VintageKustom.com: Repairing Kustom Amps » 1979 Kustom Lead I Reverb "Crackle"

Home » VintageKustom.com » Repairing Kustom Amps » 1979 Kustom Lead I Reverb "Crackle"

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

1979 Kustom Lead I Reverb "Crackle" [message #14364]

Mon, 20 September 2010 23:06

gomu
Messages: 4
Registered: September 2010

Junior Member

Hello All,

New member here. I have a 1979 Kustom Lead I combo that I picked up used. Recently it started making "crackling" noises whenever I move the amp (amp turned on guitar plugged in). Discovered it does not make the noise with the reverb turned all the way down. So evidently something with my reverb tank or circuit.

Sometimes the reverb will fade in/out, always accompanied by the crackle. If I slap the amp it will usually come on for a while. The amp works fine with reverb all the way down...

I was figuring that maybe I had some solder joints that went bad and/or loose connectors on the 'verb...would this make sense? I assume there is a small reverb tank up in the chassis, I haven't had it apart.

I'd appreciate any ideas. Now for my main admission: How do I get the chassis out? I see 4 screws on the top of the amp -- obviously these hold the chassis. But does the faceplate slide out with the chassis or do I have to take off all knobs, power light, etc (that is, faceplate stays in place and chassis slides out the back)?

Thanks in advance!

Report message to a moderator

Re: 1979 Kustom Lead I Reverb "Crackle" [message #14365 is a reply to message #14364]

Tue, 21 September 2010 11:47

chicagobill
Messages: 2005
Registered: April 2003

Senior Member

Welcome to the place.

There are a number on push on connectors inside the amp as well as a few on the back panel that could cause your crackling.

The front panel is attached to the chassis and does not need to be removed to get at the insides. I would also assume that the top screws hold in the chassis, but also look at the pack panel as some Kustoms have small "L" brackets that hold in the chassis as well.

While you're looking at the back panel, look to see if your amp's reverb tank plugs into the back panel with RCA jacks. These jacks and plugs should be cleaned with a contact cleaner like DeoxIt.

Once the chassis is slid out of the cabinet, you will see that the pc boards are all connected with push on Molex connectors. These are known to become loose and oxidized. Check these to be sure that they are firmly seated, and you could also spray a little DeoxIt on these as well.

Hope this helps. Let us know what you find out.

Report message to a moderator

Re: 1979 Kustom Lead I Reverb "Crackle" [message #14367 is a reply to message #14365]

Tue, 21 September 2010 16:07

gomu
Messages: 4
Registered: September 2010

Junior Member

Thanks very much! I will see if I can get the chassis out, keeping the faceplate etc intact. I was just afraid to try that but sounds straightforward.

Backpanel has only speaker plug connection. I see no other RCAs or reverb connectors. It is a closed back combo -- I opened the back and no reverb tank there -- it must be contained all within the chassis.

Hopefully I'll be able to get to the connectors and get them re-seated. Is De-Oxit OK to spray on any connections inside the amp? That's my plan.

Thanks again for the response.

Report message to a moderator

Re: 1979 Kustom Lead I Reverb "Crackle" [message #14369 is a reply to message #14367]

Tue, 21 September 2010 17:38

chicagobill
Messages: 2005
Registered: April 2003

Senior Member

gomu wrote on Tue, 21 September 2010 15:07

Is De-Oxit OK to spray on any connections inside the amp?

Yes, that's what it is made for. You can also use it to clean the pots if they need it.

Report message to a moderator

Re: 1979 Kustom Lead I Reverb "Crackle" [message #14374 is a reply to message #14364]

Wed, 22 September 2010 09:32

stevem
Messages: 4733
Registered: June 2004
Location: NY

Senior Member

Gumo.
Your statement you made about the reverb acting up when you move the amp around would make me also take a look inside the reverb tank itself.
First off you need to check the two long duel section springs running the lenght of the pan.
Many times due to age and being moved around/ transported alot, one or both of the two long springs get flabby/streched to the point where the will intermitantly ride on the sub pan and create a sound like a kitchen cabinet full of cooking pans coming unstacked, this condition also would mean that your reverb pan is done and would need to be replaced.

Also in side the pan at each end is a small solinoid/transfomer, each with two small wires coming off the pans RCA jacks and terminating in each solinoid.
These wires break off with age and use/vibration and sometimes are left hanging by one or two small strands of the wire.
This condition can cause noise and intermitant reverb.

If the wire(s) are intermitant at the solinoid end, then your pan is toast.
If the connection is bad at the RCA jacks end they can be resolder.

I have also had many intermitant reverb and pig squeel like noise reverb problems happen do tarnish on the RCA Female recivers and inside the ends of the cables.
These are made of Aluminum and the coonection points sould be shinny, not dull.
Most times just rotating the connector around is enough to get things back in working order. Other times I take a sharp heavy pin,scribe and or small wire wheel on a Dremel and stratch the connection points clean and then that gets things back up and running.
At that point it also helps TO keep tarnish at bay down the road by wiping on some 3-in one oil, silicone grease or spray on contact cleaner that also contains a protectant.

Checking/cleaning and tightening up all of the Modex conectors as Bill has noted in his posting should be done first, then move on to what I have posted.

To tighten up the Moldex connectorsyou need to push something sharp round and tapered into the center top of the Male pin end of each connector. This will spread the 4 sides of the Male pin and grip the Female end with more force.

And and may be even first on the list you could just have one of the 4 RCA cable ends be bad.

Lastly, if the RCA cables are not hard wired into the effects board but plug into it you need to confirm that the solder connections that retain those Female jacks to the board are good.

Let us know how you make out!

[Updated on: Wed, 22 September 2010 09:48]

Report message to a moderator

Re: 1979 Kustom Lead I Reverb "Crackle" [message #14381 is a reply to message #14364]

Thu, 23 September 2010 18:00

gomu
Messages: 4
Registered: September 2010

Junior Member

Well I got the chassis removed and took a look at this baby. What I have is a reverb tank that looks exactly like this:

http://www.tubesandmore.com/scripts/foxweb.dll/moreinfo@d:/dfs/elevclients/cemirror/ELEVATOR.FXP?item=P-R6BB2D

I have never seen one like this. Anyway, all cables seemed tight, etc. There are really no RCA jacks, just the metal sleeve type connectors on the board side and some kind of plastic connectors on the tank itself. They are really not too accessible but I'll try to see if I can remove/reseat them.

Pretty interesting looking inside this thing. It is really solidly built, for a cheap little amp.

Anyway I wiggled things around and now the crackle is gone, at least temporarily. We'll see what happens.

Thanks again for all the suggestions.

Report message to a moderator

Previous Topic:	Bypassing the preamp on a K100C-8
Next Topic:	Kustom 100 noise

Goto Forum:

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Mon Apr #d 04:56:36 EDT 2024

.:: Contact :: Home ::.