Not knowing you situation, system, or gear being used... there are a few Tg Audio HSR-i gen2 cords on Agon now, that for the $$ can't be touched. Esp with Solid State gear... They will greatly improve your soundstage (focus, layering...) and PRaT. A good barometer from which to base improvement on if you move up the ladder to more expensive cords. Not afiliated in anyway with the seller - just a Tg Audio fan myself...
I have had a number of preamps with separate power supplies (Audible Illusions, Blue Circle, Joule Electra, Pass Labs) all have benifited from the Ac cable upgrades!
I have had a number of preamps with separate power supplies (Audible Illusions, Blue Circle, Joule Electra, Pass Labs) all have benifited from the Ac cable upgrades!