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View Full Version : Digitrax Sound SDN144PS, Plug n Play N Scale Sound Decoder



Mark Watson
April 24th, 2010, 11:30 PM
Well it looks like this one from Digitrax has just hit stores and is said to be manufactured specifically for the IM AC-12. It's price point is very attractive, but how will it hold up?

Anyone here have plans to use it? I do, though I wont be able to order for another few weeks, but I'd love to hear reviews! :D (I like videos too ;))

Mark Watson
April 28th, 2010, 05:32 AM
Bump. Has anyone got a chance to play around with this decoder yet? :)

Powersteamguy1790
April 28th, 2010, 03:47 PM
Well it looks like this one from Digitrax has just hit stores and is said to be manufactured specifically for the IM AC-12. It's price point is very attractive, but how will it hold up?

Anyone here have plans to use it? I do, though I wont be able to order for another few weeks, but I'd love to hear reviews! :D (I like videos too ;))

I have three of them and installed one in one of my four my AC-12's.

Mark Watson
April 28th, 2010, 04:54 PM
So how is it?

Whats the sound quality like and how is it's motor control?

SteamDonkey74
April 28th, 2010, 05:26 PM
I installed a Tsunami 750 in my AC-12. It might have been easier to just wait for this one, but so far I am pleased with the performance of my Tsunami.

redone1992
April 28th, 2010, 05:38 PM
Im also interrested in them and how good or bad ?

slotcardave
May 2nd, 2010, 04:49 PM
Okay, I got 2 and installed them both into my 2 AC-12's. Install per instructions is a breeze. Real easy, no fit problems. Upon power up here is what happened. Sound Volume is really low. Whistle and Bell sound really good just a little low. Chuff is AC sounding but also very quiet. Adjusted CV58 (master volume) to max 15, very little help. Adjusted CV140 (Chuff Volume) to max 64...no help. Set the locomotive # so I knew system (Digitrax) was "taking" to the decoder. But I could not hear the distintive AC air pumps...I did not try chaning the Air pump type so it could be there. However...the BIG PROBLEM is running. The engine at full tilt "99" in digitrax the engine moves maybe a top speed of 15-20 smph. It barely moves even after a long distance it never gets up any speed. Changed CV2 (vstart) to 2, CV6 (Vmid) to 128 and CV5 (Vmax) to 255...help it get from 15 smph to 20 smph. Still really slow. Chuff increases like it should to a machine gun sound. Put 2nd AC-12 on track and it did exactly the same thing. Did a factor master reset CV8 to 8 and everything ran still the same except the loco # went back to 03 like it should. Any help in this are of the speed issue would help me out. I think I have covered all the basic "1st try this" things and it has moved on to more "expert" type "try this". Thanks

Mark Watson
May 2nd, 2010, 11:20 PM
Thanks for the review Dave. Also welcome to TrainBoard!

That's very interesting on the motor speed. I've read a few reviews of other Digitrax sound products and they all say similar things about the sound quality/volume, but they then say the motor control is usually very similar to that of any other standard Digitrax decoder, which is generally praiseworthy. Hopefully someone else can help troubleshoot this one.

On the sound volume, I find there are a few different opinions as to what the appropriate sound level should be. I fall into the category of, I should be able to hear it great standing 3-4 feet away, but when the train reaches the other side of the room it should not be audible except maybe the faint whistle sound.
Would you consider the sound level on the SDN144PS to fit in that category? Or is it not even loud enough to hear when 4 feet away?

Babbo_Enzo
May 3rd, 2010, 10:07 AM
Aside the motor control (I can't comment as I don't have the decoder on hand)...
the volume reported remind me something : I have the same result when I've replaced the factory speaker (32Ohm) on my Sound-only Digitraxx with an oval 8 Ohm I have!
Then, checking documentation I discover the different impedance, so order a 32 Ohm with my needed dimensions... everything works!

What I've noted on these Digitrax family is that SDH164D (6 FX3 Functions) mount a 32 Ohm but the SDN144PS (4 FX3 Functions ) mount an 8 Ohm.... but I "presume both share same Sound/motor electronics?
New Decoder Announcements from Digitrax | Tony's Tips at Tony's Train Exchange. (http://www.tonystrains.com/tonystips/2009/120909b.htm)
?????????

skipgear
May 4th, 2010, 02:04 AM
Lowering the impedence of the speaker should make more power from the audio amplifier in the decoder but possibly cause more heat. If anything the speaker should be louder if you go to a lower impedence, but maybe have a little more distortion.

I don't agree with the baffle instructions in the Digitrax decoder. The tender shell is not a good enough baffle. An enclosure needs to be created or the speaker needs to mounted in the floor of the tender, directly, not in a baffle above the speaker grille. Your sound should come close to doubling it's output if the speaker is in a proper enclosure.

