*** After 13 years in business, we are closing up the shop due to retirement and are no longer accepting any new work. A big 'Thank You' to all of our customers and many of you had multiple pieces of equipment sent in. We so do appreciate your business and it was our pleasure to service, upgrade, and restore your items ***

Please check the 'Items For Sale' page as we will be listing test equipment, parts, tools, audio upgrade procedures (intellectual property).

Instructions for audio upgrades are not available nor are any type of audio upgrade parts kits.


Classic Harman Kardon Hi-Fi Stereo Power Amplifier Restoration Service

Specializing in Harman Kardon Citation 16, 16A, 17, 17S

ADCOM & HK Citation Audio Upgrade Modifications to Maximize Performance


 "When You Are Serious About Sound"


Located approximately 15 miles east of the Continental Divide in “Big Sky” country.

We offer exceptional service and personal attention in the restoration, repair, and audio upgrading of ADCOM and Harman Kardon Citation power amplifiers and preamplifiers as our specialty.  Our goal is to provide audiophiles and music lovers with the best performance from their audio systems.  We strive for quality and integrity in everything we do.


Brands we service: Harman Kardon Citation 16/16A power amplifiers, Citation 17/17S preamplifiers only.


Audio upgrade mods for ADCOM GFA-545/545II/555/555II/555se/565/585, GFP-345/565/750,                                    Creek OBH-11, and Harman Kardon Citation 16/16A, 17/17S only. 

We no longer service or upgrade Parasound products.


>>> Before shipping your equipment to us for restoration and/or upgrading, please review both the AUDIO UPGRADES page along with the FAQ page to become familiar with our policies and terms of service. By sending your equipment to us, you agree to all FAQ terms and conditions. We do not accept 3rd party shipments and they will be refused if sent.


*** Please click on the AUDIO UPGRADES tab at the top of any page to learn more about our audio upgrades. Information on the product upgrades we perform are located further down on that page ***   


We are a fully-equipped audio service facility utilizing a Stanford Research Systems audio analyzer. 



BSA Newfoundland Dog "Tia" (2003-2015)



*** We use FedEx ground service shipping exclusively for our long distance customers ***


   Big Sky Audio, LLP services are available to USA residents only - no international shipping or pickup is available. We do not ship to APO/FPO addresses.


©2008-2020 - Big Sky Audio, LLP. All rights reserved. 'When You Are Serious About Sound' is a USPTO Federal trademark registered to Big Sky Audio, LLP. All photos and text are property of Big Sky Audio, LLP. Brand names and logos are trademarks of their respective owners.