Joe Fugate: Question regarding DCC decoder brands

Hello Joe! Hope you’re well.

Recently you posted information regarding problems/compatibility issues with using sound decoders (DSX?) and Digitrax decoders in comparison with Lenz and NCE. I hope I got it right.

I looked but can’t remember which thread it was. Could you post and comment about this, please. I’m new to DCC and am trying to learn as much as I can. From what I understand, Lenz, Digitrax, NCE, and TCS have their pro and con points when used in conjunction with sound decoders.

Based on feedback from a good friend of mine, I’m leaning towards Digitrax, however, if there are associated problems it would be good to know.

Thanks in advance, Joe! Looking forward to your new video/dvd!

10-4![;)]

Antonio:

The problem is with QSI sound decoders and their huge current draw when powering up the track. They have a capacitor that needs charged when you restore power to the track after a short, and it can fool some DCC boosters into thinking the track is still shorted and the booster will shut down again. The net affect is you can’t power up the layout if it goes down because of a short if you have some number of QSI locos on the track.

QSI puts that capacitor in their decoders to power the sound when a loco hits a dirty spot in the track, which is a nice feature. Soundtraxx decoders (pre Tsunami at least) don’t have this feature and will cut out if they hit dirty track. However it also means they don’t need near the current when powering up after a short, so they are much more forgiving with boosters.

Here’s the a link to more info on my forum:
http://mymemoirs.net/model-trains/forum/phpBB2/viewtopic.php?t=109

Tony’s Trains Exchange did a test of various boosters to find out their sensitivity to this problem … here’s more info:
http://www.tonystrains.com/technews/pshield-restart.htm

From this info it appears Digitrax boosters are more sensitive to the QSI locos and it takes fewer of them on the track to “kill” the booster so it won’t recover from a short. Lenz and NCE boosters appear to allow more QSI locos on the track before they will not recover from a short.

Joe,

Thanks very much for your quick response! I appreciate the info. I’ll check out the links you posted.

One more question, if you don’t mind. Have you noted any unusual problems with Digitrax
decoders themselves? I understand that just like car owners, DCC users may have personal favorites but just like our vehicles, each may have its “quirks”.

Thanks again!

I want to install a soundtrax decoder in a loco with an existing DH-123 decoder. It is a LL P2K GP-20. Has anyone ran into problems or have any good advice on this installation? Is there a better decoder to use with the soundtrax unit?

Digitrax decoders, other than the latest 163 series, are noisey. The motor buzzes a lot, so much so that it almost drowns out a DSX sound decoder that’s been turned down to appropriate levels. Oh you can crank up the sound decoder but you’ll drive everyone crazy it will be so loud.

Plus in tests I’ve seen of the back EMF, Digitrax back EMF rated lower than other decoders. I’ve used a lot of Digitrax decoders and they work pretty well, although the back EMF is tricky to set up with it’s three different configuration variables that aren’t real obvious as to what they mean.

These days, I’m trying out Lenz, NCE, and TCS decoders, and my switch from my Digitrax standard for decoders – but we’ll see. I’m not a transponding user so that direction with decoders doesn’t hold much interest for me. I’m leaning toward Lenz these days, with all the cool features in their “Gold” series.

Joe could you go into a bit of detail with how to set up the Back EMF for the digitrax decoders. I never understood exactly what it all meant and haven’t had the time to play with it to figure it out. Thanks

Jesse

Joe,

I just installed four of the new Lenz gold series decoders and like them a whole bunch. Looks like they combined some of the best features of their other decoders. The slow speed function and a fuction to turn off the braking glide are very nice to have. Have you experimented with the asymetrical DCC functions yet???

Jesse:

Everytime I mess with the back EMF settings I have to go read the manual again and think about it for a while to “get it”. I’ll go do that and get back to you.

And to the others … lots of decoder questions, let me get back to you soon with answers!

I would suggest TCS for begginners in DCC. They are pretty good decoders, pretty cheap too. Best of all. If you blow a decoder be it by a track problem or just a bad installation. Send it to TCS and they will replace it no questions asked. I belive they call it "goof proof " warranty or something.

Okay, Jesse …

There are three CVs in a Digitrax decoder that you can use to set the back EMF compensation:

CV 55 - Static compensation
CV 56 - Dynamic compensation
CV 57 - Droop

The analogy they give in the decoder manual for what these mean doesn’t do a lot for me, I’m sorry to say. Lots of experimentation has lead be to the following standard settings in my P2K SD9s that need a fair amount of back EMF compensation to run smoothly:

CV 55 - 128 (Default)
CV 56 - 5 (Quite a bit lower than the default of 30)
CV 57 - 8 (Higher than the default of 5)

In plain english, I haven’t found any real value in playing with CV55 so I just leave it at the default. It’s very easy, if you mess with CV55, to make the loco quickly run worse. So just leave it alone.

CV56 is the “hunt” setting, which will cause a loco to buck and jerk violently in a consist. In effect, this setting changes how quickly the loco tries to change speed to compensate. If you set this very high you will get compensation that fights any impedement with violence. I’ve found you want this pretty low if you want your locos to run smoothly together in a consist. They recommend 30, I recommend far lower – I use 5.

