Thank you, Tom Bliss. That helps. Most of my recording was done without headphones (I only used them to add the occasional harmony track). The sound that I like is on rough CDs the engineer made from playback. The sound I don't like showed up when he began mixing the raw tracks. I will talk to him today (two more songs to record). I suspect the problem might be that whatever he is doing to mix the instrumental bits is skewing my vocals -- I play a very soft six-string guitar: he uses two mikes to catch it and there is some bleed between my vocal and guitar mikes.
Thanks again, everybody. If you are interested, I'll post the continuing sage until it is resolved.