Your previous beer that was too sweet, What was the hops schedule for it? IF it wasn't balanced correctly, then it could come out a bit too sweet.
Plus, the Crystal really wouldn't add too much "sweetness" to the beer. It should just add color and flavor, not sweetness, since your only steeping the grains.
The big issue concerning your last beer could be your final gravity. If you didin't let the beer finish fermenting, then you beer could have been too sweet.
As for this beer, here's the specs on the recipe above. IMHO, I would up the total extract to 6.6 lbs. of LME or 6 lbs. of DME, your choice. The rest is fine. You're gonna have a pretty decent amber. I'd be interested in hearing how it worked out with that yeast.
10-B American Amber Ale
Size: 5.0 gal
Calories: 147.82 per 12.0 fl oz
Original Gravity: 1.045 (1.045 - 1.060)
Terminal Gravity: 1.011 (1.010 - 1.015)
Color: 15.1 (10.0 - 17.0)
Alcohol: 4.37% (4.5% - 6.0%)
Bitterness: 28.23 (25.0 - 40.0)
2.0 lbs Dry Light Extract
3.3 lbs Liquid Light Extract
0.5 lbs Crystal Malt 60°L
0.25 lbs Crystal Malt 120°L
2.0 oz Roasted Barley
0.5 oz Centennial (9.5%) - added during boil, boiled 60.0 min
0.5 oz Centennial (9.5%) - added during boil, boiled 15.0 min
0.5 oz Willamette (5.1%) - added during boil, boiled 5.0 min
0.5 oz Willamette (5.1%) - added during boil, boiled 0.0 min
1.0 ea WYeast 1084 Irish Ale
Ambient Air: 70.0 °F
Source Water: 60.0 °F
Elevation: 0.0 m
Results generated by BeerTools Pro 1.0.29