I have a Technics SL1500C + Ortofon 2mred turntable which has an onboard (can be bypassed) mm phonostage.
SQ with onboard phonostage through Superuniti with Neat SX2 is great, but will a Stageline N with external power supply like Flatcap make a (big) positive difference in SQ?
Thats the first item I’d change.
I agree, the 2M Red is a good entry level cartridge but upgrading to a better cartridge will yield the biggest improvements in sound quality.
The SL1500C built in phono stage is a complete unknown. However, the Stageline will undoubtedly be an upgrade. Having to buy an additional P/S make it a questionable value and there are probably better solutions at that price.
Sorry I cannot answer your question directly but, on paper, your 2M Red and the Stageline N look like a good match to me.
Naim’s i-supply could also power the Stageline.
The Stageline N has an input capacitance of 470pF which is well above the range suggested for most modern MM cartridges.
We had ok results with Rega cartridges (such as Elys II).
But ultimately physical change was needed. Can’t discuss that here.
I’m not sure its available new any longer, but s/h should be fine.
A Stageline + Flatcap might very well be costly vs other alternatives.
First and foremost I’d go for a better cartridge, the 2M Red is really poor IME.
2mred need higher pF too not sound dull, so both onboard and Stageline N are suitable. Bought second hand SL N, Flatcap 2x and original 4-5 din cable.
Stageline N is powered by Hicap2 which i could buy for same money as flatcap 2x or xs.
Luckely SL N + HC2 sounds better than onboard Technics phonostage. More Alive, better soundstage, better attack bla bla.
So happy now.