Massoth XLS Sound Decoder v.2.9 Analog Issue

LGB333

LGB333

Active Member
For Massoth DCC Experts: I just finished installing a customer-provided Massoth XLS older version sound decoder into his LGB Mogul locomotive. Everything is working fine in DCC mode but when powering the loco in DC/Analog power, the headlight pulses on-off. There's also a noticable low hum noise in the speaker when applying DC power to the decoder. Connected to the decoder is the standard LGB Mogul's smoke unit, the headlight, a Massoth hall sensor/chuff pulse generator, a Massoth Sound Function Trigger/PCB, and a Massoth volume control "pot." The Mogul owner plans to operate this Mogul on his MTS III layout, but also wants to be able to operate it in DC/Analog power, thus the sound function trigger installed for activating the whistle and bell with track magnets.

Using either 14 or 28 speed steps causes the headlight/sound humming issue. This older XLS decoder is finicky......I've had to reset it three times when it stopped working during various test runs of the loco, either on my programming track with roller wheels, or on my small 15 x 6 foot indoor layout. I use a Piko Central Station for my test bed/programming track, and a Massoth DCC Central Station/Power Supply for my indoor layout and my new garden railway I'm installing with over 350 feet of track.

Any CV adjustments suggested to eliminate this light pulsing/flickering would be appreciated!
Thanks
Tom
 
PhilP

PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
23,485
491
Tamworth, Staffs.
First guess:
Remember, you will need 5-6 volts 'on the rails' before anything sensible will happen, to keep the electronics happy.
Second guess:
You are running lights, smoke, motor(s) from an analogue 1 amp supply, and it is not map-enough for the job.
Third guess:
You are running with older firmware in the card, and the latest sound definitions etc? - It probably won't like that.
Work out which firmware is in the decoder... Increment up to latest release... Then load sound definitions.
 
idlemarvel

idlemarvel

Registered
13 Jul 2015
1,684
117
Ascot
Flashing lights is generally a speed step mismatch issue, but if you're running analogue speed steps don't come into it.

What functions are set on in analog mode? I can't remember the CV number but it defines what F keys are on or off when not running digital.
 
LGB333

LGB333

Active Member
First guess:
Remember, you will need 5-6 volts 'on the rails' before anything sensible will happen, to keep the electronics happy.
Second guess:
You are running lights, smoke, motor(s) from an analogue 1 amp supply, and it is not map-enough for the job.
Third guess:
You are running with older firmware in the card, and the latest sound definitions etc? - It probably won't like that.
Work out which firmware is in the decoder... Increment up to latest release... Then load sound definitions.
Philp - Thanks for your thoughts, but none of your guesses is correct. Using my normal LGB 2 amp power for my roller wheels/test stand; checked with Massoth Technical Germany and XLS version 2.9 decoder is too old so no firmware availble anymore for updating using the Massoth Service Tool. And I believe the Mogul sound file is the original one installed by the factory since the Mogul owner only has the LGB MTS III DCC system. I think he bought the XLS in Germany about 4 - 5 years ago. The owner did try to install the decoder back then but realized he was over his head when he discover the Mogul motor block only had 3-pins instead of the needed 4-pins. So perhaps he damaged the decoder in that process. The decoder is working okay right now in DCC but I advise the person to not try DC/Analog power on it.....he wasn't too happy to hear that but I don't have any other solution to offer him (don't want to suggest I install a new Massoth XLS at this point).
 
LGB333

LGB333

Active Member
Flashing lights is generally a speed step mismatch issue, but if you're running analogue speed steps don't come into it.

What functions are set on in analog mode? I can't remember the CV number but it defines what F keys are on or off when not running digital.
Idlemarvel - Yes, no pulsing headlight in DCC. The Instruction Manual for this older XLS states the decoder is fully functional in Analog, or it can be deactivated with CV29. The default for CV13 Analog Function Mode is 3 which includes activating the 5 volt headlight and F1 5 volt smoke unit. The only adjustments I've done on the decoder is to dim the headlight and smoke voltage to 5 volts; de-activate the half shunting speed feature; CV51=0 headlight on forward & reverse; address 19; and speed steps 28; and adjustments for using a pusle generator, a "pot", and a sound function trigger. Everything works fine in DCC, and also in DC/Analog except the pulsing light and low hum noise in speaker.