You are the man! I Mised this in the manual. I've set CV9 to 230 and I hear the noise for a milli second every now and again but not frequently at all....
I checked it online, it's CV9 Motor Drive Frequency. Page 22 of the LC Manual.
LC Manual
I was having problems with a couple of Soundtraxx LC - equipped engines like you describe - ran fine but had a low rumbling growl like a coffee grinder on it's last legs. I can't remember the CV right now (I'm not at home) but there is a CV you can adjust which changes the frequency and thereby the pitch of the noise that comes out. I found it was very loud when the CV had a low number in it like 70-80 but when I increase the value of the CV it became higher pitched. Eventually I got it up to like 200 and it was not only very high but it seemed to grow fainter and pretty much disappear - perhaps the higher pitch just gets masked better than the lower pitched growling does?? Anyway, I would try that before I bought a new sound decoder. Check the decoder manual, I can't remember what it's called but IIRC it has "frequency" in it??
You'll have to solder the connection at some point. Mainly, the red and black wires on the Soundtraxx decoder to the wires that come from the left and right pickups. Not sure which circuit board your loco has but it it has 4 connections at the front and 4 at the back, with the middle ones going to the light bulbs, then you would connect the red wire to one of the tabs on the right (engineer's side) and the black wire to one of the left terminals. Front or back, it won't matter, they are wired together on the board if it's as I described.
The end result is both decoders connected to track power in parallel.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Randy-
Thanks again for the help and patience - please bear with me - as the Soundtraxx as connected to the quickplug and my Digitrax decoder connects to the quickplug, how do I wire the soundtraxx decoder to the lightboard if my digitrax decoder is already connected to the quickplug? I understand that I can program each one separately on the programming track but I am confused about how to wire them together.
Thanks,
Just keep them on the same address. For programming you probably want to disconnect the one you are not programming, but the sound and motor control CVs usually don't overlap. SInce the motor decoder is a Digitrax, once you have that set up you can 'lock' it using the decoder lock feature, then you can adjust the sounds using ops mode programming without affecting the motor decoder. To program the Soundtraxx combo decoder you might need a load on the motor terminals, I used the one that came with the LT1 Loconet Tester included with my Zephyr. It's about a 100 ohm 1 watt resistor.
Randy - how do I go apart installing a separate motor decoder while still keeping the Soundtraxx connected and "synced" to the motor decoder for sounds? The Athearn model is DCC quick plug equipped. I have a Digitrax DH123 decoder currently plugged into the quick plug.
Thanks in advance,
You're pretty much S-O-L without replacing the decoder. Those older Soundtraxx DSD decoders don't have silent running or high frequency motor driver or whatever buzzword you want to call it, so it simply passes on the DCC frequency. It probably sounds about the same as if you took a non-decodered Athearn loco and put it on the DCC track. The lack of high frequency drive combined with the 'loose' assembly of the Athearn gold-sided motors makes for plenty of noise. I got one onc ebecause it was a closeout item for about $25 with the intention of installing it in a dummy loco for sound only and ignoring the motor control - which might be your best bet. If there's enough room in the loco you could install a different motor only decoder to run it and keep the sound decoder in place for the sounds.
All-
A few years ago a installed a Soundtraxx DSD-101LC into an Athearn P42 engine and then the hobby and the engine collected dust (I can't recall if I even ran the egine other than testing the sounds which work fine).
Herein lies the problem - when the motor is running, I bet a pretty bad (loud) buzzing/grinding. The sound is inconsistent (it comes and goes). At first I thought it may be the gears but before taking anything apart I swapped the decoder for a Digitrax and it runs perfectly smoothly with no noise.
Question for y'all is this a common problem with this type of decoder? Is it something that I can fix or am I, as they say, S-O-L ?