A snippet from the SSS email:

I have done my best to stock up but sales have been hot. Some things will sell out overnight or within a day. Do not delay.

For three days only, June 25 at 12:00am EST through June 27 at 11:59pm EST, everything in the store will be 10% off with coupon code SBTENOFF.

Coupon cannot be combined with other offers like free shipping w/decoder.

The sale runs WEDNESDAY, THURSDAY & FRIDAY ONLY.

I grabbed some stuff I needed, looks like there is still some stuff in stock: https://www.scalesoundsystems.com/railpro?page=2

yep, thanks for the details gents!

one niggle: a "normal" output on a decoder is an open collector transistor which conducts to minus (most people would say ground)
this "output" is either open circuit/high impedence or connected to ground

(clearly this is why the LED common is positive voltage)


a logic level output is positive when true and negative or ground when false.

open collector "outputs" can sink reasonable current, 100 ma is typical

logic level outputs can only handle a few ma, most are under 10...

but in no case would I call normal open collector outputs "amplified" they are merely a controllable switch to ground when "on"

just trying to clarify something that could be misconstrued.

In the below, when I say others I mean North American manufacturers directly competing with ESU's Loksound v5 in the marketplace, this means Soundtraxx and TCS. This is pretty much the situation summarised:

• ESU makes its 21 pin Loksound v5 decoder with all outputs on the 21 pin connector available in the standard, available . The others do not. Scaletrains apparently sometimes makes use of those extra outputs.
• ESU makes its 21 pin Loksound v5 decoders in line with both the NEM and NMRA standard ^*. The others do not. ESU's decoders contain 4 amplified outputs on the 21 pin connector (Front/Rear headlight, AUX1 and AUX2), The rest of the outputs are logic level. The others decoders are all amplified outputs. The two types of output are not interchangeable for directly hooking up lighting.
• Scaletrains motherboards are designed for ESU Loksound and therefore are designed for NEM / NMRA standards compliant decoders.

* ESU also makes the 21pin Loksound v5 with more amplified outputs on the 21pin connector but this decoder is specifically designed for Marklin models.

The LM-3S-21 according its the documentation also follows the NEM / NMRA standard with which outputs are amplified and which are logic level, and all outputs available on the 21 connector in the standard are available. Now, as to why the LM-3S-21 is not working in place of a Loksound v5 in Scaletrains is a mystery that I can't put my hand to as I don't have any LM-3S-21's (too expensive until the exchange rate radically improves) or any Scaletrains stuff.

I feel Scaletrains has been dealt an unfair amount of bashing over this, when they were the ones compliant all along.

- Tim

Edit: Grammar

Love to read that discussion, can you supply the link?

Interesting, the first paragraph says that the decoder is fully NMRA compliant so it's not their fault

The second paragraph then asks why the RP does not work, since it had the function outputs...

So, I'd love to read about this, so link please?

Scaletrains definitely does not integrate well with 3rd party 21 pins.  It's a known issue between ST and other DCC boards...

There was a lengthy discussion about this over at Model Railroad Hobbyist awhile back (Link, look for Yarons posts on page 76-100 and 126-150). What it really boiled down to was all the other decoder brands aren't fully NMRA compliant and lack the required function outputs from the standard to work with Scaletrains; there wasn't anything non standard about Loksound or Scaletrains motherboards at all.

Now, the LM-3S-21 does have the required function outputs so why doesn't it apparently work in place? Mystery!

- Tim