Monday, August 2, 2021

"Essence" - 6SN7 Preamp

 












Not the first of the 6SN7 preamps I have built but his one is not for me. And not the first in this hammertone blue. This is a commission job and the future owner has his own, fine, Psvane 6SN7s. Pictured here with my Psvane Grant Fidelity Spheres (expensive) for testing (and a lot of enjoyable listening). Two selectable inputs selected from the front switch and two outputs. One output for an active sub woofer. 

Under the bonnet are standard metal film resistors, a 24 step stepper attenuator, low ESR cathode bypass cap and my fav. 0.47uf Russian Military paper-in-oil output caps. The knob is 4oz of brass and gold plated. Combined with the stepper has a good solid feel. The heavy weight knob also helps with resonance control in the attenuator and chassis. From past builds you will recognize the Hammond wood cheek chassis. Paint is epoxy enamel with an acid etch primer. Always comes up well when the primer is used. 

The sound is what I have come to expect from similar builds with these tubes - balanced, clean and clear with detailed and warm midrange. Different tubes will have slightly different listening results but should stay very much in the enjoyable zone. PS is external with electronically filtered HT and regulated filament voltage. The preamp is absolutely dead quiet. The new owner will love this preamp. He should like the colour, he picked it.