Massoth S DCC/DC Sound Only Decoder - DC Analog Operation Challenges

[LGB333]

A customer's LGB 2019S Mogul needed repairs and the old factory sound board in the tender had also failed. I installed into the tender a Massoth S Sound Decoder with volume controller and Massoth Maxi PowerCaps. The decoder's sounds work fine except in the DC analog operation the Power Caps won't charge up well to power the decoder's standing sounds when the locomotive comes to a stop.......lasts only about 15 seconds even with making some CV adjustments to the power caps for longer holding charge. If I charge up the power caps by placing the tender alone on the track at 18v. high voltage, the power caps will charge up nicely after a few minutes but then when operating again with the locomotive on the track they will obviously not recharge well again. If I test the decoder on a DCC test track, the power caps charge up super nicely since the decoder's receiving continuous 20v. DCC to the track. So, here's the challenge operating DCC sound decoders in DC Analog: How to get the power caps to charge up well while operating the Mogul & Tender at normal speeds on the track? Are there any electronic devices I could install onto the decoder or power caps to compensate for the lack of sufficient DC power being provided to the decoder? I don't think running the track power through a DC Adjustable Voltage Regulator with Bridge Diode Rectifier to the decoder would do the trick since the continuous 18 volts it could provide the decoder would mess up the chuff sounds which adjust their sync speed based upon the amount of DC voltage the Mogul receives. Thoughts?

Maybe I should convince my customer to switch to DCC!

 

[PhilP]

It is always going to be a compromise on DC..
The loco will run on lower voltages than a DCC equipped model, and I don't think a 'S' plus power-buffer, will manage this well. - The larger power buffer will take longer to charge, and never reach its full potential.

You might be 'better' with an XLS? This will probably be more energy efficient than the older electronics, can have a buffer, and the higher (DC) voltage required to 'wake up' the electronics / loco, will allow the buffer to work better.

The customer will still need to run for a reasonable length of time, at a reasonable 'speed' (read DC voltage) to initially charge the system, but once this is done, should be able to make reasonable stops with standing sounds maintained.
They will not be able to stand for minutes, though.

PhilP.

 

[Brixham]

How about adding a chain of diodes to the loco’s motor terminal? This requires a higher analogue track voltage to get the same speed without diodes.....giving the S module more volts to work with.
A series chain of 5 or 6 3Amp diodes, with an inverse chain connected in parallel may be a good starting point.
Cost? A couple of £/$/€

Malcolm

 

[LGB333]

It is always going to be a compromise on DC..
The loco will run on lower voltages than a DCC equipped model, and I don't think a 'S' plus power-buffer, will manage this well. - The larger power buffer will take longer to charge, and never reach its full potential.

You might be 'better' with an XLS? This will probably be more energy efficient than the older electronics, can have a buffer, and the higher (DC) voltage required to 'wake up' the electronics / loco, will allow the buffer to work better.

The customer will still need to run for a reasonable length of time, at a reasonable 'speed' (read DC voltage) to initially charge the system, but once this is done, should be able to make reasonable stops with standing sounds maintained.
They will not be able to stand for minutes, though.

PhilP.

I thought the Massoth XLS DCC sound decoder has the same technology in it as the Massoth S DCC sound decoder except with the motor control. So, I wouldn't think it would work any better. The vast majority of the sound installations I do for customers are DCC, so the DC analog requirements don't happen much. I've found the very best sound decoder for analog are is the Phoenix Sound decoders, but they are very hard to find, and no one seems to know for sure whether Phoenix Sound is still in business. After this experience with the Massoth S decoder, I think I'll use instead in the future the LGB 65001 American Steam Sound Module. It doesn't have as many sound features as the S decoder, but the LGB power caps unit charges up better on analog than the S decoder. Lesson Learned for next time!

 

[LGB333]

How about adding a chain of diodes to the loco’s motor terminal? This requires a higher analogue track voltage to get the same speed without diodes.....giving the S module more volts to work with.
A series chain of 5 or 6 3Amp diodes, with an inverse chain connected in parallel may be a good starting point.
Cost? A couple of £/$/€

Malcolm

Hi Malcolm - That "sounds" like a good idea, adding some diodes to the Mogul's motor input terminals. But this is an LGB 2019S Mogul with only the 3-pin motor block. I don't think the diodes would work since the motor block's + terminal is shared for both the track power and motor outputs......it would have to be converted to 4-pin functionality.

 

[Greg Elmassian]

Yes, tell them to go DCC. I'm old enough to remember the 400 Hz constant lighting exercises, fitting batteries, etc.

Constant track power is a big boon and makes things a lot simpler.

