Classic & Vintage Hi-Fi Stereo Power Amplifier Restoration Service

Specializing in ADCOM, Harman Kardon Citation, Parasound 

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 stereo Hi-Fi 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 & upgrade:  ADCOM, Harman Kardon Citation, Parasound power amplifiers.

Creek, Lehmann Audio, Musical Fidelity headphone amplifiers.


Restoration and upgrade services for ADCOM GFA-545/555/565/585 classic series, Harman Kardon Citation 16/16A, 19, Parasound HCA-1500A, HCA-2200II, HCA-2205A, HCA-3500. We do NOT service or upgrade ADCOM GFA-5400, GFA-5500, GFA-5503, GFA-5800 or GFA-5802 MOSFET amplifiers. 

*** We now offer superb upgrades for the new ADCOM GFA-555se, GFA-565se, GFA-575se & GFA-585se amplifiers!

We also have audio upgrades for ADCOM GFP series preamplifiers (750, 715, 710, 565, 555II, 555, 345), Harman Kardon Citation 17/17S preamplifiers, Parasound PLD-1100 & PLD-2000. We do not service or upgrade the ADCOM tuner/preamp models.

We also specialize in upgrading Creek OBH-11, Musical Fidelity X-CANv3 & V-CAN headphone amplifiers, Musical Fidelity X10v3 tube buffer, along with Creek OBH-8 & OBH-18 phono preamplifiers.

>>> 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 ***     


 Authorized Service Center for ADCOM





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.


©2008-2019 - 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.