I have a one of the Digitrax decoders setting on my bench right now, tyring to decide what to put it in.

As far as the AC-12 speed issue, I think it is more of a loco issue than a decoder issue. The AC-12 I played with seemed slow at 12V. When I bumped the system up to 16V, the loco came alive, this is on DC. The motor they chose is a bit of a power hog I think. Bump up your DCC system voltage to the HO setting (16V) if possible and see how it runs.

Mark Watson
May 6th, 2010, 02:14 AM
Is the impedance related to the speaker's ohm? I did some more reading and apparently the SDN144PS has a processor for a 32 ohm speaker, but ships with an 8ohm speaker. Does this mean that if the 8 ohm speaker is replaced with the 32 ohm speaker, it will be even quieter?

Also, I found this video on youTube of the SDN144PS installed in a Life-Like E7. I love the look of its gyra-light, and the motor control appears excellent, but the audio leaves some to be desired. However, it feels like the issue is not with the sound produced form the decoder and speaker, but that it is just a terrible sound recording. In other words, it sounds like the decoder is able to make good sound, especially for the 40 dollar price tag. But whatever it was playing was probably not not doing it any justice.

http://www.youtube.com/watch?v=52EZ--4jRFc


I hope we can still get some more opinions and reviews here. :)

RBrodzinsky
May 6th, 2010, 03:15 AM
Is the impedance related to the speaker's ohm? I did some more reading and apparently the SDN144PS has a processor for a 32 ohm speaker, but ships with an 8ohm speaker. Does this mean that if the 8 ohm speaker is replaced with the 32 ohm speaker, it will be even quieter?



Not necessarily. If the decoder's amplifier is designed for 32 ohms, it may not be able to put out enough power to drive an 8 ohm speaker with appropriate volume. Not knowing all the detailed specs (it just says 1 Watt), hard to say what it can actually drive, but my bet would be that with a higher impedance, one could get quite a bit more power out of the speaker (P = R*I^2). (To get 1 watt with an 8 ohm speaker requires 350mA. To get 1 Watt with a 32 ohm speaker requires 176mA. The functions are rated for 200mA.)

This is different than connecting additional, in parallel speakers. That always has the effect of lowering impedance.

DCESharkman
May 6th, 2010, 04:21 AM
From an electrical standpoint, when impedances are matched, then that represents maximum power transfer capability.

So if the output stage of an amplifier is 32 ohms, then the optimal speaker is also 32 ohms. This may not have as much effect on volume as it would on signal clarity. The two are not related generally speaking. Volume has more to do with the volume of air displaced by the spearker cone, where the fidelity has to do with the clairty of the signal on the voice coils of the speaker.

It is the combination of the power delivered and the quality of the signal that makes the sound good or bad. Driving at different impedances may generate more volume, but it will also decrease the clarity.

Mark Watson
May 6th, 2010, 05:09 AM
So for the SDN144PS, you're saying a 32 ohm speaker replacement, to match the 32 ohm processor of the decoder, with a proper enclosure (not using the tender shell as a baffle) will be the optimum set up, correct?

DCESharkman
May 6th, 2010, 01:44 PM
So for the SDN144PS, you're saying a 32 ohm speaker replacement, to match the 32 ohm processor of the decoder, with a proper enclosure (not using the tender shell as a baffle) will be the optimum set up, correct?


That would be true, if an only if the output impedance of the amplifier was truely 32 ohms.

Mark Watson
May 7th, 2010, 11:25 PM
Ok, I just placed an order for this one! I'll be installing it in my AC-12 and providing everyone here with a complete video sample and review. :D :D

Mark Watson
May 11th, 2010, 10:32 PM
My decoder should arrive tomorrow! :D Unfortunately it may be Thursday until I get a chance to play with it.

In the mean time, has anyone else used the SDN144PS yet or herd/read any additional information we will benefit from knowing? :)

sswjim
May 11th, 2010, 11:40 PM
My decoder should arrive tomorrow! :D Unfortunately it may be Thursday until I get a chance to play with it.

In the mean time, has anyone else used the SDN144PS yet or herd/read any additional information we will benefit from knowing? :)

I got one last week, the motor drive is very good, but the sound files for the steam and SD38-2 are not very good. I did put a larger speaker (8ohms) and the volume did increase, but still a bad sound file. I base this on my experience with the Lok Sound and Tsunami Micro's. With them you have many more options. The Tsunami has the correct sound file for the Cab Foward with the weseee air pump sounds. The only good thing about the SDN144PS is the price.

