A question for the sound experts

[Mike C]

  I have a couple steam locos that I have already installed good regular decoders in the boilers . At this time I really don't want to pull the boilers apart again as they were a bear to do the first time .  Now I remember seeing somewhere that it is possible to install a sound decoder in the tender WITHOUT needing to wire the motor outputs to the motor . What all is involved with this ? Do I need a resistor wired to the orange / grey wires ?  If I use a Tusnami or an Econami  will I be able to sync the exhaust ?  What would this do to the sound settings that are dependent on the BEMF ? What else am I overlooking ?

[delamaize]

I originally was running both a decoder in the boiler, and a Tsunami 750 in the tender. IIRC, I didn't have to wire anything to the motor leads, I just heat shrinked them to keep'em from shorting. I'm also using a chuff cam, so I have no idea if a resistor or other circut would be needed for the other chuff method. It helps to keep the tender and engine wired separate as much as possible, so you can put the loco on the programming track, and put the tender on by it self. also remember to assign them to the same address.

[lyled1117]

Doing a dual decoder install like you ask is very doable. I has been my preferred way of installing decoders in steam locomotives. (WOW decoders are changing my thinking on this however   ). The decoder needs to be one that does not require back-EMF for syncing the exhaust rate. Soundtraxx's Tsunami and Econami decoders as well as Digitrax's sound decoders meet that. If the tender does not pick up power from both rails, you'll need to add a wire from the loco to the tender to power the decoder. The motor leads (ORG/GRY) need no termination. The Tsunami decoder only needs to be programmed to use auto-sync instead of a cam, then use its sync CV to adjust the rate. The Econami decoder needs its back_EMF turned off, then use its sync CV to set the rate. If you use a decoder that changes the sounds as a result of load changes, that capability will be lost. Back-EMF sensing is what gives some decoders the ability to do that. If the loco has a cam or you're willing to add one, that will allow you to use a larger number of decoders. Loksound and TCS decoders have sync wire capability. However, back-EMF load changes would still not be possible. You have to connect to a motor to use that capability.

Lyle

[lyled1117]

Meant to say this in the previous post, but can't edit it. One thing I like doing in dual decoder installs is to give each decoder a different short address (presuming long address is the true address). This can be useful if you want to change a CV in one decoder where that CV might have an undesired change in the other decoder. It doesn't happen often, but it happens when you least want it has been my experience.    What I normally do is this. I leave the sound decoder's short address as 3, and I set the motion decoder's short address to 4. I've done a triple decoder install with a function decoder, that would be 5. I program each as desired before installing the long address in each, that's my last step. Then the two decoders behave as one. (basic consisting).

I'll give an example of how I use this configuration.  Let's say the long address is 789. On the mainline I tell loco 789 to use it's short address (change CV29 = 2). Both decoders will switch to their short address. I can now program (on the main) either decoder 3 or decoder 4 as desired. When done, I tell decoder 3 to use its long address (CV29 = 34), then do the same with decoder 4. Now they are both back to being 789. Make sense? What this does for you is make it so you do not need to disconnect one decoder from power to change the other one.

An additional note. If the tender picks up power from both rails you can place it on the track BY ITSELF to change it, then connect it to the loco when done. If you need to change the loco and it is self powered, same thing applies. This would mean you don't need to have different short addresses.

Lyle

[jdcolombo]

Just to follow up on Lyle's post, the Econami does, in fact, use BEMF for chuff sync, and folks have reported that if the Econami isn't hooked to a motor, it doesn't chuff.

If you want a "sound only" decoder, use a micro-Tsunami (TSU-750) as Lyle suggests.  I have never used Digitrax sound decoders, but I've done a lot of dual-decoder installs with TSU-750's, and they work fine.   In order to get a really good sync between the chuff and driver rotation, you'll probably have to use a full 28-point speed table in the motor decoder - it depends on how picky you are about sync.  Sometimes it's easy, but often this process can take hours.

However, I will say that I've converted a lot of my dual-decoder installs to a single decoder, using an ESU LokSound Select Micro and a 4 or 6 wire harness with micro connectors from TCS (see here: http://www.tcsdcc.com/Customer_Content/Products/Supplies/Connectors/QuickPlugConnectors.htm ).  The single decoder install has several major advantages.  First, you only have to deal with programming one decoder and one decoder address.  It may not sound like a big advantage, but it really does simplify things a lot.  Second, a single-decoder install will take advantage of motor-load based sounds (for example: lowering the volume of the chuffs and introducing more rod clank when the engine is on a downgrade).   If you have a dual decoder installation, the sound decoder can't sense motor load, and hence won't take advantage of load-based sound changes.  Third, at least with the ESU LokSound, the BEMF electronic chuff matching is nearly foolproof.  ESU uses two CV's for chuff matching; you set one (CV57) at speed step 1, then move to 1/4 throttle and set the sync again using CV58.  After this, the decoder will keep the chuffs in sync throughout the speed range.   It's a whole lot easier than trying to get a good sync using a 28-step speed table in the motor decoder.

