Phonostage Build

PAC

A short while back, I ordered a Hagerman Bugle II phonostage kit from the 'States after reading great things about it (including that it matched some very expensive SS phonostages in performance).  A little research showed that this is indeed a very highly regarded and accurate phonostage which uses a very clever regulated switched mode power supply that uses smoothing caps and inductors to remove HF hash.

The kit finally arrived from the USA this afternoon.  Instructions are clear and there's a useful resistor stuffing guide included:

First job was to sort all the resistors into their respective values and test each one on the meter to ensure there were no duds:

Next, the PCB was populated with the resistors. They were soldered into place and the excess legs trimmed off.  Note:  I've kept all the brown bands towards the centre for ease of identification for fault finding if there's a problem:

Op-amps installed next taking care to align the notch so that Pin 1 is located into the correct point on the PCB for each:

Capacitors then added:

I've also added my own red LED as a replacement for the supplied yellow one.  I wanted the red glow to match the Albarry amps as I'm a tart that way  Diode and rail splitter also added.

RCA sockets soldered into place:

Underside:  All legs trimmed of excess but some cleaning up to do (removal of flux residue).  I used a small wire brush for this:

Electrical test:  the moment of truth...LED should light up, which it does

Testing rail voltages:  These should be close to 12V per channel:

Left:

Right:

Not too shabby :eyebrows:

Finally, the PCB is inserted into the casework, the grounding post added and everything screwed together:

A useful afternoon's work.  I'll plug it into the system and give it a spin this evening before reporting back, but by all accounts, this is meant to offer some seriously great performance...way above a typical branded budget phonostage.  We shall see later on.

uglymusic

I hope it sounds great Paul.

You must explain what a phono stage is, when you've got a bit of time 

O:-)

PAC

It's like a DAC David but better  

uglymusic

Touche!  )

Docfoster

I wish i understood what all those bits do...
:-/

PAC

Its pretty simple really Ben, like all good designs!  The tip bit where the power lead plugs in is the power supply smoothing circuit.  It uses inductors and capacitors (inductors eliminate HF hash from the switched mode wallwart supply), a few diodes then onto the equalisation and gain stages. The IC's are miniature complex circuits in their own right and do most of the gain duties.  The transistor at the top is a circuit splitter and helps the switched mode power supply "see" a virtual earth as it's not a mains earthed supply but a double insulated wallwart.

Sound-wise, it is pretty incredible.  The op amps are very low noise and very stable.  It betters anything I've owned (bar the Albarry on-board phono-stage) up to a four figure sum. It also goes to prove that you don't need "foo" components and fancy casework for "high end" performance;  just good design.

Brumjam

It's like a DAC David but better  

Lol!