Mark Watson
May 11th, 2010, 11:47 PM
...but still a bad sound file...

From the video we found on YouTube and reviews of other Digitrax Sound decoders, this is pretty much what I'm expecting. But as far as sound output, do you think this could be a great little decoder (given the price) if we are able to find a better sound file?

I have high hopes for the motor control, and I expect the volume, though reportedly low, will be just right for my preferences.

river_eagle
May 11th, 2010, 11:49 PM
I have so far installed two, one in the AC, (Challenger 3985 sound set)and one in an HO Aerotrain.
For the AC, I cut the weight into sections so that speaker could mount directly to tender floor, and glued the weight pieces back into the tender around the speaker.
I set the BEMF CVs (55, 56, 57) all to zero, and speed and performace inproved greatly, so I'm sure that with a bit of tinkering, those can be dialed in for best overall effect.
As for sound, the supplied speaker works fine, but I'm sure the bigger optional speaker mentioned in the install instructions, would help.
Decoder can handle an 8 ohm speaker just fine, as that's what I used in the HO Aerotrain, round 18mm 8ohm with enclosure mounted in 1st car.
Decoder motor functions, as preset were fine for the Aero, with the only adjustment being the standard bump of CV2 to two.

Mark Watson
May 13th, 2010, 06:25 PM
Well the initial results are in.

Right off the bat, the source files loaded in this guy are TERRIBLE!!! The bell AND whistle cut off mid-sound. Other sound files are acceptable at best, but probably only so when compared to that bell and whistle. And how can you call this an AC-12 sound set with out the uniquely identifying air spew?! :(

The installation went great. I installed it as per the instructions because this was my first ever sound install, so best not to take any risks yet. :)

The sound volume is low as stated, but just barely acceptable by my preferences, though that is only after setting the volume CV to its max. I prefer sound at a lower volume because at 4 feet, to scale you're about 640 feet from the loco. Chuff and idle sounds aren't really audible at that distance from the prototype. I expect later on with a better enclosure the volume might yet increase some, yes?

Sound quality I think is excellent! :) Last night I downloaded Digitrax SoundLoader and the Challenger sound project to play around with. The sounds that come out of the SDN144PS sound just like the sounds that come out of my computer when I play the sound project. But again, the source files are just terrible!!

Motor control, again excellent! On par with any other Digitrax decoder. By default, the chuff rate is not even close to the actual locomotive movement, but some quick tuning should get that set. By default, the top speed for me was about 20smph, just like slotcardave, however after setting CV 02>002, CV05>154 and CV55,56,57 all to 0 as river_eagle suggested, top speed is much improved. :)

Overall, the initial response is that this decoder is a great option for entry-level sound. Motor control, sound quality are great, volume could benefit from a boost, but is acceptable in my opinion. The worst part of this decoder are those source files, which unfortunately compromise any quality in sound output.

For entry level sound, great product. For crowd pleasing sound, make sure you have your own custom sound project, otherwise leave this one on the shelf.

SteamDonkey74
May 13th, 2010, 06:28 PM
Well, I guess I am glad I went with the Tsunami for my AC-12, then.

Hey, one question. How BIG is this thing? The Digitrax photos make it look small enough that it could potentially have a lot of applications in diesel locos. What do you think?

Adam

Mark Watson
May 13th, 2010, 06:43 PM
It's definitely a size friendly decoder. Not as small as the Micro Tsunami, but at about 1/3rd the price, its small enough for entry level sound.

http://www.trainboard.com/railimages/data/2020/IMG_9527.JPG

SteamDonkey74
May 13th, 2010, 06:51 PM
Thank you for the instant size comparison. Seeing it relative to the AC-12 tender and the quarter makes it immediately apparent how big it is.

I don't think some of these folks who take the photos for Digitrax went to architecture school, where they encourage us to put human figures in drawings to provide some scale. I used to actually WAIT for someone to walk in front of me while taking a photo of a building so that I would have a human scale figure to give me an instant feeling for the size of a place later when looking at the photos.

So, what I take from your evaluation is that the sound project files are rough, but that your feeling is that if someone had BETTER sound project files they could get excellent sound playback - something akin to you can have a good stereo set-up but if the recording you try to play on it is poorly mastered it's still going to sound terrible. Is that your impression?

Does that SoundLoader or whatever it is have some sort of editor? Does it accept files from other sound editing programs? Do you see a potential for basement hobbyists to start building their own sound files and then sharing them with each other?

Adam

Mark Watson
May 13th, 2010, 07:16 PM
...something akin to you can have a good stereo set-up but if the recording you try to play on it is poorly mastered it's still going to sound terrible. Is that your impression?

