15 foot RCA cables out of TT with no pre amp?


Im very limited with the space I have. This is kinda limiting me to keep the turntable on a 15’ cable. I’m using a Pro-ject Carbon Debut Evo with an Ortofon  2m blue to an Onkyo stereo with a phono input. Cables are midrange, nothing special but not total crap. Just wanted to get some opinions or suggestions on this. How bad the loss is gonna be if there is any. 
jacquesbarteaux
Doubtful the Onkyo has balanced inputs. If it does, XLR outs are a good idea, but would need a new cable too, and they are usually more expensive than their similar quality RCA counterparts. At the level of TT etc. you could pick up a Pro-Ject phono box for less than 100.00 and be good to go.
So, if I’m hearing this correctly. I should use the 1.23m cable provided to a phono stage. Then after the phono stage, the long cable will suffice? 
"...So, if I’m hearing this correctly. I should use the 1.23m cable provided to a phono stage. Then after the phono stage, the long cable will suffice?..."

The phono output is at a low level, you want to keep that run short.   
The main issue is not only loss but noise you want to keep the connection to the turntable as short as you can due to these reasons try to arrange a way for that to occur so you do not develop noise or hum.
Any "loss' would be overcome a noise sddition. All you can do is try and see if you can live with it.