Hey Jerry,
Well the Q1a has several benefits:
1. The Soundset is updatable if you have a QSI programmer.
2. BEMF and Regulated Throttle control (deactivated in Q1 due to lawsuit issues)
3. Better Sound of power and some cleaning up of sound files
4. Better handling of the DCC signal loss issue
You'll have to decide if it's worth the $40 for the upgrade chip (available on Tony's Train Exchange).
Personally I upgraded all my Q1->Q1a. (total of 8 steam engines + 2 diesels) The sound improvement wasn't huge. But the BEMF was appreciated.
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
Thanks my friend ,you were right on the mark ,set cv 29 for dcc only problem solved
was the upgrade chip worth it ? I'm happy with all except the fake prime mover sound " first gen. EMD" sound gets on my nerves Quick, maybe I'm just a alco guy,but all my alco s & baldwins have tsunami bone crushers
thanks again Jerry
I don't know which version of the QSI chip you have. I've seen similar behavior myself on some of the older QSI chips until I did a chip upgrade Q1->Q1a.
Also make sure your alternate power source bit in CV29 (Analog Mode) is set to false. It may be losing the DCC signal and reverting to analog mode and when it sees all that juice (14.25VDCC) it assume it's a full throttle DC signal.
I have about 10 of these guys, P2K w/QSI and for most part " I LIKE em " but I have 1 ONLY that is very,VERY sensitive about shorts ......what I mean is if ANY thing causes a momentary short or derail this 1 unit goes into a sequence of reving its motor & honking its horn & air releases and is totaly unresponsive. TILL you do a " power restart" with the command center DCC " zephyr/E.B." (shut off power to rails/restart)
Now this occurs weather its running or sleeping on the tracks(not called up) and a derail/short takes place in its section ..?
SO could this be do to a cv setting that got missed on setup ? or a loose wire on the main board ? or something simple please? I do have a PR-3 /decoder pro for cv- settings ,is there something I should look for/change ?
oh and never seen this in other units ....Jerry