I use a transformer/rectifier that steps down line voltage and converts to DC to power a 9V receiver. You could do the same with your lights, connecting two or more in parallel. Mine has a 1 amp capacity. EBay may have larger ones if needed.

There are 9 volt AC to DC transformers sold on eBay and Amazon, so just find one that has enough amperage to handle all the LEDs (they don't draw very much).

Also check the specs on your LEDs to see if they can be powered by 12 volts, since there are many 12 volt transformers that are sold for lawn lights and other low voltage lighting. One like this handles up to 5 amps, which should handle quite a few LEDs. https://www.amazon.com/inShareplus-Transformer-Adapter-Voltage-100-240V/dp/B07G4CDG5J/ref=zg_bs_5486450011_7?_encoding=UTF8&psc=1&refRID=WRRDP8PEFYZ3W1AE1BMJ

Bruce

You can use just about any DC power supply with your LEDs, if you're willing to change the series resistors. Resistors are cheap, and changing the value can allow you to buy a very inexpensive surplus power supply of some arbitrary voltage from 5 to say 20 volts.

What matters with LED is the current. Every LED has a design current that provides normal brightness without overheating the LED. The most common value for your garden-variety top-hat style LED (normal or high brightness, but not super high brightness) is 20 milliamps (0.020 amp).

You can calculate the right resistance value, but it's really easy to figure it out experimentally.

First, get a bunch of resistors in values around the ones you now have (say 1/2 present to 4-5 times present resistance in ohms).

Use a DMM to measure the current your LED draws at the present voltage (or check the spec sheet). If your new power supply is higher voltage, start with a very high resistance value (say 3-4 times what it is now). If it's lower, keep the present value for the moment.

Connect everything in series -- power supply, meter, resistance, LED. Try different resistance values, gradually lowering the value until you have the same current you have now, or maybe a little less.

That's your new resistor value. Get one for each LED, and you're all set.

Uh...I probably did not make it clear that the LEDS are sealed in the models....I do not want to do anything to blow them since...well, I'd hate to have start over!!!...the average one of these takes quite a few hours to build. Each on has the two wires that go to a battery. Is it possible to connect them in some fashion to something I can plug into the wall....or, based on how things are, is this not possible? I have around 8 or so in all....

Yes, there are chargers out there, DC output, with variable or selectable voltages. Or just plain 9vdc.

Search your favorite online electronics retailer, or the big auction site, for a 9 volt switching power adapter (or 9 volt universal power adapter). You'll turn up examples ranging from $7 up to around $20. LEDs use so little current that an inexpensive 9 volt 1 amp adapter can probably power anywhere from 10 to 50 of them.

Just cut off the little plug on the end of the cord, separate the individual wires, then strip and connect the wires to your LEDs in place of your present battery box.

Usually, if the adapter is marked with the center pin of the plug +, the wire with a white stripe is the + (positive) wire. That goes to your + or red LED wire. If the LED doesn't light up, you guessed wrong on polarity, so reverse the wires.

Hey all...hope you are all having a great holiday. I'll catch up on these posts. I just need to be sure I do not do anything to blow the lights out. I know early on I learned that without a resistor on each led, I would immediately blow them. Well, they are all sealed in the models not so I have to be even more careful.

Since you are using this in your mancave, you don't want to introduce extra (electrical) noise into the system. Batteries are inherently noise-free, but switching power supplies are not. Try what DavidR suggested, but if you get a buzz in you sound system, that might the the problem. You can get magnetic transformer power supplies rather than electronic power supplies, which should eliminate that problem, if it occurs.