Big Boy Update...

[honk honk]

http://youtu.be/xQ83LVVU4y0

An Athearn Big Boy that had the "wonderful" MRC decoder... It now has a TCS Wow Sound decoder. I added the firebox flicker and headlight. The headlight was a minor headache. The rest of this swap was straight forward.

I wasn't sure if this was a DCC thread or N scale thread. It's an N scale engine, so... If it's not the right place, move it as you see fit.

[up1950s]

Nice , real nice .

[peteski]

The decoder sounds great but to me it seems like the chuffs are way out of sync with the driver rotation. Big Boy should have 8 chuffs per driver rotation.  At the speed you were running it the chuffs would be very fast.

[honk honk]

The decoder sounds great but to me it seems like the chuffs are way out of sync with the driver rotation. Big Boy should have 8 chuffs per driver rotation.  At the speed you were running it the chuffs would be very fast.

That's my only issue with this swap so far. It's a whopping 22-23 mph there for scale speed. That should still be slow enough to pick out all 8 chuffs. TCS has some fine adjustments available for the articulation in order to dial in the chuff rate and also the articulated portion of it... I would like to bring the articulated portion of this a bit more.

For reference, here's a Wow equipped Daylight set passing the 4014. The articulation feature can be heard a bit better here.

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[peteski]

Still, from what I see and hear, there is roughly only a single chuff per driver revolution. There should be 8, which means the chuffs would sound like a machine gun at the speed the loco is running in the video.  Maybe the video is not syncing the picture and sound properly for me.

[honk honk]

The chuffs are there. They synchronize in and out. That's the setting I want to play with to make it more pronounced that there's an extra set of drivers under that engine.

[peteski]

Sure, chuffs are there but can you really count 8 per each revolution of the drivers?  I don't even think there are 4 chuffs/rev.

Could you make a video when the engine is running much slower so counting chuffs/rev will be much easier?

[honk honk]

Once I get it dialed in, yes...

 

[honk honk]

As a side note... We're watching the Pentrex video "Last of the Giants". The exhaust isn't that far off. The 8 exhaust notes are really only noticed on really slow speed stuff. For example, starting a train.

I'm still gonna work on dialing this in a bit closer on this. There's quite a bit of adjustment available with this.

Hopefully I'll be home tomorrow evening to play with this...

 

[peteski]

As a side note... We're watching the Pentrex video "Last of the Giants". The exhaust isn't that far off. The 8 exhaust notes are really only noticed on really slow speed stuff. For example, starting a train.

I'm still gonna work on dialing this in a bit closer on this. There's quite a bit of adjustment available with this.

Hopefully I'll be home tomorrow evening to play with this...

 

My point is that if the chuffs were synchronized to be 8 chuffs/driver revolution (that's at any speed), at the speed the model is running in the videos, the chuffs would occur so fast that they would sound like a machine gun.   That is assuming that the decoder you are using has a "virtual cam" which can keep track of the drivers rpms using BEMF. Most of us run our models way faster then realistic scale-speeds.

[up1950s]

The Athearn BB IIRC has a setup that both driver sets are in sync with each other , and IIRC it is not a quickie to do otherwise . I hope I am wrong though . Having said that , it should have 4 chuffs per cycle . The only perfect setup is to have both engines on their own motors with a square lobe feeding the chuff trigger , and amps feeding the chuff volume . Still it's better than what a box of Good & Plenty produces .

[honk honk]

The Athearn BB IIRC has a setup that both driver sets are in sync with each other , and IIRC it is not a quickie to do otherwise . I hope I am wrong though . Having said that , it should have 4 chuffs per cycle . The only perfect setup is to have both engines on their own motors with a square lobe feeding the chuff trigger , and amps feeding the chuff volume . Still it's better than what a box of Good & Plenty produces .

That's the mechanical portion of the equation... I'm hoping to dial this in tonight. Whether it plays out exactly how I want, the sound quality and motor control is light years ahead of the MRC decoder that was in it. If this were the final outcome of this project, I would be content.

 

[honk honk]

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[peteski]

This is how I see it:
It seems that the chuffs are paired (probably since they are simulating 2 engines running slightly out of sync, which is normal for simple articulated locos).  But I still only see 2 pairs of chuff per each driver revolution where there should be 4 pairs of chuffs).  On a real locomotive a chuff will occur with the driver's crankpin at 12, 3, 6, and 9 o'clock locations (evenly spaced). You only have a pair of chuffs around 3 and another pair around 9 o'clock crankpin location on the drivers.  Maybe you should change the chuffs to a simple loco mode (non-articulated), then adjust the rate for 4 evenly spaced chuffs per driver revolution of one of the engines.

[delamaize]

Whatever you have your low voltage chuff rate CV set at, double it (or half it, I don't remember which increases the chuff rate) and post a video of what that sounds like. Right now it's about half of what the chuff rate should be.....

This is why I try to put chuff cams on my steam sound installs. It's a pain in the a$$, but so worth it.

EDIT: Here is a short video of my Kato Mike with a Chuff cam, this is as close as the sound gets to being in sync. Your chuffs should be about the same as this, but 2 stepped, so one chuff, them immediately after a 2nd. Excuse the one skipped chuff at the end, I'm still working on an effective wiper system.