Exactamundo! :p




Does that SoundLoader or whatever it is have some sort of editor? Does it accept files from other sound editing programs? Do you see a potential for basement hobbyists to start building their own sound files and then sharing them with each other?


SoundLoader has no audio editing, however it accepts any .wav file for use as sound. Digitrax has a small list of free sound editing software recommendations listed on their site.
Not only do I see a potential for the basement hobbyist to begin building custom sound files, I think thats practically a requirement if you want this decoder to be show quality. It's really a complete shame Digitrax didn't put more work into their source files. Within 30 minutes last night, I found a bell and whistle file online that puts the file Digitrax used to utter shame.

Also, SoundLoader is a free download from Digitrax to custom build sound projects, however you'll need to purchase/rent/borrow the PR3 SoundFX Decoder Programmer ($85 MSRP) in order to install that sound project to the decoder.

SteamDonkey74
May 13th, 2010, 07:18 PM
I see some real potential here once there are some sound files worth a darn, or for enterprising individuals who have some skill in editing sounds.

Mark Watson
May 13th, 2010, 07:18 PM
... Given the price and performance so far, this decoder COULD have been a huge contender to the Micro Tsunami. Unfortunately the ugly source files dealt a severe blow to this product. :( :thumbs_down:

Worst case, you'll spend 40 bucks on a decoder just for good motor control anyways. I just muted the sound for a few laps and I'm at least satisfied with its performance with out sound. :p

RBrodzinsky
May 13th, 2010, 08:05 PM
How's the slow crawl speed, Mark? That's usually a better test than top speed and sustained

Mark Watson
May 13th, 2010, 08:32 PM
That's a tough one to call. I can get it to to do a perfect steam start one time, but then the next 2-3 times it goes 0 to 10mph instantly.

I still haven't figured out how to adjust the chuff rate to match my drivers. Maybe when I figure that out, I'll better be able to tune the start up / crawl speed. :/

skipgear
May 13th, 2010, 08:55 PM
I think the main appeal of this decoder to me is the uploadable sound files. I could care less about the default sounds. You can buy the decoder and a PR3 to program it, cheaper than the cost of a Tsunami or Loksound. I think their cost savings is in the fact that they only have to sell one sound decoder. Tsunami has to stock 6-7 different models, each with unique sound sets. That is more manufacturing and stock to deal with, thus the cost goes up.

There will be an art to creating sound files for this decoder, mainly becuase you are not just recording a single sound. To set the sound files up properly you need to break the sound down into: Attack, Sustain, and Delay. Each sound is to be saved this way meaning the decoder can vary the durations of any sound.

I think the hardware is there, it is just the sound library that is holding things back and that will grow quickly as people get these in their hands and start experimenting. The nice thing is, if somebody comes up with a better sound file than yours, it is an easy download to update it.

It has basically the same features as the Tsunami, plus programability and a better motor drive for almost a 1/3 of the price. (So far I have had 2 Tsunami's fail in my GS-4. I just gave up and put a DZ125 in the boiler and followed John Columbo's lead, don't use the Tsunami for motor drive.) Give the Digitrax a chance to prove itself. I still need to decide what to put mine in. I don't think the AC-12 is a good test mule as they were a little stiff anyhow and the start voltage is way up there. A better test will be a Spectrum or Kato Mike. Also somebody needs to play with different speakers.

Mark Watson
May 13th, 2010, 09:04 PM
There will be an art to creating sound files for this decoder, mainly becuase you are not just recording a single sound. To set the sound files up properly you need to break the sound down into: Attack, Sustain, and Delay. Each sound is to be saved this way meaning the decoder can vary the durations of any sound.

After playing around with SoundLoader a while, one thing I'm not finding is the ability to customize the sound sequencing. For instance, there's no air spew with the SDN144PS, but even if I were to load one in SoundLoader, I dont see any way to adjust the sequencing to include that spew with the locos idle sequence. :/ Hopefully this possibility is there and I just cant find it. I agree the potential of this product is huge, but if the customizable options are limited to just replacing the default stuff with better sound files and not being able to completely reconfigure the sequencing, that would be another severe blow.

CSX Robert
May 13th, 2010, 09:14 PM
...And how can you call this an AC-12 sound set with out the uniquely identifying air spew?! :(...

It's not, and never was meant to be(unless they have changed it). Form Digitrax's description of the SDN144PS: "Preloaded with generic diesel and steam sound schemes." I guess partly due to it arriving on shelves shortly after the AC-12 and partly due to having an example AC-12 install in the manual, many people seem to think this decoder was designed specifically for the AC-12, but it wasn't.