If I had a gun to my head, I would think along these lines:

1. a sound card that has separate power and "speed sensing" inputs
2. capacitor bank to the sound card, as big as needed to run as long as the customer wants
3. dc to dc boost inverter to supply higher voltage to charge caps and sound board

Of course the response will be:

1. too expensive
2. want to use my cheapo sound card not buy a new one
3. takes too much space in the loco
4. costs to much to install

to which my response is:

Tough! Trying to make a silk purse out of a sow's ear.

 

[LGB333]

Yes, tell them to go DCC. I'm old enough to remember the 400 Hz constant lighting exercises, fitting batteries, etc.

Constant track power is a big boon and makes things a lot simpler.

If I had a gun to my head, I would think along these lines:

1. a sound card that has separate power and "speed sensing" inputs
2. capacitor bank to the sound card, as big as needed to run as long as the customer wants
3. dc to dc boost inverter to supply higher voltage to charge caps and sound board

Of course the response will be:

1. too expensive
2. want to use my cheapo sound card not buy a new one
3. takes too much space in the loco
4. costs to much to install

to which my response is:

Tough! Trying to make a silk purse out of a sow's ear.

Greg, thanks for your comments. The Massoth Power Caps are connected to the Massoth DCC decoder's Dec+ Common Track Power and Dec - GND terminals. And their Power Caps also have a white wire that's connected to the decoder's BC terminal.....this Buffer Control eliminates any malfunctions to the decoder during power-up and programming. From your DCC expertise, is there any device I could install between the decoder and the Power Caps that would provide a voltage boost from what's getting while the Mogul operates on the track at normal speed, for example, a DC Adjustable Voltage Regulator with Bridge Diode Rectifier?

 

[LGB333]

Greg, thanks for your comments. The Massoth Power Caps are connected to the Massoth DCC decoder's Dec+ Common Track Power and Dec - GND terminals. And their Power Caps also have a white wire that's connected to the decoder's BC terminal.....this Buffer Control eliminates any malfunctions to the decoder during power-up and programming. From your DCC expertise, is there any device I could install between the decoder and the Power Caps that would provide a voltage boost from what's getting while the Mogul operates on the track at normal speed, for example, a DC Adjustable Voltage Regulator with Bridge Diode Rectifier?

Here are the tech specs for the Massoth 8151701 Powercap Maxi: Operating Voltage = 6 - 20v. DC; Max Charging Current = 400mA (at 20v. track voltage); Self-Consumption = 10mA; Max Output Voltage = 18v. at Full Charge; Max Output Current = 3 Amps; Charging Time = ca. 150 seconds (at total discharge , 20v.); RailCommunity = Compliant with RailCommunity Standard RCN-530 (Charing Current).

 

[Greg Elmassian]

I misread, I thought you still had the separate sound board.

So in this case, your only hope is to add capacity to the cap bank, and somehow boost the voltage charging the caps.

Greg

 

[PhilP]

You will still need to run (minimum) 150 seconds (two and a half minutes!) to charge up the power-bank..
That is a l-o-n-g time..

With a 3-pin connection, your buffer is feeding back 'everything' (not just the sound).
I can't prove it, but I believe the older 'electrics' is partly limiting what you can achieve.
I am still of the opinion that it would be worth the (trivial) work to make the block DCC compatible, and an XLS (with buffer) would give you a better perceived result.
You can also fit reeds, to give more 'play value' under analogue control.

PhilP

 

[Moonraker]

There is a quick and easy solution which avoids the considerable hassle of converting to DCC. That is to use a MyLocoSound soundcard. They are low cost, work great on analogue and G Scale Graphics in Colorado have them in stock.

Regards
Peter Lucas
MyLocoSound

 

[Greg Elmassian]

Since this is a track power application, can you indicate where the keepalive capacitors are connected?

Greg

 

[ntpntpntp]

With some DCC sound decoders is possible to achieve a "balance point" on DC where there's enough volts in the track to wake up the decoder and play the stationary sounds without the loco actually moving off. Can the XLS can do that if one were fitted?

 

[LGB333]

I misread, I thought you still had the separate sound board.

So in this case, your only hope is to add capacity to the cap bank, and somehow boost the voltage charging the caps.

Greg

Greg - The Massoth S Decoder is a separate sound only decoder that's installed into the tender........has nothing to do with the tender's old Mogul circuit board. The S decoder gets its power from the tender's two track power pickup wheels sets. Actually, the Massoth Maxi Power Caps have excellent capacity by adjusting CV47 to the max......they will provide power to the decoder for a couple minutes when fully charged. So, the trick is, how do I boost the voltage to the Power Caps? I could connect a DC Adjustable Voltage Regulator with Bridge Diode Rectifier to the Power Caps to up the voltage to say 10 - 18 volts? I need help on the wiring approach........would the device be wired in between the decoder and the Power Caps, or what?