With a TCS harness, the wiring is usually pretty easy.  But I do understand the desire to leave well enough alone if you already have a good working motor decoder in the boiler. 

John C.

[lyled1117]

John, the Econami decoder has the ability to ignore the back_EMF sensing.     I learned this from Soundtraxx. If CV217 is set to zero, back emf will be turned off. Then CV114 adjusts the chuff rate in the same fashion as CV116 does on the Tsunami. Thus the Econami can be used in either fashion, with or without motor.

Lyle

[lyled1117]

[wish I could edit a post] 

And I agree with John's point about the single decoder being a potentially better result.  With decoders like the WOW from TCS doing some great stuff that NEEDS back-EMF to trigger it, you're giving up features when you don't have a motor connection. That depends on the decoder of course.

Lyle

[peteski]

I'm also a 1-decoder man!    Having as few as 5 wires between the tender and the loco is not unreasonable solution.

[jdcolombo]

John, the Econami decoder has the ability to ignore the back_EMF sensing.     I learned this from Soundtraxx. If CV217 is set to zero, back emf will be turned off. Then CV114 adjusts the chuff rate in the same fashion as CV116 does on the Tsunami. Thus the Econami can be used in either fashion, with or without motor.

Lyle

Ah - well, this is good to know.  I probably won't use one this way, but it's nice to know it is possible.

John C.

[Mike C]

Thank you everyone for the replies ! I'd rather have just one decoder , but the B man Lt . Mtn. is a real pain to get the boiler off and back on again . But it seems that with two decoders I will get pretty much the effect of a stripped down Tsunami ( AKA B Man ) .  Now I have some more thinking to do .....Please ignore the burning smell......

[delamaize]

Steam Chuff cams are well worth it, if you have the patients, Imagination, skill, and remaining hair to pull out to make it happen!

(I need to rebuild, and reseal the speaker enclosure on this one)

[carlso]

I have questions for two of the previous posters.

John Colombo - did you ever get your Economi back, repaired, from Soundtraxx. Have you installed it and are you satisfied with the results.

delamaize - can you or have you posted anything regarding the cams for N scale? I, for one, would be interested.

Thanks in advance to both of you.

Carl

[jdcolombo]

I have questions for two of the previous posters.

John Colombo - did you ever get your Economi back, repaired, from Soundtraxx. Have you installed it and are you satisfied with the results.

delamaize - can you or have you posted anything regarding the cams for N scale? I, for one, would be interested.

Thanks in advance to both of you.

Carl

Hi Carl.

Yes, I got the Econami back and yes I am satisfied with it, although the chuff sync at speed step 1 is still not great.  But once you get beyond step 1, it's pretty good, and the sound itself is excellent (as is the improved motor control circuit).  Still, the ESU LokSound is light years better at the chuff sync. 

Here is a link to the thread which has a video of a Kato Mike that I installed the revised Econami in:

https://www.therailwire.net/forum/index.php?topic=36868.0

There's not much question that using a cam is the best of all possible solutions, but I personally have decided that the effort simply isn't worth it when the ESU LokSound does such a terrific job of electronic sync.  It's still my current "go to" decoder.

John C.

[delamaize]

I have questions for two of the previous posters.

John Colombo - did you ever get your Economi back, repaired, from Soundtraxx. Have you installed it and are you satisfied with the results.

delamaize - can you or have you posted anything regarding the cams for N scale? I, for one, would be interested.

Thanks in advance to both of you.

Carl

I have not posted too much on what I have been doing for the chuff cams...

For the GS4, I used one of Soundtraxx chuff cam kits, with less than satisfying results. I wouldn't recommend using that kit for anything where the axle must have lateral movement for the loco to run properly. It's currently on my workbench, awaiting a conversion to the same style I used on the W3...

As for the W-3, I used a highly modified version of the smallest cam available from Grizzly Mountain Engineering. (http://g-m-e.com/) it took a TON of trial and error to get it right, and even now it still has some bugs to work out. on the Kato Mikado, the conversion requires milling to the frame, and extensive modifications to the rear geared axle. It's not for the faint of heart. Unfortunately, I didn't take any pictures of the process, as it was an experiment, and I wasn't sure if it was even worth documenting.
 
Randy from GME is currently making me a custom cam for the GS4....

I will try to get a few pictures of the W3 chuff cam install here soon.

[carlso]

John,

I am still convinced that the ESU select Micro is the best for me as well.

delamaize,

You convinced me to leave the cam business alone until somebody makes a good set up for. isn't there some sort of conductive paint or material that could be painted on the driver to complete a circuit and cause a chuff ? ? ?

Thanks to both of you for the quick reply.

Carl