iFi Audio
DC Blocker

Bye bye mechanical hummm

Many (large) amplifiers have a really annoying mechanical hum, emitted from the (toroidal) transformer itself. You can often hear it from meters away. This is, most of the time, caused by a small amount of DC offset voltage on the mains which makes its way through to the mains transformer. It will become ‘saturated’ and starts to hum like a trooper.

The DC Blocker is a clever device that you place at the IEC (at the rear power inlet) and as its name implies, it stops DC from getting into the amplifier. It therefore eliminates amplifier transformer hum.

Note: All transformers hum (even new ones from the most reputable brands)! if you encounter a constant hum, chances are the DC blocker can’t prevent this. The cause may be the transformer itself. In case you have a hum that varies in hum level (and sometimes is even completely absent) this device will help you out. Be aware that it can never „repair“ a „bad“ mains transformer. American transformers, designed to take a 60 Hz mains, will nearly always have a louder hum when connected to the European 50 Hz mains. The DC blocker will not reduce their hum, as their core tends to become saturated. If in doubt, please contact us before buying!!!

Review:
A Brace of Buzz Busters from iFi – The GND Defender and DC Blocker by Bruce Kinch @ posi+ive-feedback