I have an old Proto 2K SD7 with a Loksound v5 decoder installed. In JMRI the Sprog slot monitor current meter indicates about 0.3 amps when running at a scale speed of 50 mph.
George
I suppose that decoders are advertised such that the maximum current is specified at a PWM duty cycle of 100%. You will not come anywhere near this percentage with the mentioned loco unless you like to see your trains run like a bullet train. Just about all MR locos are geared way too high. The PWM I would expect to see is probably around 30 - 40% at max (realistic) speed giving you a much lower average amperage. Thus you would come no where near cooking this decoder.
I used to have 2 P2K SD7's and 2 P2K SD9's. I only installed a dcc decoder in one of them and it was fine. I've never heard of the Proto 2000 SD's having issues with too high amperage. In fact the only P2K loco produced by LifeLike with amperage issues that I am aware of were the first runs of Alco PA's, which were known to have high amp draw motors.
Rio Grande. The Action Road - Focus 1977-1983
This particular Proto 2000 locomotive averages about .500mA or .05A after testing the load with the Volt meter. The LOK sound mini decoder should suffice for this amperage draw.
Check the MR archives for the issue where they review the model. They give amp draw.
Disclaimer: This post may contain humor, sarcasm, and/or flatulence.
Michael Mornard
Bringing the North Woods to South Dakota!
The OP says he has one but I will see your $8 and lower it to $7
Henry
COB Potomac & Northern
Shenandoah Valley
Somewhere else, I recently read that Loksound decoders shut down if they're overloaded, rather than get damaged. You could probably confirm that by calling the "head office". I've done it; they're very nice.
Also somewhere else, I said that "you" should get an ampmeter, and run your loco on DC to get a reading.
Here's one for 8 bucks:
https://www.amazon.com/YXQ-Current-Ammeter-Accuracy-Measurement/dp/B07JM3CQ74/ref=sr_1_20?dchild=1&keywords=2+amp+dc+ampmeter&qid=1621904208&sr=8-20
Ed
Use the Tsunami2 1100 series decoder if you want to save some room, that is if you want to stay with a SoundTraxx.
I meant .78 amps which is 780 ma.
That's good to know your GP-7 draws only 7.8 (milli amps, I presume). I am planning to put my Volt Meter on it this evening, but I am surprised the mfg tech spec paper work doesn't list this. Escpecially since it has the 8/9 pin socket onboard. LOK sound can handle a max of 1 amp before you damage their board.
My Proto 2000 GP7 had a stall current of 0.78 a. It did not have a socket in it so that may or may not be similar to yours..
A voltmeter is an very useful MR accessory, if not a necessity.
I have a old (but new - never used) Life Like Proto 2000 SD9 high hood locomotive that I want to convert to DCC. The factory board has the socket connection pin to plug a DCC decoder into, however Tsunami2's take up a lot of room and the speaker that I have - both would require significant surgery to the block of the locomotive to fit them both. I "could" do that, but I really want to avoid that. The Tsunami2 has a max load draw of 2 amps. Soooo, I was looking at swapping the Tsunami2 I have out with a LOK sound mini that has the socket pin connector on it with the baffled speaker enclouser. However, the LOK sound decoder recommends an amperage draw of .75 (with a max load amperage draw of 1 Amp). Unfortunately the spec's of the Proto 2000 SD9 does not indicate the curent draw. Does any one know for these older Life Like Proto 2000 model's (10-15yrs old), what amperage they drew?
Thanks,