I’d be happy to, but hopefully you read this before blowing anything up!

If you purchased equipment from Japan and it has already blown up, we need to establish what damage has been done to it.

Line Voltage

Different regions use different AC or mains supply voltages. Japan uses 100V, the USA uses 110/120V, and Europe and Asia use 220V, 230V or 240V, depending on the region. Anything other than 230V or 240V presents a problem for people living in Australia, where we have a 240/250V supply.

Higher voltage AC supplies are better from a technical perspective; more on that another time. BUT – If you plug a piece of electronic equipment set to run on 100V or 120V into a 240V socket here in Australia, IT WILL FAIL, unless a fuse saves it.

Electronic equipment doesn’t “automatically adjust”, as one bemused enquirer who’d just blown up his newly acquired equipment tried to convince me. I think he was tring to convince himself, and perhaps thinking of equipment with switching power supplies or SMPS, like phone chargers or USB power supplies. Hi-fi equipment doesn’t use switching power supplies.

The Problem

Good hi-fi equipment relies on linear power supplies using transformers. Transformers convert or ‘transform’ AC voltages proportional to the ratio of turns on their primary and secondary sides. Equipment set to run on 120VAC might contain a transformer that steps this down to 35VAC, which will be around 50VDC when rectified.

When that transformer is fed 240V, double the input voltage equals double the output voltage, and the internal 50VDC supply is now a 100VDC supply. 100V will kill electrical components that were rated for 50V. Fast-acting fuses might save the day, but in most cases, the damage is substantial, sometimes terminal. It depends on the circuit and, to some extent, luck.

My 2024 repair of a gorgeous Pioneer PL-50L turntable is an example of a 100V Japanese turntable that died when plugged into a 240V outlet. There were no internal fuses or schematics, and repair was only possible because the unit was taken to a repairer able to effect component-level repair.

Configurability

Some hi-fi equipment can be set to run on various line voltages. Configuration may be straightforward via an external adjustment or involve working inside a chassis to reconfigure taps, wires and unmarked jumpers. In some cases, new parts such as circuit breakers of a different rating will be required. These are special-order items.

Some equipment cannot be configured for other line voltages including lots of Japanese and North American market-only equipment. Step-down transformers will be needed in these cases. Over the years, I’ve become familiar with what equipment can and cannot be configured, but there are variations between examples of the same model that mean the answer often won’t be known until the equipment is inspected.

I’ve also seen locally supplied equipment misconfigured. The Mark Levinson ML-7 preamp I repaired and a pair of Accuphase M-60 amplifiers are two examples of gear set to 220V for a 240V environment. Therefore, a simple rule should be applied to all equipment:

Every piece should be checked to ensure it is correctly configured for the line voltage in your location.

False Economy

We all like to save money, but nothing is saved by having the wrong people do important jobs. An example:

In October 2024, I heard about a fellow with an Accuphase SACD player worth about $30K AUD who ended up with a lovely-looking $30K doorstop because, rather than being sensible and taking that 30K player to a specialist, he tried to save money and took it to someone who killed it. In desperation, he went to the forums, compounding his initial mistake with another.

This is so very silly, and one of my favourite quotes perfectly encapsulates this concept as it applies to high-value pieces like this:

If you think it’s expensive to hire a professional to do the job, wait until you hire an amateur.

Red Adair

Buying expensive equipment and then not having it professionally inspected and reconfigured is, quite simply, stupid. Professional inspections provide peace of mind and almost always find things in need of attention. They, therefore, pay for themselves when leveraged into price reductions, refunds, avoiding bad equipment, or worst case – avoiding blowing up newly acquired equipment!

Summary

I receive a steady stream of enquiries from people who’ve killed their hi-fi equipment by applying incorrect line voltage to it. This failure mode is completely avoidable by having equipment professionally inspected and configured. If equipment cannot be reconfigured, a step-down transformer of the correct capacity/rating is required.