Bachmann Class 66 and 21 pin TXS decoder

[Trainman1974]

I have a Bachmann Class 66 fitted with a 21 pin TXS Hornby decoder fitted with a Power Pack but the sounds that it produes is sounds distorted and grainy, how do I correct this so they sound clear, can I fit a speaker to the Class 66 PCB

[LTSR_NSE]

Are you using the speaker that came with decoder or one pre-fitted in the loco?

If using decoder’s accompanying one, confirm it is securely attached to both the decoder socket & chosen housing. Also check if it looks physically damaged.  Then contact Hornby customer services explaining the outcome of checks & request a repair/replacement.

If using a loco pre-fitted one - is it the correct impedance for the decoder? are you able to check the decoder (& speaker it came with) in a different loco? (to prove if issue is with decoder or loco speaker.)  If decoder fault contact Hornby - if loco speaker fault contact Bachmann for a replacement speaker.

[DJB61]

My Bachmann Class 66 (21 pin) was bought before TXS was available so that has a TTS decoder + 3rd party speaker. Recently fitted a TXS to my NR Class 31 as per the Hornby Magazine Jan 24 supplement. As I wanted to retain the fan assembly, opted to use one of the supplied enclosures rather than fit a different speaker which was the wrong decision. It had been running fine however days later and running for 15-20 mins noticed the sound was becoming distorted. I ran it again a couple of days later and initially seemed OK then deteriorated again. 

Hornby are sourcing thousands of sugar cube speakers made to a price point so they are not the best, so some will fail. All of my other aftermarket sound installations use the Rail Exclusive 8 ohm Baby or Big Boomer speakers which are much better. I buy mine from YouChoos and I asked John about speaker deterioration, and he confirmed this is possible with cheaply produced products.

So, my personal preference is not to fit the speaker supplied with TXS sound decoders but use a better quality alternative. With my Bachmann Class 37 (21 pin) the RE speaker was soldered to the PCB but then with a Hornby Class 60 (8 pin), cut the plug off the TXS speaker and soldered the wires onto the Big Boomer. All my sound loco's have stay alive's fitted.