Hi folks.
Zimo has been working on upgrading its EMD 567 V-16 sound file, and a week or so ago, they sent me the newly-revised version. I installed it on a Zimo MX649 sound decoder that I have on an older Atlas GP9 chassis, and did a comparison of it to the most recent ESU file.
The new Zimo file has a number of improvements. I think the prime mover sound on throttle up and throttle down is better that it was before. More importantly, they have now made the horn playable, so that it plays only for as long as you have F2 pressed. In the prior version of the file, the horn had a fixed sound length, so you couldn't do a traditional Long, Long, Short, Long horn sequence like you can with ESU's horns. The particular default horn on the Zimo file sounds really good, too (I think it is the Nathan M5; other horns include the Nathan K3H, Nathan K5LLA, Nathan M3, Nathan P3, Nathan P5, Leslie RS3K, Leslie RS3L and Leslie RS5T.
Although I still prefer the ESU sound overall, the improved Zimo file makes this mostly a toss-up in terms of sound quality, and I wouldn't be surprised if some folks preferred it, particularly for the horn sound.
One oddity of the Zimo sound file, however, is how you do speed matching. Because of the way the sound architecture is programmed, you cannot use CV5 to tame the top speed of the locomotive. Instead, you must use CV57 (the BEMF reference voltage setting) to set the top speed. After you have done that, you can use CV2 and CV6 to set the start and middle speeds (or use a full 28-step table). If you use CV5 to set the top speed, you end up losing some of the last notches on the throttle. The file also comes with the deceleration momentum set VERY high; unless you are into using the brake function to slow the locomotive, you'll need to reset this. As it comes from the factory, it takes about two minutes to come to a stop from full throttle (!). I thought at first that there was something wrong with the decoder, then finally realized that the momentum setting was near maximum.
Here is a new video that I did comparing the new Zimo file to the ESU file:
For those of you who like the idea of using the Zimo MX649 because of its 9mm width (making it an easier fit into hood-diesel shells), the new Zimo file should be very good news, at least for EMD 567-equipped locomotives (I haven't tried out Zimo's other US-prototype diesel files).
John C.
