This level of service is always recommended for equipment made before at least 1990 if you want the unit for serious listening and/or long term use. I will never say a unit doesn’t need it (However this level of service doesn’t make sense if you want to make money on the unit). The objective of this level of service is to replace anything known to cause issues that can be replaced, and to make the unit sound at least as good as new. With 1970s equipment, the sonic difference is nearly always night and day. Old dried up capacitors sound muddy; replacing them restores clarity and detail.
     Doing this level of service once saves time and money compared to bringing a unit in for a general service every time there is an issue. Some issues can take a long time to figure out if I’m trying to figure out which part out of many that should be replaced anyway is the immediate issue. Often, when I’m doing an overhaul, I won’t try to diagnose many issues before hand as I know the overhaul will probably fix them (or at least rule out the common causes)
     Eventually I will only offer overhauls.

Over the years I’ve used different terms to describe this service. “Recapping” is a common term. But that is only one thing a proper overhaul should include. “Restorations” is a suitable word but many sellers use it to describe a basic service/cleanup. I’ve settled on the word “Overhaul” as it seems most descriptive.

Costs range from $300 for very small units to $1000 for monster units. Many average units are in the 500-700 range these days.

As long as I have a workbench and am able to use it, I will service gear I’ve overhauled at any point in the past without waitlisting.

Replace All Electrolytic Capacitors

This is the biggest part of the job. Electrolytic capacitors have a rated lifespan of 20 years, so the ones in most of the gear I service are well past their prime. The electrolytic fluid will be drying out and may be leaking. Some will be better than others but all will have degraded significantly and audibly. I use only top tier capacitors from reputable suppliers like Mouser and Digikey. Most caps I use are Nichicon, Rubycon or Chemi-con. I use audio quality capacitors in the signal path and low impedance/high temperature caps in the power supply.

Contact Cleaner

All controls are cleaned with deoxit or deoxit faderlube for static free operation. Note Deoxit is not perfect, your unit may still need the occasional cleaning.

The large power supply reservoir caps are replaced. Like the smaller electrolytic caps they are past their prime, though they often have better longevity. These are typically the most expensive parts. The cost is quite variable as well and I usually have to have your unit on the bench to be able to quote them since I need to find replacements that fit well physically. Sometimes this can be a bit tricky. Ideally I will match the diameter of the original caps. I can usually do this. Failing this, I may install a smaller capacitor clamp. Sometimes I will use a few wraps of electrical tape or heat shrink to make a slightly smaller cap fit but I will never use pieces of foam or other shims to fill large caps. I will also never resort to hollowing out and restuffing the original capacitors (this is a pain!).

If my restoration quote was a bit out of your price range, we can usually leave these caps for later. However they should still be changed when possible. They rarely fail suddenly but will eventually vent and leak their insides into your amp and you won’t know when this happens unless you open up your unit and look.

Manufacturers used glue to hold capacitors in place, and the glue used by most manufacturers turned out to corrode the leads of any component it touched, and maybe even become conductive under the right circumstances. This glue is fully removed, and damaged components are replaced. This glue is often mistaken for capacitor leakage.
The pictures below are of a Sansui AU-717 power supply board. That model always has lots of assembly glue damage on the power supply and power amp boards. For that reason the AU-717 is a unit I will only touch if I’m doing a full overhaul.

Replace bias and offset trim pots – These are small potentiometers that are on the power amp board. They are replaced with Bourns sealed parts that are far more reliable than the originals. If the originals fail they can cause expensive damage, so this step is cheap insurance. The trim pots have usually been left original when I see units that have been recapped by others but it is an important step.

There is a list of transistors and diodes that are known to be prone to certain issues. For example 2SC458, 2SA726, 2SC1412, and epoxy diodes like VD1212. These are always replaced with modern equivalents. I will often replace other transistors as well. These days I usually replace all preamp transistors, as well as the differential pair in the power amp.

Speaker relays are replaced if your unit has one. The speaker relay is the part that clicks on a few seconds after you have turned on your unit, after the circuit has determined the amp is working correctly it is safe to connect the speakers. The circuit will immediately shut the relay off to disconnect the speakers in the event of certain faults that may damage them. The contacts in the relays tarnish over time. They can be cleaned but a replacement is optimal. Most speaker relays are made by Omron and the same parts are still manufactured.

Solder joins in high heat areas life a hard life, and sometimes they become intermittent. I almost always reflow both the power amp and power supply boards completely and do touchup throughout the rest of the unit as needed.

Power Cord

 Non-polarized power cords are upgraded to polarized cords unless you request I leave the original cord in place. This ensures the voltage between the chassis and house ground is as low as possible (measuring this voltage is how I determine correct polarity). This minimizes noise and may prevent you from feeling a light charge on the chassis when you touch it should the power not be in the preferred orientation. Upgrading to a 3 prong cord is generally not recommended for solid state gear due to the risk of ground loops but it is a critical safety upgrade with tube gear.

The amount of effort an overhaul takes is pretty consistent since the idea is that everything that could cause issues gets done. A unit where many of these parts are already causing issues gets the same work as a unit that is still working smoothly. Most diagnostics are included in the price even if something takes significant extra time (no one would bring their unit if I can’t make costs predictable!).
However there are a few things that can increase cost.

• Tuner issues – Adjustments and minor issues are included but major issues that require much extra time will be extra. Tuners can be very tricky to work on and I can’t always fix them, so I will generally deal with these issues before going ahead with the rest of the service. I might not know if your issue is easy before looking at the unit. For example if your unit won’t get FM stereo I can often bring this back in seconds. But other times it will take hours.
• Blown power amp sections – output transistors add moderate to high cost, especially in high power units and both channels should be built to match. Sometimes units have been previously rebuilt with a mix of badly matched parts and I will recommend rebuilding it again properly.
• Damage caused by previous repair attempts – Solder traces can be damaged if desoldering is not done carefully. I have ways of dealing with this but it can add time. Please don’t make my life harder by making a mess of your unit before bringing it to me. If you do attempt to work on it yourself and find yourself lifting solder pads STOP and either practice on a scrap board until you can get it right or bring the unit to me. Also note I frequently see subpar work from established repair shops.

Addendums

• I now replace the tuner strings in Marantz receivers. They seem to lose integrity and stretch with age. Other makes don’t seem to have the same issue but if I see any similar issues in other models I will replace the tuner string.