The Massoth Power Caps are connected to the Massoth DCC decoder's Dec+ Common Track Power and Dec - GND terminals. And their Power Caps also have a white wire that's connected to the decoder's BC terminal.....this Buffer Control eliminates any malfunctions to the decoder during power-up and programming.

 

[LGB333]

You will still need to run (minimum) 150 seconds (two and a half minutes!) to charge up the power-bank..
That is a l-o-n-g time..

With a 3-pin connection, your buffer is feeding back 'everything' (not just the sound).
I can't prove it, but I believe the older 'electrics' is partly limiting what you can achieve.
I am still of the opinion that it would be worth the (trivial) work to make the block DCC compatible, and an XLS (with buffer) would give you a better perceived result.
You can also fit reeds, to give more 'play value' under analogue control.

PhilP

PhilP - I tend to agree with you that installing a Massoth XLS DCC/DC sound decoder into the locomotive would produce a better sound in DC Analog than just using the sound only Massoth S decoder installed into the tender. There would be a problem, however, fitting even the Massoth Micro Power Caps into the Mogul for DC operation. But that's hindsight......I've already installed the S Decoder into the tender, the Mogul's motor block has already been overhauled in its current 3-pin configuration, so I'm not going to "start over" by redoing everything I've already done. I'm seeking help on how, if possible, to make the S Decoder in the tender work better in DC analog operation with its Massoth Power Caps. But I do appreciate your thoughts on alternative installations of DCC sound decoders for use by analog locomotive hobbyists. Frankly, I have found that the Phoenix Sound decoders work the best for DC analog operation but finding the PB17s the last two years are almost impossible. No one seems to know for sure whether Phoenix will still be producing their products or not, but I hope so since the PB17 would be my preference for this latest install if I had one.

 

[LGB333]

With some DCC sound decoders is possible to achieve a "balance point" where there's enough DC volts in the track to wake up the decoder and play the stationary sounds without the loco actually moving off. Can the XLS can do that if one were fitted?

Nick, yes, all the Massoth DCC/DC sound decoders have that ability if the Power Caps get charged up enough. In this LGB 2019S Mogul's case, however, the motor starts to move at low voltage before the S Decoder activates because the Power Caps are not charging up enough during the locomotive's operation on DC power. I've had better luck achieving the sound activation in low voltage while a Mogul is still stationary by installing the LGB 65001 American Steam Sound Module and the matching LGB Power Caps. Those Power Caps do charge up with moderate locomotive speed (voltage) and when the locomotive comes to a stop, if you leave the voltage on just slightly, you can play the standing sounds for a long time. But you have to adjust several CVs in the LGB Sound Module to achieve that feature. And as I mentioned my prior posting to PhilP, my preference for DC sound operation is the Phoenix Sound PB17 sound decoder.......the rechargeable batteries it uses work better than power caps.

 

[LGB333]

There is a quick and easy solution which avoids the considerable hassle of converting to DCC. That is to use a MyLocoSound soundcard. They are low cost, work great on analogue and G Scale Graphics in Colorado have them in stock.

Regards
Peter Lucas
MyLocoSound

Hi Moonraker - Yes, I'm familiar with G Scale Graphics in CO. Their specialty is battery power products. Good to know their sound card is as an option for the future.

 

[Greg Elmassian]

Since this is a track power application, can you indicate where the keepalive capacitors are connected?

Greg

Moonraker, this was directed at your suggestion to use the MyLocoSound card on track power DC.

 

[phils2um]

With some DCC sound decoders is possible to achieve a "balance point" where there's enough DC volts in the track to wake up the decoder and play the stationary sounds without the loco actually moving off. Can the XLS can do that if one were fitted?

I'm not absolutely positive but I believe that is what CV48, "Starting threshold analog operation" in the XLS does. It has a range of 0-120 with a factory default of 60. I think setting this higher essentially offsets the analog operating range on an adjustable base input voltage. This should allow the power caps to charge at a higher voltage before analog running actually begins.

I can't test whether this would extend the standing sounds with 0 voltage on the track myself. I've not needed to install PowerCaps in any of my XLS equipped locos!.

 

[Moonraker]

Moonraker, this was directed at your suggestion to use the MyLocoSound card on track power DC.

MyLocoSound soundcards work fine on DC trackpower. In fact, in the US there are more running on analogue trackpower than on battery power. We use a small, rechargeable, Ni-Mh, 7.2v battery to power the sounds when the loco is stationary or moving slowly on very low track voltages. The soundcard automatically recharges the battery when the track voltage exceeds 8.5v.

Regards
Peter Lucas
MyLocoSound