Mark Watson
May 14th, 2010, 12:18 AM
How's the slow crawl speed, Mark? That's usually a better test than top speed and sustained

Ok, I figured out some more on this one.

With CV57=000 (Speed stabilization off), the slow speed of the AC-12 is terrible. This may be, as pointed out, due to the power hungry motor used. (Remember how slow she ran at full power on your system when I last visited?). When I set the speed stabilization as follows, her slow speed performance transformed into a dropped jaw and speechless moment. It was gorgeous! CV55=064, CV56=024, CV57=005

As promised, I'll get a video posted to show it. But first, I still need to figure out the chuff rate. This one's getting me a little frustrated as at one speed step, the chuff rate is 2x slower than it should be, then on the next speed step, it will be 2x faster! :bulgy-eyes:

Slowly making progress. :)


I just cant get over how TERRIBLE the horn and bell sounds are! They absolutely have to go, as I can not stand listening to them. Unfortunately that means I have to drop another 80 bucks on this thing. Makes you wonder if Digitrax just dropped the ball, or purposely use those sounds to boost PR3 sales. Two thumbs way down on this one. :thumbs_down::thumbs_down:

Mark Watson
May 14th, 2010, 09:45 PM
Some more observations on the SDN144PS today.

I've spent the most time playing with this thing to get the chuff rate in proper sync with the AC-12 drivers. I finally conclude that it is simply not going to happen. By the time the AC-12 starts to creep along in perfect slow speed crawl, the chuff would already be going 40 miles an hour. However, what is infinitely worse, if I tune the chuff down to the correct rate at slow speed, each time the chuff sounds, the loco hiccups. And it's a big hiccup.
Furthermore, by the time the loco reaches ~20smph, the chuff is way off again.

With that issue, and the HORRIBLE, horrible sounding bell and whistle, I throw in the towel and DO NOT recommend this decoder for any steam locomotives. :(

However! Once I gave up on that, I decided to flip it over to the SD38-2 sound scheme to see what was up. Compared to the steam scheme, the sounds that came out of the decoder now were AMAZING!! The bell actually rings out without being cut off, and the horn sounds great too. Having no visual cues to distract from the notching sounds, which also sounds good, I would say this decoder will be a great option for diesel locomotives! In fact, when I visit home next week, the first thing I'm going to do is yank it out of the AC-12 and find a diesel to put it in.

There are a few other observations which I'm not too impressed with, however I'm not going to put full blame on the decoder as it may be partially my MRC Prodigy Express. But the sound response time is quite distracting. Specifically the horn. When I try to sound a quick short short start warning by tapping F2 twice, instead I get about a 1 second horn, followed by a 1 second pause, then about 4 out of 5 times, I dont even get that second blast. Also (though more noticable on the steam scheme), it seemed any function sound when activated will cut off certain background/idle sounds. For instance, with the loco sitting idle, I could hear the generator wind up and begin running. A quick tap on the bell, and the generator would cut off.

Anyways, I'll work on getting a video made tonight, but as I said, I absolutely do not recommend this decoder for any steam locomotive. :( However, I have high hopes for diesel units though. :)

Mark Watson
May 15th, 2010, 05:14 AM
As promised, here is my video review. I didn't go into as much detail as I originally hoped, but you get the main points. Sound is terrible, Motor control with chuff sound is terrible, motor control without chuff sound is beautiful.

And the sound output quality is slightly better straight from the decoder as the video clearly picked up a lot of background static. So as you can see from the video, this is definitely a great piece of electronic equipment, but gosh darn those sound source files!!

http://www.youtube.com/watch?v=Y9LygpMgazg

Enjoy! :)

*Edit*
Here is a reference for everyone on how the Tsunami Sound Decoder sounds/performs in the InterMountain AC-12, courtsey of JD Colombo.

http://www.youtube.com/watch?v=3yWMK8eX8Tg

Yes, the Tsunami MSRP is about 3 times the MSRP of the SDN144PS, but watch both videos and compare. I HIGHLY recommend saving up and using the Tsunami, as you can see it is most definitely worth it.

DCESharkman
May 15th, 2010, 03:07 PM
A couple of thoughts come to mind.

First, the Tsunami is only about 2x more expensive from what I can see talking to my DCC suppliers. It may cost a little more due to some of the extra parts like an 8 pin plug etc. Also, don't discount the possibility of using the LokSound unit. I saw one of the Cab forwards at the Niles Canyon re-opening on the Ntrak layout with the LokSound unit and it was pretty amazing as well. These units may cost more, but you are getting what you pay for.

As for the Digitrax decoder, I am not at all surprised. I have not heard great tings about thier HO SoundBug, and I have heard about problems with thier sound files. In one case, it sounded like it was recorded off an old movie or something. But sound files are easily remedied.

