To merge both amplifier,and preamplifier.
myself being an ex Audio dealer know brands components inside and out
having spent years upgrading Loudspeakers , and Tech friends that do mods parts quality is far more important then a pretty case . One Huge mistakes people make is in the preamp section , a passive preamp or low quality $25 alps volume pot
which is a Silver round can up behind the volume pot is a NOT !
it robs detail 100% find a resistive ladder to relay they are the best.