A tale of Soro and Joy

Audio Note Soro SE Line - 1994

Simon at sashwindows dot com dot au

Martin from Azurahorn has been tweaking and upgrading my Audio Note Soro valve amplifier for several years. Here I document the story of the amp from its purchase in 1994 to the upgraded 'hot rod' version it has become. I hope to include answers to the 'valve newbie' questions, (that I once asked) as well as document the upgrades for others in the DIY audio community.

Whilst this amp has provided many years of joy there have also been times of sorrow. 22 years is a long time to own the same piece of electronic equipment so a few component failures along the way could be expected. Peter Qvortrup at Audio Note UK has always been helpful with his product support.

Soro remains a current model in the AN range but has seen changes over the years but all variations retain a similar topology. Our model was bought new from Audio Farnham in 1994 - 2 ECC82 in the pre-amp; Blue AN badged capacitors in the power supply; Tape loop; Side mounted RCA sockets.

A single ended pentode design running 4x 6L6GB / 5881 tubes in parallel driven by 2 x 6SL7 and ECC82 / 12AU7 in the preamp. In essence a Soro is the Audio Note M1 pre amp and P2SE power amp integrated into 1 box.

The 'Audio Note philosophy' of using better components in the circuit, fed by an improved power supply has been adopted but the implementation is all Martins work. When selecting the components I have been guided by what AN choose for their products with an aim to retaining an Audio Note sound.

Martin makes no claim to be a technician, only to be a DIY audio hobbyist. Soro has become one of his audio projects but Azurahorn are not an upgrade company, they (he) sell small quantities of hand made horns to the DIY audio community which help fund his hobby. This page is not an advertisement for his services simply a document of our experiences. No money has changed hands - favor for a favor.

Soro Topology [Inside Layout]

2001 - AN Factory Repairs [new boards]

2006 - Australian Sorrow [Pre-amp transformer]

2006 - Power Amp Upgrade [choke, caps]

2012 - Pre Amp Upgrade [caps, switches]

2016 - Triode / NFB & More Mods [volume, choke, strapped triode]

2016. Power Supply & More Mods.[caps, resistors]

2016 - Hot-Rod Soro [case mod]

2016 - Power Amp PS Upgrade [rectifiers]

Tube rolling the Soro

Tube rolling the Hot Rod Soro

DIY Audio Note Cables

Upgrade Conclusions

Techie Stuff