What concerns me is the lurching of the locomotive with the sound turned on. When the sound is turned off, it looks like normal smooth control of the Digitrax mobile decoders. The lurching seems to indicate that the processor in the decoder is not fast enough or powerful enough to handle both tasks.

Maybe it is low on local memory resources. This may also be a reason for the sound files not sounding so great. A 2 Mb sample contains a lot less information than a 4 Mb sample does depending on the sample width. Probably a little easier way of looking at it is that a 8 bit sample stored in 2 Mb does not sound anywhere near as well as a 16 bit sample does in 4 Mb. It has to due with quantization errors and other less glamourus things in digital signal processing. So if they are constrained by smaller memory allocation and narrower sample widths, there may be a definite need to revisit this design.

In short, it looks like Digitrax is trying to do too much with too little horsepower under the hood. To fix this, the whole decoder would have to be re-designed. And it may just be in their interest to do it since Sondtraxx and ESU LokSound, Paragon2 and QSI are clearly miles ahead of this offering.

Being the time of year for my other passion, I would say the Digitrax has the fundemental talent and potential of a Class A ball player, but they need to work on execution and consistency to make it to the show and be on par with Soundtraxx and the others.

I think Digitrax can come around, but it will take a few more steps before they make it to the show.

CSX Robert
May 15th, 2010, 08:09 PM
...First, the Tsunami is only about 2x more expensive from what I can see talking to my DCC suppliers...

The street prices I see for the Micro-Tsunamis (remember we have to compare to the micro, which runs higher than the regular) are around $112 compared to around $40 for the SDN144PS, not quite 3x as much but much closer to 3x than to 2x.

river_eagle
May 15th, 2010, 08:28 PM
Just thinking out loud;
Shark may have hit on something Mark, you're using the decoder with the original loaded sound set, with both the challenger and SD 38 sounds included.
When I got mine, I loaded the Challenger sound set from the web site, which erased the memory of the entire decoder, (both sound sets) and only installed the Challenger sounds, much less memory used than original. Maybe trying to cram both sound sets into the decoder is just too much, since the chuffing is actually four seperate wav files cycling, as opposed to the diesel run wav just looping.
May be this, along with the high loading of th AC's motor is just too much?
Digitrax really need to address the lack of sound progects, especially steam, if they want these decoders to be successful.

Mark Watson
May 15th, 2010, 08:42 PM
May be this, along with the high loading of the AC's motor is just too much?
Digitrax really need to address the lack of sound projects, especially steam, if they want these decoders to be successful.

Yep I agree.

Were you able to at least get the chuff rate consistent with the drivers where it stayed in sync no matter the speed?

CSX Robert
May 15th, 2010, 09:25 PM
...With CV57=000 (Speed stabilization off), the slow speed of the AC-12 is terrible. This may be, as pointed out, due to the power hungry motor used...

I wonder if the motor could be the source of other probelms as well. Do you have the capacitor installed? If not, I wonder if it could help with the slow speed "hiccup" with the chuff. Also, if the motor has an unusual response curve, it may be impossible to get good chuff synchronization without using the cam input.

I would like to see some reviews from people using this decoder on other steam locos to see if some of the problems are loco specific or if there are inherent problems in the decoder itself.

river_eagle
May 15th, 2010, 11:41 PM
Yep I agree.

Were you able to at least get the chuff rate consistent with the drivers where it stayed in sync no matter the speed?

I'm inatalling one for a friend as I type, I will put the same #s in that you listed, and report back.

camelback
October 20th, 2010, 11:07 PM
Eyup everyone, I'm new here and I read this thread with great interest. I have just fitted an AC12 with this decoder and have experienced all the things mentioned. The chuff rate is a real let down and the top speed and motor control is woeful. Anyway I will be trying out changing the CVs mentioned to see what happens.Many thanks.
James.

Mark Watson
October 20th, 2010, 11:23 PM
Welcome to TrainBoard James!

I hope you can find a solution to the many problems faced with this decoder. I'd reinstall it in my AC-12 in a heart beat if the chuff and other issues could be corrected! :D (I'd probably stick with the TCS M1 for motor control though, smoothest decoder I've used)

camelback
October 27th, 2010, 03:17 PM
Hello back again. I changed the CVs on the decoder and that made a vast differance to the moter control. Still trying to get the chuff rate in sinc but I fear the only way is to fit a cam. Any more thoughts on this subject out there ?
James.

Carl Sowell
October 27th, 2010, 09:27 PM
Does any company make cams for N scale ?

Mark Watson
January 25th, 2011, 01:53 AM
More disappointment from this decoder. (And a little bit of anger!)

