Soundtraxx and Lenz Quell the Rumors!

Here is a joint message from Soundtraxx and Lenz clarifying the compatibility of their products. There have been erronious postings on some lists that this joint notice by Lenz and Soundtraxx addresses. The track voltage issue stems from early production Atlas Generators, power supplies, provided by Atlas for their Commander DCC. These early power supplies had a 20+ VAC output. The problem was rectified by Atlas in the Spring of 2001 and is no longer a concern. Lenz systems were never part of this issue.

04/17/03
"Using Soundtraxx Decoders With Lenz Digital plus systems"

From time to time over the past few years there have been rumors about DCC over voltage effecting SoundTraxx Decoders with Lenz GmbH DCC systems. The following message is a joint message from Lenz GmbH and SoundTraxx.

SoundTraxx produces high quality sound decoders designed for use on NMRA DCC systems. Like Lenz GmbH, SoundTraxx prefers to be conservative in the rating of their products.

To achieve good sound results SoundTraxx designed their voltage of 16 volts DCC as the recommended maximum DC track voltage for their decoders.

Lenz GmbH has designed their systems for the past 10 years to have a factory default DCC track voltage of approximately 16 volts DCC. We choose this DCC track voltage because we desire to deliver a minimum of 12 volts DC to the motor per NMRA S-9 in both standard DCC mode and in the address 0 mode which is designed to operate non decoder locomotives. We have found through experience that most layouts experience a voltage drop between the output of the power station and the track and our choice of a factory default compensates for this.

It has been reported on several newsgroups and on some dealers sites that our choice of a DCC voltage is in some way harmful to SoundTraxx decoders. As in the case of most rumors it is never a first hand report, instead it is always a friend who had a problem or we have heard from someone that there is a problem.

A Lenz DIgital plus system defaults to 16 volts but allows the DCC track voltage to be set by the user. However, this voltage change cannot be done by accident as it requires either internal dip switches to be set or a special programming sequence.

On an Atlas Commander there is a voltage limiter circuit designed to prevent voltage at the Command Station from exceeding 18 volts. This voltage will drop under load (such as operating a locomotive) and also drops with wiring.

Operating a SoundTraxx decoder in the 16-18 volt range will not damage the product provided the motor stall current and audio power output ratings are respected. To date, SoundTraxx's service department has not received any decoders that have been damaged by an over voltage condition directly attributable to any Atlas Commander or Lenz Digital Plus system.

If you are a Lenz Digital plus Set-02/4, Set-01/4, Set-90 or Set-100 user there is no need for you to change the default voltage setting on your system unless you wish to lower the top end speed for all your locomotives. The track voltage can easily be adjusted to meet your needs. Please refer to your manual for specific instructions.

If you are concerned with the DCC track voltage using Atlas Commander system or you wish to lower the top end speed for all your locomotives, you can easily lower the voltage using diodes. These can be easily obtained at Radio Shack or using the MRC voltage drop product.

In any case you will not experience a problem using SoundTraxx products on a Lenz system.

Debbie Ames
Lenz Agency of North America

Nancy Workman/Steve Dominguez
SoundTraxx

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