Kustom 200B head [message #8172] |
Mon, 05 February 2007 07:43 |
SRI_AUROBINDO
Messages: 4 Registered: January 2007 Location: Baltimore, MD
|
Junior Member |
|
|
Greetings. This is my first post on the site. I've been looking around and can't find anything to directly answer my question. Sorry if this topic has been covered in the past.
That being said, I just drove up from balitmore to new jersey on saturday to pick up this:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ih=004& ;sspagename=STRK%3AMEWN%3AIT&viewitem=&item=14007738 2004&rd=1&rd=1
The head looks A LOT more worn in the pictures than it does in person. Anyhow, as you can see in the description, the bright side isn't working. The normal is perfect. I was worried that it would be really noisy bc I've seen a lot of people complaining about that on here but it's as quiet as I'd expect an old solid state to be.
So I took out the chassis and i instantly saw what I thought might have been the problem. One of the reverb springs was not connected. Also, one of the smaller "corner" springs that suspends the pan was broken- i was able to fix this right away. I think I may need to buy a new tank though bc the TINY pieces where one of the long springs (the one closest to the knobs) hooks into are both missing. one was actually still rolling around in the pan but I can tell that i won't be able to just pop it back in. When I was testing it out at home I put a footswitch into it and the switch caused it to make noise through the speakers. This would mean that the output stage/drivers are ok, right? Then I tried to disconnect the tank and "bridge" the reverb rca jacks on the board by connecting one to the other with the rca cable. I don't know much about amps and i assumed that this would work, but it didn't. Is that bc this will NEVER work, or is something else on the bright channel messed up?
Also, one of the speakers must be blown in one of the columns bc the top pair is not working on one of them. I assume it's 2 pairs in series then parallel. How many ohms are the speakers? I'd assume they're 8 each. Is it ok to run the 4 10s in the one cab and the 2 10s in the other, or will the impedence mismatch be a problem?
Sorry if this was long winded! Any help would be greatly appreciated.
Thanks,
Mike
|
|
|
Re: Kustom 200B head [message #8175 is a reply to message #8172] |
Mon, 05 February 2007 11:36 |
chicagobill
Messages: 2006 Registered: April 2003
|
Senior Member |
|
|
Welcome to the board Mike!
You are correct in assuming that your power supply, power amp, etc. are ok, because the normal channel shares all of these sections, and if the normal channel works, your problem is located on the FX board. If you listen to the amp while turning the controls up and down, do you notice any changes in the background noise? More hum? More hiss? The problem could be as simple as a bad connection on the board, or could be more involved, like a bad transistor or cap. Try and isolate the problem to a certain section, and you will probably find it.
As for your reverb, jumpering the tank out isn't needed, because when the reverb control is turned down, the entire circuit is basically bypassed. Start by getting the pre-amp to pass a signal and them work on the reverb. Your reverb tank will probably need to be replaced, especially if the two small spring hooks at the end are missing. Each one of the hooks has a small ferrite bead magnet (that little black thing) that is needed for the tank to work.
Good luck, and keep us posted.
Bill
|
|
|
|
|
|
Re: Kustom 200B head [message #8181 is a reply to message #8172] |
Tue, 06 February 2007 06:56 |
stevem
Messages: 4772 Registered: June 2004 Location: NY
|
Senior Member |
|
|
Hi, Yes the 2 drivers with out the aluminum voice coil cover are likly replacements. If they where repaired by a autherized Kustom dealer back when, then mabe they just had the original alinco magnet CTS brand driver reconed with a regular kit. If there is a number 137 stamping on the speakers, then they are still CTS drivers.
For good PA use out of those towers I Sgest this mod to you if it turns out that when you open up the cabinets you have 8 ohm speakers only.
Depending on you EQ range you have from your mixer, these cabinets when adjusted to give good voice sibilance also give good mid-range feedback, so if you replace the top speaker in each cabinet with the parts express(eminence made) 12 inch coaxial driver(#290-504) and the matching screw on high frequency driver(#290-530) you will have a nice sounding PA.
You will also need 2 (#260-146) crossovers.
|
|
|