Small Form-Factor CD Player/Transport

The Cyrus Cdt...compact, sounds great. Yes, a bit deep dimension wise, but not very wide. A far cry from the full size audio lab it replaced. Freed up some space atop my audio credenza. Better yet, I got it brand new, $999...$300 off!

I also use my Marantz hdcd1 as a transport. It is 12 inches by 12 inches. Also sounds great.

Luxman D N150 

super small

$2800 retail but can be had for about $1,500

I have owned one for a year now with great results

Heed cd transports and Bel Canto CD3t these are all shoppers box sixes transports and are built like tanks. I think Gene Rubin may offer the Heed products. 

Caution: If looking to go I2s connection, not all are compatible. Had to return the PS Audio CD transport which was not compatible with the Gustard x26  pro dac.

You could find a used Parasound Z-CD.  Very compact good sounding player. I use one as transport with Mytek Liberty DAC and AQ Optilink-1 toslink. I like small stuff.