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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 449

post #6721 of 10501

What i did with mine is cut off all the connectors then separate all the wires by colours and connect green to any black wires and leaved a few yellow and black wires longer than the rest of the wires so i used those longer wires for the Regulator.All the wires that i don't need i cut them short then soldered all the yellow wires(12V)together and all the black wires on the other bundle.

 

 

 

post #6722 of 10501

The PS has a 20 pin connector. Can I just jump the green wire with the closest black wire there?

 

There are another 6 connectors. Is it enough to just use one black and one yellow wire to connect the voltage regulator (from the longest lead), or do I have to bundle together all yellow and black wires? (eight black and 5 yellow)?

post #6723 of 10501

   You can use a jumper for the green to black but make sure it does not move or touch anything else for this i've used a jumbo paper clips.

IMO you can use just 1 yellow and one black for the regulator that is how i hooked up mine before.I would cut 1 yellow and 1 black from the 20/24 pin connector then wrap the connector so the jumper is covered and it would not moved. 

post #6724 of 10501

Electrical tape maybe.

post #6725 of 10501

The good  thing about  using a PS with a big fan on top of the case you can used it to cool the regulator.When ever i'am running a pair of 6AS7G tubes i usually put the regulator upside down on top of the PS fan and that cools the regulator.

post #6726 of 10501

Thanks for all the advice and tips - going to try to connect everything tomorrow. With two 6AS7 tubes, do the heat sinks get too hot to touch?

post #6727 of 10501

 It gets hot but not too hot to the touch,How i wish that those Heat sink on the Chinee regulators are bigger.I forgot to mention if you put the regulator on top of the case fan put on  something on the regulator to leaved a gap between  the regulator and the fan for this i've used those clear rubber bump on/bumper for cabinet doors.


Edited by i luvmusic 2 - 7/4/14 at 6:22am
post #6728 of 10501

Hey guys...

 

A cheap laptop power supply/charger is sooo much easier lol! Not to mention neater...but then, y'all know I love neat and tidy!

 

Cheers.

post #6729 of 10501

I do have a cheap lap top power supply, but at 6.3V it puts out 8A if my calculations are correct.  It is rated 20V 2.5A. From what I have been told, a tube drawing 2.5A could use three times that current on startup, so ideally I would want something capable of 15A current draw.

 

Now I have a new problem. When I connected the power supply as per instructions, everything works, and it puts out 11.3V, but as soon as I put the 6AS7 in the socket, the PS shuts off. It does reset itself, but every time I try, it shuts off again.

 

What's the problem now? My PS is an older type, rated at 218W at 12V/14A, 5V/25A.

post #6730 of 10501

I am using a Samsung laptop 19V 4.74A AC Adapter Charger:

 

http://www.ebay.com/itm/151235154803?var=450272775764&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

 

At 6.3V, it is capable of putting out a little over 14A, which should be more than adequate to run two 6AS7's. So if you are not able to get your desktop PS working, you might want to consider something like this.

 

Edit: I have run a single 5998 in my LD1+ with a 5A regulator. If the 5998 required 3 times 2.5A, or 7.5A, at start-up, I suspect my regulator would have failed. Based on my experience, I believe that anything over 2 times the rated amperage is probably fine for 6AS7-type tubes: 2399, 421A, 5998, 6080, 7802, 7236....

 

Edit2: The LD has a 1A heater circuit for drivers and 2.5A for powers. Two EF91's draw .6A, a bit more than half of LD"s 1A capacity. And two 6N30P draw around 1.7A, again more than half of the LD's 2.5A capacity.

 

So I believe that designing your heater PS circuit to handle 3 times normal operating current is perhaps a good thing to do, it is not necessary.


Edited by gibosi - 7/4/14 at 10:17am
post #6731 of 10501
Quote:
Originally Posted by mordy View Post
 

I do have a cheap lap top power supply, but at 6.3V it puts out 8A if my calculations are correct.  It is rated 20V 2.5A. From what I have been told, a tube drawing 2.5A could use three times that current on startup, so ideally I would want something capable of 15A current draw.

 

Now I have a new problem. When I connected the power supply as per instructions, everything works, and it puts out 11.3V, but as soon as I put the 6AS7 in the socket, the PS shuts off. It does reset itself, but every time I try, it shuts off again.

 

What's the problem now? My PS is an older type, rated at 218W at 12V/14A, 5V/25A.

You have a short somewhere.I never have that problem with my PS.


Edited by i luvmusic 2 - 7/4/14 at 11:26am
post #6732 of 10501

Another thing to note about desktop PS D3LL PS have different colour coding.

post #6733 of 10501

Saw a YouTube video about using a PC PS and the guy said that you have to put in a resistor to make a dummy load. This is stuff that is beyond my abilities....

 

It's not a Dell, so I know that I need the green and black wires.


Edited by mordy - 7/4/14 at 11:34am
post #6734 of 10501

You can install one dummy load on 5V rail i used 20R 5W Ceramic resistor connected to RED(5V) and BLACK that's it very simple.

post #6735 of 10501

You mentioned your PS is older model i believed older PS you need to install dummy load or it will be unstable sounds like your PS is unstable since it is resetting if there in so short.My PS is not that old so i can run it with out dummy load and it's fine so you should install a dummy load in your PS.

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