Country_Gene Messages: 42 Registered: December 2001 Location: Northwestern New Jersey
Member
My 35-year-old K200-B1 still works great! Only "problems" are bright switch on "Hi" channel cuts volume and "Hi" inputs on *both* channels *decrease* volume. I'm not really trying to *fix* anything. I still have the Low inputs on both channels available and the Bright switch on the Normal channel works fine. This is all that I really need.
I was thinking of taking off the back, giving it a good vacuuming, and spraying everything with electrical/electronic contact spray. I figure it couldn't hurt. Is this a good idea?
Yes, that's a great idea. The cleaner will probably fix your bright switch problem.
Unlike a lot of other amps, the high and low inputs on K200's do not refer to volume, but tonal response. The "problem" with the high inputs is that there are small value caps in series with these inputs, that cut off the low frequencies thus making them "high" inputs. The loss of the low frequencies make them sound quieter. So your amp is working as it was designed to work.
Just be careful when vacuuming out the insides. Watch out for the wires, etc. when you are cleaning it up and you should be fine. I use a small paint brush to loosen the dirt and to get at areas that the vacuum can't reach.
stevem Messages: 4738 Registered: June 2004 Location: NY
Senior Member
If your power transformer(the big chunk of iron bolted to the right rear wall) has rust on its center layers, go to a auto parts store and get a jar of permatex rust converter(there are other companys that make a similar product) and treat as much of the core rust as you can get at.Most amps have only lite rust, some that I have seen that came from humid southern states have very bad rust, and this thick deep rust will effect the transformers current output. The rust converter changes this rust into a primer and restores the magnetic seperation of the core plates.If you transformer has bad rust I would suggest drilling out the rivets that retain it so you can get at the whole core area, and then re-rivet it or bolt it back down.While you are in their with the spray cleaner incert a cord into any of the input jacks, and as you slowly do that you will notice a lever on the jack that opens up once the male plug is fully incerted. this is a switch that keeps the unused jack shorted, which stops hum and noise from getting into the preamp. this switch lever has a half moon contact that should be sprayed wiped clean and sprayed again. I cut off the end of a Q-TIP, flatten some, and rub clean both opposing contact areas.You should be using a cleaner with lube in it, the shack has it.Try not to get it all over the circuit boards, pack some paper towels torn into small sections around the brite switch but take caution to not bend over and short out transistor leads and such.
stevem Messages: 4738 Registered: June 2004 Location: NY
Senior Member
WARNING!!! Do not use automotive type electrical cleaner spray, as some of these can damage plastic plus they have no lube. They are made for cleaning alternators, not amps!It does work great however for removing old dielectric grease when replacing output transistors.
Country_Gene Messages: 42 Registered: December 2001 Location: Northwestern New Jersey
Member
Well, I cleaned and sprayed the inside of my K200 B-1 head. What a difference! Control knobs are completely silent when being turned. Even the Bright switch and High channels work better.
Just an oservation........
I removed the chasis from the head (first time in 35 years) and noticed two things....
1. Given the size of the head, there wasn't a whole lot of stuff (electronics) in there.
2. There was almost no dust inside.
stevem Messages: 4738 Registered: June 2004 Location: NY
Senior Member
Yes, they could have made the amp smaller if they used cast aluminum output transistor heat sinks. They did not, so they still need a givin amount of chassie metal to act as a heat sink for the outputs. While you had the amp out, oyu may have noticed that the 4 output transistors where mounted on a C shaped piece of metal the was riveted to the main chassie/main heat sink.
Kustom was one of the first companies to use a modular chassis system. The same size cabinet, chassis, etc. was used for all of the different models. I'm sure that you noticed that the chassis front panel was already drilled for double the number of holes that your amp needed. This way they just produced and inventoried one size case and chassis for all of the 200 series amp heads. And remember that back in the sixties when these were designed, bigger was better.
Maybe some of the others here will chime in here, but I believe that Kustom was the first company to create a full line of vertical speaker cabinets. Before this, we all stood our Fender cabinets on their sides, trying to make them bigger in the backline.
stevem Messages: 4738 Registered: June 2004 Location: NY
Senior Member
I belive they where also the first instrument amp company to put casters under almost all of their speaker cabinets, the first ones to use thermal circuit breakers and speaker protection circuitry in the amps output stage, and covers came with out charge if I remember right from when I bought mine.