Over my visit back home, I had re-installed this decoder into the tender of my other Kato Mikado. Right off the bat the chuff actually matched the mike pretty well (even though the sound profile is for a mallet).

Anyways, I still never used the whistle or bell because of how terrible they sound, and I had to figure out how to turn off the generator and another idle clicking sound. With out those annoyances, hearing the chuff circle Thunder Ridge was actually quite pleasant.

...until...

I hear a crackle crackle sound and the train hesitates. I throttle down to a stop and then poof. Magic smoke.

Knowing what is about to happen, I kill the power and as quickly as possible and I tear into the tender to try and remove the decoder and capacitor.

Unfortunately... I was too late. The tender shell had already become a casualty. :( :mad:

http://www.trainboard.com/grapevine/attachment.php?attachmentid=21438&stc=1&d=1295922881

And of course, the tender shell is no longer available from Kato Parts.





It appears it was just the capacitor that went belly up as a test today showed the decoder still produced sound. However, without the capacitor the sound does not last even 1 full second before cutting out and restarting.

It's good that Digitrax has a no worries warranty. But at this point, I dont think this 50 dollar decoder is worth even the postage it would take to get a replacement. Perhaps they might exchange with me for a DZ125 or two instead of sending out a replacement? http://www.trainboard.com/grapevine/images/icons/icon9.gif

(Also, I just looked and Digitrax does not even list the SDN144PS on their website anymore. Hmmm)

skipgear
January 25th, 2011, 02:09 AM
More disappointment from this decoder. (And a little bit of anger!)(Also, I just looked and Digitrax does not even list the SDN144PS on their website anymore. Hmmm)

http://www.digitrax.com/prd_mobdec_sdn144ps.php

The link is on the front page. They haven't updated the actual sound decoder page in a while because since then they have also released a couple of drop in sound decoder light boards for Kato loco's (similar to the MRC boards).

Sorry to hear about/see the tender. Curious, what DCC system and voltage are you running at? The Cap is rated at 25V so voltage shouldn't matter but I still keep my system voltage at 12V to be safe.

Mark Watson
January 25th, 2011, 02:32 AM
Ah, I was trying to find a link from the sound decoder menu on the right. I didn't see any sound decoders for N scale listed there anymore, but I guess they just haven't updated the site like you said.

At my fathers, it logged a few hours on a Digitrax, I want to say Empire Builder, bought about 10 years or so ago. I have no idea what the output is there.

Here, I had maybe a half hour of running on a MRC Prodigy Express which outputs 14.5 volts.

mtntrainman
January 25th, 2011, 04:30 AM
Hey Mark....

Dont worry about a little melted plastic. My wife tells me on my stuff it...

"Adds Character"...LOL

.

EMD F7A
January 25th, 2011, 06:48 AM
Now THAT is a cruddy experience. I am glad I haven't fried anything lately.... but I know the feeling. Tell ya what, I have an undec. Kato Mikado tender shell just sittin' here gathering dust, it won't be used either (GHQ in the works!). You want it? Just PM me your address and I'll drop it in the post. Don't melt this one, brother!!

Mark Watson
January 25th, 2011, 08:11 AM
PM Sent! :D :D

markwr
January 25th, 2011, 12:46 PM
If your sure it's just the capacitor, it maybe easier to replace just the cap as opposed to removing the whole decoder. Try using one with a 35v rating and at least 220 micro farads. Just make sure you get the polarity right when you solder it in.

On the other hand you've never been happy with the sound from this decoder maybe it's time to get something else.

RatonMan
January 25th, 2011, 04:22 PM
Ya gets what ya pays for!

zwhit
March 2nd, 2011, 09:35 PM
Has anyone used this decoder in a KATO GS 4 to control both lights and motor?

mfgtucson
July 8th, 2012, 04:50 PM
(Bob) I'm new member. I just installed this same Digitrax decoder in my AC-12 yesterday. I'm still trying to figure on how to make this engine run above a fast crawl! Anybody have any ideas? Thanks Bob

SteamDonkey74
July 8th, 2012, 05:28 PM
I have a tsunami in my AC-12 and I have not been impressed by how slowly it moves after conversion. It's a problem IM has acknowledged and fixed for the HO Cab-Forwards but not the N. Basically, the motor needs a lot of juice and so when you have a sound decoder also drawing juice the motor doesn't get enough to move beyond a crawl. I haven't devised a fix for this as it will probably mean re-motoring.

skipgear
July 8th, 2012, 06:47 PM
(Bob) I'm new member. I just installed this same Digitrax decoder in my AC-12 yesterday. I'm still trying to figure on how to make this engine run above a fast crawl! Anybody have any ideas? Thanks Bob

