| Kustom 150-PA reverb problem [message #25920] |
Wed, 15 February 2017 12:48  |
shnaggle
Messages: 8
Registered: February 2017
|
Junior Member |
|
|
Question: Does the Kustom 150-PA unit require a footswitch to trigger the reverb? I can hear the spring inside the unit, but manipulating the reverb dials has no effect. Can any old guitar effects pedal, jacked into the rear footswitch jack, work the same as a dedicated A/B footswitch?
[Updated on: Wed, 15 February 2017 13:30] Report message to a moderator |
|
|
|
|
|
|
|
| Re: Kustom 150 reverb problem [message #25926 is a reply to message #25924] |
Wed, 15 February 2017 17:47  |
chicagobill
Messages: 2010
Registered: April 2003
|
Senior Member |
|
|
Welcome to the site! If it has blue power and polarity lights, it's a metalfront head. Is there a reverb lock knob on the back of the amp?
The usual problem with dead reverb is a dirty plug in connector or a broken wire inside the reverb tank itself. What sorts of skills and equipment do you have?
To fix it you will have to pull the chassis out of the case, remove the top chassis cover and get to the reverb tank that is mounted on the back wall of the chassis. Then you will need an ohm meter to test the wires and the reverb tank transducer coils.
|
|
|
|
|
|
| Re: Kustom 150-PA reverb problem [message #25931 is a reply to message #25920] |
Thu, 16 February 2017 00:33 |
chicagobill
Messages: 2010
Registered: April 2003
|
Senior Member |
|
|
Sometimes the reverb lock will stick and stop the springs from sending the signal through. There also is a foam rubber pad on the lock mechanism that sometimes deteriorates into a black tar like mess that gobs up the two springs.
The reverb tank has two RCA jacks on the side of the case. The two wires run to the pc board on the front panel. If you unplug the wires from the pc board, you can then use your ohm meter to read the resistance across each RCA plug. Each wire will be connected to the tank's input and output coil, so you should get a resistance reading from 50 to 200 ohms. If the meter reads the same as when the two leads are not connected to anything or open circuit, either the transducer coil wire is broken or the RCA plug wires are not making good contact.
See what readings you get.
|
|
|
|
|
|
|
|
| Re: Kustom 150-PA reverb problem [message #25947 is a reply to message #25920] |
Sun, 19 February 2017 16:32 |
shnaggle
Messages: 8
Registered: February 2017
|
Junior Member |
|
|
Thanks. After removing the tank from the rear supports (but not yet the bottom anchor wire), I can see the RCA plugs now on the tank. One plug is easy to remove and reinsert from the PC board, but the other, because it's caged-off by a big metal section, will be problematic to remove and harder to reinsert, so I've left that alone just for the moment.
To test the coils, I'm to place the multimeter leads on the metal sides of the tank's RCA jacks? Am I also testing the jacks on the PC board?
There was a bit of tar gum-up on the reverb lock. I've placed a couple of bits of electrical tape over the lock's affected section and cleaned up the springs with some isopropyl alchohol.
Lastly, I am listening to the Grateful Dead -- "Europe '72" LP while am I doing all of this 
[Updated on: Sun, 19 February 2017 17:37] Report message to a moderator |
|
|
|
| Re: Kustom 150-PA reverb problem [message #25948 is a reply to message #25920] |
Sun, 19 February 2017 18:35 |
shnaggle
Messages: 8
Registered: February 2017
|
Junior Member |
|
|
Okay, I think I've figured some of it out. I removed the tank completely from the unit and tested the tank's RCA jacks with the multimeter: around 175 ohms for each jack. I cleaned the three RCA plugs that are accessible to me, as best I can, as well as the two jacks on the reverb tank and the input jack on the PC board. Unfortunately, I don't have much access to the output plug on the PC board nor its jack (that interior chassis shield, again; I thought only the Japanese made their 1970's electrical things impossible to service  ) There's always the possibility that either/both of the RCA cables are bad, but until I can figure out how to gain access to the PC board's output jack, that will be tough to diagnose.
I'll put everything back together and try it out again.
[Updated on: Sun, 19 February 2017 18:35] Report message to a moderator |
|
|
|
|
|
|
|
| Re: Kustom 150-PA reverb problem [message #25960 is a reply to message #25920] |
Thu, 23 February 2017 12:42 |
stevem
Messages: 4778
Registered: June 2004
Location: NY
|
Senior Member |
|
|
Hearing the tank crash means that atleast the output side of the tank and the reverb recovery circuit / amp is working.
When you tested the tanks input side did you do so thru the cable to also prove that out?
You only need the foot switch to turn the recovery amp off, if you had a ft switch to do such you would no longer hear the tank rattle/ crash when you tap it!
[Updated on: Thu, 23 February 2017 12:46] Report message to a moderator |
|
|
|
|
|
| Re: Kustom 150-PA reverb problem [message #25968 is a reply to message #25920] |
Tue, 28 February 2017 06:03 |
stevem
Messages: 4778
Registered: June 2004
Location: NY
|
Senior Member |
|
|
That's strange as I have never had the drive side tank amp in a any model kustom go bad!
I would try one last thing out.
The white multi pin connectors in these amps are Aluminum and as such tarnish with age and make poor or intermittent connections .
On the cable that feeds that board I would unplug it and squeeze up the Female pins A bit to see if that helps.
Some times just plugging and unplugging the connectors 3 or 4 times is enough to restore a good conection!
If not atleast that amps drive section is made up of just 3 Transistors who's total cost is 5 bucks these days!
[Updated on: Tue, 28 February 2017 06:11] Report message to a moderator |
|
|
|
VintageKustom.com
Search
Help
Members
Register
Login
Home
]