Percybigun Posted March 23, 2017 Share Posted March 23, 2017 I recently bought a new TTS scotsman, it was my first digital sound loco so i thought it was fine.i then got a TTS a4 chip/speaker and fitted it to my railroad golden shuttle, and the sound is far better and more realistic at speed, the scotsman's chuff sound rate never gets above the equivalent of approx 35mph (no matter how fast i run it). Also the scotsman runs much slower when attempting to double-head with the a4. the scotsman runs fine generally, and i dont want to return it because it was in a sale and was the last in stock. I did "run it in" on dc before using on dcc.Considering these are virtually identical decoders, the difference between them is massive!can i adjust the chuff rate in the cv settings to sort this? I'm not too bothered about setting it exactly as per wheel revolution at low speed,, i'm not a rivet counter, but it sounds pretty naff at mid-high speed cruising now i've got another sound loco to compare it to! Link to comment Share on other sites More sharing options...
Howbi Posted March 23, 2017 Share Posted March 23, 2017 Unfortunately you cannot adjust the chuff rate on TTS decoders.........HB Link to comment Share on other sites More sharing options...
96RAF Posted March 23, 2017 Share Posted March 23, 2017 Try CV150 set to value 1 (algorithm 2) which may improve the speed response. Failing that reset Scotty by writing value 8 to CV8. Link to comment Share on other sites More sharing options...
WilliamDavid Posted March 23, 2017 Share Posted March 23, 2017 I have a number of A3s and A4s with the relavent TTS decoders, and don't have your problem.Can you swap the decoders over to see what happens?Reset the decoder as recommended by RAF96. Always worth a try. Link to comment Share on other sites More sharing options...
mjb1961 Posted March 23, 2017 Share Posted March 23, 2017 Basicly it is what you get for around £40 ,,,I've got five tts steam locos and I have three proper HORNBY sound locos which have the loksound v4 decoders ,although the tts are good for the money they are not a patch on the loksound which cost around £100 ,as already mentioned ,you cant adjust the chuff rate on tts ,but you can change the agorythm ,but that is designed to help with poor running ,did / does your Scotsman judder at slow speeds ,?,,,if it does then change the agorythm ,it is written in the instructions ,,,,,,,mjb Link to comment Share on other sites More sharing options...
Percybigun Posted March 25, 2017 Author Share Posted March 25, 2017 the loco does not jerk at any speed, its a smooth runner, its just a faulty sound decoder by the look of it.the a4 decoder in my golden shuttle (identical motor to my scotsman) is far superior.the only other fault on my scotsman is the tender sits high at the front, and derails on points.. The wires from tender to loco impede things aswell. Hornby did not put any weights in the tender so i'll fo it myself. Also the decoder (factory fitted) is totally loose and unprotected Link to comment Share on other sites More sharing options...
96RAF Posted March 25, 2017 Share Posted March 25, 2017 Try a sound decoder parts reset by writing value 5 to CV8. High riding tender - can you tweak the drawbar to better align the loco and tender or maybe a washer under one end. Link to comment Share on other sites More sharing options...
Percybigun Posted March 26, 2017 Author Share Posted March 26, 2017 I havent had chance to try any of the above yet, but now am ready. should i try a full reset (value 8) first, and if i do will it change the loco id number back to 0003? Link to comment Share on other sites More sharing options...
Chrissaf Posted March 26, 2017 Share Posted March 26, 2017 Writing value 8 will reset ID back to 003 Link to comment Share on other sites More sharing options...
Percybigun Posted March 26, 2017 Author Share Posted March 26, 2017 Ok i tried a full set (cv8) value 8, it made no difference, then i changed the loco id no back to what i wanted.then i tried changing cv150 to value 1 (i didnt know what alogorythm 2 meant?) and it has virtually cured the slow speed and slow chuffing problem, but it still doesnt sound quite as good as my A4 but it is a vast improvement. Only thing is its a bit fast now, is there a halfway point i could set cv150 to instead? Link to comment Share on other sites More sharing options...
Fishmanoz Posted March 26, 2017 Share Posted March 26, 2017 Sorry Percy, 2 only algorithms. However, take a look at your brochure to see the additional CVs that go with algorithm 2 and check out if adjusting them improves things. Link to comment Share on other sites More sharing options...
Percybigun Posted April 21, 2017 Author Share Posted April 21, 2017 I thought i'd report back since further tinkering has now fully resolved the original problem, whereby the chuff speed got stuck at say 40mph when the loco was going faster, so there was a whole range of sounds i didnt know existed until i got an A4 TTS to compare it with. Also the A3 lacked top speed.When i changed CV150 from 0 to 1, it seemed to "kick start" the stuck sound cycle and the missing higher rate chuff sounds emerged, and the top speed increased to where it should be (not that i run loco's fast, but i'd rather all functions work fully). The only minor bugbear was that alogorythym 2 is a bit "trigger happy" for speed control.The loco had light use for a week on this setting, then i tried adjusting CV's 153 & 154 to make it less trigger happy. I tried many different settings, and they made no difference whatsoever! So then i switched CV150 back to default 0 (to try various settings on alogorythm 1 instead), and guess what, the loco and sounds all worked perfect on the default settings (255 & 1), and now its got perfect speed control without being trigger happy.It only occasionally slightly jerks at low speed (which is a common prob on this model) but it might be cos my track needs cleaning.So it seems switching cv150 from 0 to 1 and then back to default has cured the problem.However, a few days ago i did change CV124 to 6, which i saw suggested in another thread, and i fitted a washer under the drawbar bolt which has made the loco & tender run perfectly level. So i dont know which of these tweaks, or a combination of them all, and more "running in" has solved the problems.Before i cured it, i did also try turning off back EMF (by setting CV10 to 1) but the loco ran awful, so i changed it back to default.I'm so grateful to the advice on this forum which has totally sorted the loco, and its given me a basic understanding of cv's and fine tuning. I could tell from experience that it was a good loco with a good motor.Finally, i sealed around the speaker with blue/tac, and secured the loose decoder while i was there, and now the sound quality is much better. Although i'll probably fit a bass reflex speaker and put the hornby speaker in a smaller loco because its not really man enough for a big A3 (ironically i have two 2P TTS chips in other loco's, with standard 28mm hornby speakers sealed with blue tac, and they sound as good & powerful as a big enclosed oval bass reflex speaker???!!!). Link to comment Share on other sites More sharing options...
Wobblinwheel Posted April 21, 2017 Share Posted April 21, 2017 Remember, an A4 should sound a bit "fast" at higher speeds... It is a three cylinder locomotive. Isn't the Scotsman 3-cylinder also? Link to comment Share on other sites More sharing options...
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