Turn off BEMF on the decoder. Set CV57=0

There is an issue with the decoder that limits top speed to roughly 50% with BEMF turned on. There is no real cure other than to not use BEMF. As SteamDonkey mentioned, the AC-12 do draw quite a bit of power as is so they are making the decoder work hard for a living, add the extra draw of sound and it will bog down things.

woodone
July 10th, 2012, 04:45 PM
I have a tsunami in my AC-12 and I have not been impressed by how slowly it moves after conversion. It's a problem IM has acknowledged and fixed for the HO Cab-Forwards but not the N. Basically, the motor needs a lot of juice and so when you have a sound decoder also drawing juice the motor doesn't get enough to move beyond a crawl. I haven't devised a fix for this as it will probably mean re-motoring.
Don't understand this. The Tsunami (TSU-750) has a internial fuse on the motor drive. If shorted it will blow the fuse and you will still have sound but no drive.
To say that there is power being drawn from the drive circuit to power up the sound circuit seems unlikley to me. I have done several Tsunami sound installs into the IM AC-12s and they all ran well. The sound was good and the motor control was good too. Not great, but good on the motor control. You have to work with CV's 209 and 210 for motor control. Check your setting on CV2- might want to up it a bit? BTW when you set CV's 209-210 you have to have CV's 3 and 4 set to zero.

SteamDonkey74
July 10th, 2012, 05:09 PM
Mine runs okay, it's just that even at top throttle it's going about 10 scale MPH but sounding like it's really hammering down the track. If I could just get the thing to go even a modest 40 scale mph at 100% throttle I would be happy.

If you have suggestions for CVs to start with (e.g., what values would I start with for CVs 209 and 210?) I will try that.

SteamDonkey74
July 10th, 2012, 05:11 PM
To say that there is power being drawn from the drive circuit to power up the sound circuit seems unlikley to me.

I am not saying that sound is coming directly from the drive circuit, but some power must be getting diverted. When I ran it before conversion it ran at reasonable speeds. Since I converted it, it's topped out at about 10 scale mph. I have turned off BEMF.

I have it with me and I am taking it to the club tonight to try some of these ideas.

woodone
July 10th, 2012, 07:16 PM
Mine runs okay, it's just that even at top throttle it's going about 10 scale MPH but sounding like it's really hammering down the track. If I could just get the thing to go even a modest 40 scale mph at 100% throttle I would be happy.

If you have suggestions for CVs to start with (e.g., what values would I start with for CVs 209 and 210?) I will try that.
Go to the SoundTraxx Steam Sound User Guide : http://www.soundtraxx.com/manuals/tsunamisteam_users_guide.pdf
Look on pages 58-59 and 60. This might help you.

SteamDonkey74
July 10th, 2012, 07:19 PM
I have that guide downloaded so I will look at those pages. Thanks! Sometimes I just need to know what to do when X happens. The user's guides tell you how to change things and what you may change them too, but not often much on what to do if in X situation Y happens.

Thank you,
Adam

woodone
July 11th, 2012, 01:39 AM
Forgot to tell you that CV116 will change the chuff rate. Try using a value of 100 or so. Hope that you are using Decoder Pro! Makes taming a Tsunami much easier!

SteamDonkey74
July 11th, 2012, 05:40 AM
Well, I fiddled around a bit programming in OPS mode tonight those CVs mentioned in those pages, and I broke the 10 smph barrier. I got up to a very respectable 55-60 smph, which is about as fast as I ever want to go. I have the chuff mostly right. I can't remember if I had programmed a speed curve which does have om bearing on the chuff rate adjustment method. I will take a look later. Thank you, woodone, for helping me determine which part of te annual to apply. I had read the thing, it I was not clear on which section was the applicable one for my problems. I was trying to approach it through speed settings, which was not unite the answer.

Adam

woodone
July 11th, 2012, 02:01 PM
Glad you have it running the way you want. One more thing- if you operate the unit for a long time you may find that the decoder will overheat and shut itself down. I have found that using a piece of aluminum and mounting the Tsunami to it stops this from happening.
The Tsunami's have more CV's than you find in a magic hat.

SteamDonkey74
July 11th, 2012, 04:58 PM
After problems like that initially, I pulled the tender back apart, added the optional capacitor and mounted the decoder to a piece of brass stock that I had on hand. The overheating seems to have gone away. This was a few years back. Yesterday was a good test, as it was 90 F in the clubhouse and it never cut out.

Somehow in all of that I screwed up the tail-light. I am trying to decide whether I care enough about that to pull it all apart again and replace or repair that. It's kind of hard to shove it all back in the tender, which is why I am hesitant.