CV57 is the setting we all think of when we think of back EMF – how much do you want the compensation to be? The values go from 0-15, with zero being none and 15 being total compensation. If you set this value to 15, you’ll get a loco that will run uphill, downhill, through rough trackage, around curves, etc all at a smooth constant speed. You can set the throttle and then forget about it.

Setting this value to 15 is a great stunt, but it isn’t railroading. A prototype loco, just like a car, is affected by uphill and downhill and curves. You need to adjust the throttle on your car when it encounters these things and the same (if not more so) with a loco pulling a train.

I have found a middle of the road sett

Thank you again, Joe!

So from what you’re saying, Digitrax made an improvement to the DH163 decoder which results in it not buzzing with a Soundtraxx DSX decoder. I’ll continue to read and research DCC as I am an electronic klutz, but understanding it has become much easier.

High Greens!

No decoder with a high frequency drive should buzz. THat’s why the Soundtraxx sound and motor decoders buzz - they don’t have a high frequency drive. Same with the super low end Lenz decoder used by Bachmann. I know someone else here got an EZ-Command and mentioned the loco buzz - and changed the deocder int he included loco to a better one and no more buzz.
Finding out about this feature can be fun - each manufacturer uses their own term for it. Digitrax calls is SuperSonic. NCE says "Silent Running (thus the D13SR decoder - SR for Silent Running), etc. But all but the lowest end decoders usually have it these days.
And the critical thing - if you have a loco that has a coreless motor - they definitely REQUIRE a high frequency drive, if you don’t want to burn up the motor.

–Randy

Tweet:

You can go with a Soundtrax DSX sound only decoder in the loco, but it’s tricky to program a loco with two decoders in it, not to mention trying to find the space.

A simpler solution is to put a DSDLL110LC plug and play decoder in the loco. This is more or less a direct replacement for the LL circuit board, but it will cost you about $120. Just add a speaker and enclosure and you’re all set.

If you don’t mind carving on the weight a bit to make room, you can go with the generic DSD100LC for less than $80 + speaker. This is what I use for my diesel sound decoder and I’m pleased with it … a good compromise between quality and price.

Guy:

I have a Gold series decoder but haven’t installed it in anything yet. That’s next on my list.

Joe,

Re: Your response to Tweet. I’ve been to the Soundtraxx website before.

Yet, I was not aware of the decoder you’re mentioning being “generic”. By that do you mean that the sound quality is poorer than the DSDLL110LC decoder? The price appears affordable however, I’m assuming that something is sacrificed somewhere.

I’ve read before and have passed the info that certain “L” series decoders from Soundtraxx have a rather “weak” ampllifier. Is the DSD100LC the unit?

Thanks!

Antonio:

Yes, that’s the decoder. The LC series is “low cost”. For EMD diesels, the generic $80 Soundtraxx diesel is a honey, I think. The other plug and play decoders in the LC series are similar, except they have specific EMD or Alco sounds, and you pay more for that.

If you can listen to a sound recording and tell what model and year of loco diesel you are listening to, you probably won’t be satisfied with the DSD100LC. But it sounds okay to me (I can’t differentiate specific diesels that well, although I can tell the difference between an ALCO, EMD, or Baldwin diesel just by hearing it).

For a really cool web site with great details on sound decoders, see:
http://home.pcmagic.net/ogdenj/addsound/addsnd.htm

So for about the same price, I can install the generic DSD decoder which is a motor decoder also, instead of installing a DSX type with my DH-123? I guess the price of the Digitrax DH-123 would be considered as extra, but I have several more locos needing decoders so it would not go unused. Thanks for the info.

How about MRC sound decoders? what do you think of them?

Well, I’ve not heard them so I can’t really say. However, I do know the generic Diesel Soundtraxx DSD100LC is very nice and has lots of features I really appreciate in an $80 package. I can have the sound automatically come on only when the decoder’s addressed by a throttle and then go off after 60 seconds when I deassign the decoder from a throttle.

I can independently control the volume on all the sounds, change the bell ringing rate, change the loco RPM rate to match whatever speed step increment I like.

I don’t think you can set any of this with the MRC decoder. You just get what you get, and you had better like it cause you can’t change it.

True, the MRC decoder somes with a speaker, but what if I want a different speaker (like a better one that sounds nicer?).

To add a speaker plus enclosure to the SoundTraxx you’ll add another $15 or so from TTX (see: http://www.tonystrains.com/products/tteexclusive_spkr.htm) but then you can get the largest speaker possible that will fit into your space. Believe me, there’s nothing like getting a wimpy tinny sounding speaker to disappoint you, so you don’t want to scrimp on the speaker and enclosure. A few bucks more here can make a big difference.

The bottom line for me is the price difference between the DSD100LC and an MRC just isn’t that much (we’re talking diesel sound decoders now), and the SoundTraxx is really worth it considering the huge difference in features that you can control.

And one last point on MRC versus Soundtraxx … you want control if you intend to equip a layout with loco sound decoders. There’s nothing more annoying than a layout room full of locos with sound that you can’t adjust as you would like.