Please help me identify a K100 part [message #8501] |
Thu, 05 April 2007 15:16 |
swwhit
Messages: 6 Registered: April 2007 Location: Windsor, CT
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Junior Member |
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Hello:
I have an original Kustom 100 from the late 60's I managed to pull the wires off a part: it is a small metal cannister-shaped part 3/8" long X 3/16" diameter, located in a metal clip between two large transistors on the bottom of the chassis.
The part is made by RCA: N3754. There might be a "1" in front of it, the lettering is smudged.
There is also the text "8L" on it.
If you have any suggestions regarding how to identify and/or find such a part, I'd appreciate it. Meanwhile, I'm interested in ordering a schematic. I don't know whether I have a K100-1 or K100-2. The Model# label on the head is unreadable, but the s/n is 34966. PC board has the letters: KEI-1 PC104 on it.
Can you tell from this info which model this is? Maybe there are other distinguishing features that would help me identify it.
Thanks in advance for your help.
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Re: Please help me identify a K100 part [message #8502 is a reply to message #8501] |
Fri, 06 April 2007 06:43 |
stevem
Messages: 4775 Registered: June 2004 Location: NY
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Senior Member |
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Hi,That semiconductor you broke is a diode, and its part number is 1N3754,.It is used to sence the two output transistors running temperature and adjust the output stages current as needed.
You can get a replacement from mouser electronics in the NTE line they carry,their part number is NTE5801.
You will also need a tube of heat sink compound to dab a blob on the new diode before you place it back in its mounting clip, and the clip must fit tight on atleast 2 sides of the diode.
The new diode will have a plastic case not a metal one like the original.
The k100-1 head is 2 channels, the k100-2 head is one channel with reverb and tremolo, so depending which amp you have the schematic part number will be CR102, or CR106 in the K100-2 model.
Why where you messin around down in that part of the amp, does it have a problem?
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Re: Please help me identify a K100 part [message #8507 is a reply to message #8502] |
Fri, 06 April 2007 14:15 |
swwhit
Messages: 6 Registered: April 2007 Location: Windsor, CT
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Junior Member |
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Stevem: thanks for the excellent information! I think I saw that part on mouser but wasn't sure if it was the right one.
I was messin' around to see if I could find the source of it's reverb & trem problems. It also had a hum; I think the diode was hanging on by 1 lead so maybe that was the culprit.
The reverb feeds back waaaay to easy. I opened up the head a few years ago and the tank had a kinda fiber cover on it that was coming apart. I reglued it but no difference. The springs were springy and didn't seem overly loose but I'm no expert, and the tank is original, so ... ?
The trem has practically no depth.
The footswitch isn't controlling them correctly; I forget exactly what it does or does not do. When I replace that diode I'll fire the thing up again and can give you a better description.
thanks again,
Scott
... almost forgot, I've got a single channel (2 inputs) with reverb & trem so it must be a dash-2
[Updated on: Fri, 06 April 2007 14:18] Report message to a moderator
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Re: Please help me identify a K100 part [message #8553 is a reply to message #8501] |
Thu, 19 April 2007 13:11 |
stevem
Messages: 4775 Registered: June 2004 Location: NY
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Senior Member |
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Hi, the cathode, or banded end of the diode goes to the 4700 ohm resistor that goes to another 4700 ohm resistor that is in parallel across a cap that is a 68 mfd at 35 volts.the other end of your doide goes to another doide that is in serise with yet another diode.
Hope this helps.
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