Bachmann 2 Truck Shay DC sound problems

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The Mohawk Valley Railroad has just taken delivery of a Bachmann 2 truck Shay, with factory fitted DCC. It’s the last type with a metal cab. Running it on DCC there are no problems, apart from it missing a beat every so often, sounds as if the wheels are slipping, but they’re not. The problem I have is that the sound when running in DC is very distorted. My layout is DC, (at the moment), so I need to find a solution.
I’ve read there was a problem with these from the factory that wires touched the speaker cone and caused a distorted sound, but my thinking is that would also make the DCC sound distorted, which it isn’t!
Any help would be gratefully received as it really is a superb loco.
I’ve wanted one ever since I saw a stuffed and mounted one at Williams AZ on holiday last year.

Cheers
Martin
 

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Distortion sounds like not enough power, or marginal voltage to run the electronics..

What controller are you using, and what are it's ratings? - Voltage to the track, and current rating.

You may find it is better, if you run at a higher speed? - You will need several volts on the track, before the electronics in the loco will 'wake up'.

PhilP
 
Thanks PhilP

I’ve tried it on a Beatties, made by Gaugemaster, 12-15v, 1 amp. And I’ve also taken the loco up to the layout and tried it on a Gaugemaster 10 LGB, giving 20v and 3 amps. It’s distorted on both controllers. I’ll live with it unless a fix is forthcoming. The layout might go DCC one day…if I don’t have another heart attack.;)

Cheers
Martin
 
Just a thought, can you put the speaker in a ‘sound box’ some old bog roll tube can work with tape over the ends and a few holes cut into it to allow sound out.
 
Just a thought, can you put the speaker in a ‘sound box’ some old bog roll tube can work with tape over the ends and a few holes cut into it to allow sound out.
Hi Jon,

I’m not sure this will make any difference as the sound is fine when in DCC mode. It’s only in DC that the sound is distorted.
Cheers
Martin
 
Some digital decoders will not work properly on pulsed power DC. Aristocraft made a product that 'smoothed) the pulses to pure DC. I just made one for the MRC 10 amp supply for a friend and there was a huge difference in top speed and better sound. Unfortunately Aristo is no longer in business and one has to make these themselves.
 
Ah, now that’s interesting Dan. I’ve no idea what decoder is installed, I think Bachmann used Soundtraxx in their installations, but with taking the back end apart I don’t really know. I have read somewhere that pulsed power and DCC don’t mix very well. I don’t have an Aristocraft controller, so I probably will never find out…is this what is called PWM?
Strangely enough, I have two locos with NCE 808 decoders in them and Phoenix sound add ons. One when trying to run in DC mode just revs the engine sound like a volume control and nothing else. The other revs the engine sound, then when I turn the controller back to zero and try again, works perfectly, sound and all! The one that doesn’t work, I’ve bypassed the decoder so it only works on DC. Simple matter to turn it back to DCC though, just in case I ever do go back to full DCC again.
Cheers
Martin
 
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Some digital decoders will not work properly on pulsed power DC. Aristocraft made a product that 'smoothed) the pulses to pure DC. I just made one for the MRC 10 amp supply for a friend and there was a huge difference in top speed and better sound. Unfortunately Aristo is no longer in business and one has to make these themselves.
You can get a PWM to DC convertor from G Scale Graphics PWM to Linear DC Converter. Price and shipping may be an issue. Try looking on eBay.
 
I still retain my Aristocraft/Crest 5471 (TX + RX) Train Engineer 10 amp. I have one of Bachmann's DCC sound Climax locos, I am able to run this loco in DC mode using this power supply set to DC satisfactorily. Yes, Soundtraxx, see link below, I paid a lot less for mine :DThere are a few of these TE's knocking about, a bit old, on Ebay and sometimes here. If anybody does come up with an economical PWM - DC "converter" let me know. Sadly RCS, in Australia, no longer exists. Tony Walsham, the proprietor passed away not long ago. I think I got the last he had of his SSI-9 converter/regulators. John Scanlon, who used to be here, made me one 6/7 years ago. Max

Bachmann Europe plc - Two-Truck Climax #3 Demonstrator (DCC Sound)
 
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