Custom Built SR-45 Tube Amplifier built by Paul Birkeland

These "Custom SR-45" Mono Block Tube Amps were built by Paul Birkeland...considered to be on of the great Bottlehead master builders in the Northwest. If you want to learn more about Paul, check out Bottlehead Forum and HiFi Haven, where he's a frequent contributor.

We took these amps in on trade from a customer who had many years of great listening with them...and only then moved on to another custom amp built by the same master builder.

Here's what the previous owner had to say about this great amp..."These are my longest serving type 45 tube amps...I won't bore you with adjectives and poetic description of these beauties, except to say they're sublime in musical delivery. I'm only selling to fund another amp from Paul."

Here are additional notes that show just how much care went into the build and how special these pieces are...

The amps are built on curly maple bases with 1/8 inch powder coated top plates. They are point-to-point wired with no circuit board. Power transformers are off-the-shelf MQ Bottlehead variety but output transformers are very sought-after Magnequest EXO-045 and Magnequest BH-2 plate chokes, which are 50H/40mA and excellently suited to match the EXO-45. It took two years to find the EXO-045s but Paul acquired them brand new last year from Gordon Rankin from Wavelength Audio. Output tubes are of course 45s and input/driver tubes are 6CM7s. Paul chose solid state rectifiers for reliability and minimal noise. I will try to ask Paul for schematics but doubt if your buyer will find it useful as there is nothing esoteric about the design but instead are made of high quality parts. I am the original owner and the amp was built from scratch, with the wood bases as the only reused parts from my original Bottlehead Parabee 300Bs. I am certain you won't find another amp like them. Hope that helps.

Includes:

Custom SR-45 Amplifiers & Tubes