How can I open the Little Dot MKII to access the DIP switches? Which of the screws need to be unscrewed?
Little Dot Tube Amps: Vacuum Tube Rolling Guide
- Thread starter Dept_of_Alchemy
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For the MKIII, which might be similar, I unplug the tubes, turn it upside down and can see them through holes in the housing with a flashlight.
In this case, the MKIII is not identical to the MKII because, unlike the MKII, you don't have to open the case of the MKIII.
MKII case looks similar to my LD 1. If that's the case, you need to unscrew the bottom screws, two at the front and two at the back to open the case.
Any thoughts on Russian Red Tip Power Tubes?
Anyone can dip tube tips in a colour of their liking. This has been done for several reasons, not neccessarily as a stamp of quality. You often see sheep with a dot of colour on them. The message isn't one about quality. When tubes are dipped in paint this usually means something but you need vital information to know what this is.
This is what the seller says:
"RED TIP TUBES HAVE BEEN SPECIFICALLY MANUFACTURED AND SELECTED FOR THE USE IN MEDICAL AND PRECISE MEASUREMENT EQUIPMENT"
Was just wondering if anyone ran them.
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Months ago I negotiated the purchase of a variety pack of cosmetic pairs of $2-$3 per tube 6J2P, and -ev from Ukraine. Some had painted tips, some had various numbers of painted-on red or white dots, some were tall bottle, some short, some Svetlana and some Vinniza. The paint barely adheres to the tubes and flakes off extremely easily. I didn't ask what the paint meant, and the painted didn't have a remarkable difference in sound quality. I consider them competent when it comes to bass but often nothing special elsewhere. The sensibly Western Electric 409A has competent bass and treble and very nice midrange, reminding me of Mullard 8161 but with probably better treble and bass. I haven't tried sensibly equivalent generally less expensive 6AS6 / 5725.
What would be more interesting is to know what tube type it is. I have 6C4/CV133 type tubes from the Swiss army. I suppose they tested the tubes and then dipped them into paint to know that they were tested and had passed the test. But this is just a guess on my part. Some of them have green tips and others have pink tips. The fact that they are dipped doesn't say anything about how they perform today.
I have also seen collections of tubes from radio/TV servicemen where their tubes were dipped. I guess this was in order to know that the tubes belonged to them and not the customer they were assisting. Or something like that.
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I've sometimes wondered if some tubes were painted colors to make replacement easy for people who did not know what all the numbers and codes on tubes mean. I've encountered sellers on facebook marketplace, Craigslist, eBay that do not know how to provide the identity of the tubes they are selling.
A reasonable explanation. 'Replace the red tip tube with a red tip tube'. But they would need to know which tube that was faulty...
Do you mean the two bottom screws on the front and back plates? Or do you mean the 4 screws on the bottom that hold the rubber feet!?
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Not glowing, blown heater. If not that, replace some and see if it works again. If neither works, shucks it will cost more: call the house call tube repairman or take the equipment to his office. I color-coded connections for a 1970's solid state receiver for my parents. I also labelled the buttons and knobs that interested them: On/Off, Volume, and Selector. There were oodles of additional buttons and knobs in which they took no interest, considering it a waste of time busywork to figure out.
Does anyone have experience with the Little Dot 1+ and the Little Dot MKII?
Do they sound identical?
I have an MKII and it's fantastic. I do a bit of tube rolling and listen a lot with an HD800 and a Grado GH2.
Does it make sense to buy an LD 1+ as well? I've read that Burson offers opamp rolling options for the LD 1+.
This isn't available for the MKII.
Do they sound identical?
I have an MKII and it's fantastic. I do a bit of tube rolling and listen a lot with an HD800 and a Grado GH2.
Does it make sense to buy an LD 1+ as well? I've read that Burson offers opamp rolling options for the LD 1+.
This isn't available for the MKII.
