VintageKustom.com: Repairing Kustom Amps » Kustom charger crakles at high volume

Home » VintageKustom.com » Repairing Kustom Amps » Kustom charger crakles at high volume

Show: Today's Messages :: Polls :: Message Navigator

Kustom charger crakles at high volume [message #10447]

Mon, 09 February 2009 10:02

norlon
Messages: 4
Registered: February 2009
Location: portland maine

Junior Member

hello again everybody.
I have an old Kustom Charger that crackles at high volume. It's not the speaker as that sounds fine thru another amp head. the pots are clean. it doesn't crackle too bad just a little when i play at top volume and play a low e string on my bass any idea's?

Report message to a moderator

Re: Kustom charger crakles at high volume [message #10450 is a reply to message #10447]

Mon, 09 February 2009 12:23

stevem
Messages: 4745
Registered: June 2004
Location: NY

Senior Member

More than likly a solder connection on one of the circuit boards.

Report message to a moderator

Re: Kustom charger crakles at high volume [message #10454 is a reply to message #10450]

Tue, 10 February 2009 19:55

norlon
Messages: 4
Registered: February 2009
Location: portland maine

Junior Member

whats the best way to check that. go thru and re solder everything?

Report message to a moderator

Re: Kustom charger crakles at high volume [message #10458 is a reply to message #10454]

Tue, 10 February 2009 22:10

pleat
Messages: 1453
Registered: June 2004
Location: Belding, Mi

Senior Member

I'm not a tech but if you are going to resolder the board, be careful not to use to much heat on the transistors. I had a kustom challenger that did the same thing. I talked with Bob Brinkman who was with Kustom from almost the beginning. That series of metal face amps used some odd transistors in the pre amp. One was a 4 pin 40841, one was a 8 pin 80848, and a really odd 10 pin #540 which hasn't been made since 1975. All look just like a regular 1/4" round metal transistor. My amp happened to need the odd ball 10 pin and Bob figured that was the problem. The amp now is a charcoal covered end table. He also suggested that if the amp had white diodes with red bands to replace all of them with 1N4007. So my advice is to take the amp to someone qualified in amp repairs. No need to burn out a part with too much heat.
pleat

Report message to a moderator

Re: Kustom charger crakles at high volume [message #10461 is a reply to message #10447]

Wed, 11 February 2009 06:06

stevem
Messages: 4745
Registered: June 2004
Location: NY

Senior Member

I have had two K 250s that had the same large orange coupling cap making a bad connection,these large caps can vibrate around quite a bit when transporting the amp. I go over mine by plopping a dab of silicone glue on one or both bottom sides of the cap. If you use a 30 watt soldering iron you will not fry any transistors unless you holf the iron to the contack point for more than 10 seconds.

Report message to a moderator

Re: Kustom charger crakles at high volume [message #10464 is a reply to message #10461]

Wed, 11 February 2009 09:19

chicagobill
Messages: 2005
Registered: April 2003

Senior Member

Getting back to norlon's question, I'd suggest trying this first. While playing the amp, give the top of the amp a good whack with your fist. Not so hard as to hurt yourself, but see if you can make the noise happen by physically bumping or shaking the amp.

If you can make the amp act up, then I'd suggest opening up the chassis and again with the amp on, carefully probe around the circuit board, using an insulated tool like a wooden or plastic rod. Most people call this the chopstick method, as they use a wooden chopstick as a probe. Personally I use the plastic handle of my screwdriver.

Use the probe to push and tap on the different components on the different pc boards. As Steve pointed out, the large capacitors are really prone to vibrating themselves loose, and so are the plastic pc board Molex connectors. Be sure that they are all securely seated in their sockets and making good contact.

If you do find a loose component, then that pc board will need to be removed so that you can resolder or replace it.

Please remember that working on a amp while it's plugged in and running can be dangerous, and you should use caution if and when doing so.

Report message to a moderator

Re: Kustom charger crakles at high volume [message #10465 is a reply to message #10447]

Wed, 11 February 2009 12:11

stevem
Messages: 4745
Registered: June 2004
Location: NY

Senior Member

One other thing you might check would be to see if the any of the control knobs may have got hit hard enough to to crack the connection between the pots internal carbon trace and its solder tag. Do this by grabing the knob and seeing how much it may move up and down and if the noise and signal cut out takes place.

Report message to a moderator

Re: Kustom charger crakles at high volume [message #10468 is a reply to message #10465]

Wed, 11 February 2009 23:06

pleat
Messages: 1453
Registered: June 2004
Location: Belding, Mi

Senior Member

One more thing to be careful of, if you have to remove the circuit board, use caution when removing the nuts that hold all the pots to the front panel. They sometimes rust and I have seen tech's wrench on them and actually twist and break the pot right out of the circuit board. The Slant face amps are more prone to this, they used a cheap black colored nut and lock washer on a lot of those amps. If your poking around the amp when it's plugged in and on, keep your left hand in your pocket. Left hand is a direct path to the heart.
pleat

Report message to a moderator

Re: Kustom charger crakles at high volume [message #10470 is a reply to message #10447]

Thu, 12 February 2009 06:36

stevem
Messages: 4745
Registered: June 2004
Location: NY

Senior Member

Good point about the nuts! At times I had to resort to cutting the nut one one side with a small cut off disc in a dremel tool so I could split it and pry it off.
This was after using automotive rust breaker that has never failed for me on my car, and plus using heat from a torch!!

Report message to a moderator

Previous Topic:	Kustom 150 doesn't work
Next Topic:	reverb pan, which way do I put it in?

Goto Forum:

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Sun Jun 16 10:30:02 EDT 2024