other tubes to check the AC voltage coming off of the power transformer. Because the rectifier is removed, there is no DC getting to the can capacitor or the rest of the circuit so the can won't get hot.

Just don't power it up again with the rectifier until you have all new capacitors and ready to play.
 
Cap can is not getting hot now with output tubes removed,is it possibe i had a shorted tube? Ill know more when i put some known good tubes in it
 
,i removed all the junk from the octal socket and it left me with two green lookin wires goin to nothing now ,,so ive got heater wires from transformer,the 320-ct-320 wires and two backs that get power from the wall,and now those two extra that went to the preamp octal,guess theyre ok to fold back and shrinkwrap? I dont know what they went to,the tuner pre wouldve just plugged in to the amps extra 120v outlet ,maybe yall know
 
You could just follow them back to where they came from, and clip, or de-solder them.
With the output tubes removed the voltages will climb above the operating voltage the unit is supposed to run, and could even be over the cap rating
 
klipschoid said:
Cap can is not getting hot now with output tubes removed,is it possibe i had a shorted tube? Ill know more when i put some known good tubes in it
Click to expand...

The can, if shorted, would only get warm with the 6CA4 tube plugged in. Without it, no DC so it can't do anything at all. Ok, let's clear some things up. At the moment you have 3 tubes, one 6AQ5, one 12AX7, and one 6CA4.

The missing 6AQ5 won't matter except that only that one channel will not work. If the can is shorted (I already think it is), then it will get warm with the 6CA4 tube ONLY.
 
Ok ill retry all this when i get the tubes here,i ohmed the multicap from a good ground,none of the leads went low,using a fluke 45 ,i got no low or near short readings there ,ill keep you posted,yes your tube count and type for what i have is right,but with the 6ca4 in earlier and 12ax7 in but with no output tubes in,it does not get hot now(the mallory multi can) so ill see what readings i get when the tubes get here,i have no open resistors or shorted ones that i checked,thanks again,yall are veterans at this ,not me
 
s-petersen said:
You could just follow them back to where they came from, and clip, or de-solder them.
With the output tubes removed the voltages will climb above the operating voltage the unit is supposed to run, and could even be over the cap rating
Click to expand...
Those green wires that went to the octal is a 6.8 or so tap for lighting i guess for the pre that plugged there i guess,i measured them while ago,but the amp chassis also has an rca jack too thats tied in with the heater circuit ,i wonder why have one at octal and one at the rca? Wierd i guess ,a packard thing huh
 
cademan said:
The can, if shorted, would only get warm with the 6CA4 tube plugged in. Without it, no DC so it can't do anything at all. Ok, let's clear some things up. At the moment you have 3 tubes, one 6AQ5, one 12AX7, and one 6CA4.

The missing 6AQ5 won't matter except that only that one channel will not work. If the can is shorted (I already think it is), then it will get warm with the 6CA4 tube ONLY.
Click to expand...
Ok thanks ,i posted below in thread ill change those caps,im jus learning the wiring,reminds me of that tangled fake easter grass we got as kids to put in the basket lol
 
johnblue said:
One or some of those caps in the can might go to the external preamp/tuner through the octal socket. you might not need to replace that one if that's the case.

As you are moving forward, try to figure out that octal socket, if you can clean that up, and clean up the can cap area, you will have a better understanding of the circuit.
Click to expand...
Yep thanks,did what you said ,can see more now,i ended up with two unused green wires ,they are 6.8 volts,but did something with the preamp,the come straight from the transformer on my amp,the PT ,do i need to now run a virtual load on the wires now? Or cut and shrink,thanks again for helping
 
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