Negatron
100+ Head-Fier
- Joined
- Aug 5, 2006
- Posts
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There have been several postings and I have been PM'd regarding the Little Dot MKIII and odd noises. The problems are easily solved, actually just normal tube routine. Old tubes, some 40-50 years, need the pins cleaned. Most have been sitting with nothing better to do than oxidize and were not pristine when they left the factory for that matter. Tubes are high impedance devices and a small amount of oxide on the grid pin especially, can make a very noisy tube.
I highly recommend Caig Products, Deoxit and ProGold, you can readily find it on the Internet. In the U.S. Radio Shack carries it (?) Clean the pins with Isopropyl Alcohol using an old toothbrush and then use the Caig treatments per instructions. A little goes a long way. This goes for any tube gear, not just the MKIII. DO NOT use WD40, cheap contact treatment or other substances. They can in time with the heat of the tube turn to varnish, a lousy conductor.
$1000 amps may leave the factory clean but not these $300 jewels, so some are ending up with noises. It's worth spending 5 minutes.
One other thing to check on the MKIII is that the input tubes are vertical in the sockets. If they lean to the side they can touch the chassis and weird microphonics may follow. With these things dealt with, it's a fantastic little amp.
I highly recommend Caig Products, Deoxit and ProGold, you can readily find it on the Internet. In the U.S. Radio Shack carries it (?) Clean the pins with Isopropyl Alcohol using an old toothbrush and then use the Caig treatments per instructions. A little goes a long way. This goes for any tube gear, not just the MKIII. DO NOT use WD40, cheap contact treatment or other substances. They can in time with the heat of the tube turn to varnish, a lousy conductor.
$1000 amps may leave the factory clean but not these $300 jewels, so some are ending up with noises. It's worth spending 5 minutes.
One other thing to check on the MKIII is that the input tubes are vertical in the sockets. If they lean to the side they can touch the chassis and weird microphonics may follow. With these things dealt with, it's a fantastic little amp.
