Restore or repair?


This is question which I get asked a lot. Is it better to restore or repair? And the answer is: “it depends”.

Both are valid but not always in the same situation. If you just want to get your amp running again and not spend a whole lot on it, then a repair might be the way for you to go. This is the most cost effective way but also comes with some trade offs. Remember, these units are often 50 or so years old and if we just fix what issue you’re having right now, that doesn’t foreclose the possibility that something else will pop up in the future. It’s not guaranteed that you’ll have issues, of course but I can’t guaranteed that you won’t either.

Restorations however, are a more holistic approach. In a restoration, I dig in deeper to the unit, known problem areas or components and take a proactive approach in addressing them before they become issues. Because of this, I’m able to offer a 6 month local warranty on parts and labor for the entire unit, not just the repair that was done. The trade off is, of course, the cost that comes with more parts and hours.

We can also discuss a hybrid option between the two which is what I call a “targeted restoration” where we focus on just on problematic areas and components. The cost of which is usually quite a bit less than a full restoration. When we talk, we’ll discuss the options and estimates for your job and find the option which works for you.

Physical Restoration :

Upon arrival, the unit undergoes a complete diagnostic evaluation using state-of-the-art test equipment. From there:

  • All switches, pots, and contacts are meticulously hand-cleaned (no "spray and twist") with premium cleaners and lint-free swabs.

  • Pots and faders are lubricated with non-corrosive, audio-grade lubricant for long-term smoothness and reliability.

  • All RCA jacks are hand-polished for optimal signal transfer.

  • The faceplate and knobs are cleaned and polished. Missing or damaged knobs are replaced with proper OEM parts when necessary.   

  • The wood case, if there is one, is cleaned, refinished up with Danish Oil, and waxed. 

Electronic Restoration:

The amplifier is rebuilt board by board.

  • Every electrolytic capacitor (including main filter caps when necessary) is replaced with a modern, equal or higher voltage equivalent using only top-quality brands: Nichicon, Panasonic, WIMA, TDK, or Cornell Dubilier. No sketchy eBay/Amazon caps in here. 

  • All small signal and power circuit transistors are replaced with modern equivalents as a matter of good practice -  especially known problem-prone transistors (such as 2SA1313, 2SC1451, etc.) If you have a targeted restoration, some transistors may be retained.

  • This unit's output transistors are tested and retained if possible. I like to keep those in when I can. Transistors are removed and a new coat of heat transfer compound is applied. 

  • Heat-stressed resistors, select diodes, and all trimmers are also replaced. 

  • Every solder joint is visually inspected under magnification. 

  • Idle current and DC offset are precisely set to factory specifications using calibrated bench instruments. DC offset at speaker terminals is confirmed to be less or equal to +/- 2mV

  • Test signals are passed through all inputs and outputs, and the resulting waveforms are analyzed with precision test equipment to verify performance.

Audio Testing and Burn-In:

After restoration, the amplifier undergoes at least 10 hours of bench testing. This ensures that all components are stable, and allows me to verify that the unit performs reliably under real-world conditions. If any issues present themselves, I can button those up before sending it home