# How to handle existing sound?



## rreiffer (Jan 14, 2009)

Hello all,
I was wondering how you can adapt an existing sound system that you might want to keep when you go to DCC? I have an older system that has 1) the steam sound is synced to the DC voltage and 2) has an additional trigger to produce a bell. Any ideas?


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## George Schreyer (Jan 16, 2009)

Done it a bunch of times with a variety of sound systems. 

See http://www.girr.org/girr/tips/tips6/sound_tips.html for a table that leads to a variety of upgrades with existing sound


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## Trains West (Oct 4, 2008)

on older systems the power to the board gets hooked to the same leads as the motor so it sees the change in voltage ..

the trigger can be used as is and you can add a micro relay 12v that a fuction lead would trigger to complete the ground "loop" and trigger the sound

if you want the sound to start before the loco moves then just add a few diodes to the power going to the motor to burn a few volts and delay the start of the motor while the sound gets more power

I have made every sound system work with dcc


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## rreiffer (Jan 14, 2009)

Scott,
Duh, the epiphany! Hooking the sound module to the motor.... boy feeling like I am lost in space!








It's one of those things I was trying to over complicate! Thanks


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## George Schreyer (Jan 16, 2009)

Just hooking the sound system to the motor does NOT work in every case, especially Sierra systems. I had to go to lots of work to get them to play. The diesel systems were especially difficult. 

Dallee seems to have the least trouble. The Phoenix P5 needed an external storage capacitor to keep it from resetting all the time. Plain old Bachmann chuff doesn't care as it runs from a battery anyway.


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## Trains West (Oct 4, 2008)

with Sierra systems most of the time I add two full wave briges to the motor side of the wiring ...

this bumps the voltage to the board by 3 volts or so which means you see 6 volts or better at the sound board most of the time before the loco moves 

I then program the start voltage on the decoder so the first click will bump the voltage to a level to start the sound but not make the loco move 

so if you want sound you just move the throttle and let the sound run then give it more gas to make the loco move then when you stop you just dont go to 0 you drop to one or 2 and leave it to idle


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## rreiffer (Jan 14, 2009)

Thanks everyone for the great input. I am looking forward to putting my first DCC decoder in one of my engines and I will let you know how it goes!


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